Method for transferring a security element onto a target substrate

Abstract

The invention relates to a method for transferring a security element (3) onto a target substrate (1), comprising the steps of: - providing the security element (3); - applying the security element (3) to the target substrate (1); - irradiating a radiation-curable adhesive layer on the security element side to cure the radiation-curable adhesive layer which permanently bonds the security element (3) to the target substrate (1), wherein the security element is opaque to the irradiation in an effect region (32) and is transparent to the irradiation in at least one transparent element (31, 33, 34). For the irradiation on the security element side, a plurality of transparent elements (34; 31, 34; 33, 34; 31, 33, 34) are distributed in the security element (3) in such a way that, when irradiating through the transparent elements (34; 31, 34; 33, 34; 31, 33, 34), a plurality of cured partial surfaces (314, 334, 344) of the adhesive layer are formed which are separated from one another by at least one non-cured partial surface (324) of the adhesive layer. The plurality of transparent elements (34; 31, 34; 33, 34; 31, 33, 34) comprises a plurality of transparent grid elements (34).

Description

[0001] Method for transferring a security element to a target substrate

[0002] The invention relates to a method for transferring a security element, in particular from a transfer carrier, to a target substrate, wherein a radiation-curable adhesive layer is cured, as well as to a corresponding target substrate with a security element.

[0003] It is known to apply security elements provided on a transfer carrier to a target substrate in a transfer device and then remove them from the transfer carrier. The security element is usually attached to the target substrate using an adhesive layer.

[0004] WO 2010 / 031543 A1 describes a transfer carrier with security elements. WO 2016 / 188624 A1 relates to a device for transferring security elements to a target substrate.

[0005] It is also already known that a UV-curable adhesive layer can be used for transfers. Irradiation of the adhesive layer for curing occurs after application to the target substrate, but especially before removal of the transfer carrier. If irradiation occurs through the transfer carrier, it has proven disadvantageous that the security elements are not always equally UV-transparent to UV light, and additional irradiation from the other side is usually necessary.

[0006] WO 2009 / 127325 A1 relates to a method for securing a valuable document having an applied security element by introducing weakening lines and markings into the security element using a laser. The object of the invention is to provide a reliable method for transferring security elements, which is preferably flexible in use and simultaneously provides a high level of protection against counterfeiting, in particular protection for the target substrate with the applied security element.

[0007] This object is achieved by the subject matter of the independent claims. Further developments of the invention are the subject matter of the dependent claims.

[0008] A method for transferring a security element to a target substrate comprises the following steps:

[0009] - Providing the security element;

[0010] - Applying the security element to the target substrate;

[0011] - irradiating a radiation-curable adhesive layer on the security element side to cure the radiation-curable adhesive layer which permanently bonds the security element to the target substrate, wherein the security element is opaque to the irradiation in an effect region and transparent to the irradiation in at least one transparency element.

[0012] In the security element, a plurality of transparency elements are distributed for irradiation on the security element side such that irradiation through the transparency elements creates a plurality of cured partial areas of the adhesive layer that are separated from one another by at least one uncured partial area of ​​the adhesive layer. The plurality of transparency elements comprises a plurality of transparent grid elements. The irradiated and thus cured adhesive area permanently connects the security element to the target substrate. Since a plurality of cured partial areas (or sections) of the adhesive layer are created, the connection is secured by the plurality of partial areas. In particular, the arrangement (comprising target substrate and security element) as a whole is simultaneously secured against tampering with each individual connection.Any attempt to separate the security element from the target substrate will result in the target substrate and / or the security element being destroyed.

[0013] In some embodiments, the majority of transparency elements also comprise a plurality of transparency regions. The transparency regions transparent to the irradiation are each surrounded by the effect region opaque to the irradiation. Accordingly, the partial areas of the adhesive layer that have cured through the transparency regions are each surrounded by one of the uncured partial areas of the adhesive layer.

[0014] The majority of transparency elements comprises a plurality of transparent grid elements. Optionally, one or more (in particular, a few, such as two to five) transparency regions can be additionally present in the distribution. The grid elements (and transparency regions) that are transparent to the irradiation are each surrounded by the effect region that is opaque to the irradiation. The partial areas of the adhesive layer that have cured through the transparent grid elements (and transparency regions) are each surrounded by one of the uncured partial areas of the adhesive layer.

[0015] The majority of transparency elements can optionally comprise a transparent edge region of the security element. The edge region is transparent to visible light as well as to irradiation, which is preferably UV light. The edge region generally delimits a central region on at least two sides, preferably surrounding it. If an edge region is present, the security element preferably comprises the edge region and a central region formed by the effect region and the raster elements and / or transparency regions (which are then also referred to as inner regions) surrounded by the effect region.

[0016] The majority of the transparency regions and / or the grid elements can be regularly distributed, in particular arranged in a (two-dimensional) periodic grid. Alternatively, the transparency regions and / or the grid elements are arranged irregularly (or aperiodically). The distribution across the surface then appears random or quasi-random, but can also be recognizable as a deliberate, area-wide but irregular distribution. The grid elements are provided in a plurality of more than 6, preferably more than 10, more preferably more than 15. The transparency regions are provided in a plurality of more than 4, preferably more than 8, more preferably more than 12. The majority of the transparency elements accordingly additionally comprises the optional one or two edge regions and, in the case of grid elements, the few optional two to five transparency regions.

[0017] The shape of the transparency regions is preferably recognizable to a viewer of the security element in plan view and / or in transmitted light. In particular, the security element may contain transparency regions either with a uniform (first) shape or with a first shape and at least one second shape. The shape of the transparency regions may, for example, be a symbol, a character, a number, or a geometric element such as a circle or n-gon. Thus, for example, there could be a plurality of transparency regions of a first, in particular geometric shape, such as a circle, stripe, or star, which are distributed where no transparency region(s) with a second shape(s), in particular different numbers, letters, and / or symbols, are present.

[0018] The grid elements, however, are invisible to the viewer when viewed from above and / or visible when viewed through, without their shape being discernible to the viewer. The optically variable effect of the effect area is therefore not influenced by the distributed arrangement of the grid elements.

[0019] The radiation-curable adhesive layer can be a UV-curable adhesive layer. Irradiation is carried out using UV light, preferably UV-A light.

[0020] The security element can be provided on a transfer carrier. The transfer carrier is then detached from the security element applied to the target substrate. Preferably, the irradiation of the security element takes place before the detachment step and through the transfer carrier. The transfer carrier will generally comprise a plurality of security elements, which are in particular separate from one another and are preferably arranged one behind the other and / or next to one another on the transfer carrier in the transport direction.

[0021] The security element can, for example, be a patch or a stripe. Patches are known to be located locally within a single panel, such as a banknote, of the target substrate. Stripes, on the other hand, extend at least from edge to edge of a single panel, such as a banknote, of the target substrate. The target substrate can be in the form of a sheet or a web.

[0022] The security element is an optically variable security element, preferably with a reflective optically variable security feature. The security element is, in particular, optically variable depending on the viewing angle. For example, it displays different colors, motifs, or views of a motif depending on the viewing angle. The security element can comprise one or more relief layers, for example with reflective or refractive elements such as microlenses, microrefractors, or micromirrors. In principle, the security element can contain machine-readable and / or viewer-readable security features or combinations of such security features (diffractive, refractive, luminescent, magnetic, etc.).

[0023] For the sake of completeness, it should be noted that where reference is made to a viewer or viewing, a normal viewing situation is assumed. The viewing distance, for example, is approximately between 20 and 40 cm. The viewer does not use any technical aids and views with the unaided eye.

[0024] The effect layer which is opaque to the irradiation is or preferably comprises a reflective metal layer and / or a colour layer, which can in particular be arranged on an embossed relief layer.

[0025] The surface area of ​​the adhesive layer generally corresponds to the surface area of ​​the effect area plus the surface area of ​​the transparency elements, for example, plus the surface area of ​​the grid elements, plus the edge area and grid elements, plus the optional inner area(s), plus the surface area of ​​the inner areas, or plus the edge area and inner areas. However, it is known that the surface area of ​​the adhesive layer can also be smaller than the base area of ​​the security element (not reaching the boundary of the security element in the edge area). In the present case, it is preferably assumed that the maximum size of the grid elements is less than 300 gm (length and width in both directions), preferably between 10 gm and 250 gm, more preferably between 20 gm and 150 gm. The minimum size of the transparency (or inner) areas is more than 300 gm in one direction, preferably more than 300 gm in two directions (length and width).

[0026] The adhesive layer can have an irradiation area (or cured partial areas) consisting of at least a plurality of grid element irradiation areas or a plurality of transparent region (or inner region) irradiation areas. Optionally, it further consists of an edge irradiation area and / or, in the case of a plurality of grid element irradiation areas, of one or a few (two to five) transparent region (or inner region) irradiation areas.

[0027] The radiation-curable adhesive layer can be provided as a layer of the security element. Alternatively, it is provided with the target substrate or applied to the target substrate or the security element in the transfer device, in particular printed onto the target substrate in certain areas.

[0028] A region or layer is opaque to curing radiation in the present sense from an opacity of 85%, preferably 95%, for the curing radiation. A region, an element, or a layer is transparent to curing radiation in the present sense from a transparency of more than 65%, preferably more than 80%, more preferably more than 90%, for the curing radiation.

[0029] Overall, preferably at least 40%, in particular between 40% and 80%, of the surface area of ​​the adhesive layer of the security element is cured. Advantageously, in an area containing only raster elements and the surrounding effect region, between 10% and 50%, preferably 10% to 25%, of the surface area of ​​the adhesive layer can be cured. In total, 40% to 66% of the surface area of ​​the adhesive layer of the security element could be cured. Advantageously, in an area containing transparency regions and the surrounding effect region, on average between 25% and 66%, preferably 30% to 60%, of the surface area of ​​the adhesive layer can be cured. In total, 50% to 80% of the surface area of ​​the adhesive layer of the security element could then be cured.

[0030] The radiation-curable adhesive layer can be an adhesive layer that cures with UV light, particularly in the UV-A range, or with short-wavelength light, particularly <450 nm. It can also be a heat-activatable, radiation-curable adhesive layer, particularly a heat-sealable adhesive layer, preferably a UV-curable heat-sealable adhesive layer.

[0031] A transfer carrier with security elements is provided, wherein the security elements are detachably arranged on the transfer carrier and comprise an adhesive layer curable with curing radiation for transfer to a target substrate, in particular according to one of the previously described methods or in the sense of the previous embodiments. The transfer carrier is transparent to the curing radiation. The security elements each have an effect area opaque to the curing radiation and at least one transparency element transparent to the curing radiation.Now, for irradiation with curing radiation on the security element side, a plurality of transparency elements are distributed in each security element such that, upon irradiation through the transparency elements, a plurality of cured partial areas of the adhesive layer are created, which are separated from one another by at least one uncured partial area of ​​the adhesive layer. The plurality of transparency elements comprises a plurality of transparent grid elements.

[0032] A system for carrying out, for example, one of the described methods comprises such a transfer carrier and a transfer device. The transfer device comprises, in particular, an application unit (for applying the security element to the target substrate), an irradiation unit, and a detachment unit (for detaching the transfer carrier from the security element applied to the target substrate).

[0033] A plurality of security elements are arranged on the transfer carrier. The security elements can be arranged one behind the other in the transport direction and / or separated from one another, preferably spaced apart, and / or present as a patch or strip, each with or without its own carrier layer.

[0034] A target substrate with a security element can be provided, wherein the security element is attached to the target substrate by means of an adhesive layer, wherein the adhesive layer is formed from radiation-curable material and comprises at least one cured portion and an uncured portion, wherein the security element has an effect region opaque to curing radiation of the radiation-curable material and at least one transparency element transparent to the curing radiation.

[0035] A plurality of transparency elements are arranged in the security element, each of which lies above a cured section of the adhesive layer. The cured sections of the adhesive layer are separated from one another by at least one uncured section of the adhesive layer. The plurality of transparency elements comprises a plurality of transparent grid elements.

[0036] The arrangement of target substrate and security element can be produced according to one of the methods described above and accordingly have the partial features or properties already mentioned for the target substrate and / or the security element and / or the adhesive layer.

[0037] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations without departing from the scope of the present invention, insofar as this is covered by the scope of protection of the claims.

[0038] Some further advantages of the invention are explained with reference to the following exemplary embodiments and the supplementary figures. The representations in the figures are highly schematic for the sake of clarity; in particular, the proportions shown in the figures do not correspond to the actual conditions and thus serve primarily to improve clarity. The following schematically show:

[0039] Fig. 1 shows a device for transferring a security element to a target substrate with an irradiation unit,

[0040] Fig. 2 shows a security element with an effect region, a plurality of inner regions transparent to the irradiation and a transparent edge region, Fig. 3 shows a security element with an effect region, a plurality of grid elements transparent to the irradiation and a transparent edge region, and

[0041] Fig. 4 a security element on a transfer carrier.

[0042] Fig. 1 shows a device 10 for transferring security elements 3 to a target substrate 1. The device 10 comprises an application unit 11, 12, a removal unit 13, and at least one irradiation unit 14, 15. Not shown in the figure are, for example, transport devices that transport the target substrate and / or carrier substrate within the device. The basic transport direction within the device 10 is indicated—right and left in the figure—by two dashed arrows (from left to right).

[0043] The target substrate 1 and a transfer carrier 2 with the security elements 3 detachably arranged on the transfer carrier 2 are provided in a feed area ZFB of the device 10. The security elements 3 comprise a UV-curable (heat-seal) adhesive layer. The adhesive layer bonds the security elements 3 to the target substrate 1 and must be cured with UV light to ensure a permanent bond to the target substrate 1. Alternatively, the adhesive layer can be applied, preferably in the transfer device, to the security elements 3 and / or in certain areas to the target substrate 1. The adhesive layer can also be formed from two partial layers, which, for example, only come into contact during application.

[0044] In the example shown, the application unit 11, 12 (in the application area ABB) comprises a preferably heated, structured stamping roller 12 and a counterpressure roller 11. The stamping roller is designed such that, of the majority of security elements 3 arranged one behind the other on the transfer carrier 2, every second security element 3 is applied to the target substrate 1. Application is carried out by means of pressure (and heat). Other types of application units (e.g., unstructured rollers, linear stamps, or those in the sense of WO 2016 / 188624 A1) are conceivable and well known.

[0045] The irradiation unit 14 is arranged between the application unit 11, 12 and the removal unit 13 (irradiation area BB). It comprises at least one UV emitter, which is in particular a UV-LED emitter. The irradiation can be selectively provided or not provided, for example with the aid of a control that switches the emitter(s) on or off or masks or unmasks them (manual aperture / shutter, etc.). The or each applied security element 3 is irradiated by the first irradiation unit 14 (and / or the second irradiation unit 15). Optionally, possible security elements 3 not applied by the application unit 10, 11 are not irradiated. The wavelength of the irradiation is in the UV-A range (>315 nm). As an alternative to this irradiation, irradiation in the short-wave visible range (wavelength <450 nm) can also be carried out if a correspondingly curable adhesive layer is used.

[0046] The UV irradiation unit 14 irradiates the adhesive layer of the security element 3 through the UV-transparent transfer carrier 2 and through the security element 3 or the other partial layers of the security element 3. The adhesive layer is irradiated on the security element side. In particular, an effect layer, such as a metallization or a color layer, of the security element can, however, be opaque to UV radiation. The removal unit 13 (in the removal area ABB) is shown as a roller, but can also be designed differently, for example as an edge. The transfer carrier 2, in the example together with the unapplied (and accordingly unirradiated) security elements 3, is removed from the applied security element 3. The removal of the security elements can, as is known, be assisted by means of a release layer (not shown) (in the layer structure of the security element or the transfer carrier).

[0047] The transfer carrier 2 is guided out of the device in a return area RFB and can be reused / provisioned / returned. The transfer carrier 2 without security elements could be reused by applying new security elements. The transfer carrier 3 with remaining security elements can be reused by re-provisioning it for the device 10 or another device. The remaining security elements, every second or every nth security element, are later transferred to a (possibly different) target substrate.

[0048] A second irradiation unit 15 can be provided alternatively or optionally and also irradiates the adhesive layer on the security element side. For example, the second irradiation unit 15 can cure the adhesive layer alone or it can post-cure the adhesive layer. The UV irradiation unit 15 irradiates the adhesive layer of the security element 3 through the security element 3 or the other sublayers of the security element 3.

[0049] The transfer device 10 according to Figure 1 can be assumed to be essentially already known. It is also known to alternatively design a transfer without the illustrated detachment from the transfer carrier after application, for example, by detachment before application, by punching out the security element, or even without a transfer carrier.

[0050] The following figures 2 and 3 are intended to illustrate possible optimized designs of safety elements.

[0051] Figure 1 shows a cross-section through the transfer device 10. In contrast, in Figures 2 and 3, a view of the security element 3 on the target substrate 1 is chosen in plan view in order to make the areas or surfaces of the security element 3 more clearly visible.

[0052] Fig. 2 shows a security element 3, which could optionally be arranged on the transfer carrier (not shown), which is already applied to the target substrate 1.

[0053] The security element 3 comprises a central area 32, 33 and a transparent edge area 31.

[0054] The transparent edge region 31 is transparent at least to curing UV radiation, preferably also to visible light. The UV radiation is only absorbed in the radiation-curable adhesive layer of the security element. An outer boundary of the security element 3 is simultaneously the outer boundary 311 of the edge region. The edge region 31 extends from its outer boundary 311 to its inner boundary 312, which simultaneously forms the outer boundary of the central region 12, 13.

[0055] The central region 32, 33 comprises a UV-opaque effect region 32 and a plurality of UV-transparent inner regions 33. In the effect region 32, the security element is completely opaque (> 95% opacity) or opaque (> 85% opacity) to UV light. The effect region 32 of the security element provides the viewer with an optically variable security feature, i.e., in particular, a viewing-angle-dependent and / or reflectively optically variable security feature. A UV-opaque color layer and / or a UV-opaque metal layer are preferably present in the effect region 32.

[0056] The inner regions 33 in the central region 32, 33 are UV-transparent. For example, there may be recesses in the UV-opaque color layer and / or the UV-opaque metallization. The inner regions 33 each have a shape recognizable to the viewer in transparent view (and optionally also in plan view), for example a cross, circle, n-gon, or sign. The visible shapes of the inner regions 33 can differ (different symbols or numbers) or be uniform as shown. Each inner region 33 has an outer boundary 331. The UV-transparent inner regions 33 are surrounded by the UV-opaque effect region 32. An outer boundary 331 of the inner region 33 is therefore simultaneously an inner boundary of the effect region 32.

[0057] If the security element 3 with its adhesive layer is UV-irradiated on the security element side, for example, irradiated through the transfer carrier 2, the irradiation passes through the transparent edge region 31 and through the UV-transparent inner regions to the adhesive layer. The adhesive layer cures in the irradiated areas 314, 334. The adhesive layer is not cured in the non-irradiated area(s) 324. The UV light passes through the edge region 31 to the underlying section of the adhesive layer and partially also into an adjacent section of the adhesive layer located below the effect region 32. The edge irradiation area 314 irradiated through the edge region begins at the outer boundary 311 of the edge region 31 and ends at its inner boundary 313.The UV light passes through the inner region 33, reaching the underlying section of the adhesive layer as well as an adjacent section of the adhesive layer located below the effect region 32. The inner irradiation area 334 irradiated through the inner regions 33 is delimited by its outer boundary 333.

[0058] The inner regions 33 are now distributed across the security element 3 or across the central region 32, 33 of the security element 3 in such a way that, upon irradiation through the transparency elements 33, a corresponding plurality of cured partial areas or inner region irradiation areas 334 of the adhesive layer is created, which are separated from one another by the – in the example, exactly one – uncured partial area 324 of the adhesive layer. Each inner region irradiation area 334 is surrounded by one (or the) uncured partial area 324 of the adhesive layer. The uncured partial area 324 of the adhesive layer also lies between the cured edge irradiation area 314 of the adhesive layer and the inner region irradiation areas 334. The inner regions 33 are evenly distributed in the central region 32, 33 and are also arranged either periodically – as in the figure – or aperiodically (not shown).As a result, the security element is permanently bonded to the target substrate. For example, when using the irradiation unit 14 in Figure 1, the security element 3 is already bonded for detachment of the transfer carrier 2.

[0059] The distributed arrangement with separate, cured partial surfaces also provides increased protection against tampering. Removing the security element 3 from the target substrate 1 without destroying the security element 3 and / or the target substrate 1 (particularly in the case of security elements with their own carrier layer / foil) is prevented or at least made significantly more difficult.

[0060] Providing an edge region 31 is advantageous both for production and later for tamper protection. The majority of the isolated, cured partial areas are surrounded by the contiguous edge irradiation area, making non-destructive removal even more difficult. However, the transparent edge region 31 can be omitted or, in a further variant, replaced by a partially opaque surrounding area in which the transparency regions 33 are spaced closer together than in a central area (e.g., by a factor of >= 1 / 3 or >= 1 / 4).

[0061] Due to the small thickness of the partial layers of the security element 3, the adjacent irradiated sections are relatively small (for example: 1 <= edge irradiation area / edge region < 1.05). UV-scattering relief structures or scattering bodies can be present in the transparency elements 31, 33, for example, in a relief layer of the security element or a (full-surface) UV scattering layer of the security element, which is arranged between the UV-opaque and adhesive layers during irradiation.

[0062] The transparent edge region has an average size (length or width) that is, for example, between 0.2 and 1.5 mm. Security elements 3 can be arranged one behind the other on the transfer carrier at a distance that is, for example, between 3 and 10 mm. Between the security elements 3, the transfer carrier is preferably free of the partial layers of the security element (these have already been removed before the transfer carrier was provided). The transport direction continues to run from left to right. The length of the security element 3 extends from left to right in the figure. The width of the security element 3 is measured from top to bottom in the figure. Figure 2 shows a patch as a security element. A security element 3, such as a strip or patch, can be present on each individual panel, such as a banknote, of a target substrate, which is present, for example, as a target substrate sheet or web in the transfer device.

[0063] Since the security element is transported through the device, a single irradiation unit irradiating the width of the security element 3 is sufficient to irradiate the entire surface of the security element 3. The irradiation unit is preferably switched on for the security element when it reaches the unit and switched off again when the security element leaves the unit. The irradiation unit is selected such that it selectively irradiates only one security element (and none of the adjacent security elements) in the transport direction.

[0064] Fig. 3 illustrates, in a similar representation to Fig. 2, a security element 3 with the target substrate 1.

[0065] In the central area 32, 34 of the security element, a plurality of UV-transparent raster elements 34 are arranged (regularly or irregularly) distributed. For the observer, the security element shows the optically variable effect of the effect area in plan view (and / or in transmitted light). The raster elements 34 are not visible to the observer in plan view. In transmitted light, the raster elements 34 may be visible, in particular as formless dots. The observer cannot recognize a possible shape of the raster elements 34 even in transmitted light. The raster elements 34 have, for example, a round or rectangular shape. Their maximum size (such as length or width) is less than 300 μm, generally between 10 μm and 150 μm. They are created by locally removing, for example by etching, washing, or lasering, a UV-opaque partial layer of the security element.

[0066] Optionally, the edge region 31 may be present and / or one or more (few, in particular two to five) inner regions 33 may be present. The grid elements 34 are arranged evenly distributed over the security element 3, provided that no edge or inner region 31, 33 is present locally.

[0067] Each UV-transparent raster element 34 generates a raster element irradiation area 344 on the adhesive layer when irradiated from the security element side (possibly through the transfer carrier). The outer boundaries 343 of the raster element irradiation areas 344 can lie within the effect area 32. The adjacent sections irradiated by the raster elements 34, which lie within the effect area 32, form an increasing proportion of the irradiated area as the size of the raster elements decreases. The ratio of raster element irradiation area to raster element is greater than 1.1, for example, it is in the range of 1.2 to 5.

[0068] The distribution of the grid elements 34 in the security element 3 or in the central region 32, 33, 34 of the security element 3 is selected such that irradiation through the grid elements 34 creates a plurality of grid element irradiation surfaces 344 or cured partial areas of the adhesive layer, which are separated from one another by at least one, in Figure 3 precisely one, uncured partial area 324 of the adhesive layer. The edge region irradiation surface 314 is also separated from the grid element irradiation surfaces 344 by the uncured partial area 324 of the adhesive layer. Thus, after irradiation, a plurality of mutually isolated / separated / spaced-apart permanent connections exist between the security element 3 and the target substrate 1.

[0069] The number of grid elements 34 is selected such that a good, permanent connection is also present in the central region. For example, in the central region (without taking interior regions into account) or in an area with grid elements, between 10% and 50%, preferably 10% to 25%, of the surface area of ​​the adhesive layer can be cured. Overall, preferably at least 40%, in particular between 40% and 80%, of the surface area of ​​the adhesive layer of the security element is cured. Interior regions have a size of more than 300 gm in at least one direction (such as edges or width), preferably in two mutually perpendicular directions (such as length and width). For example, an elongated or several closely adjacent interior regions 33 can create several uncured partial areas 324 (instead of a single one). However, each grid element irradiation area remains surrounded by one of the uncured partial areas 324.

[0070] The majority of the interior regions 33 of Figure 2 are replaced in the embodiment according to Figure 3 by the majority of the grid elements 34. All further comments on details, variants, and configurations already made in Figure 2 will not be repeated here, but are also applicable in Figure 3.

[0071] Fig. 4 shows a cross-sectional view of a security element 3 on a target substrate 1, which can correspond to any of the previously discussed embodiments, but is based on the example from Fig. 3. An arrow indicates the direction of observation and / or irradiation. The figure shows in more detail an adhesive layer 7 and a partial layer 6 of the security element 3 that is opaque to (UV) irradiation. The security element 3 comprises the already known regions 31 to 34. The security element 3 preferably exhibits an optically variable effect in the effect region 32, for example by means of a relief structure on which a reflective metallic layer is arranged as partial layer 61.

[0072] The adhesive layer 7 comprises cured sections 71, 73, 74 and a contiguous uncured section 72 or several uncured sections 72, which separate the cured sections 71, 73, 74 from one another. The opaque partial layer 6 has one (or, in the case of a strip, exactly two) edge cutout(s) 61. The partial layer 6 is present in all sections 62. The partial layer 61 is cut out in the interior region 32, 33, 34 of the security element 3 in a plurality of grid elements 64 and in an interior region 63.

[0073] The cured sections 71, 73, 74 of the adhesive layer were created by irradiating the adhesive layer through the transparency elements 31, 33, 34. The edge recess 61, the inner recess 63, and the grid elements 64 are located above the cured sections 71, 73, 74, respectively. The irradiation areas in Figures 2 and 3 correspond to the cured sections in Figure 4. To avoid repetition, reference can also be made to the previously discussed explanations.

[0074] Fig. 5 shows, by way of example, various conceivable partial layers of a security element 3 on a transfer carrier 2 (in cross-section). The carrier 2 itself can comprise two carrier layers 21, 23 with a lamination layer located between them, as already described in more detail in WO 2010 / 031543 A1. The security element 3 is a multilayer element. The external shape of the security element can correspond to a first motif or a simple geometric shape. It is preferably an optically variable security element that comprises an optical security feature for viewing in plan view and / or through view.

[0075] The following partly optional sub-layers 91 to 97 of the transfer element are shown in Fig. 5.

[0076] The optical security feature is formed by one or more sublayers 94 to 96. Particularly preferably, the optical security feature is structured differently in certain areas and / or is optically variable (changing impression for the viewer when tilted or rotated), for example in the form of a second and / or third motif. The optical security feature of the security element comprises an embossed lacquer layer 94 into which an optically effective relief structure is embossed. A reflection-enhancing sublayer 95, for example a metallization or an HRI layer, is provided on the relief structure. This can be present over the entire surface, over part of the surface with the aforementioned recesses, and / or partially as a screened sublayer.Preferably, a further color sub-layer (or functional sub-layer) 96 is located on the reflection-enhancing sub-layer 95, which can be opaque or translucent and / or differently colored (pigmented) and / or optically variable (OVI pigments) or activatable (luminescent, thermochromic and / or reversibly or irreversibly changeable ...).

[0077] The radiation-curable adhesive layer 97, which is relevant here, in particular a UV-curable heat-sealing lacquer, is arranged above the optically active partial layers 94 to 96. When cured, the adhesive layer ensures a permanent bond to the target substrate.

[0078] To assist in the detachment of the security element 3 from the transfer carrier 2, a detachment sublayer 91 of the security element 3 can be arranged—as usual—on the surface of the transfer carrier 2. In the present case, the security element 3 could optionally comprise a further intermediate adhesive layer 92. Also known as an optional sublayer is a foil sublayer 93, which can serve as a supporting sublayer in the security element 3. The height of such multilayer security elements 3 is typically between 20 and 100 μm.

[0079] Reference symbol:

[0080] 1 Target substrate

[0081] 2 transfer carriers

[0082] 3 Security element

[0083] 10 Transfer device

[0084] 11 Counterpressure roller

[0085] 12 pressure stamp roll

[0086] 13 Release roll

[0087] 14,15 UV irradiation unit

[0088] 31 UV-transparent edge area

[0089] 311 Outer boundary of the peripheral area

[0090] 312 Inner boundary of the edge area

[0091] 313 Inner boundary of the edge irradiation area

[0092] 32 UV-opaque effect area

[0093] 324 Unirradiated area

[0094] 33 UV-transparent interior

[0095] 314 Edge irradiation area

[0096] 331 Outer boundary of the interior area

[0097] 333 Outer boundary of the indoor irradiation area

[0098] 334 indoor irradiation area

[0099] 34 UV transparent grid element

[0100] 343 Outer boundary of the grid element irradiation area

[0101] 344 grid element irradiation area

[0102] 6 UV-opaque partial layer

[0103] 61 edge recess

[0104] 62 sub-shift section

[0105] 63 interior recess

[0106] 64 grid elements

[0107] 7 radiation-curable adhesive layer

[0108] 71, 73, 74 cured sections

[0109] 72 uncured sections

[0110] 21 first film layer

[0111] 22 Laminating adhesive

[0112] 23 second film layer

[0113] 91 Release layer

[0114] 92 Intermediate adhesive layer

[0115] 93 film layer

[0116] 94 Relief structure / embossed lacquer layer

[0117] 95 Reflection-enhancing layer

[0118] 96 layers of paint

[0119] 97 radiation-curable adhesive layer

Claims

patent claims 1. Method for transferring a security element (3) to a target substrate (1), comprising: - Provision of the safety element (3); - Applying the safety element (3) to the target substrate (1); - irradiation of a radiation-curable adhesive layer on the safety element side to cure the radiation-curable adhesive layer which permanently connects the safety element (3) to the target substrate (1), wherein the safety element is opaque for irradiation in an effect area (32) and transparent for irradiation in at least one transparency element (31, 33, 34); characterized in that in the safety element (3) for the safety element-side irradiation a plurality of transparency elements (34; 31, 34; 33, 34; 31, 33, 34) are arranged in such a way that, when irradiating through the transparency elements (34; 31, 34; 33, 34; 31, 33, 34) a plurality of cured partial surfaces (314, 334, 344) of the adhesive layer are created, which are separated from each other by at least one uncured partial surface (324) of the adhesive layer, and the plurality of transparency elements (34; 31, 34; 33, 34;31, 33, 34) comprises a plurality of transparent grid elements (34).; 2. Method according to claim 1, characterized in that the transparent grid elements (34) are visible to the viewer - are not recognizable under supervision; and / or - are visible when viewed through, but do not have a recognizable shape. A method according to claim 1 or 2, characterized in that the plurality of transparency elements (31, 34; 33, 34; 31, 33, 34) comprises one or more transparency areas (31; 33). A method according to any of the preceding claims, characterized in that the plurality of transparency elements (31, 34; 31, 33, 34) comprises a transparent edge area (31) of the security element (3), wherein the security element (3) comprises, in particular, the transparent edge area (31) and a central area (32, 34; 32, 33, 34) in which the effect area (32) and the plurality of grid elements (34) are located.A method according to any one of the preceding claims, characterized in that the security element (3) is provided on a transfer carrier (2), wherein the transfer carrier (2) is detached from the security element (3) applied to the target substrate (1), wherein the irradiation on the security element side preferably takes place before detachment and through the transfer carrier (2). A method according to any one of the preceding claims, characterized in that the grid elements (34) are arranged regularly, in particular in a periodic grid, or irregularly. A method according to any one of claims 3 to 6, characterized in that the transparency areas (33) are arranged regularly, in particular in a periodic grid, or irregularly.

8. Method according to one of claims 1 to 7, characterized in that the grid elements (34) and preferably also the transparency areas (33) are surrounded by the effect area (32).

9. Method according to one of claims 3 to 8, characterized in that the transparency areas (31; 33) have a form recognizable to the observer in top view and / or through view; in particular, transparency areas (31; 33) are present in the security element (3). - with a first form and at least one second form; or - with a uniform shape.

10. Method according to one of the preceding claims, characterized in that - the radiation-curable adhesive layer is a UV-curing adhesive layer and the irradiation is carried out using UV light; and / or - the transfer carrier (2) comprises a plurality of safety elements (3), which are in particular separate from one another and preferably arranged one behind the other and / or next to one another on the transfer carrier (2); and / or - the security element (3) is a transfer patch or a transfer strip; and / or - the safety element (3) is an optically variable safety element, in particular optically variable depending on the viewing angle; and / or - the safety element (3) in the effect area has an opaque effect layer (6), in particular a reflective metal layer or color layer, and / or an embossed relief layer.

11. Method according to one of the preceding claims, characterized in that - the adhesive layer is irradiated over more than 20% but less than 80% of its area, in particular in a central area (32, 33, 34) over more than 10% but less than 50% of its area; and / or - the area of ​​the security element corresponds to the area of ​​the effect area (32) together with the area of ​​the transparency elements (34; 31, 34; 33, 34; 31, 33, 34); and / or - the adhesive layer has an irradiation surface (314, 334, 344) consisting of an optional edge irradiation surface (314) and either a plurality of grid element irradiation surfaces (344) with optional one or a few transparency area irradiation surfaces (334) or a plurality of transparency area irradiation surfaces (334).

12. Method according to one of the preceding claims, characterized in that the radiation-curable adhesive layer - is provided as a layer of the security element (3), and / or - an adhesive layer that hardens through UV light, especially in the UV-A range, or through short-wavelength light, especially < 450 nm, and / or - a heat-activated, radiation-curable adhesive layer, in particular a heat-sealable adhesive layer, preferably a UV-curing heat-sealable adhesive layer.

13. Transfer carrier (2) with safety elements (3), wherein - the safety elements (3) are detachably arranged on the transfer carrier (2) and comprise an adhesive layer that can be cured by curing radiation for transfer to a target substrate (1), in particular according to a method according to one of claims 1 to 12; - the transfer carrier (2) is transparent for the curing radiation; - the safety elements (3) each one for the curing radiation have an opaque effect area (32) and at least one transparent element (34; 31, 34; 33, 34; 31, 33, 34) that is transparent to the curing radiation; characterized in that in the safety element (3) for irradiation on the safety element side a plurality of transparency elements (34; 31, 34; 33, 34; 31, 33, 34) are arranged in such a way that, when irradiating through the transparency elements (34; 31, 34; 33, 34; 31, 33, 34) a plurality of cured partial surfaces (314, 334, 344) of the adhesive layer are created, which are separated from each other by at least one uncured partial surface (324) of the adhesive layer, and the plurality of transparency elements (34; 31, 34; 33, 34; 31, 33, 34) comprise a plurality of transparent grid elements (34).System, in particular for carrying out a method according to one of claims 1 to 11, comprising a transfer carrier according to claim 12 and a transfer device, wherein a plurality of safety elements (3) are arranged on the transfer carrier (2), and wherein in particular. - the safety elements (3) are arranged one behind the other in the direction of transport, and / or - the safety elements (3) are arranged separately from each other and preferably spaced apart from each other, and / or - the security elements (3) are in the form of a patch or a strip, with or without their own carrier layer (93). Target substrate (1) with a security element (3), in particular manufactured according to or with the features of any one of claims 1 to 12, wherein the security element (3) is attached to the target substrate (1) by means of an adhesive layer (7), wherein the adhesive layer (7) is formed of radiation-curable material. is and comprises at least one cured section (71, 73, 74) and one uncured section (72), wherein the safety element (3) has an effect area (32) opaque to curing radiation of the radiation-curable material and at least one transparency element (34; 31, 34; 33, 34; 31, 33, 34) transparent to curing radiation, characterized in that a plurality of transparency elements (34; 31, 34; 33, 34; 31, 33, 34) are arranged in the safety element (3), each of which lies over a cured section (71, 73, 74) of the adhesive layer (7), and the cured sections (71, 73, 74) of the adhesive layer (7) are separated from each other by at least one uncured section (72) of the adhesive layer (7), and the The majority of the transparency elements (34; 31, 34; 33, 34; 31, 33, 34) comprise a majority of transparent raster elements (34).

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