JP2023540646A - Decorative foil manufacturing method - Google Patents

Abstract

The present invention relates to a process for manufacturing high performance resin saturated decorative foils designed for outdoor and indoor surface linings. Decorative foils are 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. be able to.

Description

<Technical field>
The present invention relates to a process for manufacturing high performance resin saturated decorative foils designed for outdoor and indoor surface linings. Decorative foils are 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. be able to.

High pressure laminate (HPL) panels and continuous pressure laminate (CPL) panels are used in applications that require scratch resistance, abrasion resistance, chemical attack, or resistance to vandalism of any kind, as well as color fastness. is an example of panels made from different materials that have the specificity of maintaining To achieve these specific characteristics, surfaces consisting of decorative panels and coatings impregnated with modified melamine resins have been described in the state of the art, which are able to meet the properties required in each case.

Melamine-impregnated paper has limited resistance to acid attack and is particularly unsuitable for use in outdoor applications. This problem is described and partially solved in U.S. Pat. applying a decorative layer; applying a liquid coating to the decorative layer consisting essentially of a radiation-polymerizable mixture; applying radiation to form a radiation-polymerized layer on the decorative layer; and The underlay, the decorative layer, and the radiation-polymerized layer are heat pressed together under elevated temperature and pressure conditions such that a scratch resistance of 1.5 Newtons or more is achieved.

Furthermore, European Patent No. EP 1631454 B1 discloses a decorative panel comprising a decorative layer on one or both sides of a carrier layer, the decorative layer comprising a base layer and a surface layer, The material layer is printing paper, the surface layer is a synthetic resin containing one or more radiation-curable components, and an adhesive layer exists between the support layer and the decoration layer, and this adhesive layer connects the base layer and the surface layer. It is in contact with the base material layer, characterized by the presence of a transparent layer made of a synthetic resin containing a radiation-curable component selected from the group of unsaturated (meth)acrylates, between the layers.

European Patent No. EP 2406086 B1 discloses a method for producing decorated paper and panels using an aqueous resin impregnated into a substrate.

More specifically, European Patent No. EP 2406086 B1 discloses a method comprising the following steps: providing 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. Obtaining a resin-impregnated decorated paper, characterized by an initial drying process with residual moisture <5%, calculated on the basis of the weight obtained after the above drying step.

Also relevant is European Patent No. EP 2574476 B1, which discloses a method for producing a decorative film comprising a resin-impregnated base paper and one or more top layers. The method includes the following steps: preparing a resin-impregnated base paper; printing the base paper with an ink composition using inkjet technology; drying and/or curing the previously printed base paper. subjecting to treatment; imparting 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 this 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. It is. The resin present in the base paper contains reactive groups, and the resin is present throughout the entire thickness of the base paper.

Although the process disclosed in the above state of the art generally improves the characteristics of melamine resin-impregnated panels, some limitations are still observed in the following respects: insufficient adhesion between the layers; the internal cohesion of the paper is insufficient, the impermeability of the decorated paper is insufficient, it is difficult to achieve a flat product, and the lifespan of the decorative foil is limited even before use. too early, difficulty in stable processing of the product, insufficient resistance to atmospheric conditions, high risk of permeable porosity or areas of unsaturated paper, ensuring saturation of the paper. dependence on external adhesive layers to bind to the adhesive, as well as the inability to reduce or eliminate the content or reliance on formaldehyde-containing resins as adhesives, etc. One of the objects of the present invention is to solve these problems by means of the manufacturing method and the resulting panel as defined in the claims appended hereto.

<Description of the invention>
One of the objects of the present invention is a method for manufacturing a decorative foil. The method according to the invention allows the foil to be saturated with an anhydrous resin, which resin can be cured, in a non-limiting manner, through UV radiation and/or electron beams, increasing the internal bond strength or "Z strength". Despite the fact that it can have a high crosslinking density while exhibiting excellent mechanical properties with respect to paper traction in the direction perpendicular to the plane of the paper surface, also known as It does not have the problem of shrinkage caused by the viaduct level, which strongly complicates the process. This object is achieved by the method of claim 1. The dependent claims set out details of particular and/or preferred embodiments of the invention.

More specifically, the invention discloses a method that includes performing the following:
First step of preparing the substrate;
a second step of sealing one side of the base material with the first resin;
a third step of drying and/or curing the surface sealed with the first resin;
a fourth step of impregnating the substrate with an anhydrous resin containing radiation-curable functional groups on the side of the substrate opposite to the side sealed with the first resin;
a fifth step of curing 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 sides of the by-product obtained in the above step, wherein the at least one resin is a sixth step comprising radiation-curable functional groups; and a seventh step drying and/or curing the foil obtained through all the above steps.

In one embodiment of the invention, the execution of the above process is performed sequentially in a defined order. However, in other practical embodiments of the invention, the order of execution of the method may include, but is not limited to, the addition of intermediate steps or duplication of steps.

In the present invention, it is necessary to emphasize the difference between sealing with resin (second step) and impregnation with resin (fourth step). In this discussion, impregnating with resin refers to applying as much resin as the substrate can receive until the substrate is saturated with the applied resin (i.e., "clogged" with this resin). means. On the other hand, sealing with a resin means creating a surface resin film or layer that makes the substrate impermeable so that the impregnating resin does not penetrate, at least temporarily.

Furthermore, although the present invention distinguishes between drying and curing of the resin, these are not technically equivalent. The drying process involves extraction by evaporating the solvent, while a polymerization reaction occurs during curing. Thus, according to this specification, radiation curing processes include, in a non-limiting manner, both ultraviolet irradiation processes and media and electron beam irradiation processes and media. This is because both technologies are well known to those skilled in the art and are radiant energy sources.

From the foregoing, in the context of the present invention, 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.

In the present invention, there are two forms of inactivation. One involves creating an inert atmosphere, most commonly using high purity nitrogen, to reduce oxygen in the air that contacts the resin. The other is physical inertization, which is achieved by eliminating the presence of oxygen from the surface by creating a physical barrier between the oxygen contained in the air and the surface. This can be done by (in a non-limiting manner) direct contact of the resin with the film or the surface of the resin with a flat or cylindrical surface to prevent the presence of oxygen. For example, it is conceivable to contact the resin with the BOPET film and avoid contacting the uncured resin with oxygen.

In the present invention, a partially oxygen-enriched atmosphere refers to an atmosphere in which surface hardening is significantly inhibited by the presence of oxygen. In systems in which the radiation-curable component is selected from unsaturated acrylate and methacrylate groups, surface hardening inhibition phenomena are observed when oxygen values exceed 200 ppm.

Thanks to the methods and products described herein, a good level of mutual and durable adhesion between the different layers of the decorative foil is obtained, as well as adhesion with the substrate. Therefore, cross-linking and permanent covalent chemical bonds are ensured, all of which can use one or more chemical reaction mechanisms. The impregnation of the substrate has the particularity that it can be colorless or pigmented and can be formulated to achieve a certain resistance to different adverse weather conditions. In particular, the impregnation of the substrate can be formulated to exhibit high color stability despite exposure to UV radiation. As a result, it is possible to impregnate already printed substrates, and it is possible to minimize the influence of deterioration caused by sunlight.

This UV resistance has become important not only for outdoor applications, but also for surfaces used in medical and hospital applications, where disinfection by UV light is more frequent.

Furthermore, with the present invention it is possible to completely saturate the decorative foil that integrates the panel with non-hygroscopic resin and render it impermeable before adhering to the substrate, regardless of external factors. For HPL or CPL panels, there is no dependence on the substrate resin being pressed or the pressure and temperature process. Furthermore, when glued by an external adhesive, the impermeability of the decorative foil does not depend on the adhesive used.

The above-mentioned properties are of particular importance. It is observed that when relying on the transfer of resins or external additives, the process is very difficult to control, as the external additives must be flowable and at the same time, air trapped in the substrate must be suctioned. has been done. It has also been observed that in outdoor use it is difficult to ensure that no unsaturated areas remain, as moisture can seep in and degrade the foil. Since it is complicated to check whether any part remains unsaturated, it is extremely difficult to discover the effect before application, and it may be too late. It should also be noted that in applications where the resin or adhesive flows through the substrate, it is difficult to obtain covalent chemical adhesion and peeling between the substrate and the resin may occur.

Furthermore, the decorative foil of the present invention retains its adhesive ability even under adverse conditions such as those associated with transportation and storage. Therefore, it can be seen that the currently used resins such as melamine-formaldehyde and phenol-formaldehyde have limited stability because the chemical reaction is slowed down but not inhibited. Unlike these, in the present invention, the resin used to ensure adhesion does not undergo a slow chemical reaction, so its stability and perfect adhesion are guaranteed for a much longer period, and the There is no gradual decline in adhesion due to deterioration of the foil over time, and it is possible to extend the life of the product before use.

Finally, the decorative foil according to the invention can be used on HPL or CPL panels, or on two-dimensional planar or curved elements covered with a Finish-Foil, and according to the method of the invention described. It has the special feature that after being impregnated with resin, it can be printed using traditional techniques or other digital printing methods.

<Preferred embodiments and examples of the present invention>
As mentioned above, the present invention discloses a method of manufacturing a decorative foil, as well as the resultant product and its use in different types of panels, said manufacturing method comprising the following implementation:
First step of preparing the substrate;
a second step of sealing one side of the base material with the 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 anhydrous resin containing radiation-curable functional groups on the side of the substrate opposite to the side sealed with the first resin;
a fifth step of curing 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 sides of the by-product obtained in the above steps, wherein the at least one resin is a sixth step of comprising radiation-curable functional groups; and a seventh step of drying and/or curing the foil obtained through all of the above steps.

Next, different practical embodiments of the invention will be analyzed, as well as practical examples illustrating in a non-limiting manner the method of the claims contained herein. Throughout this specification, the phrase "embodiment" means that a feature, structure, or particular characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase "in one embodiment" in multiple places throughout this specification are not necessarily all referring to the same embodiment, but are merely illustrative and non-limiting references. Furthermore, several embodiments and examples of the invention, along with alternatives to its different components, may be referred to herein. Such embodiments, examples, and alternatives are not to be construed as de facto equivalents therebetween, but as independent embodiments of the invention. Additionally, 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 embodiments of the invention. However, one skilled in the art will recognize that the invention may be practiced without one or more of these specific details, or with other methods, components, materials, or additional steps in the process. It would be recognizable.

Some practical non-limiting embodiments are described below as to how the different steps of the method of the invention can be carried out in practice. As mentioned above, these embodiments are merely 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 amounts.

First step: Providing the substrate In a practical non-limiting embodiment of the first step, between 25 g/m ² and 200 g/m ² , preferably between 50 g/m ² and 140 g/m ² , more preferably between A cellulose-based paper (foil) having a weight of 60 g/m ² to 120 g/m ² is provided. 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. obtain. This paper thus serves as a substrate for all other resin layers that are applied successively under the method of the invention. In a practical embodiment, cellulose-based paper is used, but other types of materials can also be used, for example non-woven fabrics, the weight of which is between 5 g/m ² and 100 g/m ² , preferably from 10 g/m ² to 60 g/m ² , more preferably from 15 g/m ² to 50 g/m ² .

Second step: Sealing one side of the base material with the first resin Next, one side of the base material is sealed with the first resin. The amount of resin should be sufficient to impermeate one side of the substrate so that it can hold back the liquid resin that is applied to the opposite side in the next step of the method of the invention. Will. In certain embodiments, such a first resin layer used as an encapsulant may contain oligomers, monomers, adhesion-promoting additives, rheology modifiers, and chemistries to ensure fixation with adjacent surfaces. Includes crosslinking reagents capable of acting as crosslinking agents, or any combination thereof. As mentioned earlier, it is important to emphasize that in this second step there is no impregnation, i.e. the first resin does not completely fill the interior of the substrate, but in subsequent steps An impermeable layer is created so that all other liquid resins applied do not soak into the substrate.

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

The first encapsulant resin described for this HPL panel example is suitable for use in both adjacent layers in the final product (i.e., processed resins completed with the method of the present invention), even if they do not share the same crosslinking chemistry. Adjacent layers of decorative foils) and extend covalent bonds to exhibit chemical functionality configured to suitably crosslink, thus establishing connections between chemical groups that do not naturally react between themselves.

Furthermore, considering that the underlying substrate to which the foil in this example is applied is a kraft paper impregnated with phenol-formaldehyde resin, such resin may be utilized in the sealing layer during the high temperature and pressure pressing step. Crosslinking reaction with possible blocked isocyanates gives a decorative board or end product to which the paper obtained from the process of the invention is applied.

In another particular embodiment for producing finishing foils, a sealing layer is applied which is also an adhesive, and for that purpose the sealing layer is made of a physically drying vinyl resin or a blocked isocyanate. Contains vinyl-acrylic resin. In this way, the foil obtained 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/m ² , preferably between 20 and 60 g/m 2 , more preferably between 25 and 60 g/m ² , depending mainly on the substrate to which the sealing layer is adhered. 55 g/m ² , but the amount penetrating the substrate will still be between 1 and 30 g/m ² , preferably between 1 and 25 g/m ² and more preferably between 1 and 15 g/m ² .

Third step: drying and/or curing the surface sealed with the first resin. Immediately thereafter, the base material containing the sealing layer of the first resin is dried and/or hardened in the third step. I am made to do so. This drying and/or curing process may include, but is not limited to, curing by ultraviolet light, curing by electron beam, curing by polymerizing thermal initiator, curing by exposure to moisture, curing by oxidation, thermal curing, physical drying of water, solvent selected from drying by removal, or a combination thereof. Additionally, when adding thermally decomposable components such as blocked isocyanates for covalent chemical reactions with adjacent layers, the drying and/or curing techniques applied should be carefully selected to prevent premature reactions. can be adjusted.

Fourth step: Impregnating the base material with an anhydrous resin containing a radiation-curable functional group on the side of the base material opposite to the side sealed with the first resin Sealing one side of the base material After drying and/or curing the first resin to be sealed, apply anhydrous resin in an amount sufficient to saturate the base material by impregnation on the side of the paper opposite to the side sealed with the first resin. Impregnate. In the process of the invention, this impregnating resin can be a formaldehyde-free resin. The film that the first resin forms on one side makes that side of the substrate impermeable, as described above, so that the second resin does not seep out and can be used as a support surface for product manufacturing lines and for transportation. Since it comes into contact with the surface, contamination of the product and staining of the contact area are prevented. This anhydrous resin can be a transparent resin or a pigmented resin in different embodiments.

The sealing film formed by the first resin can be a low molecular weight resin with a high density of functional groups and a very low viscosity, although it can be an anhydrous resin, a solvent, or formaldehyde. Allows the impregnating resin to be applied to the opposite side of the substrate. Therefore, even if only one side is impregnated, the substrate can be quickly saturated by removing all the air therein. Without the problems caused by such impregnations penetrating into the opposite side, it is possible to obtain substrates with chemical reactivity and sealing layers that may have different properties than the impregnations.

During the fourth step of the method, this anhydrous resin incorporated into the substrate ensures covalent crosslinking with the adjacent layers of the finished end product, completely saturating the substrate and preventing subsequent moisture infiltration. (especially important in outdoor applications exposed to inclement weather). The anhydrous resin applied in this fourth step can, without limitation, in different practical embodiments, be oligomers, monomers, additives with properties suitable for obtaining covalent type interfacial crosslinking with adjacent layers. and mixtures of pigments, filler nanoparticles, rheology modifiers, humectants, compatibilizers, UV absorbers, light stabilizers, flame retardants, polymerization thermal initiators, and/or combinations of any of the foregoing.

In order to obtain a strong network of cross-linked polymers in the body of the substrate, the anhydrous resin applied in the fourth step may contain, but is not limited to, methacrylic and acrylic monomers and/or oligomers with a global functionality of preferably two or more. may be included. Optionally, multifunctional softening oligomers and/or chain extenders are included that can modify the flexibility of the product by combining different monofunctional and multifunctional monomers that can generate a network.

Optionally, oligomers or oligomer mixtures can be used, which include combinations of epoxy acrylates, preferably polyester acrylates, more preferably urethane acrylates and/or their corresponding methacrylates as oligomer precursors, as acrylate monomers. and their corresponding monomethacrylates and polyfunctional methacrylates. Any of these may 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 corresponding methacrylates containing functional groups and/or ethoxylated melamine groups in the chain.

In certain embodiments, acrylate monofunctional monomers having hydroxylated end groups (-OH), 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 are added to the mixture.

In another specific embodiment, the use of HDDA monomer (hexanediol diacrylate monomer) difunctionality alone exhibits a very high ability to penetrate the paper structure, thereby facilitating air trapped between the cellulose fibers. It is possible to obtain a high degree of saturation of the compound. In another embodiment, UV absorbing additives as well as light stabilizers and/or metallic pigments and/or iridescent pigments (synthetic mica) may be used for clear finish papers. Finally, in another embodiment, the second resin can include amorphous silica as a thickener, configured to adjust the viscosity and impart thixotropic behavior to the mixture.

Fifth step: Curing the by-product obtained in the above steps Next, in the method of the invention, the by-product obtained by performing the first to fourth steps is at least partially cured to If present, it helps to obtain a cure that even allows paper to be rolled, while at the same time ensuring chemical anchor points and reactivity that connect adjacent layers within the coating.

The curing method is selected from, without limitation, electron beam curing, UV curing, polymerization thermal initiator curing, moisture curing, oxidative curing, thermal curing, or combinations thereof.

Preferably, the foil obtained from the previous step is cured by electron beam and/or UV radiation, more preferably by electron beam (E.B). In either case, it is also possible to cure and crosslink all layers by, but not limited to, exposure to moisture, oxidation, thermal mechanisms, two-component resin polymerization, free and/or blocked isocyanate polymerization. to obtain interconnections and thus ensure interfacial adhesion and achieve curing of all previously applied layers.

Warping issues are one of the main problems with this type of product and occur when one layer of foil contracts in a different way than another, creating tension that causes the foil to become unbalanced. . This warpage occurs during drying and/or curing, and occurs to a greater or lesser extent depending mainly on the resin used.

In one embodiment, curing is performed by electron beam. In this embodiment, a highly crosslinked density resin is used for impregnation, which, despite the problem of leading to strong warping, is minimized thanks to the method of the invention and still allows subsequent layers to be applied. By performing this partial curing of the substrate in the absence of oxidation, the substrate may be allowed to shrink more freely. Therefore, by controlling the uncured functional groups, it is possible to control the amount of remaining shrinkage, and it is possible to adjust the desired shrinkage to be left to the next curing step.

In this embodiment, the above process allows great control over one of the key points, since it is possible to adjust the curing to obtain a flat finished foil. In this embodiment, it has been found that both the dose and voltage can be adjusted, as well as the amount of oxygen on the surface, in order to adjust the warpage without compromising adhesion with the adjacent layer(s). ing. Therefore, in an example using electron beam curing, the results are as follows.
The dose can be used to adjust the number of electrons emitted from the device, thereby controlling the amount of crosslinking of the surface through which the electrons pass. It is preferable to use doses 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, with the dose decreasing rapidly as the electrons enter the material. It is desirable 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. Moreover, even if the atmosphere is not an inert atmosphere, surface hardening can be performed by oxygen partially or completely inhibiting surface hardening on at least one of both surfaces of the foil.

By adjusting these parameters, residual shrinkage can be adjusted both in terms of quantity and distribution. By adjusting the voltage and/or the surface oxygen level, it is also possible to create fewer polymerized surfaces or an asymmetrical distribution.

Surprisingly, thanks to the process of the present invention, acrylic resins with a high density of unsaturated groups can be used without harmful warping effects and the inherent brittleness of strongly crosslinked systems can be minimized. It turns out that there is something. More surprisingly, after this electron beam curing, a high density of reactive groups remains active on the surface, resulting in even a stoichiometric excess with respect to the reactive groups of the adjacent layer.

All of this results in a highly saturated (optionally pigmented) substrate with translucent resin exhibiting high color stability upon exposure to UV light. In addition, it has high crosslinkability and internal cohesiveness, and the degree of shrinkage can be appropriately adjusted in the step following the curing process. In addition, the viscosity can be adjusted, winding and printing are easy, and many reactive groups are present on the contact surface with adjacent layers to ensure covalent bonding.

In a variation of the above specific embodiment, a hydroxylated functional group (-OH) and a free isocyanate functional group are added to the radiation-cured resin. In this application, electron beam curing is performed as in the previous embodiment, but a heat curing step is combined before or after radiation curing to particularly accelerate the reaction of free isocyanates at the surface, resulting in a tack-free surface. Such properties can be achieved with a slight surface curing process of radiation-cured resins. This system can be cured in an inert atmosphere with a high oxygen concentration or in an inert atmosphere.

In another specific embodiment, thermal curing is performed on a substrate pre-impregnated with a resin consisting of radiation-curable functional groups, hydroxylated groups, free and/or blocked isocyanates together with a thermal initiator. be exposed. First, a thermal curing step of the free isocyanate and/or the blocked isocyanate is carried out, and reaction of the radiation-curable group and the optionally blocked isocyanate group is suspended. Therefore, it becomes possible to form a covalent bond with an adjacent layer.

Optional First Step: Printing a Decorative Design Optionally, the method includes a step of printing a decorative design on one of the sides of the by-product obtained by performing the first to fifth steps. implement. In a special embodiment, a digital printer is used and the printed image is partially cured by ultraviolet light and/or an electron beam. During partial curing, the image is fixed on the decorative foil, but at the same time some of the reactive groups on the surface are activated, and the subsequent layer, i.e. the radiation curable resin, is cured by the radiation irradiation in the sixth step. to be able to establish a covalent bond with the layer formed by.

Sixth step: Applying one or more layers of one or more resins to one of the two sides of the by-product obtained in the above step, where at least one resin is (contains curable functional groups)
In this sixth step, one or several resins are applied (ie, it can be one resin or several layered resins), at least one of which contains radiation-curable functional groups. Additionally, any of the surfaces of the by-products obtained through the first to fifth steps and the optional decorative design printing step may contain moisture, oxidation, thermal mechanisms, two components, etc. It can be cured to thicknesses between 10 and 300 μm by resin polymerization, blocked isocyanate polymerization or exposure to other types of radiation other than UV or electron beams.

The resin used in this sixth step includes, but is not limited to, oligomers, monomers, additives with suitable functionality to obtain interfacial crosslinking with adjacent layers, and mechanical scratch hardness and abrasion resistance. Improving fillers, nanoparticles, short fibers, pigments, rheology modifiers, humectants, surface tension modifiers, sun protection additives, antioxidants, vandal protection agents (e.g. antigraffiti), antifouling additives , antimicrobial agents, flame retardants, infrared reflective additives, antistatic agents, anti-fingerprint agents, or combinations of any of the above.

In certain embodiments, 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, especially a urethane acrylate oligomer or its corresponding methacrylate oligomer, such as a radiation-polymerizable polymer. If present, it is diluted with monofunctional and/or polyfunctional acrylate monomers and/or their corresponding methacrylates. In another specific embodiment for enhancing color stability upon exposure to ultraviolet light, the prepolymer is an aliphatic urethane acrylate oligomer optionally diluted with 1,6-hexanediol diacrylate monomer (HDDA). .

In certain embodiments of this step, the second paper or foil (optionally surface-treated with a release effect resin) is not provided with a layer of the aforementioned resin; It is desirable to apply a layer or multiple layers. The foil may consist, without limitation, of biaxially oriented polyethylene terephthalate (BOPET) or a biaxially oriented paraffinic thermoplastic, especially BOPP, and may have a thickness of 19 to 90 μm, more preferably 20 to 50 μm. By mechanical bonding by means of a calender, the faces of the two foils are placed in contact with this second foil on the one hand and with the face of the foil to which the layer or layers of resin have been applied, as described above, on the other hand. Ru.

Optional second step: Applying one or more layers of adhesion promoting and/or adhesive resin Optionally, the method of the invention provides that the layer(s) in the sixth step It involves applying one or more layers of resin(s) that promote adhesion and/or function as an adhesive on the side opposite to the side to which it has been applied or to be applied. Thereafter, if necessary, UV curing, curing by electron beam irradiation, curing by polymerization thermal initiator, curing by exposure to moisture, curing by oxidation, physical drying of water, drying by removal of solvent, or Drying and/or curing steps selected from any combination of the above processes can be applied.

In embodiments for producing HPL, water-based physically drying and/or radiation curable resins are used. The amount of this first sealing resin is 1 to 30 g/m ² , preferably 2 g/m ² to 25 g/m ² , more preferably 2 g/m ² to 10 g/m ² . Furthermore, it has been found desirable to contain up to 10% of the blocked isocyanate based on the dry weight of the first resin. In this embodiment, it is preferred that the blocked isocyanate has a rated unblocking temperature of greater than 110°C, especially 130°C or higher.

In another particular embodiment for producing finished foils, an adhesive layer comprising a physically drying vinyl resin or vinyl-acrylic resin (containing blocked isocyanates) is applied. In this way, the foils obtained from the method of the invention can be bonded by pressure and temperature, without the need to add other adhesives. In this application, the weight of the resin layer is from 1 to 80 g/m ² , preferably from 20 to 60 g/m ² , more preferably from 25 to 55 g/m ² .

Seventh step: drying and/or curing of the product obtained through all of the above steps. This drying and/or curing method includes curing by electron beam, curing by ultraviolet light, curing by polymerization thermal initiator, curing by moisture. , oxidative curing, thermal curing, drying by solvent removal, or combinations thereof.

Preferably, the foil obtained from the previous step (possibly including the optional step) is cured by electron beam and/or ultraviolet light, more preferably by electron beam (E.B.) . In either case, it can also be cured by, but not limited to, exposure to moisture, oxidation, thermal mechanisms, two-component resin polymerization, blocked isocyanate polymerization, to obtain cross-linked interconnections of all layers. can ensure interfacial adhesion and achieve curing of all previously applied layers.

In certain embodiments, curing is applied at a dose of 1 to 90 kGy, preferably 10 kGy to 80 kGy, more preferably 20 to 60 kGy, at a voltage of 80 to 300 kV, preferably 100 to 300 kV, more preferably 150 to 300 kV. This is done by means of an electron beam. This is carried out under physically inert conditions or under conditions of an inert atmosphere with an oxygen content of less than 1000 ppm, preferably less than 500 ppm, more preferably less than 200 ppm.

Having provided a detailed description of the method of the invention, a series of non-limiting examples of several practical applications of the invention will now be described.

<Example 1>
A 70 g/m ² decorated paper (high pigment mass known in the art) with decorative printing on the surface is prepared.

Then, in a practical embodiment of the second step of the method of the invention, a dry amount of 7 g/m ² of radiation-curable group-containing aqueous physically drying urethane acrylate resin with added blocked isocyanate aqueous dispersion; Seal the opposite side of the decorative print by applying with a roller coater.

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 Bayhydrur BL2867 with a solids content of 38%. An aqueous dispersion of blocked isocyanate with a reagent content is incorporated such that the dry percentage of the second product is 5% with respect to the solids content of the resin. The difunctional monomer hexanediol diacrylate (HDDA) is incorporated into the mixture at a rate of 10%, based on the dry content of the resin.

The obtained by-product is subjected to physical drying (third step of the invention) in a drying tunnel with injection of hot air at a temperature of 100 °C so as not to induce the reaction of the blocked isocyanate. This corresponds to a non-limiting practical example of the third step of the inventive method.

Then, as a fourth step, the opposite side of the substrate or paper is impregnated. This impregnation is carried out, without limitation, with a roller coater, and the excess is removed with a blade. For this purpose, 35 g/m ² of a resin consisting only of radiation-curable HDDA monomers are used, to which are 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 obtained from the first resin and the sealing film.

Thereafter, the paper saturated with the first resin and the second resin in the previous step is subjected to electronic beef irradiation, applying a dose of 20 kGy and 200 kV to the impregnated surface, and imparting an oxygen content of 500 ppm to the surface. However, the sealing surface is physically inactivated.

In this non-limiting example and after the steps described, the blank is rolled up for further processing in a subsequent step.

On the previously prepared material, on the side opposite to the side containing the first resin, add 80 g/m ² of urethane acrylate resin EBECRYL 284, 1% TINUVIN 400 + 1% light stabilizer HALS TINUVIN 292, and add HDDA monomer. to apply a third layer having an applied viscosity of 2000 mPa·s at 25° C., measured at a shear rate of 1000 s ⁻¹ . This corresponds to the sixth step of the method of the invention.

Finally, the surface of the sixth step is irradiated with an electron beam and cured with a dose of 60 kGy and a voltage of 200 kV. The process is carried out under an inert atmosphere with an oxygen content of less than 200 ppm on the side of the sixth step and physical passivation on the other side, achieving complete deep curing with radiation in all layers. Ru. This preserves the blocked isocyanate functionality of the sealing layer.

The products thus completed were placed one after another with the decorated side outward on a pile of kraft paper sheets impregnated with phenol-formaldehyde resin, and pressed at a temperature of 160°C and a pressure of 80 kg/cm ² for 20 minutes. Perform processing. During this pressing process, the phenolic resin cross-links with the blocked isocyanate present at the interface to obtain a covalent chemical bond, which prevents the ingress of water and atmospheric chemicals, thereby making it possible to combine the foil-like material of this patent with the base sheet. chemical adhesion is ensured and surface tensile strength values (Z strength according to DIN 52366) of 3 N/mm ² or more are achieved.

<Example 2>
A 70 g/m ² decorated paper (high pigment mass known in the art) with decorative printing on the surface is prepared. Thereafter, the printed surface is sealed by applying a dry amount of 7 g/m ² of urethane acrylate-based physically drying resin (i.e., the first water-based resin containing a radiation-curable group) using a roller coater. represents a non-limiting embodiment of the first two steps of the method.

The encapsulating resin mixture consists of an aqueous dispersion of MIWON MIRAMER W8365NT with a solids content of 43%, to which the difunctional monomer hexanediol diacrylate (HDDA) is added at a rate of 8% based on the dry weight of the resin. The paper foil obtained is subjected to physical drying, ie initial curing and/or drying, in a drying tunnel with a jet of hot air.

The substrate or paper is impregnated on the opposite side with a roller coater and the excess removed with a blade (fourth step). For this purpose, 35 g/m ² of resin consisting of radiation-curable HDDA monomers are required. This resin, i.e. the resin applied in the fourth step of the method of the invention, exhibits a very low viscosity, penetrates very easily and forms a structure between the surface and the sealing film consisting of the first resin. Completely saturate the portion of the substrate to be treated.

The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation, imparting a dose of 20 kGy, 135 kV to the impregnated side and an oxygen content of 500 ppm to that side; Physical inactivation is performed on the sealing side. In this example, after these steps, the blank is rolled up for further processing in subsequent steps.

Thereafter, the same type of resin as described in the sixth step of Example 1 is applied, but this time on the side to which the first resin was applied. On the side impregnated with the second resin, apply 5 g/ ^m2 of the sealing mixture (i.e. the same third resin as the first resin in Example 1) and dry and/or cure from Example 1. Perform the same drying process as in step.

Finally, the product undergoes a final curing step by applying an electron beam to the surface of the sixth step with a dose of 60 kGy and a voltage of 225 kV. This is done on the side of the sixth step under an inert atmosphere with an oxygen content of less than 200 ppm and on the other side with physical passivation, achieving complete deep curing with radiation in all layers. Ru. This preserves the blocked isocyanate functionality on the sealing layer.

The products thus completed were placed one after another on a pile of kraft paper sheets impregnated with phenol-formaldehyde resin with the decorated side facing outward, and pressed at a temperature of 160°C and a pressure of 80 kg/cm ² for 20 minutes. Perform processing. During this pressing process, the phenolic resin cross-links with the blocked isocyanate present at the interface to obtain a covalent chemical bond, which prevents the ingress of water and atmospheric chemicals, thereby making it possible to combine the foil-like material of this patent with the base sheet. chemical adhesion is ensured and surface tensile strength values (Z strength according to DIN 52366) of 3 N/mm ² or more are achieved.

<Example 3>
A mixture of physically drying urethane acrylate resin containing a radiation-curable group and an aqueous blocked isocyanate dispersion was applied to 80 g/m ² of white base paper ^using a roller coater in a dry amount of 7 g/m 2 . One of the two sides of the is sealed.

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 with a solids content of 38%. A blocked aqueous dispersion of blocked isocyanate having a content is incorporated such that the proportion of the second product is 5% with respect to the solids content of the resin. The difunctional monomer hexanediol diacrylate (HDDA) is incorporated into the mixture at a rate of 10% based on the dry content of the resin.

The obtained by-product is physically dried in a drying tunnel injecting hot air at a temperature of 100° C. (third step of the invention) in order to avoid inducing reactions from the blocked isocyanate, which is the third step of the invention. corresponds to a non-limiting practical embodiment of the third step of the method.

Next, the paper is impregnated with anhydrous resin using a roller coater, and the excess is removed using a blade. For this purpose, it is necessary to add 40 g/m ² of a resin consisting of HDDA monomers and 20% of the white pigment KRONOS 2220, as well as 1% of the UV absorber TINUVIN 400 and 1% of the light stabilizer HALS TINUVIN 292. This resin has a low viscosity and penetrates very easily, completely saturating the paper.

Subsequently, the paper saturated with the first and second resins in the previous step was subjected to electron beam irradiation, applying a dose of 20 kGy and 200 kV to the impregnated surface, and imparting an oxygen content of 500 ppm to the surface. , the sealing surface is physically inertized.

Next, a photoreactive ink containing an inorganic pigment is printed on the surface impregnated with the second resin using a digital printer, and the printed image is partially cured by exposure to ultraviolet light, and when cured, the image is transferred onto the paper. Make it stick. However, at the same time, the reactive groups remain activated, allowing them to form covalent bonds with the next layer.

On the printed side of the previously prepared material, apply another layer: a third resin. This layer was made by adding 1% Tinuvin 400 + 1% light stabilizer HALS Tinuvin 292 to 80 g/m ² of urethane acrylate resin Ebecryl 4680, diluted with HDDA monomer, and coating viscosity at 25 °C measured at a shear rate of 1000 s ^-1 . is set to 2000 mPa・s.

Finally, the product undergoes a final curing step by applying an electron beam on the surface of the sixth step with a dose of 60 kGy and a voltage of 200 kV. This is done on the side of the sixth step under an inert atmosphere with an oxygen content of less than 200 ppm and on the other side with physical passivation, achieving complete deep curing with radiation in all layers. Ru. This preserves the blocked isocyanate functionality on the sealing layer.

The products thus completed were placed one after another with the decorated side outward on a pile of kraft paper sheets impregnated with phenol-formaldehyde resin, and pressed at a temperature of 160°C and a pressure of 80 kg/cm ² for 20 minutes. Perform processing. During this pressing process, the phenolic resin cross-links with the blocked isocyanate present at the interface, resulting in a covalent chemical bond that prevents the ingress of water and atmospheric agents, thereby allowing the foil-like material and base sheet of this patent to chemical adhesion is ensured and surface tensile strength values (Z strength in DIN 52366) of 3 N/mm ² or more are achieved.

<Example 4>
A dry amount of a physically drying urethane acrylate resin containing radiation-curable groups (i.e., the first water-based resin) was applied to a 80 g/m ² white base paper (high pigment mass known in the art). 7 g/m ² with a roller coater to seal one side of the white base paper, which corresponds to a non-limiting embodiment of the first two saps in the method.

The encapsulating mixed resin was obtained by adding hexanediol diacrylate (HDDA), a difunctional monomer, to an aqueous dispersion of MIWON MIRAMER W8365NT with a solid content of 43% at a ratio of 8% based on the dry amount of the resin. This resin layer has two roles: to form a film to prevent the impregnating liquid from seeping in, and to prepare the outer surface for subsequent printing steps. Due to its chemical composition, this thin film allows the ink to penetrate slightly into the surface, resulting in improved fixation. The finished paper foil is physically dried in a drying tunnel that blasts hot air.

Next, the paper is impregnated with anhydrous resin using a roller coater, and the excess is removed using a blade. For this purpose, it is necessary to add 40 g/m ² of a resin consisting of HDDA monomers and 20% of the white pigment KRONOS 2220, as well as 1% of the UV absorber TINUVIN 400 and 1% of the light stabilizer HALS TINUVIN 292. This resin has a low viscosity and penetrates very easily, completely saturating the paper.

Subsequently, the paper saturated with the first and second resins in the previous step was subjected to electron beam irradiation, imparting a dose of 20 kGy, 135 kV to the impregnated side and an oxygen content of 500 ppm to that side. , the sealing surface is physically inertized. After these steps, the blank is rolled up for further processing in subsequent steps.

Next, a photoreactive ink containing an inorganic pigment is printed on the first resin-impregnated surface using a digital printer, and the printed image is partially cured by exposure to ultraviolet light. Make it stick. However, at the same time, the reactive groups remain activated and can form covalent bonds with the next layer.

On the printed side of the previously prepared material, apply another layer: a third resin. This layer was made by adding 1% Tinuvin 400 + 1% light stabilizer HALS Tinuvin 292 to 80 g/m ² of urethane acrylate resin Ebecryl 4680 and diluting with HDDA monomer to give a coating viscosity of 2000 mPa・s at 25°C. (measured at a shear rate of 1000 s ^-1 ). 5 g/m ² of the sealing mixture (i.e. the same third resin as the first resin in Example 1) was applied to the surface coated with the second resin, followed by drying and/or curing from Example 1. Perform the same drying process as in step.

Finally, the product undergoes a final curing step by applying an electron beam on the surface of the sixth step with a dose of 60 kGy and a voltage of 225 kV. This is done on the side of the sixth step under an inert atmosphere with an oxygen content of less than 200 ppm and on the other side with physical passivation, achieving complete deep curing with radiation in all layers. Ru. This preserves the blocked isocyanate functionality of the sealing layer.

The products thus completed were placed one after another with the decorated side outward on a pile of kraft paper sheets impregnated with phenol-formaldehyde resin, and pressed at a temperature of 160°C and a pressure of 80 kg/cm ² for 20 minutes. Perform processing. During this pressing process, the phenolic resin cross-links with the blocked isocyanate present at the interface, resulting in a covalent chemical bond that prevents the ingress of water and atmospheric agents, thereby allowing the foil-like material and base sheet of this patent to chemical adhesion is ensured and surface tensile strength values (Z strength in DIN 52366) of 3 N/mm ² or more are achieved.

<Example 5>
By applying 8 g/m ² of radiation-curable resin with a solid content of 100% to 80 g/m ² of decorated white paper (known from traditional techniques, with a high pigment mass) using a roller coater. , sealing one side of Mr. White.

The sealing resin mixture was prepared by diluting the tetrafunctional polyester acrylate MIWON Miramer P2291 with the difunctional monomer HDDA and having a viscosity of 1000 mPa·s at 25°C measured at a shear rate of 1000 s ⁻¹ . Add 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). .

The resulting foil is partially chemically dried on the surface by UV irradiation, with particular care being taken during the exposure to a temperature that does not induce a reaction of the blocked isocyanate. 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/m ² of resin consisting of radiation-curable HDDA monomers are required (ie impregnation with the second resin).

Subsequently, the paper saturated with the first and second resins in the previous step was subjected to electron beam irradiation, applying a dose of 20 kGy, 200 kV to the impregnated side and an oxygen content of 500 ppm to that side. , the sealing surface is physically inertized. After these steps, the blank is rolled up for further processing in subsequent steps.

HDDA monomer and 8% oxidized yellow pigment were applied to the surface of the previously prepared material opposite to the side containing the sealing resin so that the coating viscosity at 25°C measured at a shear rate of 1000 s ^-1 was 2200 mPa・s. A layer of 50 g/m ² of acrylate urethane resin EBECRYL 284 diluted with Lanxess Bayferrox 3910 is applied.

On one side of the microstructured "release foil" BOPET film, 50 g/m ² of urethane acrylate resin EBECRYL 284 with 25% addition of nanocryl nanoparticles and 1% addition of Tinuvin 400 + light stabilizer HALS Tinuvin 292 A layer is then applied by diluting with HDDA monomer to give a coating viscosity of 2200 mPa·s at 25° C. (measured at a shear rate of 1000 s ⁻¹ ). After bringing the liquid surfaces of both foils into contact with each other using a calender, curing is performed using an electron beam.

Finally, the product undergoes a final curing step by applying an electron beam on the surface of the sixth step with a dose of 60 kGy and a voltage of 225 kV. This is done under physical passivation conditions on both sides in order to achieve complete curing by radiation in all layers. Therefore, the blocked isocyanate functionality of the sealing layer is retained. When the PET is separated, it has been confirmed that the foil of the present application has a microstructure that remains even after being subjected to high temperature and high pressure pressing.

The products thus completed were placed one after another with the decorated side outward on a pile of kraft paper sheets impregnated with phenol-formaldehyde resin, and pressed at a temperature of 160°C and a pressure of 80 kg/cm ² for 20 minutes. Perform processing. During this pressing process, the phenolic resin cross-links with the blocked isocyanate present at the interface, resulting in a covalent chemical bond that prevents the ingress of water and atmospheric agents, thereby allowing the foil-like material and base sheet of this patent to chemical adhesion is ensured and surface tensile strength values (Z strength in DIN 52366) of 3 N/mm ² or more are achieved.

<Example 6>
A 80 g/ ^m2 decorative paper with a decorative print on the surface (high pigment mass, known from traditional techniques) was coated with radiation-curable groups on the side opposite the design using a roller coater. It is sealed by applying a physically drying urethane acrylate resin having a dry amount of 7 g/m ² . The sealing resin is ESACOTE® LX 101 dispersion manufactured by Lamberti, and the solids content is 34% to 36%.

The difunctional monomer hexanediol diacrylate (HDDA) is present at a rate of 6% on a dry resin basis, and the monofunctional hydroxylated monomer (-OH) is present at a rate of 4% on a dry resin basis. incorporated into the mixture. The paper foil obtained is physically dried in an evaporation furnace that injects hot air.

The other side of this substrate is impregnated with a roller coater and the excess is removed with a blade. For this purpose, it is necessary to use 40 g/m ² of a resin consisting of radiation-curable HDDA monomers and to add 1% of the UV absorber Tinuvin 400 and 1% of the light stabilizer HALS Tinuvin 292. This resin has a very low viscosity and is very easy to penetrate and can completely saturate the paper.

Subsequently, the paper saturated with the first and second resins in the previous step was subjected to electron beam irradiation, imparting a dose of 20 kGy, 200 kV to the impregnated side and an oxygen content of 500 ppm to that side. , the sealing surface is physically inertized. After these steps, the blank is rolled up for further processing in subsequent steps.

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

Finally, the product undergoes a final curing step by applying an electron beam on the surface of the sixth step with a dose of 60 kGy and a voltage of 200 kV. This is carried out under an inert atmosphere with an oxygen content of less than 200 ppm on the side of the sixth step and with physical passivation on the other side, achieving complete curing by radiation in all layers.

The product developed in this example is bonded to an aluminum honeycomb panel using a thermofusible polyurethane water-reactive adhesive (PUR), and in this example, a corresponding square aluminum section is also wrapped. A covalent chemical bond is obtained between the polyurethane reactive adhesive and the -OH functional group, which ensures excellent adhesion, prevents water ingress, and provides strong resistance to atmospheric agents. Mechanical adhesion between the laminated product object of this patent and the support to which it is adhered is ensured.

Finally, while the foregoing examples are illustrative of the principles of the invention in one or more specific applications, one skilled in the art will appreciate that without exercising inventive activity and in the claims below. It will be obvious that many changes may be made in form, use and implementation details without departing from the principles and concepts of the invention as described.

Claims (17)

Method of manufacturing decorative foil, including carrying out the following:
First step of preparing the substrate;
a second step of sealing one side of the base material 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 with an anhydrous resin containing a radiation-curable functional group on the surface of the substrate opposite to the surface sealed with the first resin;
a fifth step of curing 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 sides of the by-product obtained in the above steps, wherein the at least one resin is a sixth step comprising a radiation-curable functional group;
Seventh step of drying and/or curing the foil obtained through all the above steps. The base material is
Cellulose paper having a weight of 25 g/m ² to 200 g/m ² , preferably 50 g/m ² to 140 g/m ² , more preferably 60 g/m ² to 120 g/m ² ; or a weight of 5 g/m ² to Process according to claim 1, consisting of a non-woven fabric of 100 g/m ² , preferably 10 g/m ² to 60 g/m ² , more preferably 15 g/m ² to 50 g/m ² . The type of first resin is selected from physical drying, radiation curable, thermal initiator-induced polymerization, crosslinking between hydroxylated groups and free and/or blocked isocyanates, and any combination thereof. is;
The first resin further includes:
When configured to promote adhesion, the weight is between 1g/m ² and 30g/m ² , preferably between 2g/m ² and 25g/m ² , more preferably between 5g/m ² and 20g/m ² . can be,
When configured to act as an adhesive, the weight is from 1 g/m ² to 80 g/m ² , preferably from 20 g/m ² to 60 g/m ² , more preferably from 25 g/m ² to 55 g/m ² and the amount of resin penetrating into the substrate is 1 g/m ² to 30 g/m ² , preferably 1 g/m ² to 25 g/m ² , more preferably 1 g/m ² to 15 g/m ² .
The method according to claim 1 or claim 2. According to any one or more of claims 1 to 3, during the third step, the drying and/or curing process is performed by at least one process selected from ultraviolet curing, electron beam irradiation, physical drying. Method described. During the fourth step, the radiation-curable functional groups are present in one or more of claims 1 to 4, with thermal initiators and/or hydroxylated groups and free and/or blocked isocyanates. Method described. Claims 1 to 4, wherein the resin from the fourth step comprises more than 50%, preferably more than 75%, more preferably more than 85% of monomers having unsaturated acrylate and/or methacrylate groups. The method described in any one or more of the items. In the fifth step, curing is performed at a dose of 1 to 90 kGy, preferably 10 to 80 kGy, more preferably 20 to 60 kGy, a voltage of 80 to 300 kV, preferably 100 to 300 kV, more preferably 120 to 250 kV, physical 7. The method according to any one or more of claims 1 to 6, carried out by means of an electron beam, with an oxygen content ranging from the lowest value obtained by activation techniques to a concentration comparable to the natural oxygen content of the atmosphere. Method. curing is carried out under a partially oxygen-enriched inert atmosphere, such that the oxygen partially or completely inhibits surface curing on at least one of the two sides of the foil, or 8. The method according to claim 7, which may be carried out without inactivation. Decorative designs on either side, operable after the fifth step of curing and before the sixth step of applying one or more layers of one or more radiation-curable resins. A method according to any one or more of claims 1 to 8, comprising an optional step comprising printing. Digital printing is used, the ink is partially cured by ultraviolet light and/or electron beam,
When partially cured, the image is immobilized on the decorated foil, but at the same time at least some of the surface-reactive groups are removed so that covalent bonds can be established with the subsequent layer in the sixth step. 10. The method of claim 9, which remains active. an optional step comprising applying one or more layers of one or more adhesion promoting and/or adhesive resins before or after the sixth step;
A layer or layers of such one or more adhesion promoting and/or adhesive resins are applied to the opposite side to that on which the sixth step has been or will be carried out, and subsequently: A method according to any one or more of claims 1 to 10, in which drying and/or curing steps may be carried out if necessary. The one or more adhesion promoting and/or adhesive layers may be physically drying, radiation curable, thermally initiator induced polymerization, crosslinking between hydroxylated groups and free and/or blocked isocyanates; selected from any combination;
When such resin or resins are configured to promote adhesion, the weight is between 1 g/m ² and 30 g/m ² , preferably between 2 g/m ² and 25 g/m ² , more preferably. is 2g/m ² to 10g/m ² ,
If such one or more resins are configured to act as an adhesive, the weight may be between 10 g/m ² and 80 g/m ² , preferably between 20 g/m ² and 60 g/m ² , and more. Preferably 25g/m ² to 55g/m ² .
The method according to claim 11. In the seventh step, curing is performed at a dose of 1 to 90 kGy, preferably 10 kGy to 80 kGy, more preferably 20 kGy to 60 kGy, a voltage of 80 to 300 kV, preferably 100 kV to 300 kV, more preferably 150 kV to 250 kV, physical inertness. 13. The process according to any of claims 1 to 12, carried out by means of an electron beam under oxidizing conditions or under an inert atmosphere with an oxygen content of less than 1000 ppm, preferably less than 500 ppm, more preferably less than 200 ppm. A method according to any of claims 1 to 13, wherein the radiation-curable component is selected from unsaturated acrylate and methacrylate groups. The radiation-curable component in the sixth step is formed from an epoxy acrylate oligomer, preferably a polyester acrylate oligomer, especially a urethane acrylate oligomer or a corresponding methacrylate oligomer, such as a radiation-polymerizable polymer, if appropriate. 15. Process according to any of claims 1 to 14, diluted with functional and/or polyfunctional acrylate monomers and/or their corresponding methacrylates. The method according to any one or more of claims 1 to 15, wherein the prepolymer in the sixth step is an aliphatic urethane acrylate oligomer suitably diluted with a diacrylate or triacrylate monomer. Use of a decorative foil obtained by the method according to any of claims 1 to 16 in panels selected from HPL panels, CPL panels and 2D flat or curved elements lined with finishing foils.