Method and apparatus for the manufacture of metallic surface layers on substrates.

p0001The invention relates to a method and an apparatus for the production of localized metal layers on substrates, optionally with a rough surface in the transfer process in which the metal layers are prepared on a transfer surface and subsequently transferred to the substrate.

p0002Metallic surface elements is of considerable importance in the field of anti-counterfeiting of documents of value. On the one hand provide metallic surfaces due to their reflective properties a good copy protection, because the reflective surfaces with copy technical means can not be adjusted. In the simplest case, usually metallic inks are used to create shiny metallic surface or print images. Because of the granular fine structure but these methods are suitable only for metallic surfaces, in which only small demands are made on the reflection behavior of the surface and where there is no defined surface structures are required.

p0003The highest demands on the metal surface are provided in the production of metal-coated holograms, which are a widespread type of anti-counterfeiting today. Holograms due to the elaborate and costly production, if at all, only imitated with relatively high effort and provide for their optical properties that depend on the viewing angle, a good copy. Apart from the safety aspects holograms are also like applied from an aesthetic point of value documents.

p0004Reflection holograms are typically either by means of specially prepared die-plates which have a the interference pattern of the hologram corresponding surface relief, produced by the surface relief is impressed in a cured lacquer layer and is subsequently metallized and provided with a protective lacquer layer. Alternatively, the relief of the stamping die can also equal imprinted directly into a thin metal layer and are then provided with the protective lacquer layer. Metallization provides for a sufficient brilliance of the hologram, so that it is visually well recognizable.

p0005There have been proposed several ways to apply such metal layers or holograms in localized form of securities, bank notes or ID cards. One of the most advanced techniques that will also preferably used in the hologram application, is preparing a separate hot embossing belt from which it is transferred to the final support (DE-OS 33 08 831, US Patent No. 4,758,296). Here, on a substrate which is provided with an easily peelable release layer to be transferred layers in reverse order as they should be present later in the document deposited. The top layer forms an adhesive layer, for example a heat seal adhesive layer. This adhesive layer, the hot embossing belt and the document can be connected to each other under the influence of heat and pressure. The substrate of the hot embossing belt can then be easily removed because of the separation layer.

p0006Although the transfer belt is produced as a continuous band, that the metallization is carried out in a continuous process (eg. As in a vacuum deposition), only the desired surface areas are transferred to the document. The transfer of the to be transferred surface areas can be accomplished in different ways. For example, the adhesive layer may be printed in a certain pattern, so that the layer to be transferred structure (optionally with large-area heating) only partially adhered to the document or the plunger used in laminating has an outline corresponding to the to be transmitted form, so that even when the use of large surface-applied heat seal adhesive only the areas of the adhesive layer to be activated, in which the die pressure and heat exerted (DE-OS 33 08 831).

p0007This hot stamping transfer method, however, is less suitable for applying holograms on banknotes. Because banknotes are printed by steel intaglio printing and Dafur a rough paper surface is necessary to usually impresses the surface structure of the paper in the thin transfer layer. The surface roughness of the paper thus superimposes the relief structure of the hologram, the diffraction grating or the like, whereby the hologram to sharpness and brilliance loses. To avoid this effect, additional measures to smooth the subsoil necessary (EP-OS 0,440,045) on the banknote in the field of applied hologram.

p0008Such additional measures may be avoided by the banknote paper is provided in such a way with the to be embossed lacquer layer that is applied in the liquid state resist layer compensates for the unevenness of the surface of the banknote.

p0009For example, EP-OS 0,338,378 a continuous process, is first printed on both sides in the banknote paper in roll form and then provided in certain areas with a holographic structure. Here, the lacquer to be embossed and the relief structure are simultaneously transferred on the paper by the surface structure of the die is covered with a radiation-curable lacquer. Once paper and stamping dies are brought into contact, the paint is cured with UV radiation or electron beam. The paint adheres well to the paper surface and, the holographic relief structure. In the next step this relief structure is metallized by means of masks in a vacuum-deposition. To protect the thin metal layer and the fine relief structure from abrasion and destruction, the hologram area is provided in a further step with a protective layer.

p0010A similar method is known from DE-OS 25 55 215th In this case, a thermoplastic layer is transferred onto the document by means of a heated embossing die of a hot stamping foil, with at the same time the optical markings are embossed into the thermoplastic layer. The carrier substrate is peeled off after the embossing and the relief structure subsequently metallized.

p0011This procedure, ie first shape and then metallized, has the decisive disadvantage that the metal layer the contours of the fine relief structure does not exactly reproduces but blurs by different deposits on the vertical or horizontal structural elements. This applies even in those cases in which the metal to be deposited layer is only a few nm thick. The hologram therefore also loses its brilliance.

p0012The alternative approach to characterize the metallization only following is likewise prior art. US Patent No. 4,420,515 discloses for example a method in which a pre-metallized paint surface is provided with a relief structure. An endlessly circulating transfer belt is continuously metallized and reacted with a document in Beruhrung, which was selectively coated with a lacquer. The paint is cured and binds the metal stronger than the transfer belt and pulls thus in separating the transfer belt and document the metallization partially of this transfer tape. In a final step of on the substrate metallized coating area is provided with an embossing.

p0013As is embossed into the already cured paint layer, the embossed relief to low sharpness. The quality of the hologram is thus also adversely affected in this method. Further, the embossing must be carried out at high pressure, so that the embossing dies are subjected to high wear.

p0014The invention is therefore based on the object to provide a method and an apparatus for applying, if appropriate locally limited metal layers on substrates while avoiding the abovementioned disadvantages. In particular, a method and an apparatus for manufacturing flexible hologram on difficult substrates and under difficult constraints to be specified.

p0015The solution of this problem is defined in the characterizing clause of the main claim. Special embodiments and refinements are the subject of dependent claims.

p0016The invention is based on the fundamental idea that the production and the transfer of a surface structure is only possible in an optimal mold when the to be transferred structures are taken as purely as possible from the master structure and the transfer to the final substrate, neither the to be transferred structure nor the structure changed the Masters or damaged.

p0017According to the invention in this sense, the creation of elements and structure not by stamping an existing planar metal layer, but by "depositing" the metal layer on the master structure, the metal layer a cast similar fills all structural elements of the master structure and detected. Master and metal layer thus have Negativund positive structures that fully complement each other and which are intimately linked. To avoid changes or damage during transfer or while removing the metal layer from the master, a separation of the two structures shall be applied only after the fixes the metal layer on the final substrate and mechanically stabilized by Stubstrat and adhesive layer.

p0018The term "structure" is generally seen, that can be used as structure both an extremely smooth reflective surface as well as any relief structure can be used. According to the invention important that the currently selected or predetermined structure is as purely as possible implemented as positive or negative structure and also transmitted unaltered to the substrate.

p0019The term "coating layer" is intended to cover all materials and substances that are to be made so soft and sticky in the transfer of the metal layer in the contact time that the metal layer with its back is eindruckbar without damage to the layer, the metal layer intimately on the one hand with the paint layer combines and other obstacles between substrate surface and rear metal surface compensates the other hand, the metal layer adheres so firmly that, optionally after an additional curing phase, the metal layer can be completely removed from the master.

p0020In practice this means that,<ul><li>that a 1 on the master structure: 1-reproduction is produced by depositing the metal layer,</li><li>that either the metal layer or the substrate, a resist layer is applied, which are returned to the time that the substrate and the master into contact, is sufficiently soft and sticky and</li><li>that the substrate is peeled off together with the metal layer from the master, the resist layer is so far dimensionally stable that it allows removing the metal layer from the master and the metal layer extent stabilized even after separation from the master, that being taken by the master structures are preserved.</li></ul>

p0021In this way it is ensured that the metal layer present in the structure during the Anpreßvorgangs on the substrate is stabilized so long as the master structure, until the lacquer layer can assume this supporting function. Then the separation from the master and, if appropriate, further processing for further stabilization, to protect against environmental influences, for further creative education etc .. Such action takes place may be, the further curing of the paint layer, applying a protective lacquer layer, the provision of blind embossing with different structures overprinting with inks etc.

p0022Since neither in the preparation of the metal layer even when transferring the same localized mechanical forces act on the master structure, production and transfer operation are extremely gentle to both the master structure and the structure generated in the metal layer. A mechanical wear during this manufacturing phase largely excluded.

p0023As the carrier of the master structure, such. As a cylindrical platen roller, an endless belt or a stamp to be used etc.. The production of the metal layer is carried out using known metallization how Vakkumbedampfung, electrolysis or photolysis and other special procedures in the art under special terms such as "Gas Jet Deposition (GJD)", "spray deposition", "laser deposition", etc. are known. The curing of the lacquer layer is possible in different ways. This can be done by using a liquid-melt adhesive, for example, by simple cooling in multi-component coatings by heating and depending on the use of other substances also by other power supply, eg., By UV irradiation, microwave irradiation, electron beam etc..

p0024The inventive method is particularly suitable for the transmission of localized metal layers, since both the metalization and the transfer process can be locally precisely defined and structured.

p0025The preparation of the metal surface elements, as already explained, on an intermediate carrier with the master structure, from which they are transferred to the substrate. In contrast to known methods in which the metallization is carried out directly on the substrate itself, this approach has the advantage that any metallization process can be used, ie, methods are used that for when applied directly to the substrate, destruction or damage to the substrate would result.

p0026Especially advantageous for metallisation photolytic methods such. As shown in the DE-OS 38 40 199 or DE-OS 38 40 200 are described that provide the ability to particularly easy to modify the metallic surface elements in their contour shapes, so that in this way, in a particularly economical form series of different surface elements or surface elements with varied additional information content can be produced.

p0027The metallization process consists basically of the following steps:<ul><li>Conditioning of the intermediate carrier, ie the implementation of adapted to the metallization steps for selecting the areas to be metallized of the intermediate carrier,</li><li>Metallization of the intermediate carrier,</li><li>Transfer of local metal layers on the substrate,</li><li>Cleaning the intermediate carrier.</li></ul>

p0028In the photolytic process, the conditioning of the intermediate carrier (master) can be divided into individual steps, namely<ul><li>the scale sensitization of Masters with a catalyst or precursor, z. B. palladium acetate,</li><li>the optical activation of the palladium acetate with UV radiation and</li><li>the metal deposition in the sensitized and activated surface areas.</li></ul>

p0029Selective influencing one or more of the three steps can be done a variety of varying the metallization continuously created. This is possible, for example by carrying out the sensitization of the Masters in localized form. All subsequent steps can then be carried out over a large area, as a metal deposition takes place only at the locations at which the catalyst is present. Alternatively, can be selectively carried out by large-scale sensitization and activation. This variant is particularly advantageous because, for example, with the aid of a controlled UVLasers also very fine and well-defined lines can be displayed in this way. These structures are also retained in subsequent full-surface wetting in wet chemical baths for electroless plating in their fine "strokes". Ultimately, the local limitation of the metal layers by a defined application of the wet-chemical means are formed on a large area sensitized and activated master surface.

p0030If the shape of the metal layers is the same over several cycles, it may be possible to omit a duplicated conditioning of the intermediate carrier, that the intermediate carrier is not completely cleaned in the last step, but merely freed of metal residues.

p0031In the specific case of the hologram or diffractive structure application, the embossing roller is coated with metal according to the invention. This results in a further inventive aspect. Because with the inventive method it is now possible to manufacture or hologram stamping, metallization of the embossed hologram and transfer of metallized hologram made in a continuous process.

p0032Particularly advantageously, this affects where previously when subsequently placed application of the metallization registry problems had to be solved, because especially in the cases where a printing cylinder is used as an intermediate carrier for Master and metal layer, all known from printing technology process steps and tolerance ranges are available. With the process of the invention for the first time also has the option, current data in the variation of the surfaces elements involve. This can, for example, with the use of securities, identification cards, identification cards, etc. make sense, because this also ongoing Serial no., Personal alphanumeric or pictorial (Photo!) Data can be included in the preparation of the metal layer.

p0033In addition to these design possibilities and advantages are also obtained an absolutely faithful reproduction of the master structure, since the metal layer, the master structure completely abformt. This is noticeable, as already mentioned, advantageous in the optical quality of the hologram diffraction structures etc. noticeable.

p0034Further advantages and particular embodiments of the invention will become apparent from the following examples, which are explained with reference to figures.

p0035Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>the basic principle of the invention,</dd><dt>FIG. 2</dt><dd>electrolytic plating a cylindrical platen or embossing mold and transfer of metallization on a substrate, </dd><dt>Fig. 3</dt><dd>Layer structure of the substrate after the metal transfer,</dd><dt>Fig. 4</dt><dd>photolytic metalization of a cylindrical platen roller or stamping mold,</dd><dt>Fig. 5</dt><dd>photolytic metallization of a cylindrical high-pressure roller and transfer of metallization on a substrate,</dd><dt>Fig. 6</dt><dd>electrolytic plating of an endless printing nzw. Embossing belt and transfer of metallization on a substrate,</dd><dt>Fig. 7</dt><dd>photolytic metalization of an endless printing or embossing band,</dd><dt>Fi.g 8</dt><dd>metallic vacuum deposition of an endless printing or embossing band,</dd><dt>Fig. 9</dt><dd>Layer structure of a photolytically metalized embossing belt.</dd></dl>

p0036Fig. 1 shows, in schematic form, the basic principle of the invention. According to this scheme the master 1 is provided with a metal layer in a first station. As already explained in the introduction, comprises the master 1 some kind of surface structure 3 which in the illustrated case a surface relief, on this relief 3 a metallic layer 2 is deposited such that the structure 3 in the metal layer 2 is present as an exact negative structure. The metal layer 2 is preferably localized or has a defined outer contour on.

p0037In a second work station, a substrate 4 is prepared, which may be a virtually any medium. In the present case there is a security with glued, naturally rough surface.

p0038As a further work station, a varnish coating device is provided with which, either on the metal layer 2 or on the substrate 4 a locally limited lacquer layer may be applied. The local restriction of the lacquer layer preferably corresponds to that of the metal layer 2. However, it is also conceivable that both contours differ from one another, it being noted that the metal layer is defined withdrawn only in the areas by the master, in which they are in the lacquer layer coverage is.

p0039After the lacquer coating Master 1, metal layer 2, lacquer layer 6 and substrate 3 are brought together and pressed together. The arrows 7, 8 are thereby symbolizing the press pressure.

p0040Depending on which paint is used, optionally by additional measures, the lacquer layer 6 at least as far as cure that a sufficient adhesion to metal layer 2 and substrate 4 and an inherent strength is ensured, which allows removal from the master at the same time stabilizing the metal layer 2. FIG. In the simplest case, the curing can be done by the resist layer 6, a heated hot melt adhesive, is the relatively fast solidified by cooling from Master 1 and metal layer 2 after the merge. In the same way, but can also be used materials which cure under the action of IR or UV rays, microwaves, electron beams, etc.. In the event that the lacquer layer has a consistency which allows, without additional measures, both the pressing and bonding of the layers as well as the removal and stabilization of the metal layer, the final curing, if desired, also be done at any later point in time.

p0041In the last in Fig. 1 shown station the substrate 4 together with the metal layer 2 by the master 1, z. B. is withdrawn in the direction of the arrow 9. The thus transferred to the substrate metal layer is to subject, depending on the later application under certain circumstances further steps, such. As the equipment with a transparent protective lacquer layer. However, these additional steps are known to the expert and need not be explained in detail.

p0042In the embodiments described below, various applications of the inventive principle will be explained.

p0043For reasons of clarity has been omitted to scale and detaillgetreue representation in FIG. 1 and the other figures. The figures show rather principal arrangements which allow the implementation of the inventive method. In the figures, functionally identical elements have the same reference numbers will be provided.

example 1

p0044In FIG. 2, a cylindrical pressure roll is matallisiert partially with a smooth surface by electrolytic means and brought into contact with an adhesive-coated substrate.

p0045The sheet-shaped substrate 4, in this case paper, is transported by a transport system, which is indicated in Fig. 2 by the rollers 10. Before the sheet material 4, the pressure roller 11 is supplied, it goes through a paint coating station 5. The web 4 is coated here with the aid of a gravure or stencil cylinder 12, in particular surface areas with a transparent adhesive.

p0046Then, the substrate 4 passes through the transfer zone, which is formed from the cylindrical transfer roller 11 and a likewise cylindrical platen roller thirteenth In the contact zone of coated substrate 4 and metallized transfer roller 11, the curing of the adhesive, eg., By polymerization with electron beams or UV radiation may also be added. During further transport of the material web 4, the metal coating 2 is peeled from the intermediate carrier eleventh In a further processing station 14, the metallized portion 2 can also, if required, the entire or larger areas of the material web 4 to be provided with a transparent protective lacquer layer. The material web 4 provided such metallic surface elements 2 can be finally supplied to further printing stations 15 in order to print alphanumeric characters or patterns that can overlap may also parts of the metal coating. 2 It is also conceivable, instead of conventional printing inks to use special offset with feature substances printing inks, which can be transparent in the visual spectral range. As feature substances are, for example fluorescent substances, magnetic or pearlescent pigments.

p0047Fig. 3 shows the layer structure of the metallized substrate 4 after passing through the resist coating station 14. Directly on the substrate 4 is arranged in the station 5 locally applied adhesive layer 6. Since this layer 6 is transparent and very thin and therefore does not affect the visual appearance of the final product, its areal extent need not correspond exactly to the dimensions of the metallization. 2

p0048In any case, the extension of the adhesive layer 6 must not be less than that prescribed for metallization 2, since this would have an incomplete metal transfer result. To protect the metallization 2 against abrasion and destruction, it is also covered by a transparent protective lacquer layer sixteenth

p0049In the metallization station shown in Fig. 2, as already mentioned, the intermediate carrier, the cylindrical roller 11, here provided with the metallic surface to be transferred elements 2.

p0050In this example, the transfer roller 11 is metallised electrolytically. The parts of the cylinder which are not to be metalized are coated in the station 19 with electrically insulating material, eg. As with a lacquer layer. In the, in the circumferential direction of the platen 11 seen next station passes through the roller 11 an electroplating bath 17. The dissolved in the bath metal condenses because of the transfer cylinder 11 and the bath voltage applied to the electrically conductive surface areas of the roll 11 down, so that a metallic pattern on the roll surface. The following washing station 18 chemical residues are removed. The metal coating 2 will now be transferred to the substrate. 4 Then the roll is cleaned in the station 20 11 of any metal residues. If the outlines (or the shape) of the metal coating to be changed, as in the cleaning station 20, the electrically insulating coating of the roll 11 is also removed. In the varnish coating station 19, the roller 11 is finally prepared for the next metallization cycle.

example 2

p0051Fig. 4 shows a metallisation, in which the above-mentioned cylindrical transfer roller is metallized partially photolytically and brought into contact with an adhesive-coated substrate. The pre- and post-treatment of the substrate 4 as well as the transfer of the metal regions is carried out analogously to Example 1. For this reason, has been omitted in Fig. 4 a representation of the corresponding additional processing stations.

p0052Photolysis is a modern metallization which or in the production of metal fabric for shielding electric fields (DE-OS 38 40 200) has been used for several years successful in the metallic coating of semiconductor devices (38 40 199, DE-OS) has been.

p0053At the beginning of metalizing the intermediate support 11 is wetted with a Palladiumacetatfilm. For this, powdery palladium acetate in a solvent such as, for. Example, chloroform, and applied by dipping, spraying or centrifuging. Fig. 4 representatively shows a dipping station 21 The solvent evaporates immediately, leaving behind a thin Palladiumacetatfilm whose thickness can be adjusted via the concentration of the solution and the application process. In the station 22 to be metallized portions of the pressure roller can be exposed to UV radiation to produce by selective photo cleavage at the exposed areas, a thin palladium layer. These few nm thick palladium layer then serves as an activator for the subsequent chemical metallization, wherein micron thick copper, nickel and gold layers can be applied. In FIG. 4, a metallization 23 is shown, in which the intermediate support roller 11 is immersed. In another variant example, the metallization may also by an appropriate printing process, eg. Screen printing, are printed directly on the intermediate carrier 11.

p0054In the cleaning station 24, the non-exposed and hence non-metallized Palladiumacetatreste and fluid residues are removed from the plating bath 23, which have remained on the roll 11, rinsed off.

p0055Since the metal 2 is reflected exactly congruent to the activated or exposed portions of palladium acetate, this method that at sharply contoured and high definition exposure, eg., By a computer-controlled UV laser beam (z. B. excimer laser) has the decisive advantage , arbitrary, and per exposure process different finely structured surfaces can be metallized.

p0056After transfer of the metal coating 2 on the substrate 4, the intermediate carrier 11 is cleaned at station 25th Thereafter, the above described procedure is repeated cyclically.

p0057The finished substrate has in this example the same layer structure as in Example 1, which was described with reference to FIG. 3.

example 3

p0058Instead of a printing roller with a smooth surface can be used for example also a cylindrical high-pressure roller (letterpress printing) as shown in Fig. 5. In the example shown, this roller is metallized likewise after photolytic method. Again, the pre- and post treatment of the substrate 4 is analogous to example 1.

p0059The process steps for the metallization of the high-pressure roller 26 are analogous to record 2. The raised portions 27 of the platen 26 are wetted with palladium 21 and irradiated in accordance with the information to be transferred over a large area with UV light 22nd The dissolved in the plating bath 23 metal is deposited on the activated regions, while the unexposed areas are cleaned in the cleaning station 24th

p0060In the contact zone between the substrate 4 and the raised print areas 27 of the previously applied to the substrate, adhesive is cured, and thus binds the metal layer 2 to the substrate 4. Before the metallization cycle starts again, the print areas 27 are completely cleaned in station 25th

example 4

p0061In this example, which is shown in Fig. 6, an endless belt 28 is used having a smooth surface as an intermediate carrier, which is partially metallised electrolytically and brought into contact with the adhesive-coated substrate 4.

p0062The substrate is coated but here only with a component 29 of the metal coating 2 departing from the intermediate carrier 28 varnish locally. Then, the substrate 4 is transported in analogy to the previous examples through the transfer zone, and possibly after-treated according to Example 1st

p0063The metallisation consists in this case of a over the rollers 30, 31 revolving endless belt 28 which is electrolytically metallized. According to Example 1, the endless belt 28 is prepared in the stations 20 and 19 and subsequently metallized in the plating bath 17 locally. After purification of interfering Badresten in station 18 the second component 32 of the detaching paint, for. Example, a bonding agent for the metal layer to be transferred and / or a curing agent for the first component applied to the metal coating 2. At the touch of the two components in the transfer zone, the diffusion of the hardener causes together with power supply, which is adapted to the materials used in each case, an accelerated curing and excellent bonding of the transferred metal layer to the substrate.

p0064This two-component adhesive can also be used in all other examples described.

example 5

p0065A further variant of a metallisation is shown in Fig. 7. The pre- or post-treatment of the substrate 4 carried out analogously to Example 1. Fig. 7 is therefore only necessary for the metallization of the endless belt 28 and the devices, the transfer zone forming rollers 13 and 30.

p0066The partial metallisation of the intermediate carrier 28 is done here in analogy to Example 2 after the photolytic process. The endless belt 28 is wetted with the Palladiumacetatfilm 21 which is locally activated by UV irradiation for 22 Metallanlagerung in the metallizing 23rd The stations 24 and 25 provide for the previously described belt cleaning 28th

example 6

p0067Since in this example extends the pre- or post-treatment of the substrate in accordance with the preceding examples, the illustration in FIG. 8 also limited to the metallisation and the transfer zone. Serving as intermediate support endless belt 28 is thereby partially metallized by vacuum coating on masks.

p0068The belt 28 is cleaned of any metal residues in station 33 before each metalizing. The conditioning of the areas to be coated is effected in the vacuum chamber 34 itself optionally with the aid of masks 35. As a vacuum coating process, both the vacuum deposition and the cathode ray sputtering (sputtering) can be used. The transfer of the metallic areas extends, as already explained, by curing or cooling of the adhesive in the contact zone of the substrate 4 and the endless belt 28 between the rollers 13 and 30th

p0069In Figures 2-8 and shown in Examples 1 -. A process for the metallization of a local-described substrate 6 may be a hologram used also very beneficial for the coating verspiegelnde a diffraction structure, preferably. In this case, the intermediate carrier is formed as a stamping die, that is, it carries on its surface, the diffractive relief structure is impressed according to the prior art in the resist on the substrate. Optionally, the lacquer can also, as already explained, applied to the metallized areas of the intermediate carrier and are simultaneously transferred to the metal layer to the substrate.

p0070The metallization of the invention of the insensitive stamping die instead of photosensitive substrate allows a chemical metallization with corrosive chemicals to perform. In the following examples Metallisierungsstationen are described which are characterized by such formed as a stamping die subcarrier.

p0071All statements made in connection with the above examples, in terms of process variants can be easily transferred to the following Beipiele.

example 7

p0072A cylindrical pressure roll having a relief-like surface structure is partially or vollfächig electrolytically metallized and brought into contact with an adhesive-coated substrate.

p0073The apparatus shown in Fig. 2 can be adopted in principle. Only the cylindrical press roll 11 must have the appropriate hologram relief surface.

p0074The substrate 4, such. As a paper web, is preferably placed with a gravure or a stencil cylinder 12, locally coated with a lacquer 5 and that at the points at which the hologram is to be embossed. Subsequently, the substrate 4 is transported in the stamping and metal transfer zone between the pressing roller 13 and the metallised embossing form 36th The cylindrical form 36 has embossing the hologram embossed structure placed in register in relation to the locally coated surfaces of the substrate 4 on.

p0075The surface relief of the die 36 is metallized entire surface or partially after the electrolytic process already described in Example. 1 The metallization may also take the entire surface, because the register accurate transferring is determined by the points coated on the substrate. 4 A sharper contouring of metal surfaces 2 will only be reached by partial metallization of the die 36th

p0076In the contact zone of coated substrate 4 and removable metallized embossing mold 36, the relief structure is transferred faithfully to the paint. At the same time the curing of the lacquer, for. Example, by cooling, UV radiation or polymerization with electron beams. As in Example 1 pulls the cured lacquer layer, the metallization of the embossing mold 36 from.

p0077In this way, operations can be saved during the hologram production, because stamping and mirror-coating of the relief structure are carried out simultaneously in a single operation.

p0078extend the remaining steps anlaog example 1.

example 8

p0079In accordance with Example 2 and Fig. 4 described metallizing, the cylindrical pressure roller with a smooth surface 11 is replaced by a likewise cylindrical embossing mold 36 and metallized photolytically.

Examples 9-11

p0080Also in Examples 4 - 6 Metallisierungsvorrichtungen described that use an endless belt as an intermediate carrier, can be used in the combined hologram embossing and metallization of the invention. The endless belt 28 carries in these cases the hologram relief structure.

p0081Fig. 9 shows a section of the metallized photolytically embossing belt 37 (FIG. 7) before it is brought into contact with the substrate 4. The endless belt 37 has a relief structure 38. there is a thin palladium layer 39 which is formed by photolytic decomposition of the palladium acetate film over the relief structure 38th The unexposed areas of the film were removed in station 24th About the palladium layer 39, the metal 2 has been reflected. It has exactly the outline shapes of the palladium layer 39 and gives the relief structure 38 faithfully recreated.

p0082By simultaneously transmitting metallization and relief structure quality losses caused by the subsequent application of the metal coating, because the subsequently deposited metal layer, the relief structures blurred. Simultaneously, the negative influence of the surface structure of the substrate is avoided because the coating layer compensates the roughness of the ground.

p0083Known from EP-OS 0,440,045 measures to smooth the subsoil in the area of ​​applied later hologram can of course still be made, if due to special circumstances, eg. As because for some reason particularly thin layers of lacquer to be used, be necessary should.

p0084The photolytic metalizing the embossed form provides, as already explained, the possibility of producing finely structured metallic surfaces. That fact is also just in the design of holograms in combination with other features of great advantage. Thus, the hologram can be provided or screened, for example, with a line or Guillochenrahmen so that a surface pressure remains visible. It would also be conceivable to provide recesses in the form of characters or patterns in the metallization. Due to the variable exposure possibilities of palladium acetate and a consecutive numbering could be provided in the form of metallic numbers on the hologram.

p0085In contrast to the usual requirement in the art for metal coatings, to achieve a good adhesion of the coating, a releasable adhesion of the metal layer on the master surface according to the invention is required.

p0086This is less of a problem than that, to produce a good. While few materials adhere to each well and generally additional measures (such as roughening the surface) need to be applied, the poor adhesion of coatings the norm and easy to reach, if you consider the following.<ul><li>The "Master" -Oberflachenstruktur must not "undercuts", "Hohlungen" or "overhangs" exhibit, but only simple "mountains" and "valleys". This is given for smooth surfaces or hologram relief.</li><li>The "Master" substance and the chemically Metallisierungssubstanz may not be too closely related, for. Example is copper in brass unsuitable, copper on aluminum or on many plastics suitable for producing a releasable connection.</li><li>By adjusting the thickness and the degree of activation of the precursor at the photolytic metalization the solvability of the metal layer can be adjusted.</li><li>By the amperage and thus by the rapidity of the deposition, the adhesion of the layer can be set in the electrolytic coating. A rapid deposition results in a releasable layer.</li><li>When depositing a metallisation is obtained by previously applying a monolayer of a release agent a releasable layer, if one does not prefer to make the master mold directly out of a substance that has poor adhesion to metal evaporation.</li></ul>

p0087The introductory remarks show that the variation of bandwidth is not exhausted by the examples mentioned by far. In principle, arise in the present process some function blocks in which very different design variants are again partly usable. A variation is particularly appropriate in the selection<ul><li>the intermediate carrier (cylindrical platen roller, endless belt, stamp)</li><li>the structure (high-gloss, rough structure, microstructure, hologram, diffraction grating, etc.),</li><li>the metallization process,</li><li>the nature of the local limitation (limited metal layer on the master or limited adhesive layer)</li><li>the placement of the adhesive (on a metal layer, or substrate),</li><li>the adhesive and the associated cure method,</li><li>the additional steps to stabilize etc.</li></ul>

p0088Another basic variant is to dispense with the substrate. In this example, the paint is cured directly on the metallic intermediate carrier and removed with the metal layer as a self-supporting film.

p0089Although in the examples described only some of the possible combinations have been described, should thus be taken a final selection. Other combinations that fall under the general inventive idea, but should also fall under the scope.