Method for decorating a wheel element, and a wheel element

Abstract

The invention relates to a method for decorating a wheel element (1), wherein the method comprises the following steps: a) providing the wheel element (1), b) arranging a primer (2) on the wheel element (1), c) arranging a transfer film (3) by means of hot stamping, the transfer film (3) comprising a carrier film (4) and a transfer layer (5), wherein that side of the transfer layer (5) which faces away from the carrier film (4) is formed by a primer system (6), wherein a decorative layer (7) is arranged on the primer system (6), and a protective layer (8) is arranged between the decorative layer (7) and the carrier film (4), d) obtaining the wheel element (1) comprising the transfer layer (5); and to a wheel element (1).

Description

[0001] 63747WO / NZ / TH

[0002] LEONHARD KURZ Stiftung & Co. KG, Schwabacher Str. 482, 90763 Fürth

[0003] Method for decorating a wheel element and a wheel element

[0004] The invention relates to a method for decorating a wheel element and a wheel element.

[0005] Traditionally, wheel components, such as light alloy wheels, are coated over a large area and / or completely using various spray paints or powder coatings. For this purpose, the wheel components are, for example, mounted on a "carousel" and then coated on all sides with one or more layers.

[0006] Applying additional partial decoration to the wheel element is considerably more challenging. While it is possible for wheel elements to have large areas to be decorated, preferably within a two-dimensional plane, it is also possible for wheel elements to have areas to be decorated, such as spokes, with very small surface areas. Furthermore, it is possible for the wheel element to have areas to be decorated that are not perpendicular to the feed direction of a decoration tool, such as a turning tool, printing tool, or embossing tool.

[0007] Alternatively or additionally, the surface to be decorated may have a radius, an angle or chamfer, and / or a curvature. Typically, processes such as pad printing, laser ablation, milling, water transfer printing, partial turning of the interface (so-called diamond turning), or similar methods are used when additional partial decoration is to be applied to the wheel component. The aforementioned methods severely limit the decoration options for wheel components, particularly due to a lack of cost-effectiveness and the geometric challenges of the surfaces to be decorated, as listed above.

[0008] For example, color gradients or motifs and / or decorations in the form of individual images are not possible with the most common methods, such as water transfer printing. Alternative methods like pad printing severely limit the choice of varnishes and are particularly expensive for larger areas.

[0009] In burnishing, the wheel components are painted with one or more layers of lacquer and then turned using a material-removing process. Turning can only process exposed surfaces, meaning surfaces that are perpendicular to the feed direction when viewed along it and have a shorter distance to the decorative tool compared to other surfaces. After turning, a corrosion protection coating and / or a topcoat is applied to the wheel components to protect them from environmental damage. Disadvantages of burnishing include its time-consuming nature, the high rate of scrap, and the fact that it is a material-removing process that results in material loss from the metal of the wheel component. Furthermore, all surfaces on the same circular path and at the same distance from the turning tool are necessarily machined.Turning individual surfaces located in recesses is not possible. It is therefore an object of the invention to provide an improved method for decorating wheel components that makes it possible to arrange visually appealing and diverse designs economically on a single wheel component. In particular, it is an object of the invention to replace the burnishing process.

[0010] The problem is solved by providing a method, in particular a method according to any one of claims 1 to 28, for decorating a wheel element, wherein the method comprises the following steps, which are carried out in particular in the specified order: a) providing the wheel element, b) applying a primer to the wheel element, c) applying a transfer film by hot stamping, wherein the transfer film has a carrier film and a transfer layer, wherein the side of the transfer layer facing away from the carrier film is formed by a primer system, wherein a decorative layer is arranged on the primer system and a protective layer is arranged between the decorative layer and the carrier film, d) obtaining the wheel element comprising the transfer layer.

[0011] The problem is further solved by a wheel element, in particular a wheel element obtained and / or manufactured according to a method according to any one of claims 1 to 28, wherein the wheel element has a primer, and a transfer layer is arranged on the primer, the transfer layer having a primer system arranged in contact with the primer, and wherein the transfer layer has a protective layer arranged on the side of the transfer layer facing away from the primer, and a decorative layer arranged between the primer system and the protective layer. The present method offers the advantage over prior art methods used for decorating wheel elements that it is economical and flexible in the selection of designs and / or decorations.

[0012] Applying the decoration using transfer film makes it possible to arrange multicolored motifs, organic patterns, and / or color gradients on the wheel element. The transfer film provided for the inventive method can generally be obtained from an unlimited selection of decorative elements, functional elements, and / or paint layers. This flexible selection of transfer films also makes it possible to arrange decorative layers with relief structures that feature visually variable design elements and / or imitate other materials, such as carbon fibers.

[0013] In contrast to the inventive method, even the multi-colored decoration of a wheel element using diamond turning, milling, or laser ablation is very complex. It is only possible by building up multi-layered paint packages, each with different color layers. The multi-colored decoration is achieved by at least partially removing the paint packages using the aforementioned methods, so that the underlying differently colored paint layers become visible. However, these methods have a high rate of rejects, as even minor manufacturing deviations can lead to too much or too little material being removed. Correcting the material removal is not possible, so any design correction would require a complete repainting.

[0014] Furthermore, the inventive method makes it particularly possible in

[0015] Unlike burnishing, this method also allows motifs to be arranged in isolated recesses. Burnishing, on the other hand, only allows the removal of raised structures, i.e., structures that are closer together than the turning tool in the feed direction. Furthermore, unlike the method according to the invention, burnishing, due to the rotation around the axis of rotation of the wheel element perpendicular to the feed direction of the turning tool, does not make it possible to obtain decorated surfaces that lie on the same plane as undecorated surfaces. In other words, the method according to the invention makes it possible to apply a decoration to surfaces that, when viewed along the feed direction of the tool, are not only arranged perpendicular to the feed direction but are also further away from the tool compared to other surfaces. In the method according to the invention, the feed direction corresponds to an embossing stroke and the tool to an embossing die.

[0016] Even pad printing, known from the prior art, does not offer the wide selection of decorative elements of the inventive method, but must rely on a limited selection of varnishes, which makes large-area decoration uneconomical. Furthermore, unlike the inventive method, water transfer processes generally do not allow for the targeted arrangement of smaller decorative areas with non-random patterns.

[0017] Further advantageous embodiments of the invention are described in the dependent claims.

[0018] Step a) is the first step of the process. Here, a wheel element, in particular a wheel element for motor vehicles, is provided. The wheel element can be selected from the group consisting of rim, wheel disc, wheel flange, spokes, wheel flange and / or combinations thereof. Preferably, a wheel, in particular for motor vehicles, is provided which includes or consists of the wheel element. It is possible that the wheel element includes or consists of metal, in particular light metal and / or steel.

[0019] The term "light metal" preferably refers to a metal or alloy whose density is less than 5.0 g / cm³. 3Preferably, the metal of the wheel element is selected individually or in combination as an alloy from the group consisting of: aluminum, magnesium, titanium. Steel is preferably understood to be an iron-carbon alloy, which in particular has a carbon content of no more than 2 wt.% (wt.% = weight percent).

[0020] It is possible that the wheel element has one or more surfaces to be decorated, such as spokes, which have a surface area ranging from 1 cm. 2 up to 1000 cm 2 , preferably 1 cm 2 up to 800 cm 2 , further preferably from 1 cm 2 up to 200 cm 2The selected wheel element has one or more surfaces to be decorated, which are preferably located within a plane, particularly a two-dimensional and / or three-dimensional plane. Furthermore, the wheel element may have one or more surfaces to be decorated that are not perpendicular to the feed direction of the embossing die. Alternatively or additionally, the surface to be decorated may have a radius, particularly from 0.2 mm to 20 mm, preferably from 1 mm to 12 mm, and / or an angle or phase from 0° to 40°, preferably from more than 0° to 40°, and more preferably from 25° to 35°, relative to the surface to be decorated.

[0021] In step b), which is carried out particularly after step a), a primer is applied to the wheel element, in particular the metal of the wheel element. In other words, a primer area is formed by the surface where the primer is in contact with the wheel element, in particular the metal of the wheel element. The primer is applied in at least one layer. It is possible for the primer to be applied in multiple layers, preferably at least two or at least three layers.

[0022] Furthermore, it is possible for the primer to be applied at least partially, preferably over the entire surface, of the wheel element. In particular, the primer is applied at least on the surface facing an observer of a motor vehicle that includes the wheel element. It can be advantageous for the primer not to be applied in areas that are contacted by other wheel elements for connection purposes.

[0023] The inventors have surprisingly discovered that sufficient adhesion of paints or polymer films to the metal of the wheel component is not possible without a primer. The primer thus forms the necessary transition between metal and polymer, enabling the adhesion of the subsequently applied transfer film. The adhesion-promoting properties of the primer can be influenced by the composition and structuring of the individual layers of the primer. Furthermore, the primer provides additional corrosion protection to the wheel component or can serve as a background or contrast for the decoration covered by the transfer film.

[0024] The application of the primer, in particular the layers covered by the primer, can be carried out, for example, by means of methods selected individually or in combination from the group: spraying, dipping, cataphoresis, powder coating, painting.

[0025] The primer may include a primer. In particular, the primer is applied in contact with the wheel component, especially by means of the coating processes described for the primer. In a preferred embodiment, the primer is a powder coating, for example, a corrosion-resistant powder coating. The primer may be composed of one or more material classes, selected individually or in combination from the group consisting of polyesters, epoxy resins, and copolymers of polyesters and epoxies. The primer ensures particularly good adhesion of the primer and thus of all subsequent layers to the wheel component. The primer is specifically tailored to the material, especially the steel and / or light metal, of the wheel component and the subsequent layer. Furthermore, the primer protects the wheel component from corrosion.

[0026] It is possible that the primer includes a base coat. Preferably, the base coat is applied on top of the primer, in particular covering the entire surface.

[0027] The basecoat can be applied by liquid coating and / or powder coating. In a preferred embodiment, the primer, in particular the basecoat, is applied by powder coating.

[0028] The primer, in particular the basecoat, can be thermally crosslinked and / or radiation-cured. It is possible that the primer, in particular the basecoat, is composed of one or more classes of materials, individually or in combination, and / or as copolymers and / or as blends selected from the group consisting of: poly(meth)acrylates, polyesters, epoxy resins, melamine resins, and polyurethanes. Preferably, the primer, in particular the basecoat, is composed of poly(meth)acrylates and / or polyesters.

[0029] Especially in liquid coating applications, the primer, particularly the base coat, can be applied as a solvent-based, water-based, and / or dispersion coating. A solvent is understood to be an organic solvent. A dispersion preferably comprises a continuous aqueous phase.

[0030] Furthermore, the primer, preferably the basecoat, may be colored, preferably by means of dyes and / or color pigments. Alternatively or additionally, the primer, preferably the basecoat, may also contain metallic pigments and / or effect pigments. The degree of pigmentation of the primer, preferably the basecoat, is preferably selected from a range of 10 wt.% to 60 wt.%, more preferably from 20 wt.% to 50 wt.% (wt.% = weight percent).

[0031] The term "degree of pigmentation" refers in particular to the percentage of the mass of the pigments in relation to the total dry mass of the pigmented element, preferably layer.

[0032] The primer may consist of two or more layers of basecoat, which may have different color appearances. The two or more layers of basecoat are preferably arranged one above the other.

[0033] Preferably, the base coat is opaque, translucent or transparent for the wavelength range perceptible to the human eye, preferably for the range from 400 nm to 700 nm.

[0034] The terms "opaque" and "translucent" are defined as having a transmission of less than 50%, "translucent" as having a transmission of 50% to 70%, and "transparent" as having a transmission of more than 70%, each referring to the wavelength range perceptible to the human eye, preferably the range from 400 nm to 700 nm. In a preferred embodiment, the primer, preferably a pigmented primer, and in particular the basecoat, has a transmission of less than 70%, more preferably less than 50%, and further preferably less than 25%, for the wavelength range perceptible to the human eye, preferably the range from 400 nm to 700 nm. This makes the primer, and in particular the basecoat, opaque, so that the color of the material beneath the primer, and in particular the basecoat, is not perceptible to the human eye.The aforementioned transmission of the primer, in particular the basecoat, is preferably obtained in which the primer, in particular the basecoat, comprises dyes and / or pigments, in particular color pigments, metallic pigments and / or effect pigments.

[0035] It is possible that the primer includes an adhesion promoter, which is referred to below as the primer adhesion promoter. Preferably, the primer adhesion promoter is applied as a layer to the basecoat, at least partially, and preferably completely. Alternatively or additionally, the basecoat can be designed to act as a primer adhesion promoter, in particular if the basecoat is opaque and / or opaque. The primer adhesion promoter is intended, in particular, to improve the adhesion of the embossed transfer film to the primer. The primer adhesion promoter can be a clear coat, which is understood to be a transparent layer that contains no colorants.

[0036] Preferably, at least one coating is used as a primer, in particular as a primer-adhesion promoter, which is selected individually or in combination from the group consisting of: acrylic powder coating, cut-resistant coating, corrosion-resistant powder coating, acrylic basecoat, acrylic liquid coating,

[0037] Corrosion protection coating based on polyester. Alternatively and / or additionally, the primer, in particular the primer adhesion promoter, can consist of a combination of water-based and / or solvent-based coatings, the composition of which is not restricted.

[0038] It is possible to arrange a pigmented coating layer between the basecoat and the primer adhesion promoter. This coating layer may contain metallic pigments and / or color pigments and / or effect pigments, preferably with a relief structure being introduced and / or embossed into at least part of the pigmented coating layer in an additional step. It is also possible for the basecoat to contain metallic pigments and / or color pigments and / or effect pigments, preferably with a relief structure being embossed into at least part of the basecoat in an additional step. In this case, the primer adhesion promoter is transparent and can preferably act as a leveling layer over the relief structure in the basecoat or in the pigmented coating layer. The leveling layer allows the optical effect created by the relief structure to be perceived by an observer, but it is not perceptible to the touch.

[0039] The transfer layer of the transfer film applied to the wheel element is preferably arranged in areas on the wheel element that are adjacent to the areas with the relief structure introduced and / or embossed into the base coat or the pigmented paint layer. The transfer layer thus does not obscure the relief structure, or only in small areas, particularly in the case of an opaque transfer layer.

[0040] Alternatively or additionally, particularly with a transparent or translucent transfer layer, it is possible for the transfer layer of the transfer film applied to the wheel element to overlap, at least in some areas, with the relief structure introduced and / or embossed into the base coat or the pigmented paint layer. This makes it possible, for example, to cover the relief structure with a translucent color layer in the transfer layer and thus color it in the overlapping areas.

[0041] It is possible that after applying the primer, the wheel element, particularly in the area where the primer is applied, will be cleaned. Cleaning can be carried out using methods selected individually or in combination from the following: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, and vacuuming.

[0042] In step c), which is carried out particularly after step b), a transfer foil is applied to the wheel element by means of hot stamping, whereby in particular at least one decorated area is obtained. Preferably, the transfer foil is applied only in areas that have the primer. An embossed area formed in step c), which comprises the at least one decorated area, is in particular arranged completely within the primer area. After step c), the primer is at least partially, and preferably completely, covered by the transfer foil.

[0043] It is possible that at least one decorated area has a surface area that consists of a range of 1 cm. 2 up to 1000 cm 2 , preferably 1 cm 2 up to 800 cm 2 , further preferably from 1 cm 2 up to 200 cm 2, is selected, has. It is possible that the at least one decorated surface lies entirely within a plane, particularly a two-dimensional and / or three-dimensional plane. Furthermore, it is possible that the at least one decorated surface has interruptions, such as wheel hub bores or screw holes.

[0044] It is possible that the at least one decorated surface extends at least partially perpendicular to the feed direction of the embossing die. Alternatively or additionally, it is also possible that the at least one decorated surface does not extend at least partially perpendicular to the feed direction of the embossing die. For example, the at least one decorated surface can extend in a defined angle along at least one spatial direction in certain areas and / or be concave and / or convex relative to the perpendicular to the feed direction of the embossing die. The method according to the invention advantageously makes it possible for the at least one decorated surface to be arranged at least partially in a plane extending, in particular, perpendicular to the feed direction of the tool. Thus, it is possible for the at least one decorated surface to have a radius, in particular, in the range of 0.2 mm to 20 mm, preferably from 1 mm to 12 mm.Alternatively or additionally, it is possible for the at least one decorated surface to have a first and a second sub-area, wherein a plane of the second sub-area is arranged at an angle to a plane of the first sub-area. The angle is preferably selected from a range of 0° to 40°, more preferably from 25° to 35°. Such a design is not possible using methods known from the prior art, or only with increased effort, which increases costs and the probability of rejects. In particular, with larger radii and / or angles, the embossing pressure is no longer sufficiently transferred to the surface of the wheel element to be decorated by the embossing die, which can result in insufficient adhesion between the applied transfer foil and the wheel element.

[0045] For hot stamping, a stamping unit is provided, which includes a stamping die. The stamping unit, in particular the stamping die, preferably has a clamping device and / or a device for applying pressure to fix the transfer foil. For the method according to the invention, a stamping die that is preferably larger than those used in other applications is provided. For example, a stamping die is provided that extends along at least one spatial direction perpendicular to the feed direction over a distance, wherein the distance is selected from a range of 1 cm to 100 cm, preferably from 10 cm to 80 cm.

[0046] Alternatively or additionally, the embossing die has a contact surface for contacting the wheel element, which extends from an area of ​​1 cm. 2 up to 1000 cm 2 , preferably 1 cm 2 up to 800 cm 2 , especially preferred by 1 cm 2 up to 200 cm2 , selected, on.

[0047] The die is preferably made of metal, in particular selected individually or in combination from the group: brass, copper, steel, titanium, magnesium.

[0048] In particular, the embossing die has a silicone coating on the surface that comes into contact with the transfer foil. Preferably, the silicone is a silicone rubber. The coating conforms in particular to the geometry or contour of the surface to be embossed.

[0049] The coating can be formed from one or more silicone layers. In a preferred embodiment, the coating has at least two or more silicone layers. The two or more silicone layers are preferably arranged one above the other, so that they overlap, at least in certain areas. It is also possible for at least two of the two or more silicone layers to be arranged side by side, thereby preferably varying the thickness of the coating in certain areas.

[0050] By selecting the type of silicone and / or the thickness of one or more layers, it is possible to adjust the thermal conductivity of the coating, particularly of the one or more silicone layers, at least in certain areas. Adjusting the thermal conductivity can involve a positive or negative change in thermal conductivity, at least in certain areas. Furthermore, the two or more silicone layers can have different compositions. For example, they can contain different additives. This allows the thermal conductivity, hardness, and / or elasticity of the coating to be adjusted, particularly in certain areas.

[0051] The coating thickness, particularly the thickness of one or more silicone layers, can remain constant or vary across the surface of the stamping die. It can even be advantageous to adapt the coating thickness, especially of one or more silicone layers, to the expected variations in the wheel element. This ensures a consistent pressure distribution across the surface to be stamped. Alternatively or additionally, it is also possible for the coating to contain a different number of silicone layers in different areas.

[0052] The surfaces to be decorated can vary considerably on wheel components due to the manufacturing process. Particularly with wheel components, variable dimensional deviations of up to 2 mm are common. It has therefore proven advantageous for the embossing die to have a coating with a greater layer thickness compared to embossing tools in other application areas, in order to compensate for dimensional deviations. Specifically, the coating has a layer thickness selected from a range of 2 mm to 50 mm, preferably 2 mm to 30 mm, more preferably 2 mm to 20 mm, and even more preferably 3 mm to 10 mm. If the embossing die has two or more silicone layers, it has proven advantageous for these layer thicknesses to each have an independent thickness from a range of 1 mm to 10 mm, preferably 1 mm to 5 mm.This allows for particularly precise adjustment of the shape, hardness, and / or elasticity of the embossing die. The silicone of the coating, especially of one or more silicone layers, preferably has a hardness selected from the range of 30 Shore A to 95 Shore A, more preferably from 60 Shore A to 90 Shore A. If the coating has two or more silicone layers, it can be advantageous if at least two of the silicone layers have different hardnesses.

[0053] It is possible to use an embossing unit comprising the embossing tool, which is designed or provided in such a way that a vacuum can be created between the transfer foil and the embossing die. This allows the transfer foil to be drawn onto the embossing die, thereby conforming to the contour of the die. In particular, for this purpose, the embossing die has at least one element on the surface that is in contact with the transfer foil, selected individually or in combination from the group consisting of bore, hole, groove, and slot, wherein the at least one element is connected to a device for creating the vacuum.

[0054] The contour of the embossing die and / or the transfer foil is preferably convex and / or concave in at least one spatial direction. Preferably, the contour of the embossing die and the transfer foil are identical. Furthermore, the embossing unit may include a clamping device for attaching the transfer foil to the embossing unit, preferably the embossing die.

[0055] It is also possible for the embossing unit, preferably the embossing die, to be configured such that the transfer foil is heated in the area where it contacts the primer before the embossing step. Preheating the transfer foil makes it more ductile and flexible. This allows the transfer foil to better conform to the contour of the embossing die. It also makes it easier to position the transfer foil on curved surfaces. The vacuum is preferably selected from a range of 100 mbar to 900 mbar, more preferably from 300 mbar to 900 mbar, and even more preferably from 700 mbar to 900 mbar. The vacuum values ​​refer to an ambient pressure of 1 bar. The transfer foil is preferably heated to a temperature selected from a range of 150 °C to 250 °C, more preferably from 180 °C to 220 °C, particularly before the vacuum is applied.

[0056] For example, step c) may include at least one or more of the following sub-steps:

[0057] - Providing the embossing unit including the embossing die;

[0058] - Clamping the transfer foil into a clamping device of the embossing unit;

[0059] - Suction of the transfer foil onto the embossing die;

[0060] - Warming up the transfer foil;

[0061] - Arranging and aligning the transfer foil and / or embossing die according to the wheel element;

[0062] - Heating the embossing unit, preferably the embossing die, to embossing temperature;

[0063] - Contacting the transfer foil with the wheel element, especially the primer, using the embossing die;

[0064] - Method or turning of the embossing unit, preferably the embossing die.

[0065] Step c), in particular one or more sub-steps of step c), can also be carried out several times, especially with different or identical transfer foils.

[0066] It is possible that the embossing pressure is in the range of 100 N / cm². 2 up to 500 N / cm 2 preferably 200 N / cm 2 up to 350 N / cm 2 , further preferably from 250 N / cm 2 up to 300 N / cm 2 , even more preferably from 260 N / cm 2 up to 280 N / cm 2 The embossing temperature is preferably selected from a range of 125 °C to 250 °C, more preferably from 150 °C to 210 °C, more preferably from 170 °C to 200 °C, and even more preferably from 180 °C to 190 °C. The aforementioned temperature range ensures the transfer of the transfer foil without the layers of the transfer foil being damaged by the temperature.

[0067] It is possible that a longer stamping time is necessary compared to hot stamping processes in other applications, because the stamping die with its thick coating requires more time to reach the stamping temperature. Preferably, the stamping time is selected from a range of 0.3 s to 8 s, more preferably from 0.5 s to 5 s, more preferably from 1 s to 3 s, and even more preferably from 1.3 s to 2 s.

[0068] The embossing process is, in particular, a stroke embossing, preferably using a surface die, a form die, and / or a contour die. It is possible that the embossing die and / or the coating at least partially replicate the three-dimensional shape and / or dimensions of the wheel element to be decorated. In other words, the surface of the embossing die and / or the coating follows the contour of the surface of the wheel element to be decorated. Preferably, the embossing die and / or the coating has at least partially a complementary shape and / or dimensions to the wheel element being decorated.

[0069] In step e), the decoration of the wheel element can be carried out by means of sequenced embossing, in particular where the transfer foil is arranged in several individual embossing passes. Alternatively, the transfer foil can be arranged in a single embossing pass. Furthermore, in step c), several transfer foils can be arranged on different surfaces or embossing areas of the wheel element, in particular side by side without overlapping. It is also possible for several transfer foils to be arranged overlapping at least partially, in particular overlapping completely.

[0070] Furthermore, it is possible for the transfer film to be positioned with precise registration to an element of the wheel component, for example, a web, a spoke and / or a bore, another wheel component and / or an element of the primer. It is also possible for the transfer film to be positioned with precise registration to an already existing transfer film.

[0071] Register accuracy refers to the positional accuracy of two or more layers, elements, areas, and / or strata relative to each other. This register accuracy should fall within a predefined tolerance and be as low as possible. At the same time, the register accuracy of multiple layers, elements, areas, and / or strata relative to each other is an important characteristic for increasing process reliability and / or product quality, as well as counterfeit protection. Precise positioning can be achieved, in particular, using sensor-based, preferably optically detectable, register markers. These register markers can either represent specific, separate layers, elements, areas, and / or strata or be themselves part of the layers, elements, areas, and / or strata to be positioned.

[0072] The transfer film provided for the inventive method comprises a carrier film and a transfer layer. The side of the transfer layer facing away from the carrier film is formed by a primer system. A decorative layer is arranged on the primer system. Furthermore, a protective layer is arranged between the decorative layer and the carrier film. The protective layer thus forms the outermost layer of the transfer layer on the side facing the viewer. In particular, the protective layer at least partially protects the decorative layer of the transfer layer from mechanical, physical, and / or chemical stress. The transfer film, and in particular the transfer layer, may have further layers. The transfer film is, in particular, a hot stamping film.

[0073] The carrier film is made of PET and is provided in a way that allows it to be removed from the transfer layer. Removal of the carrier film preferably occurs after the transfer film has been applied to the primer, with the transfer layer remaining on the primer. After removal of the carrier film, the visible side of the transfer layer is formed, in particular, by the protective layer.

[0074] It is possible that the carrier film has a release layer on the side facing the transfer layer. The release layer preferably remains on the carrier film, at least partially, and preferably completely, after the carrier film has been removed.

[0075] Preferably, the release layer comprises at least one material, selected individually or in combination from the group: wax, carnauba wax, montanic acid ester, polyethylene (PE) wax, polyamide (PA) wax, polytetrafluoroethylene (PTFE) wax, silicone, melamine formaldehyde resin.

[0076] The primer system is specifically formulated for the coating it is intended to overcoat, particularly the primer itself. This results in particularly good adhesion to primed surfaces, such as those painted with liquid paint. Especially good adhesion is achieved on powder-coated surfaces.

[0077] The primer system can be single-layered or multi-layered and comprised of one or more layers of different adhesives and / or adhesion promoters. Preferably, the primer system has one to three layers of adhesives and / or adhesion promoters. More preferably, the primer system has at least one thermally activatable adhesive layer, which can be activated, in particular, by the thermal energy of the embossing die. The primer system has a layer thickness selected from a range of 0.5 pm to 10 pm, preferably from 1 pm to 6 pm, and more preferably from 1.5 pm to 3 pm.

[0078] Preferably, the class of materials used in the primer system, in particular the one or more layers of the primer system, is selected individually or in combination and / or as copolymers and / or blends from the group consisting of: poly(meth)acrylates, polyvinyl chloride copolymers, polyamides, ethylene vinyl acetate copolymers, rosin resins, and polyester resins. The primer system may also contain inorganic fillers and / or modified renewable raw materials, such as vegetable oil derivatives.

[0079] In one embodiment, the protective layer is a poly(meth)acrylate-based lacquer. The thickness of this protective layer is preferably selected from a range of 0.5 pm to 5 pm, more preferably from 1 pm to 3 pm, and more preferably from 1.3 pm to 2.3 pm. The poly(meth)acrylate-based lacquer is preferably thermoplastic and / or uncrosslinked. It is also possible for the protective layer to be formed from a crosslinked poly(meth)acrylate-based lacquer. The crosslinker can be selected individually or in combination from the group consisting of: blocked isocyanates, unblocked isocyanates, melamine resins, preferably melamine-formaldehyde resins, carbodiimides, and aziridines.

[0080] Choosing this layer thickness ensures that the transfer foil can be processed further in a hot stamping process, preventing delamination at the interface between the protective layer and the other layers of the transfer layer, especially the decorative layer. This also improves the resistance of underlying layers to mechanical, physical, and / or chemical environmental influences.

[0081] In an alternative embodiment, the protective layer can consist of a dual-cure lacquer. The thickness of this protective layer is preferably selected from a range of 1 pm to 10 pm, more preferably from 4 pm to 6 pm, and more preferably from 4.5 pm to 5.5 pm. A dual-cure lacquer is understood to be a lacquer that, in a first step, is thermally pre-cured during and / or after application in liquid form, and in a second step, after processing the transfer film, is radically post-cured, particularly by high-energy radiation, preferably UV radiation. Dual-cure lacquers offer the advantage that, due to their durability, they can be used as external protective layers. The application of further protective layers is advantageously unnecessary.Dual-cure coatings can consist of various saturated and / or unsaturated monomers, oligomers, and / or polymers, which in particular contain at least partially unsaturated acrylate or methacrylate groups. The aforementioned functional groups can be radically crosslinked together in the second step described above. Preferably, the class of unsaturated polymers and / or oligomers is selected individually or in combination and / or as copolymers and / or blends from the following group: epoxy acrylates, polyether acrylates, polyester acrylates, urethane acrylates, and acrylic acrylates. Urethane acrylates and acrylic acrylates are particularly preferred. For thermal pre-crosslinking in the first step, it is advantageous if the monomers, polymers, and / or oligomers contain at least two or more alcohol groups. The dual-cure coating can be crosslinked with these alcohol groups using isocyanates and / or melamine crosslinkers.The isocyanates are preferably based on a group consisting of blocked and / or unblocked representatives selected individually or in combination from the following: toluene-2,4-diisocyanate (TDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI). The melamine crosslinkers are preferably melamine-formaldehyde resins.

[0082] The protective layer may contain additives and / or fillers, which are selected in particular individually or in combination from the group of: cellulose compounds, silicone resins, UV absorbers, inorganic fillers.

[0083] The decorative layer can be provided as a single-layer decorative layer or as a multi-layer decorative layer.

[0084] The decorative layer may have one or more layers of adhesion promoters, referred to below as decorative layer adhesion promoters. The decorative layer adhesion promoter is tailored to the layers in contact with it. For example, a metal adhesion promoter and / or a paint adhesion promoter may be included to improve the adhesion of a metal layer and / or paint layer to another layer.

[0085] The decorative layer adhesion promoter can be based, for example, on uncrosslinked and / or crosslinked classes of substances, selected individually or in combination and / or as copolymers and / or blends from the group consisting of: polyacrylates, poly(meth)acrylates, polyurethanes, and cellulose compounds. The crosslinker can be selected individually or in combination from the group consisting of: blocked isocyanates, unblocked isocyanates, melamine resins, preferably melamine-formaldehyde resins, carbodiimides, and aziridines.

[0086] The protective layer may contain one or more layers of adhesion promoters, referred to below as protective layer adhesion promoters. The protective layer adhesion promoter is adapted to the layers that are in contact with it. For example, a protective layer adhesion promoter may be arranged to improve the adhesion of a topcoat to the protective layer. Similarly, a protective layer adhesion promoter may be arranged to improve the adhesion of the protective layer to the decorative layer.

[0087] The decorative layer preferably comprises one or more color layers, in particular colored lacquer layers. The one or more color layers can each be colored differently. Preferably, the one or more color layers are transparent and / or translucent and / or opaque. Furthermore, it is possible that two or more color layers are separated by one or more additional layers, in particular transparent layers. The one or more color layers can preferably cover part or all of their respective layers. The one or more color layers can consist of a binder and dyes and / or fillers and / or pigments. In particular, the pigments are selected individually or in combination from the group consisting of: optically variable pigments, interference layer pigments, liquid crystal pigments, magnetically alignable pigments, thermochromic pigments, and metallic pigments.It is possible that one or more color layers contain phosphorescent, luminescent and / or thermochromic dyes.

[0088] Furthermore, the decorative layer can also comprise one or more replicated layers. These replicated layers are preferably opaque and / or translucent and have a relief structure. The one or more replicated layers and / or the relief structure can preferably be present partially or fully within their layer plane. Advantageously, a transparent and / or translucent protective layer is arranged on the side of the relief structure facing the viewer, wherein the protective layer, in particular, smooths out the relief structure. Alternatively, it is possible that the relief structure is at least partially uneven, so that the relief structure can be perceived haptically.

[0089] The one or more replicated layers can be based, for example, on uncrosslinked and / or crosslinked material classes, individually or in combination and / or as copolymers and / or as blends selected from the group: polyacrylates, poly(meth)acrylates, polyurethanes, cellulose compounds, in particular nitrocellulose. The crosslinker can be selected individually or in combination from the group: blocked isocyanates, unblocked isocyanates, melamine resins, preferably melamine-formaldehyde resins, carbodiimides, aziridines.

[0090] It is possible that the decorative layer also features one or more optically active relief structures, in particular diffractive structures and / or holograms and / or refractive structures and / or matte structures. At least one reflective layer is arranged directly on the relief structure, at least partially.

[0091] Furthermore, the decorative layer can also comprise one or more reflective layers, which are preferably opaque and / or translucent. The one or more reflective layers can preferably be present partially or fully within their layer plane. In particular, the one or more reflective layers can consist of metals and / or HRI layers (HRI = High Refractive Index), i.e., layers with a high refractive index, especially with a refractive index greater than 1.5. Suitable metals are, for example, selected individually or in combination as an alloy from the group consisting of: aluminum, tin, indium, chromium, copper, gold, and silver. Suitable HRI layers include, for example, metal sulfides or metal oxides, preferably ZnS or SiO2. The decorative layer can comprise one or more metal layers.Preferably, one or more metal layers are arranged in the decorative layer by vapor deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD), and / or sputtering. Different metal layers can also consist of different metals, and in particular, metals of different colors. Suitable metals are, for example, selected individually or in combination as alloys from the group consisting of: aluminum, tin, indium, chromium, copper, gold, and silver.

[0092] Metal layers are preferably arranged in contact with a clear lacquer layer and / or a pigmented lacquer layer, for example, a layer of a decorative layer adhesion promoter. Advantageously, the one or more metal layers are contacted on at least one side, preferably both sides, with a layer of the decorative layer adhesion promoter, which is designed in such a way as to improve the adhesion between the metal layer and further layers of the transfer layer.

[0093] The layers of the decorative layer, for example, the one or more color layers of the decorative layer, can each be present across the entire surface or only partially. If several layers of the decorative layer are each present only partially, several layers of the decorative layer can be arranged next to each other, in particular directly adjacent to each other, or at least partially overlapping. It is also possible that a partial layer of the decorative layer is arranged on top of another full-surface layer of the decorative layer, with the full-surface layer serving as a background or substrate for the partial layer. The background or substrate contrasts with the partial layer of the decorative layer, particularly in color, brightness, reflectivity, and / or roughness. It is possible that one or more layers, in particular partial layers, of the decorative layer form one or more motifs and / or decorations.In a preferred embodiment, the decorative layer has a full-surface color layer and / or metal layer, as well as a further color layer and / or metal layer that is only arranged in certain areas, so that it forms a decoration.

[0094] A motif and / or decoration can be selected individually or in combination from the following groups: graphically represented outline, figurative representation, image, visually recognizable design element, symbol, logo, portrait, organic patterns, technical patterns, brushed patterns, brushed textures, continuous patterns, alphanumeric characters, coding, code patterns, cryptographic patterns, text, and color scheme. The one or more motifs and / or decorations are designed in such a way that they retain their intended appearance when the transfer film is applied, particularly when the transfer film is stretched. Such a design is particularly advantageous when the motif and / or decoration is positioned in an area that has a concave and / or convex surface and / or a radius and / or a chamfer.

[0095] It is possible that the transfer layer has further partially and / or fully covered layers, selected individually or in combination from the group: electrically conductive layer, antenna layer, electrode layer, magnetic layer, magnetic storage layer, semiconductor layer, barrier layer, further protective layer, reflective layer.

[0096] Preferably, the transfer film, in particular the transfer layer, is designed to have an elongation of at least 10%, more preferably at least 20%, and more preferably at least 45%. This elongation is advantageous for decorating surfaces that are not completely flat, have radii, and / or chamfers. The elongation can be achieved and / or adjusted, in particular, by the material classes and layer thicknesses of the different layers.

[0097] It is possible that step c) includes a cleaning step, which is carried out in particular after the removal of the carrier film. Preferably, the area on which the primer and / or the transfer layer is applied is cleaned. This involves removing transfer film residues, especially from edges, radii, and curves. The cleaning can be carried out using methods selected individually or in combination from the following group: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, and vacuuming.

[0098] It is possible that the procedure includes at least one of the following steps, which is carried out in particular after step c): e) ordering at least one upper-class custody intermediary, in particular on the transfer site, f) ordering at least one upper-class custody intermediary, in particular on the transfer site.

[0099] Steps e) and / or f) can be carried out once or several times, whereby layers with different or identical properties can be arranged. Preferably, at least one top-layer adhesion promoter and / or at least one top layer is applied over the entire surface of the transfer layer. It is also possible for at least one top-layer adhesion promoter and / or at least one top layer to be applied over the entire surface of the primer and / or over the entire surface of the wheel element. Steps e) and / or f) provide improved corrosion and abrasion protection. Preferably, the at least one top layer and / or the at least one top-layer adhesion promoter is colorless and / or translucent. In particular, the at least one top layer and / or the at least one top-layer adhesion promoter has a pigmentation level of 0%.Preferably, at least one top layer and / or at least one top layer adhesion promoter is a clear coat.

[0100] The one or more layers applied in steps e) and / or f) are preferably applied as thermally crosslinking liquid coatings and / or as UV-curing coatings. These coatings can be provided as solvent-based coatings, water-based coatings, and / or dispersions. Solvent-based coatings are preferred.

[0101] Preferably, the material class of the one or more layers applied in steps e) and / or f) is selected individually or in combination and / or as copolymers and / or as blends from the group consisting of: poly(meth)acrylates, polyurethanes, epoxy resins, polyesters, and melamine resins. The material class of poly(meth)acrylates and / or polyurethanes is particularly preferred. The top layer and / or the top layer adhesion promoter may comprise different or the same material classes and / or be designed in the same or different ways.

[0102] In a preferred embodiment, the at least one top layer and / or the at least one top layer adhesion promoter is at least one coating which is selected individually or in combination from the group: acrylic powder coating, cut-resistant coating, corrosion-resistant powder coating, acrylic basecoat, acrylic liquid coating, polyester-based corrosion-resistant coating.

[0103] It is possible that cleaning and / or post-treatment is carried out, at least in certain areas, before, between, and / or after steps e) and f). Cleaning can be performed using methods selected individually or in combination from the following group: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, and vacuuming.

[0104] Post-treatment can be carried out using methods selected individually or in combination from the following group: laser ablation, milling, polishing, UV irradiation, thermal hardening, relief embossing.

[0105] In step d) the wheel element, comprising the transfer position, is obtained, wherein the wheel element is in particular encompassed by or forms a wheel.

[0106] The wheel element according to the invention comprises the primer. Furthermore, the primer system of the transfer layer is arranged in contact with the primer, wherein the transfer layer comprises the protective layer, which is arranged on the side of the transfer layer facing away from the primer, and the decorative layer, which is arranged between the primer system and the protective layer. It is particularly possible that the wheel element comprises further and / or additional layers. For example, one or more topcoat adhesion promoters and / or topcoats can be arranged on the protective layer. The primer can also comprise one or more layers, for example, the primer, the basecoat, and / or the primer adhesion promoter.

[0107] It is possible that the process steps are carried out once or several times. In particular, process steps may be repeated. A preferred process comprises at least the following steps a), b), c), d), preferably a), b), c), e), f), d).

[0108] The tests described below are preferably carried out in a test area. The test area comprises the material of the wheel element, on which a primer, comprising a base coat and optionally a primer adhesion promoter, is applied over the entire surface, with a transfer layer being applied over the entire surface of the primer by means of hot stamping.

[0109] The adhesion of the transfer film to the primer is checked by means of a cross-cut test according to DIN EN ISO 2409:2013-06 (“Paints and varnishes - Cross-cut test (ISO 2409:2013); German version EN ISO 2409:2013”, German title: “Beschichtungsstoffe - Gitterschnittprüfung (ISO 2409:2013); Deutsche Fassung EN ISO 2409:2013”, issue date: 2023-06) or by means of ASTM D 3359 - 09, test method B.

[0110] In the cross-cut test, six cuts are made vertically and six horizontally (at a 90° angle to the vertical cuts) into the coating down to the substrate, i.e., the material of the wheel element, using a knife and preferably a template. The cut width depends on the coating thickness. For coatings with a thickness of less than 60 µm, the cut spacing is preferably about 1 mm.

[0111] A clear adhesive tape or a fabric adhesive tape with an adhesive strength of 2.3 N / cm to 4.3 N / cm was applied to the resulting square of sections (measuring area). This was then peeled off at an angle of 60° within a time of 0.5 s to 1 s.

[0112] The evaluation is performed by visually assessing the measured surface and classifying it into cross-cut adhesion values ​​according to DIN EN ISO 2409:2013-06 from 0 (very good adhesion) to 5 (very poor adhesion), abbreviated GT 0 to GT 5, or according to ASTM D 3359-09, Test Method B, from 5B (very good adhesion) to OB (very poor adhesion). The criteria for classifying the corresponding values ​​are summarized in the following table, with schematic representations of the surfaces obtained by the cross-cut test in Figures 7a to 7d. Table 1: Criteria for classifying cross-cut adhesion values, in particular according to DIN EN ISO 2409:2013-06 and ASTM D3359-09. Schematic representations of the surfaces obtained are shown in Figures 7a to 7d.

[0113] Preferably, the transfer film on the primer exhibits a good level of adhesion in the range of GT 0 to 1 or 4B to 5B.

[0114] Furthermore, the adhesion of the transfer film to the primer of a test specimen is checked by means of a pressure water jet test (steam jet test) according to test method B of DIN EN ISO 16925:2022-06 (“Paints and varnishes - Determination of the resistance of coatings to pressure water-jetting (ISO 16925:2021 ); German version EN ISO 16925:2022“, German title: “Beschichtungsstoffe - Prüfung der Beständigkeit von Beschichtungen gegen Druckwasserstrahl (ISO 16925:2021 ); Deutsche Fassung EN ISO 16925:2022“, Publication date: 2022-06) in the test area described above.

[0115] For pressure water jet testing, a Sikkens scoring tool (scoring tool S) with a 1 mm wide cutting edge is used to cut a primary and a secondary score into the coating down to the substrate, i.e., the material of the wheel element. The primary and secondary scores each intersect half of the coating at an angle of 45°, forming a St. Andrew's cross. The resulting cuts in the transfer film are approximately 1 mm wide. The length of the primary score is > 100 mm and the length of the secondary score is > 20 mm.

[0116] If the test area is too small, it is possible that only the main scribble is made and the secondary scribble at approximately 45° is omitted. However, such a test area has no intersection and is preferably avoided if possible.

[0117] The specimen is then clamped into the pressure water jet device and subjected to test method B of DIN EN ISO 16925:2022-06. Demineralized water is used for spraying, and the spray jet is directed centrally above the intersection point of the St. Andrew's cross along the main scratch. The spray jet has a water temperature of (60 ± 2) °C, an angle of impact of (90 ± 2)°, and a mass flow rate of

[0118] The injection speed is (11.3 ± 0.2) kg / min. Furthermore, the distance between the nozzle and the test area is (100 ± 1) mm and the injection time is (30 ± 1) s.

[0119] The adhesion of the transfer film is evaluated with regard to the resulting flaking according to the criteria shown in Figs. 8a to 8f, where a value of 0 corresponds to no flaking and 5 to severe flaking.

[0120] Preferably, the transfer film exhibits an adhesion value in the range of 0 to 2, which is considered sufficient. A value in the range of 0 to 1 is preferred, as this indicates good adhesion of the transfer film to the primer.

[0121] Table 2: Criteria for classifying pressure water jet testing (steam jet testing) according to test method B of DIN EN ISO 16925:2022-06 into characteristic values. Surface finishes obtained are shown schematically in Figures 8a to 8f.

[0122] Naturally, the above-mentioned material characteristics can also be applied equivalently in a process, or the above-mentioned process characteristics can be applied in the product.

[0123] The invention is explained below by way of example using several embodiments and the accompanying drawings. The embodiments shown are therefore not to be understood as limiting.

[0124] Figs. 1a, b show schematic sectional views of a

[0125] Wheel elements with transfer layer and a transfer film.

[0126] Figures 2a to 2d show further schematic sectional views of wheel elements and process steps.

[0127] Fig. 3 shows another schematic sectional view of a

[0128] Wheel element with a radius and an angle. Fig. 4 shows another schematic sectional view of a wheel element without a transfer position.

[0129] Figures 5a to 5d show further schematic sectional views of transfer foils.

[0130] Figures 6a to 6c show further schematic sectional views of wheel elements with transfer position.

[0131] Figures 7a to 7c show results of cross-cut tests for classifying adhesion strength into characteristic values.

[0132] Figures 8a to 8f show results of pressure water jet tests for a classification of adhesion strength into characteristic values.

[0133] Fig. 1a shows a wheel element 1, which can be obtained in particular by the method according to the invention. The wheel element 1 has a primer 2 on which a transfer film 3 is arranged.

[0134] An exemplary transfer foil 3 is shown in Fig. 1b. The transfer foil 3 has a transfer layer 5 comprising a primer system 6. The primer system 6 is designed to be applied to the wheel element 1 in contact with the primer 2 by means of hot stamping. Furthermore, the transfer layer 5 has a protective layer 8 on the side facing away from the primer system 6. This protective layer 8 is designed to form the layer of the transfer layer 5 that is located on the visible side of the wheel element 1. The transfer layer 5 also has a

[0135] The decorative layer 7 is arranged between the primer system 6 and the protective layer 8. Furthermore, the transfer film 3 has a carrier film 4, which is arranged on the side of the transfer film 3 facing away from the primer system 6. The transfer film 3 is, in particular, a hot stamping film, which, especially its transfer layer 5, may have further layers.

[0136] Figures 2a to 2d schematically show the inventive method or its method steps a), b), c) and d) and optionally e) and f) for decorating a wheel element 1, as well as further and more detailed embodiments of the wheel element 1 shown in Figure 1.

[0137] Fig. 2a shows a schematic wheel element 1, which is provided at the beginning of the process in step a) and on which a primer 2 is subsequently applied in step b), in particular on the metal of the wheel element 1.

[0138] The provided wheel element 1, which in particular comprises or consists of metal, preferably light metal and / or steel, may preferably be selected from the group consisting of rim, wheel disc, wheel flange, spokes, wheel flange and / or combinations thereof. Preferably, a wheel comprising or consisting of the wheel element 1 is provided.

[0139] The wheel element 1 preferably has one or more surfaces to be decorated that are not perpendicular to the feed direction of the embossing die. It is possible that, as schematically shown in Fig. 3, one or more surfaces to be decorated have a radius R, in particular from a range of 0.2 mm to 20 mm, preferably from 1 mm to 12 mm, or an angle α or phase from a range of more than 0° to 40°, preferably from 25° to 35°, to the surface to be decorated.

[0140] The primer 2 shown in Fig. 2a is applied in two layers and comprises a primer 9 and a base coat 10. Alternatively, the primer 2 can also be applied in one or at least three layers. In the schematic embodiment shown in Fig. 2a, the primer 2 is applied over the entire surface of the wheel element 1, although a partial application is also possible.

[0141] Step b) shown schematically in Fig. 2a, the arrangement of the layers covered by the primer 2, can be carried out, for example, by one of the methods described above.

[0142] As shown in Fig. 2a, the primer 2 may comprise a primer 9, which is arranged in contact with the wheel element 1, wherein in a preferred embodiment the primer 9 is a powder coating. The primer 9 may be composed individually or in combination of one or more classes of materials, selected individually or in combination from the group consisting of: polyesters, epoxy, and copolymers of polyesters and epoxies.

[0143] Furthermore, the primer 2, as shown in Fig. 2b, can comprise a base coat 10, which is preferably arranged on the primer 9, in particular arranged over the entire surface.

[0144] The basecoat 10 of the primer 2 is preferably applied by powder coating, although liquid coating is also possible. The primer 2, in particular the basecoat 10, can be thermally crosslinked and / or radiation-cured. It is possible that the primer 2, in particular the basecoat 10, is composed of one or more classes of materials, individually or in combination and / or as copolymers and / or as blends selected from the group consisting of: poly(meth)acrylates, polyesters, epoxy resins, melamine resins, and polyurethanes. Preferably, the primer 2, in particular the basecoat 10, is composed of poly(meth)acrylates and / or polyesters. Particularly in the case of liquid coating, the primer 2, in particular the basecoat 10, can be applied as a solvent-based coating, a water-based coating, and / or a dispersion. Furthermore, it is possible that the primer 2, in particular the basecoat 10, is colored, preferably by means of dyes and / or color pigments.Alternatively or additionally, the basecoat 10 can also contain metallic pigments and / or effect pigments. Preferably, the pigmentation level of the primer 2, and more preferably of the basecoat 10, is selected from a range of 10 wt.% to 60 wt.%, more preferably from 20 wt.% to 50 wt.%.

[0145] Preferably the basecoat 10 is opaque, translucent or transparent for the wavelength range perceptible to the human eye, preferably for the range from 400 nm to 700 nm.

[0146] In the schematic embodiment shown in Fig. 2a, the base coat 10 acts as an adhesion promoter to improve adhesion to the transfer film 3. However, it is also possible that the primer 2 of the embodiment shown in Fig. 2a comprises a primer adhesion promoter 11, which is preferably applied as a layer on the base coat 10, at least partially, and preferably completely.

[0147] Preferably, at least one coating is arranged as a primer 2, in particular as a primer-adhesion promoter 11, which is selected individually or in combination from the group: acrylic powder coating, cut-resistant coating, corrosion-resistant powder coating, acrylic basecoat, acrylic liquid coating,

[0148] Corrosion protection coating based on polyester. Alternatively and / or additionally, the primer 2, in particular the primer adhesion promoter 11, can consist of a combination of water-based and / or solvent-based coatings, the composition of which is not restricted.

[0149] Fig. 4 shows a wheel element based on Fig. 2a as a supplementary

[0150] Exemplary embodiment of a specific primer 2. Here, a two-layer primer-adhesion promoter 11 is arranged on the basecoat 10. One layer of the primer-adhesion promoter 11 is arranged as a pigment-containing lacquer layer that has metallic pigments and / or color pigments and / or effect pigments.

[0151] Furthermore, in the embodiment shown in Fig. 4, a relief structure is introduced and / or embossed into this pigment-containing lacquer layer, particularly at least in certain areas, in an additional step. In this embodiment, a second layer of the primer adhesion promoter 11 is applied to the relief structure of the pigment-containing lacquer layer. The second layer of the primer adhesion promoter 11 is transparent and acts as a leveling layer, so that the optical effect created by the relief structure is perceived by an observer but is not perceptible to the touch.

[0152] It is possible that after the application of primer 2, the wheel element 1, particularly in the area where primer 2 is applied, will be cleaned. The cleaning can be carried out using methods selected individually or in combination from the following group: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, and vacuuming.

[0153] Figure 2b schematically illustrates step c) of arranging the transfer foil 3 by means of hot stamping, whereby in particular at least one decorated area is obtained. Preferably, the transfer foil 3 is arranged only in areas that have the primer 2, in particular wherein the primer 2 is at least partially, preferably completely, covered by the transfer foil 3 after step c), as shown in Figure 1 and / or Figure 2c.

[0154] It is possible that at least one decorated area has a surface area that consists of a range of 1 cm. 2 up to 1000 cm 2 , preferably 1 cm 2 up to 800 cm 2 , especially preferred by 1 cm 2 up to 200 cm 2 , is selected, has. It is possible that the at least one decorated surface lies entirely within a plane, particularly a two-dimensional one. Furthermore, it is possible that the at least one decorated surface has interruptions, such as a wheel hub bore or a screw hole.

[0155] In the embodiment shown in Fig. 2b, the at least one decorated surface extends at least partially perpendicular and at least partially non-perpendicular to the feed direction of the embossing die, symbolized by an arrow. As shown, the at least one decorated surface can extend in certain areas at a defined angle along at least one spatial direction to the perpendicular to the feed direction of the embossing die. Thus, as shown in Fig. 2b and / or Fig. 3, the at least one decorated surface can have a first and a second sub-area, wherein a plane of the second sub-area is arranged at an angle to a plane of the first sub-area. The angle is preferably selected from a range of more than 0° to 40°, preferably from 25° to 35°. Alternatively or additionally, as shown in Fig.Figure 3 shows that the at least one decorated surface is concave and / or convex relative to the perpendicular to the feed direction of the embossing die. It is possible for the at least one decorated surface to have a radius, in particular from 0.2 mm to 20 mm, preferably from 1 mm to 12 mm.

[0156] For hot stamping, a stamping unit is provided, which includes a stamping die, but which is not shown in Fig. 2b for clarity. The stamping unit, in particular the stamping die, can have a clamping device and / or a device for applying pressure to fix the transfer foil 3. Preferably, a stamping die is provided which extends along at least one spatial direction perpendicular to the feed direction over a distance, wherein the distance consists of a

[0157] The range is selected from 1 cm to 100 cm, preferably from 10 cm to 80 cm.

[0158] Alternatively or additionally, the embossing die has a contact surface for contacting the wheel element 1, which extends from an area of ​​1 cm. 2 up to 1000 cm 2 , preferably 1 cm 2 up to 800 cm 2 , especially preferred by 1 cm 2 up to 200 cm 2 selected, on.

[0159] The embossing die is preferably made of metal and preferably has a coating of silicone, preferably silicone rubber, on the surface that is in contact with the transfer foil.

[0160] The coating can be formed from one or more silicone layers, which in a preferred embodiment comprise at least two or more silicone layers. The two or more silicone layers are preferably arranged one above the other, such that they preferably overlap at least partially and / or are arranged side by side.

[0161] The coating thickness, particularly the thickness of one or more silicone layers, can remain constant or vary across the surface of the die. It can even be advantageous to adapt the coating thickness, especially of one or more silicone layers, to the expected deviations of the wheel element 1. Alternatively or additionally, it is also possible for the coating to contain a different number of silicone layers in certain areas.

[0162] In particular, the coating has a layer thickness selected from a range of 2 mm to 50 mm, preferably from 2 mm to 30 mm, more preferably from 2 mm to 20 mm, and even more preferably from 3 mm to 10 mm. If the embossing die has two or more silicone layers, it has proven advantageous for these layer thicknesses to each have an independent thickness from a range of 1 mm to 10 mm, preferably from 1 mm to 5 mm.

[0163] It is possible to use an embossing unit comprising the embossing tool, which is designed or provided such that a vacuum can be applied between the transfer foil 3 and the embossing die. This allows the transfer foil 3 to be drawn onto the embossing die, thereby conforming to the contour of the embossing die. In particular, for this purpose, the embossing die has at least one element on the surface that is in contact with the transfer foil 3, selected individually or in combination from the group consisting of bore, hole, groove, and slot, wherein the at least one element is connected to a device for applying the vacuum.

[0164] The contour of the embossing die and / or the transfer foil 3 is preferably convex and / or concave in at least one spatial direction. Preferably, the contour of the embossing die and the transfer foil 3 is the same.

[0165] Furthermore, the embossing unit may have a clamping device for attaching the transfer foil 3 to the embossing unit, preferably the embossing die. It is also possible that the embossing unit, preferably the embossing die, is configured such that the transfer foil 3 is heated in the area where it contacts the primer 2 before the embossing step. In this case, the transfer foil 3 is preferably heated to a temperature selected from a range of 150 °C to 250 °C, more preferably from 180 °C to 220 °C, particularly before the pressure is applied.

[0166] For example, step c) may include at least one or more of the following sub-steps:

[0167] - Providing the embossing unit including the embossing die; - Clamping the transfer foil 3 into a clamping device of the embossing unit;

[0168] - Suction of the transfer foil 3 onto the embossing die;

[0169] - Warming up the transfer foil 3;

[0170] - Arranging and aligning the transfer foil 3 and / or the embossing die according to the wheel element 1 ;

[0171] - Heating the embossing unit, preferably the embossing die, to embossing temperature;

[0172] - Contacting the transfer foil 3 with the wheel element 1, in particular the primer 2, by means of the embossing die;

[0173] - Method or turning of the embossing unit, preferably the embossing die.

[0174] It is possible that the embossing pressure is in the range of 100 N / cm². 2 up to 500 cm 2 preferably 200 N / cm 2 up to 350 N / cm 2 , further preferably from 250 N / cm 2 up to 300 N / cm 2 , even more preferred from 260 N / cm 2 up to 280 N / cm 2The embossing temperature is preferably selected from a range of 125 °C to 250 °C, more preferably from 150 °C to 210 °C, more preferably from 170 °C to 200 °C, and even more preferably from 180 °C to 190 °C. The embossing time is preferably selected from a range of 0.3 s to 8 s, more preferably from 0.5 s to 5 s, more preferably from 1 s to 3 s, and even more preferably from 1.3 s to 2 s.

[0175] The embossing is, in particular, a stroke embossing. It is possible that the embossing die and / or the coating at least partially replicate the three-dimensional shape and / or dimensions of the wheel element 1 to be decorated. In other words, the surface of the embossing die and / or the coating follows the contour of the surface of the wheel element 1 to be decorated. Preferably, the embossing die and / or the coating has at least partially a complementary shape and / or dimensions to the wheel element 1 to be decorated. In step e), it is possible that the decoration of the wheel element 1 is carried out by means of sequenced embossing, in particular wherein the transfer foil 3 is arranged in several individual embossing strokes. Alternatively, it is possible that the transfer foil 3 is arranged in a single embossing stroke. Furthermore, it is possible that several transfer foils 3 are applied in step e) to different surfaces orThe transfer foils 3 are arranged in the embossing areas of the wheel element 1, in particular arranged side by side without overlap. It is also possible that several transfer foils 3 are arranged overlapping at least in certain areas, in particular overlapping completely.

[0176] Furthermore, it is possible that the transfer foil 3 is arranged with register precision to an element of the wheel element 1, another wheel element 1, and / or an element of the primer 2. It is also possible that the transfer foil 3 is arranged with register precision to an already arranged transfer foil 3.

[0177] The carrier film 4 of the transfer film 3 is made of PET and is provided in a manner that allows it to be detached from the transfer layer 5. The carrier film 4 is preferably detached after the transfer film 3 has been placed on the primer 2, with the transfer layer 5 remaining on the primer 2.

[0178] In addition to the layers shown in Fig. 1b, it is possible that the carrier film 4 has a layer on the side facing the transfer layer 5.

[0179] has a detachable layer 14, which can be designed as described above.

[0180] The primer system 6 is specifically designed for the coating to be overcoated, in particular the primer 2. The primer system 6, shown schematically in Fig. 1b, can be single-layered or multi-layered and can be formed by one or more layers of different adhesives and / or adhesion promoters. For information regarding the layer thickness and the material classes of the primer system 6, please refer to the descriptions above.

[0181] The protective layer 8 of the transfer film 3 shown in Fig. 1b can be designed differently. In one embodiment, the protective layer 8 is a poly(meth)acrylate-based lacquer, and in another, it is a dual-cure lacquer. For details regarding the embodiments of the protective layer 8, please refer to the descriptions above.

[0182] The decorative layer of the transfer foil 3 shown schematically in Fig. 1 b can be provided as a single-layer decorative layer 7 or as a multi-layer decorative layer 7.

[0183] The decorative layer 7 can, for example, have one or more layers of decorative layer adhesion promoters 71.

[0184] The decorative layer 7 preferably comprises one or more color layers 73, 74, in particular colored lacquer layers. The one or more color layers 73, 74 can each be colored differently. Preferably, the one or more color layers 73, 74 are transparent and / or translucent and / or opaque. Furthermore, it is possible that two or more color layers 73, 74 are separated by one or more further layers, in particular transparent layers. The one or more color layers 73, 74 can preferably each be present partially or fully within their layer plane. The one or more color layers 73, 74 can consist of a binder and dyes and / or fillers and / or pigments. In particular, the pigments are selected individually or in combination from the group consisting of: optically variable pigments, interference layer pigments, liquid crystal pigments, magnetically alignable pigments, thermochromic pigments, and metallic pigments.It is possible that one or more color layers 73, 74 contain phosphorescent, luminescent and / or thermochromic dyes.

[0185] Furthermore, the decorative layer 7 can also comprise one or more replicated layers 75. These replicated layers 75 are preferably opaque and / or translucent and have a relief structure. The one or more replicated layers 75 and / or the relief structure can preferably be present partially or fully within their layer plane. Advantageously, a transparent and / or translucent protective layer is arranged on the side of the relief structure facing the viewer, wherein the protective layer, in particular, compensates for the relief structure. Alternatively, it is possible that the relief structure is at least partially uncompensated, so that the relief structure can be perceived haptically.

[0186] The one or more replicated layers 75 can, for example, be based on uncrosslinked and / or crosslinked classes of materials, individually or in combination and / or as copolymers and / or as blends selected from the group: polyacrylates, poly(meth)acrylates, polyurethanes, cellulose compounds, in particular nitrocellulose. The crosslinker can be selected individually or in combination from the group: blocked isocyanates, unblocked isocyanates, melamine resins, preferably melamine-formaldehyde resins, carbodiimides, aziridines.

[0187] It is possible that the decorative layer 7 also comprises one or more optically active relief structures, in particular diffractive structures and / or holograms and / or refractive structures and / or matte structures. At least one reflective layer is arranged directly on the relief structure, at least partially. Furthermore, the decorative layer 7 can also comprise one or more reflective layers, which are preferably opaque and / or translucent. The one or more reflective layers can preferably be present partially or fully within their layer plane. In particular, the one or more reflective layers can consist of metals and / or HRI layers, especially with a refractive index greater than 1.5. Suitable metals are, for example, selected individually or in combination as an alloy from the group consisting of: aluminum, tin, indium, chromium, copper, gold, and silver.Suitable HRI layers include, for example, metal sulfides and metal oxides, preferably ZnS or SiO2.

[0188] The decorative layer 7 can comprise one or more metal layers 72. Preferably, the one or more metal layers 72 are arranged in the decorative layer 7 by vapor deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD), and / or sputtering. Different metal layers 72 can also consist of different metals, and in particular, metals of different colors. Suitable metals are, for example, selected individually or in combination as an alloy from the group consisting of: aluminum, tin, indium, chromium, copper, gold, and silver.

[0189] Metal layers 72 are preferably arranged in contact with a clear lacquer layer and / or a pigment-containing lacquer layer, for example a layer of a decorative layer adhesion promoter 71. Advantageously, the one or more metal layers 72 are contacted on at least one side, preferably both sides, with a layer of the decorative layer adhesion promoter 71, which is designed in such a way that the adhesion between metal layer 72 and further layers of the transfer layer 5 is improved.

[0190] The layers of decorative layer 7, for example the one or more

[0191] Color layers 73, 74 of the decorative layer 7 can each be present over the entire surface or only partially. If several layers of the decorative layer 7 are present, each only partially, several layers of the decorative layer 7 can be arranged next to each other, in particular directly adjacent to each other, or at least partially overlapping. It is also possible that a partial layer of the decorative layer 7 is arranged on another full-surface layer of the decorative layer 7, with the full-surface layer of the decorative layer 7 serving as a background or substrate for the partial layer of the decorative layer 7. The background or substrate contrasts with the partial layer of the decorative layer 7, in particular in color and / or brightness and / or reflectivity and / or roughness.

[0192] It is possible that one or more layers, in particular partial layers, of the decorative layer 7 form one or more motifs and / or decorations. In a preferred embodiment, the decorative layer 7 has a full-surface color layer 74 and / or metal layer 72, as well as a further color layer 73 and / or a metal layer 72, which is only arranged in certain areas, so that it forms a decoration.

[0193] A motif and / or decoration can be selected individually or in combination from the following group: graphically represented outline, figurative representation, image, visually recognizable design element, symbol, logo, portrait, organic patterns, technical patterns, brushed patterns, brushed textures, continuous patterns, alphanumeric characters, coding, code patterns, cryptographic patterns, text, and color scheme. The one or more motifs and / or decorations are designed in such a way that they retain and / or maintain their intended appearance when the transfer film 3 is applied, particularly when the transfer film 3 is stretched.

[0194] It is possible that the transfer layer has 5 further partially and / or fully covered layers, selected individually or in combination from the group: electrically conductive layer, antenna layer, electrode layer, magnetic layer, magnetic storage layer, semiconductor layer, barrier layer, further protective layer, reflective layer.

[0195] Figures 5a to 5d show different embodiments of the transfer foil 3, which can be arranged, for example, in the method according to the invention, in particular in step c).

[0196] Based on the transfer foil according to Fig. 1, each transfer foil 3 shown in Figs. 5a to 5d has a transfer layer 5 comprising a primer system 6. On the side of the transfer layer 5 facing away from the primer system 6, the transfer foil 3 has a protective layer 8. Furthermore, the transfer layer 5 includes a decorative layer 7, which is arranged between the primer system 6 and the protective layer 8. The transfer foil 3 also has a carrier film 4, which is arranged on the side of the transfer foil 3 facing away from the primer system 6. The transfer foils shown in Figs. 5a to 5d have multilayered decorative layers 7 and differ in their design. The individual layers of the decorative layer 7 can each be designed as described above.

[0197] The transfer foil 3 of the embodiment according to Fig. 5a has a decorative layer 7 with a metal layer 72, which is in contact with the primer system 6. Furthermore, a layer of a decorative layer adhesion promoter 71, in particular a metal adhesion promoter, is arranged on the metal layer 72 in contact with the protective layer 8. Advantageously, the decorative layer adhesion promoter 71 and the protective layer 8 are transparent or translucent, so that the transfer layer 5 has a metallic appearance on its visible side.

[0198] The transfer foil 3 of the embodiment according to Fig. 5b has a

[0199] Decorative layer 7 with a metal layer 72 which is in contact with the

[0200] Primer system 6 is applied. Furthermore, on the side facing away from the primer system 6 and the metal layer 72, a decorative layer adhesion promoter 71, in particular a metal adhesion promoter, is arranged. A color layer 74 is applied over the entire surface of the decorative layer adhesion promoter 71. The full-surface color layer 74 acts as a background and / or substrate for a further color layer 73 with which it is in contact. The further color layer 73 is applied only in certain areas, thereby forming a decoration and / or motif. The color layers 73, 74, and the decoration can be designed as described above. Advantageously, at least the full-surface color layer 74 is transparent or translucent, so that a metallic, glossy, and colored background and / or substrate is obtained for the decoration and / or motif.

[0201] The transfer foil 3 of the embodiment according to Fig. 5c has a decorative layer 7 with a metal layer 72, which can be designed as described above, and is in contact with the primer system 6. Furthermore, a replicated layer 75 is arranged on the side of the metal layer 72 facing away from the primer system 6. A layer of a decorative layer adhesion promoter 71 is arranged in the decorative layer 7 in contact with the protective layer 8.

[0202] The transfer foil 3 of the embodiment according to Fig. 5d has a decorative layer 7 with a full-surface color layer 74, which is in contact with the primer system 6. The full-surface color layer 74 can be in contact with an optional further color layer 73. The further color layer 73 is only applied in certain areas and thus forms a decoration and / or motif.

[0203] Preferably, the transfer film 3, in particular the transfer layer 5, is designed such that it has an elongation of at least 10%, more preferably at least 20%, and more preferably at least 45%. It is possible that step c) includes a cleaning step, which is carried out in particular after the removal of the carrier film 4. Preferably, the area on which the primer 2 and / or the transfer layer 5 is arranged is cleaned. The cleaning can be carried out by methods selected individually or in combination from the group consisting of: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, and vacuuming.

[0204] As shown in Figures 2c and 2d, it is possible to arrange further layers on the transfer film 3. For this purpose, the method may comprise at least one of the following steps, which is carried out in particular after step c): e) Arranging at least one top-layer adhesion promoter 13, in particular on the transfer layer 5, f) Arranging at least one top layer 12, in particular on the at least one top-layer adhesion promoter 13 and / or the transfer layer 5.

[0205] Fig. 2c shows an embodiment in which steps e) and / or f) are each carried out once, wherein the at least one top layer adhesion promoter 13 and / or the at least one top layer 12 are arranged over the entire surface of the transfer layer 5.

[0206] In the embodiment according to Fig. 2d, steps e) and / or f) are carried out several times, whereby layers with different or identical configurations can be arranged. A wheel element 1 is obtained, based on Fig. 2c, and comprising at least one further upper layer 12.

[0207] In the embodiments according to Fig. 2c and Fig. 2d, at least one

[0208] Top layer adhesion promoter 13 and / or at least one top layer 12 arranged over the entire surface of the primer 2 and / or over the entire surface of the wheel element 1.

[0209] Preferably, the at least one top layer 12 and / or the at least one top layer adhesion promoter 13 is formulated to be colorless and / or translucent. In particular, the at least one top layer 12 and / or the at least one top layer adhesion promoter 13 has a pigmentation level of 0%. Preferably, the at least one top layer 12 and / or the at least one top layer adhesion promoter 13 is a clear coat.

[0210] The one or more layers applied in steps e) and / or f) are preferably applied as thermally crosslinking liquid coatings and / or as UV-curing coatings. Regarding the preferred class of materials for the one or more layers applied in steps e) and / or f), reference is made to the above descriptions.

[0211] In a preferred embodiment, the at least one top layer and / or the at least one top layer adhesion promoter 13 is at least one lacquer which is selected individually or in combination from the group: acrylic powder coating, cut-resistant lacquer, corrosion-resistant powder coating, acrylic basecoat, acrylic liquid lacquer, polyester-based corrosion-resistant lacquer.

[0212] It is possible that cleaning and / or post-treatment is carried out, at least in certain areas, before, between, and / or after steps e) and / or f). Cleaning can be performed using methods selected individually or in combination from the following: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, and vacuuming. Post-treatment can be performed using methods selected individually or in combination from the following: laser ablation, milling, polishing, UV irradiation, thermal hardening, and relief embossing.

[0213] Finally, in step d) of the inventive method, the inventive wheel element 1 comprising the transfer position 5 is obtained, wherein the wheel element 1 is in particular encompassed by or forms a wheel.

[0214] Figures 6a to 6c show different embodiments of the wheel element 1, which can be obtained, for example, by the method described in Figures 2a to 2d or can be based on the wheel elements 1 shown there.

[0215] The wheel elements 1 shown in Figures 6a to 6c have in common that they each have a primer 2. Furthermore, the primer system 6 of the transfer layer 5 is arranged in contact with the primer 2, wherein the transfer layer 5 has the protective layer 8 on the side of the transfer layer 5 facing away from the primer 2 and the decorative layer 7, which is arranged between the primer system 6 and the protective layer 8. The primer 2 of the wheel elements 1 shown in Figures 6a to 6c further comprises a primer 9 and a base coat 10, which additionally acts as a primer adhesion promoter 11.

[0216] In the embodiment according to Fig. 6a, one or more layers of a top-layer adhesion promoter 13 and / or a top layer 12 are additionally arranged on the protective layer 8 of the transfer film 3. These additional layers are in particular designed as clear lacquer layers 120, 130.

[0217] In the embodiment shown in Fig. 6b, the primer 2 comprises, in addition to a primer 9 and a basecoat 10, a primer adhesion promoter 11, which is arranged on the basecoat 10. The primer adhesion promoter 11 is designed as an acrylic powder coating 110. The transfer film 3 is arranged on the primer adhesion promoter 11. Furthermore, at least one or more layers of a topcoat adhesion promoter 13 and / or a topcoat 12 are arranged on the transfer film 3. In this embodiment, the one or more layers of the topcoat adhesion promoter 13 are in the form of a polyester lacquer 131 and / or an acrylic lacquer 131 and / or the one or more layers of the topcoat 12 are in the form of an acrylic lacquer 121. The top-layer adhesion promoter 13 and / or the top layer 12 or the polyester lacquer and / or the acrylic lacquer 121 , 131 , can be applied by powder coating or as a spray liquid coating.

[0218] In the embodiment shown in Fig. Be, the primer 2 also comprises, in addition to a primer 9 and a basecoat 10, a primer adhesion promoter 11, which is arranged on the basecoat 10. In this embodiment, the primer adhesion promoter 11 is designed as a cut-resistant coating 111. The transfer film 3 is arranged on the primer adhesion promoter 11. Furthermore, at least one or more layers of a topcoat adhesion promoter 13 in the form of a polyester lacquer 131 and / or acrylic lacquer 131 and / or a topcoat 12 in the form of an acrylic lacquer 121 are formed on the transfer film 3. The topcoat adhesion promoter 13 and / or the topcoat 12, or the polyester lacquer and / or the acrylic lacquer 121, 131, can be applied by powder coating or as a liquid spray coating.

[0219] Figures 7a to 7d show schematic results of a test to determine the adhesion strength of the transfer film 3 to the primer 2 using a cross-cut test, viewed from above. For details on how to perform the cross-cut test and determine the characteristic values ​​for the adhesion strength, please refer to the corresponding explanations above. In the cross-cuts shown in Figures 7a to 7d, the adhesion strength decreases from Figure 7a to Figure 7d. No cross-cuts are shown for the highest and lowest characteristic values, respectively.

[0220] Figures 8a to 8f show schematic top views of damage patterns from a test to determine the adhesion strength of the transfer film 3 to the primer 2 using a pressure water jet test. For details on how to perform the pressure water jet test and determine characteristic values ​​for the adhesion strength, please refer to the corresponding explanations above. Figure 8a shows no damage, or preferably the initial state before the test. Figures 8b to 8f each show three exemplary damage patterns, each corresponding to a characteristic value. In the depicted damage patterns, the adhesion strength decreases from Figure 8a to Figure 8f.

[0221] Naturally, the listed design variants can be combined in any way and do not represent a limitation.

[0222] Reference symbol list

[0223] 1 wheel element

[0224] 2 Primer

[0225] 3 Transfer foil

[0226] 4 carrier film

[0227] 5 Transfer situation

[0228] 6 Primer system

[0229] 7 decorative layer

[0230] 8 Protective layer

[0231] 9 primers

[0232] 10 Basecoat

[0233] 11 Primer-Adhesion Promoter

[0234] 12 Upper class 13 Upper class custody broker

[0235] 14 Delamination layer

[0236] 110 acrylic powder paint 111 cut protection paint

[0237] 120, 130 clear coat

[0238] 121, 131 Acrylic lacquer and / or polyester lacquer

[0239] 71 Decorative layer adhesion promoter 72 Metal layer

[0240] 73 Decorative paint layer

[0241] 74 Full-surface paint layer

[0242] 75 Replicated layer R radius a angle

Claims

LEONHARD KURZ Stiftung & Co. KG, Schwabacher Str. 482, DE - 90763 Fürth Patent claims 1. Method for decorating a wheel element (1) wherein the method comprises the following steps: a) providing the wheel element (1), b) applying a primer (2) to the wheel element (1), c) applying a transfer foil (3) by hot stamping, wherein the transfer foil (3) comprises a carrier foil (4) and a d) Transfer layer (5) wherein the side of the transfer layer (5) facing away from the carrier film (4) is formed by a primer system (6), wherein a decorative layer (7) is arranged on the primer system (6) and a protective layer (8) is arranged between the decorative layer (7) and the carrier film (4), d) obtaining the wheel element (1) comprising the transfer layer (5).

2. Method according to claim 1, characterized in that the primer (2) is at least partially covered by the transfer film (3) after step c).

3. Method according to one of the preceding claims, characterized in that the transfer film (3) is arranged only in areas which have the primer (2).

4. Method according to any of the preceding claims, characterized by the fact that the hot stamping is a stroke stamping process.

5. Method according to one of the preceding claims, characterized in that an embossing unit is provided for hot stamping, comprising an embossing die, wherein the embossing die has a silicone coating on the surface that is contacted with the transfer foil, the coating being formed from one or more silicone layers.

6. Method according to one of the preceding claims, characterized in that the coating has a layer thickness selected from a range of 2 mm to 50 mm, preferably from 2 mm to 30 mm, more preferably from 2 mm to 20 mm.

7. Method according to one of the preceding claims, characterized in that the embossing pressure is from a range of 100 N / cm² 2 up to 500 N / cm 2 preferably 200 N / cm 2 up to 350 N / cm 2 , further preferably from 250 N / cm 2 up to 300 N / cm 2 , even more preferably from 260 N / cm 2 up to 280 N / cm 2 , is selected.

8. Method according to one of the preceding claims, characterized in that the embossing temperature is selected from a range of 125 °C to 250 °C, preferably from 150 °C to 210 °C, more preferably from 170 °C to 200 °C, and even more preferably from 180 °C to 190 °C.

9. Method according to any of the preceding claims, characterized in that the embossing time is selected from a range of 0.3 s to 8 s, preferably from 0.5 s to 5 s, more preferably from 1 s to 3 s, and even more preferably from 1.3 s to 2 s.

10. Method according to one of the preceding claims, characterized in that at least one decorated surface is obtained, wherein the at least one decorated surface does not extend completely in a plane, which is in particular perpendicular to the feed direction of the embossing die.

11. Method according to one of the preceding claims, characterized in that the at least one decorated surface has a radius in particular from a range of 0.2 mm to 20 mm, preferably from 1 mm to 12 mm.

12. Method according to one of the preceding claims, characterized in that the at least one decorated surface has a first and a second sub-area, wherein a plane of the second sub-area is arranged at an angle to a plane of the first sub-area, wherein preferably the angle is selected from a range of more than 0° to 40°, preferably from 25° to 35°.

13. Method according to one of the preceding claims, characterized in that step c) comprises at least one or more of the following partial steps: - Providing the embossing unit including the embossing die; - Clamping the transfer foil (3) into a clamping device of the embossing unit; - Suction of the transfer foil (3) onto the embossing die; - Warming up the transfer film (3); - Arrange and align the transfer foil (3) or the embossing die according to the wheel element (1); - Heating the embossing unit, preferably the embossing die, to embossing temperature; - Contacting the transfer foil (3) with the wheel element (1) by means of the embossing die, in particular the primer (2); - Method or turning of the embossing unit, preferably the embossing die.

14. Method according to one of the preceding claims, characterized in that step c) and / or step b) comprises a cleaning step, in particular wherein the cleaning is carried out by means of methods selected individually or in combination from the group: brushing, wiping, washing, pickling, plasma treatment, flame treatment, corona treatment, compressed air treatment, suction.

15. Method according to one of the preceding claims, characterized in that the primer (2) is arranged at least partially, preferably over the entire surface, and / or at least in one layer, preferably in multiple layers, on the wheel element (1 ).

16. Method according to one of the preceding claims, characterized in that the primer (2) comprises a primer (9) which is arranged in contact with the wheel element (1).

17. Method according to one of the preceding claims, characterized in that the primer (2) comprises a basecoat (10), in particular wherein the basecoat (10) is arranged on the primer (9).

18. Method according to one of the preceding claims, characterized in that the base coat (10) is applied by means of liquid coating or powder coating.

19. Method according to one of the preceding claims, characterized in that the basecoat (10) is composed of one or more classes of materials, individually or in combination and / or as copolymers and / or as blends selected from the group: poly(meth)acrylates, polyesters, epoxy resins, melamine resins, polyurethanes.

20. Method according to one of the preceding claims, characterized in that the primer (2), preferably the base coat (10), is colored.

21. Method according to one of the preceding claims, characterized in that the primer (2) comprises a primer adhesion promoter (11), in particular wherein the primer adhesion promoter (11) is arranged at least partially over the base coat (10) as a layer and / or that the base coat (10) acts as an adhesion promoter.

22. Method according to one of the preceding claims, characterized in that that as a primer (2), in particular as a primer-adhesion promoter (11), at least one coating is arranged which is selected individually or in combination from the group: acrylic powder coating, cut-resistant coating, corrosion-resistant powder coating, acrylic basecoat, acrylic liquid coating, polyester-based corrosion-resistant coating, and / or from a combination of water-based coatings and / or solvent-based coatings.

23. Method according to one of the preceding claims, characterized in that the method comprises at least one of the following steps, which is carried out in particular after step c): e) arranging at least one upper-layer bonding agent (13), in particular on the transfer layer (5), f) arranging at least one upper layer (12), in particular on the at least one upper-layer bonding agent (13) and / or the transfer layer (5).

24. Method according to one of the preceding claims, characterized in that at least one top layer (12) and / or at least one top layer adhesion promoter (13) is arranged as the at least one top layer, which is selected individually or in combination from the group: acrylic powder coating, cut-resistant coating, corrosion-resistant powder coating, acrylic basecoat, acrylic liquid coating, polyester-based corrosion-resistant coating.

25. Method according to one of the preceding claims, characterized in that the carrier film (4), preferably after the transfer film (3) has been arranged on the primer (2), is separated from the transfer layer (5) is replaced, with the transfer position (5) remaining on the base (2).

26. Method according to one of the preceding claims, characterized in that the carrier film (4) has a release layer (14) on the side facing the transfer layer (5), wherein the release layer (14) remains at least partially on the carrier film (4) after release.

27. Method according to one of the preceding claims, characterized in that the primer system (6) is one or more layers and is formed by one or more layers of different adhesives and / or adhesion promoters, wherein the class of materials of the primer system (6) is selected individually or in combination and / or as copolymers and / or as blends from the group consisting of: poly(meth)acrylates, polyvinyl chloride copolymers, polyamides, ethylene vinyl acetate copolymers, rosin resins, polyester resins.

28. Method according to one of the preceding claims, characterized in that the wheel element (1) comprises metal, preferably steel and / or light metal.

29. Wheel element (1), in particular a wheel element (1) obtained according to a method according to one of the preceding claims, wherein the wheel element (1) has a primer (2), and a transfer layer (5) is arranged on the primer (2) which has a primer system (6) arranged in contact with the primer (2), 65 and wherein the transfer layer (5) comprises a protective layer (8) arranged on the side of the transfer layer (5) facing away from the primer (2) and a decorative layer (7) arranged between the primer system (6) and the protective layer (8).

Images