Interlaminar structure for security element

Translation of description of equivalent WO 03106185 A2

p0001Laminate for security element

p0002The invention relates to a multilayer security element, a layer composite for further production to such a security element, a Nerfahren for the preparation of the layer composite and the security element and a equipped with the security element object, in particular document of value, such as banknotes and the like.

p0003Security elements according to the invention are, for example, security threads and strips for bank notes and other security documents, tear-open f aeden for packaging, labels and tags, which are suitable for detecting the authenticity of a associated with them assets, in particular document of value, are suitable. Documents of value according to the invention can be bank notes, ID cards, checks, passports, tickets, tickets and the like. However, the invention is also suitable for securing any other valuables and their packaging, such as books, CDs and the like.

p0004Multilayered security features found in the form of security threads in banknotes wide use. They comprise at least one - typically formed as a transparent plastic film - carrier substrate on which further layers. These additional layers are mostly printed and particularly in the case of metallic layers also deposited, but can for example also be sputtered or sprayed.

p0005Not always all the layers are applied all over. They can next to and / or above each other can be arranged. You can make characters or patterns or have from the outset or by subsequent partial removal of material recesses to form, for example, a negative Sri t, which is barely visible when viewed in reflected light, when loading trachtung in transmitted light but produced a clearly visible contrast because of the transparency of the support substrate. In addition, the layers may also have optically variable effects and to this end in particular diffraction structures in the form of grid patterns or Hölogram- frame, etc. have. The layers can also have --naschinenlesbare security features, such as electrical conductivity in the case of continuous metallic coatings or in the case of doped electrically conductive particles print layers. Additionally or alternatively, magnetic properties and / or luminescent properties can be ten yet, especially luminescent substances are not in the visible range frequently used. The machine-readable security features can also be localized as mascMnenlesbarer code, for example, be a bar code formed.

p0006A fundamental concern in the preparation of such multilayer security elements is to achieve an independent website appearance so that no special measures for their application seitenrichti- ge be required in their application to or embedding in order to be backed up objects. This problem arises is particularly dependent on the introduction of security threads as windows threads in securities, in particular bank notes, as these threads and strips tend to twist.

p0007In the case of a simple metallised security thread with hidden Maghetschicht a page independent appearance readily be reached by, for example, a supporting substrate first layer with the magnetic printed and is then metallized on both sides all over. In this context, it is also known to metallize a film is first to apply the magnetic layer onto the metal layer, the film then to cut, superimpose and glued in a Rollenkaschieranlage so that a thread-like composite film with two outer sheets, two internal metal layers and a central, situated between the metal layers, double magnetic layer is formed (EP 0374763 A2). By the two outer foils, the coatings are protected from external influences. Moreover, the absolutely symmetrical layer structure of the film composite prevents leading to formation garlands rolling tendency of the yarn produced.

p0008However, this lamination is not suitable for complex layer structures, in which different layers localized present at different, precisely arranged mutually bodies. Because the cutting and superimposing of the individual composite films inevitably leads that different, localized layers will be placed in the final composite layer is not exactly evenly to each other.

p0009Complex layered structures are therefore constructed on a single substrate. For example, multiple variants of a security thread with hidden magnetic layer or hidden magnetic code and integrated negative writing are described in WO 92/11142.

p0010In the simplest case, the Negativsch-rift is identical generated in the magnetic layer and the magnetic layer in two masking metal layers. For this is first applied an activatable ink in the subsequent negative writing on a transparent plastic sheet in the usual manner. Then, a first metal layer is deposited and a magnetic layer full surface printed about that is eventually covered with a second vapor-deposited metal layer. By subsequently activating the Ink arise congruent recesses in the three higher than the ink layers. ensures the inner metal coating, that the security thread page independently has the same external appearance due to the transparency of the carrier film.

p0011For complex layer structures, in which the negative writing is not produced congruent in all the layers, however, it is difficult to obtain an exact same appearance from both viewing sides.

p0012In the case of such complex layer structures therefore at least one, possibly both metallic layers is printed in register in the desired regions (WO 92/11142). The problem is that metallic-effect inks, such as Super Silver, less brilliant than on edampfte metal layers and Super Silver has also not a good electrical conductivity. In the event that one of the two metallic layers printed and the other a real, eg vapor-deposited metal layer, thus resulting not exactly page independent appearance. For the other case where both metallic ones layers are printed, the visual appearance is indeed page independent identical, but overall not as brilliant as you would want it, and not electrically conductive.

p0013Object of the present invention is therefore to provide a multilayer security element is available, which can be produced in a simple manner with a complex layer structure with page independent appearance. Object of the present invention, it is equally, a layer composite for further production of a security element and corresponding manufacturing process as well as a the Security element equipped object, in particular document of value, to provide.

p0014This object is achieved with the features of nebengeord- Neten claims. In dependent claims, advantageous features and refinements of the invention are given.

p0015Accordingly, at least one security feature is formed on a first carrier foil, and likewise at least formed on a different second carrier foil a safety feature. The two films are then laminated to form a laminate. To ensure that the two security features emnehmen a vorbestimnite, evenly spaced position to each other, it is provided that the carrier films each in foil lengthwise and / or transverse directions have register marks by which the register accurate joining of the two films is controlled. To this end, a first of the two carrier foils under a predetermined, preferably constant tension is maintained, and the second carrier film is controlled in the film longitudinal direction by their register marks accurate register to the register marks of the first film. From the laminate security elements can then be separated into the desired shape, for example, as labels, or the layer composite can be divided into threads or strips and wound onto so-called continuous rolls.

p0016The carrier sheets may be plastic substrates, for example made of PET; but it is also conceivable a plastic / paper composite, wherein at least one base sheet is made of paper, for example, from cotton paper. The security features can be any maschi--readable features such as electrically conductive, magnetic, luminescent, in particular in the invisible spectral luminescent security features. But also any other security features, such as a negative writing or print, are possible.

p0017The advantage attained with the invention lies in the fact that the generation of the respective security features can be produced regardless of their shape and arrangement of the final layer structure among the security feature optimal process conditions. Their production is not at any time depending on the shape, location or method of manufacture of other security features of the same layer composite. Insofar as it is possible without any problems, even different security features can be generated on a common carrier film course. On the other hand, it is also possible that the layer composite of more than two films asst umf if, for example, the production of three different security features otherwise not be combined easily. This may be for example, a security element having two differently colored metals which are arranged in a certain pattern. Each of the metals is vapor-deposited onto a carrier film and patterned accordingly by etching or washing process. Subsequently, the support film are laminated by the method according to the invention. Preferably in this case are the metal layers inside to lie so that they are protected by the carrier films.

p0018but the invention can also be applied very advantageously in the preparation of security elements, which have inner, exclusively the machine testing accessible security features that on the basis of their intrinsic color or other properties disturb the visual appearance of the security element and must therefore be covered by additional layers. Using the invention, the cover may in register and take place only in necessary areas.

p0019Finally, the invention is also advantageously for the production of security elements, which are composed of two carrier foils and exhibit safety features that need to be arranged congruently. This is for example in a security element of the case, which has on both sides of a different diffraction structure whose reflection layers, especially metal layers have a congruent negative writing.

p0020The control of the second carrier foil in longitudinal direction of film is carried out relative to the under tensile stress first carrier foil, preferably by stretching the second carrier foil in film longitudinal direction. If two equally long support films, however, the problem of adjustment in case of deviations of image register against the film longitudinally. For this reason view two preferred embodiments of the invention provides that either the to be controlled by stretching the second carrier foil is shorter than the first, which is under tensile stress carrier film or that the two carrier foils, in principle, have the same length, which is under constant stress when first carrier film but constantly at least slightly stretched. The latter variant of has the advantage that both backing sheets are loaded and stretched in the normal case with approximately the same tensile stress, wherein the tensile stress is reduced or increased to the elongation controlled second carrier film depending on the deviation direction of the image registration. The third embodiment may also be controlled by stretching either the first or the second carrier foil, depending on which of the other film precedes.

p0021The stretching of the carrier film is preferably achieved by controlled braking of the roll from which the carrier film is peeled off, and moreover, constant draw-off speed. Caused thereby in increased tension of the support film leads to a controlled expansion of the base sheet material.

p0022The tailor-lamination of the two carrier films in the transverse direction is less of a problem, but is not to be especially at wide support films disregarded, as they experienced a significant reduction in their transverse dimensions due to the longitudinal expansion. To compensate for these dimensional variations a traction system is provided which is preferably also controlled on the basis of register marks in the two carrier foils.

p0023The registration marks are preferably read without contact by means of light guides or CCD cameras, either in reflected or transmitted light. When register marks also the security features can serve themselves.

p0024In the following the invention with reference to the accompanying drawings is illustrated by way of example. Therein:

p0025Figure 1 is a Doppelbandkaschiervorrichtung and

p0026Figures 2-8 several Ausführungsf ormen a two-layer composite film. Figure 1 shows a Doppelbandkaschiervorrichtung. A first carrier foil 1 and a second carrier foil 2 are drawn off supply rolls 3, 4, laminated in a double belt press 5 with each other and then wound up as a composite film 6 on a further supply roll 7 for intermediate storage before further processing. For this purpose, on the first carrier film 1 in a glue station 8, a radiation-curing, transparent adhesive etragen which in the double pelbandpresse by merging the two carrier foils 1, 2, 5 radiation cured by means of the radiation source. 9 Instead of a radiation-curing adhesive, other adhesives can supply used are, for example, thermosetting adhesives, including the double belt press is 5 preferably heated.

p0027The withdrawal speed of the carrier films 1 and 2, belt press 5 initially determined by the transport speed of the double of the supply rolls 3 and 4. FIG. According to a first embodiment, the supply roll 3 of the first carrier foil 1 is controlled, that is braked or driven such that it is under a defined tensile stress. This tensile stress should be constant throughout the process. Due to the enormous weight of such supply rolls at the beginning of the unwinding process and during the unwinding process ever decreasing weight, it can happen is that the supply roll 3 first driven and braked in the further course of the unwinding process, where appropriate. Also, the second carrier film 2 is in a similar manner under tensile stress.

p0028To ensure now that applied to the first carrier film 1 security features with the pressure applied to the second carrier foil 2 security features are combined in perfect register, each carrier film 1, 2 provided with register marks, which are detected by register mark detectors 10th If by evaluating the detected identified register mark positions that the register marks of the first carrier foil 1 2 no longer lie in relation to the register marks of the second carrier foil within a still acceptable tolerance range, one of the two carrier foils 1, 2 is stretched according to the invention. For this purpose, offer the following three variants ah:

p0029Both carrier foils 1, 2 are usually under the same tension, below which do not stretch the carrier films. Once it is determined by the register mark detectors 10 that the security features run after one of the two carrier foils relative to the security features on the other of the two carrier foils, this other of the two carrier foils to the security features of the two carrier foils again set within a tolerance range is slightly stretched, are positioned to each other. The stretching is preferably carried out by controlled braking of those supply roll, from which is deducted to be stretched support film.

p0030Alternatively, the second carrier foil 2 can be made shorter than the first carrier film 1, so that the second sheet 2 must be stretched relative to the first carrier Gerf olie 1 in principle to a precise register

p0031to allow lamination of the two carrier foils. The necessary degree of elongation is again determined by the register mark detectors 10th

p0032- According to a further alternative, the first carrier film can be peeled off 1 under such a tension that it basically expands by a predetermined percentage. Normally, the second carrier film 2 is then peeled with the same strain of the stock roll. 4 If now again on the basis of Registermarkende- detectors 10 detected a deviation from the register position, the supply roll is 4, depending on the deviation direction more or less slowed down to increase the stretch of the second carrier foil 2 corresponding or reduce.

p0033The carrier films 1, 2, the width of it have to be produced later security element, for example, the width of a security thread or strip of paper money. Preferably, however, they possess a multiple of the width and the products to be security elements thereof are subsequently divided out from the laminated composite film by the film composite is cut, for example, in filaments or strips or by individual security elements from the film composite, for example, by punching in Etikettenf orm, cut out will.

p0034In the case of broad support films it makes sense to place the register marks at each of the two outermost film edges, which are then accumulate as waste in the further processing of the film composite. Alternatively, serve as the register marks present on the carrier foils safety features itself.

p0035For non-contact detection of the register marks in reflected or transmitted light, in particular light guides or CCD cameras are.

p0036When Doppelbandlεmiiniervorrichtung specifically illustrated in Figure 1, the first support film 1 is kept under a constant tensile stress and scored the register accuracy by stretching the second carrier foil 2nd Since the width of the second carrier foil 2 increase or abmmmt depending on their degree of longitudinal expansion, a traction system 11 is provided to equalize the deviations of the second film 2 in the film transverse direction. one such che traction system is not necessary in the processing of films in thread or strip widths, since the width of fluctuation is minimal. In the case of wide sheets having a plurality of juxtaposed security elements, however, these mi-nimum width variations add up to a not negligible value to its full extent affects the respective outermost security elements, so that, although the security elements in the middle of the two carrier foils accurate register would laminated, the edges of the support films but would result in a non-negligible deviation of the register location in Folienquer- direction. Train groups that are individually adjustable in the current process, are as so-called expanders Spreader rolls available. This spreader rolls have disks whose inclination is adjustable to tension by acting on the carrier foils shaped bands. The greater the inclination of the disks, the greater the spreading effect is on the foil-en. The expander roller adjustment for stretching the carrier film in the transverse direction is also controlled on the basis of the register marks.

p0037It is understood that more than two carrier films can be laminated together by the Doppelbandpressvorrich- illustrated in Figure 1 device is supplemented by equivalent means, ie in particular by one or more additional storage rolls.

p0038Figure 1 already shows a concrete example of producing a two layer composite comprising backing films 6, wherein the security features are arranged evenly to one another. Made is a security thread in endless form here. The section A of the first film 1 umf asst a carrier film 100 made of transparent plastic with a vapor-deposited, partial metal layer 101 and a bar code 102 of magnetic material. The metal layer 101 can be a central strip 103 of the carrier film 100 freely through the carrier film 100 appears transparent through. The magnetic bar codes 102 composed of a magnetic particle ink containing and are applied to the metal layer 101 so on rinted that they are fit on one side covered by the metal layer one hundred and first

p0039The segment B of the second carrier foil 2 uf also asst a carrier film 200 of transparent plastic and turn a vapor-deposited metal layer 201. The metal layer 201 has generated gaps in the form of negative writing 202 in the usual manner. The width of the second Tägerfo- lie 2 corresponds to the width of the first carrier foil 1. The negative writing 202 is placed in the metal layer 201 at the same location at which the carrier film 100 of the first film 1 has the transparent area 103rd The second carrier foil 2 is itself transparent in the range of negative writing 202nd Thus, the security thread is retained even after the lamination of the olive Trägerf s 1, 2 in the area of ​​transparent Negativsch-rift 202nd

p0040The section C in Figure 2 shows the laminated layer composite in supervision and in two cross sections. It is apparent that the magnetic bar code is 102 hidden between the two metal layers 101 and 201 (section C₂ - C₂), Whereas the negative writing 202 for the transparent portion 103 is visible from both sides of the layer composite (average

p0041The embodiment illustrated in Figure 1 of a layer composite 6 thus covers security features, which are arranged in the longitudinal direction of the layer composite and in the transverse direction of the layer composite accurate register with each other. Because the magnetic bar code 102 of the first carrier foil 1 is in slide longitudinally imrner exactly between the reverse type 202 of the second carrier film 2 and the reverse type of 202 second carrier foil 2 are in film transverse direction always exactly above the transparent area 103 of the first carrier sheet. 1

p0042Figures 2a and 2b show a simple embodiment in which the register accuracy of the security features available in film transverse direction in the foreground. The embodiment of Figure 2 differs from the variant shown in Figure 1 only in that instead of the formed on the first carrier film 100 magnetic bar code 102 extends over the entire length of the layer composite 6 extending magnetic stripe 204 on the metal layer 201 of the second carrier sheet 200 parallel to negative writing 202 printed. In Figure 2b, in turn, is a cross section corresponding to the cross sections C - and C2 - C2 of Figure 1, but at a time prior to the lamination of the two carrier foils. In the lamination of the two carrier films 100, 200, these are controlled so that the magnetic stripe 204 hidden between the metal layers 101, 201 of the carrier sheets 100, are 200, whereas the negative writing 202 due to the transparent portion 103 is perceptible from both sides of the layer composite.

p0043Figure 3 shows a further embodiment EADERSHIP shape in which ankomn both the register accuracy in the transverse direction and in longitudinal direction it t. Shown here is merely a cross-sectional view. The second carrier film 2 is identical in structure to the second carrier film 2 of Figure 2 and converted accordingly summarizes a transparent support film 200 with a metal layer 201 including negative writing 202 and two on the metal layer 201 in parallel with the negative writing printed magnetic strip 204. The carrier film 100 also has a full-surface metal layer 101, in turn, a negative writing is introduced 104th The negative writing 104 of the first carrier film 100 is identical but mirror image of the negative writing 202 of the second carrier film 200, so that the two reverse type 202, 104 come during lamination of the foils 1, 2 congruent to overlie one another. Thereby, the magnetic stripe on the one hand hidden 204 between metal layers 101, 201 in the final film composite, on the other hand the negative writing 104, 202 from both sides of the film composite of visible and legible.

p0044In addition, the metal layer 101 is contiguously provided with an at least semitransparent, preferably completely transparent coating in the embodiment of Figure 3, which contains fluorescent particles. This coating 105 could also be applied over the metal layer 201 of the other carrier foil 200th Due to the semi-transparency of the coating 105, the negative writing 104, 202 when viewed in transmitted light is visible for both viewing sides of the film composite. The fluorescent particles constitute a further authenticity feature of the produced from the film laminated safety element. The semi-transparent coating can also be designed differently, for example, an optically variable thin-film structure or other optically variable layers.

p0045Figure 4 shows another embodiment, in this case with an integrated optical diffraction structure. The first carrier film 1 corresponds again to the carrier film 1 from Figure 2, the 101 includes a first transparent substrate foil 100 with a vapor-deposited metal layer in the form of two parallel to the film outer edges extending strips and an intermediate, central, transparent portion 103rd The second carrier foil 200 has an embossed into the carrier foil 200 diffraction structure 206 with metal coating 201 on. The metal coating 201 in turn is printed with a magnetic layer 204 in the form of two parallel to the film edge extending strips. The final laminate the magnetic stripe 204 are through the metal layers 101 and 201 covered. The diffraction structures are perceived as optically variable authenticity feature of both sides of the layer composite. If a folding symmetrical in carrier foil longitudinally diffraction structure pattern is selected, the appearance of the layer composite of both viewing sides is identical from. If the diffraction structure, however, is a specific image, every second repeat would be mirrored to provide the image to produce a composite layer betrachtungsseitenunab- pending.

p0046The diffraction structures 206 need not necessarily be impressed into the carrier foil 200th It is equally possible to apply a diffraction structures exhibiting transfer element accurate register on the carrier foil 200th Instead, however, can also be provided in this embodiment, other optically variable security devices, such as for example thin-film structures, and the like.

p0047Figure 5 shows another embodiment, in which both carrier foils 1, 2 each diffraction structures and a negative writing exhibit that congruent are in the final composite layer superimposed. In the carrier gerfolien 100, 200 are different diffraction structures 106, 206 imprinted. The diffraction structures 106, 206 are in turn covered with metal layers 101, 201, which does not present the entire surface in this case, but each have recesses 104, 202nd The recesses 104 of MetaUschicht 101 of the first carrier foil 100 are identical, albeit mirror-gelverkehrt to the recesses 202 in the metal layer 201 of the second carrier film 200, so that they are congruent superposed in the finished film composite and perceptible from both viewing sides of the film composite, at least in transmitted light are , The metallized diffraction structures of the two carrier foils are in each case by a transparent lacquer layers 107, 207 protected. This facilitates the temporary storage and subsequent lamination of the two carrier foils 1, 2. The recesses 104, 202 can form any pattern and alphanumeric characters as in the preceding examples.

p0048The security element according to Figure 5 is particularly suitable for use as a label over a hole in a bank note or other security document. The different diffraction structures 106 and 206 may be bäudes or other object, for example, the front view and rear view of a head, Ge, so that the object displayed depending on the viewing side of the document from the front or from behind appears.

p0049Figure 6 shows a further embodiment in which it arrives in turn to a register accurate lamination in longitudinal and transverse directions of the film material. In this case, the first carrier film 100 is provided in a circular sections full-surface with a MetaUschicht one hundred and first Register Exactly on this metal layer circuits is respectively also printed a circular, but magnetic layer 108th The second carrier film 200 described merely sits corresponding circular MetaUschichten 201. Through register accurate laminating the magnetic layer circuits 108 between the two MetaUschichten 101, 201 are hidden in the final film composite.

p0050Figure 7 shows an embodiment in which it depends on the exact register lamination film in the longitudinal direction substantially. In this case, the first carrier foil 100 carries a full-surface metal layer 101 having printed at a defined spacing bar 109 of magnetic material. The second carrier foil 200 has MetaUschichten 201 at an appropriate distance. In the intervening areas 203, the carrier film remains 2 transparent. Through register accurate lamination of the two carrier foils 1, 2 in the film longitudinal direction, the magnetic bars are 109 hidden between MetaUschichten 101 and two hundred and first

p0051Figure 8 shows a further embodiment. In this case, the first carrier foil 100 is regionally coated with a first coating 110, which has a first color and is gebÜdet example by a colored metal. The carrier film 100 remains uncoated and therefore transparent in the past between the color layers 110 areas 103rd The sec- ond carrier film 200 is in turn in regions coated with an ink layer 210, color is different from the color layer 110 of the first carrier foil 100th The intervening regions 203 of the carrier film 200 remain transparent again. The transparent areas 103, 203 correspond in size and relative position of the color layer areas 110 and 210, the other carrier foil. When Laπümeren the two carrier foils 1.2 then gives a film composite, which is not transparent and is characterized by a total of equally spaced regions of different color.

p0052In addition, have the color layers 110, 210 in the embodiment of Figure 8 respectively recesses 104 and 202, which complement each other in the final film composite to a negative writing "PL". The negative writing is alternately read properly and mirror provided so that it is regarded processing page independently readable.