Multi-layer body and method for the production thereof

Abstract

The invention relates to a method for producing a multi-layer body, in particular a security element, in which a partial first layer or partial first layer system is produced on a substrate, wherein the partial first layer or partial first layer system is present in a first partial area and not in a second partial area. Subsequently, a partial second layer or partial second layer system is produced, wherein the partial second layer or partial second layer system is present in a third partial area and not in a fourth partial area, and wherein the third partial area overlaps with the first and second partial areas. Finally, the partial first layer or partial first layer system is structured as a mask using the partial second layer or partial second layer system.

Claims

1. A method for producing a multi-layer body comprising the following steps: a) producing a partial first layer or partial first layer system on a substrate, wherein the partial first layer or partial first layer system is present in a first partial area and not in a second partial area; b) producing a partial second layer or partial second layer system, wherein the partial second layer or partial second layer system is present in a third partial area and not in a fourth partial area, and wherein the third partial area overlaps with the first and second partial areas; and c) structuring the partial first layer or partial first layer system using the partial second layer or partial second layer system as a mask.

2. The method according to claim 1, wherein the structuring of the partial first layer or partial first layer system in step c) takes place by etching.

3. The method according to claim 2, wherein the partial second layer or partial second layer system is an etch resist, or at least comprises an etch resist.

4. The method according to claim 3, wherein the etch resist is a lacquer that comprises binders, colored or non-colored pigments and/or special-effect pigments, thin-film systems, cholesteric liquid crystals, dyes and/or metallic or non-metallic nanoparticles.

5. The method according to claim 1, wherein the structuring of the partial first layer or partial first layer system in step c) takes place by lift-off.

6. The method according to claim 5, wherein the partial second layer or partial second layer system is a washcoat that is soluble in water, or at least comprises such a washcoat.

7. The method according to claim 6, wherein the washcoat is a lacquer that comprises binders and fillers.

8. The method according to claim 1, wherein the structuring of the partial first layer or partial first layer system in step c) takes place by mask exposure.

9. The method according to claim 8, wherein the partial second layer or partial second layer system is a protective lacquer or at least comprises a protective lacquer.

10. The method according to claim 8, wherein the partial first layer or partial first layer system is a photoresist or at least comprises a photoresist, wherein the protective lacquer is a washcoat that is soluble in water.

11. The method according to claim 9, wherein the protective lacquer and/or photoresist is a lacquer that comprises binders, colored or non-colored pigments and/or special-effect pigments, thin-film systems, cholesteric liquid crystals, dyes and/or metallic or non-metallic nanoparticles.

12. The method according to claim 1, wherein, in steps a) and/or b) the partial first layer or partial first layer system and/or the partial second layer or partial second layer system is first produced over the entire surface or at least in large areas of the surface and is then structured.

13. The method according to claim 12, wherein the structuring of the partial first layer or partial first layer system and/or of the partial second layer or partial second layer system in steps a) or b) takes place by etching, lift-off or mask exposure.

14. The method according to claim 13, wherein, during the structuring of the partial second layer or partial second layer system in step b), the structuring of the partial first layer or partial first layer system according to step c) takes place simultaneously.

15. The method according to claim 1, wherein, in step a) and/or b), the partial first layer or partial first layer system and/or the partial second layer or partial second layer system is produced in structured form.

16. The method according to claim 15, wherein the partial first layer or partial first layer system and/or the partial second layer or partial second layer system are produced by intaglio printing, flexographic printing, offset printing, screen printing, digital printing, or ink-jet printing.

17. The method according to claim 1, wherein the partial first layer comprises a reflective layer of a metal.

18. The method according to claim 1, wherein the partial second layer comprises at least one single-colored lacquer layer.

19. The method according to claim 1, wherein the partial first layer is applied in the form of at least one motif, pattern, symbol, image, logo or alphanumeric characters, numbers and/or letters.

20. The method according to claim 1, wherein the partial first layer or partial first layer system and/or the partial second layer or partial second layer system is applied in the form of a one- or two-dimensional line and/or dot grid.

21. The method according to claim 20, wherein the line and/or dot grid has a grid spacing of less than 300 m, and of more than 25 m.

22. The method according to claim 1, wherein the substrate comprises a carrier layer comprising polyester or PET (polyethylene terephthalate) and/or a release layer.

23. The method according to claim 1, wherein the substrate comprises a replication layer with a diffractive surface relief or the substrate itself is designed as a replication layer.

24. The method according to claim 23, wherein the surface relief introduced into the replication layer forms an optically variable element, a hologram, a sinusoidal diffraction grating, an asymmetrical relief structure, a blazed grating, an isotropic or anisotropic matt structure, or a light-diffracting and/or light-refracting and/or light-focusing micro- or nanostructure, a binary or continuous Fresnel lens, a microprism structure or a combination structure thereof.

25. The method according to claim 1, wherein, in a further step d), a third layer or a third layer system is applied, which is or comprises an HRI layer and/or an adhesive layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is illustrated more clearly below by way of example, based on several embodiment examples with the aid of the drawings. There are shown in:

(2) FIG. 1A-C: a multi-layer body and the production steps of a multi-layer body with a metal layer and a single-colored lacquer layer;

(3) FIG. 2A-C: a multi-layer body and the production steps of a multi-layer body with a metal layer and a two-colored lacquer layer;

(4) FIG. 3: a sectional view through a first intermediate product in the production of a multi-layer body according to FIG. 2;

(5) FIG. 4: a sectional view through a second intermediate product in the production of a multi-layer body according to FIG. 2;

(6) FIG. 5: a sectional view through a third intermediate product in the production of a multi-layer body according to FIG. 2;

(7) FIG. 6: a multi-layer body with a metal layer, a single-colored lacquer layer, a diffractive structure and an HRI layer;

(8) FIG. 7A-C: a multi-layer body and the production steps of a multi-layer body with two metal layers and a single-colored lacquer layer;

(9) FIG. 8A-C: a multi-layer body and production steps of a multi-layer body with a metal layer, an HRI layer and a single-colored lacquer layer;

(10) FIG. 9A-C: a multi-layer body and production steps of a multi-layer body with a finely structured metal layer and a single-colored lacquer layer;

(11) FIG. 10: a sectional view through a first intermediate product in the production of a multi-layer body according to FIG. 9;

(12) FIG. 11: a sectional view through a second intermediate product in the production of a multi-layer body according to FIG. 9;

(13) FIG. 12: a sectional view through a third intermediate product in the production of a multi-layer body according to FIG. 9;

(14) FIG. 13: a sectional view through the finished multi-layer body according to FIG. 9;

(15) FIG. 14 a detailed view of the structures for the metal and lacquer layer for the multi-layer body according to FIG. 9;

(16) FIG. 15A-C: a multi-layer body and production steps of a multi-layer body with a metal layer and a lacquer layer on the front;

(17) FIG. 16A-C: a multi-layer body and production steps of a multi-layer body with a gridded metal and lacquer layer;

(18) FIG. 17A-C: a multi-layer body and production steps of a multi-layer body with a finely structured metal layer and a multi-colored lacquer layer;

(19) FIG. 18A-E: a multi-layer body and production steps of a multi-layer body with a finely-structured metal layer and a single-colored lacquer layer.

DETAILED DESCRIPTION OF THE INVENTION

(20) FIG. 1 shows a first embodiment example of a multi-layer body 10, which can be used as a security element for bank notes, securities, identity documents, tickets or protected product packaging. The multi-layer body 10 comprises a first layer 11, which is in the form of a metal layer, for example of aluminum, as well as a second layer 12, which is in the form of a colored etch resist lacquer. Besides aluminum, copper, silver or chromium or a wide variety of metal alloys are also suitable.

(21) As FIG. 1a shows, to produce the multi-layer body 10 the first layer 11 is initially produced, which can take place for example by vapor deposition on a substrate that is not shown. The vapor deposition preferably takes place in a vacuum by thermal vapor deposition, electron beam vapor deposition or also by sputtering. The layer thickness of the first layer 11 is preferably 5 nm to 100 nm, further preferably 15 nm to 40 nm.

(22) The first vapor-deposited layer can then be partially removed by known methods, for example by the partial application of an etch resist after the vapor deposition and subsequent etching, including removal of the etch resist; by the partial application of a washcoat before the vapor deposition and washing off (lift-off) after the vapor deposition or by partial application of a photoresist after the vapor deposition and subsequent exposure followed by removal of the exposed or unexposed components of the photoresist, depending on the type (positive or negative) of the photoresist.

(23) Alternatively, the substrate is not vapor coated over the entire surface; rather, the layer 11 is partially produced, so that it is present in a first area 111 and not in a second area 112. Various methods of achieving this are known, such as for example screening using a rotating mask or printing of an oil which prevents the deposition of the metal layer in the vapor deposition process.

(24) A replicated diffractive structure, for example in the form of an optically variable element (OVD=optical variable device), in particular a hologram, Kinegram or Trustseal, a preferably sinusoidal diffraction grating, an asymmetrical relief structure, a blazed grating, a preferably isotropic or anisotropic matt structure or a light-diffracting and/or light-refracting and/or light-focusing micro- or nanostructure, a binary or continuous Fresnel lens, a microprism structure, a microlens structure or a combination structure thereof, may already have been applied to the substrate beforehand. However, this does not necessarily have to be present.

(25) The first layer 11 also does not have to be continuous, as shown, but can have any structure and any shape.

(26) In the next step, the second layer 12, here in the form of a radial pattern, is printed onto the first layer. Intaglio printing, flexographic printing, offset printing, screen printing or digital printing, in particular ink-jet printing, is preferably used as the printing technique.

(27) The second layer 12 here extends both into the area 111 covered by the first layer 11, but does not completely cover this, and into the area 112 not covered by the first layer 11. Where a replicated diffractive structure is present, the printing preferably takes place in register with this structure, with target tolerances of +/1 mm, preferably +/0.5 mm, depending on the printing method.

(28) The lacquer used for printing the second layer 12 is an etch resist, i.e. resistant to an etching agent that can dissolve the metal of the first layer 11. If aluminum is used for the first layer, this etching agent can be for example sodium hydroxide solution. A lacquer based on PVC/PVAc (polyvinyl acetate) copolymer, for example, is then suitable as etch resist.

(29) The lacquer further contains dyes, pigments, in particular colored or non-colored pigments or special-effect pigments, thin-film systems or cholesteric liquid crystals or nanoparticles, so that it produces an optically visible effect.

(30) After the second layer 12 has been printed, the intermediate product shown in FIG. 1b is treated with the etching agent described. The etching then takes place preferably at a concentration of 0.1% to 5% and a temperature of the etching agent of 15 C. to 75 C. over a period of 5 seconds to 100 seconds. A suitable etch resist is for example a lacquer based on PVC/PVAc (polyvinyl acetate) copolymer, which is printed on in a layer thickness of preferably 0.1 m to 10 m. In the areas not covered by the second layer, the first layer 11 dissolves. The etching can be followed by a rinsing operation, for example with water, and a drying step.

(31) FIG. 1c shows the resulting multi-layer body 10 from the side opposite the print side. It can be seen that the structures of the first layer 11 and second layer 12 blend seamlessly into one another, i.e. are arranged accurately in register. This side is also the side from which the multi-layer body 10 is typically viewed. If a replicated diffractive structure is present, the first layer 11 acts as a reflective layer, so that the diffractive structure is particularly clearly visible in the area of the first layer 11. By means of an additional coating with an adhesive layer, which is not shown, the diffractive structure can be completely obliterated in the area 111 not covered by the first layer 11 if the adhesive layer has a similar refractive index (e.g. approximately 1.5) to the replication layer and therefore no optically active barrier layer is formed between adhesive layer and replication layer. The refractive indices of the two adjacent layers should differ from one another by no more than 0.1. The adhesive layer simultaneously serves for the application of the multi-layer body 10 to a substrate, for example a bank note. The color can be designed to be largely transparent or translucent, so that the underlying substrate is visible, but a largely opaque design is also possible.

(32) Instead of a metal layer as first layer 11, several adjoining color layers can also be used, which are printed on the substrate. Suitable lacquers for this purpose are for example photoresists, such as for example AZ 1518 from AZ Electronic Materials. The second layer 12 is then preferably a protective lacquer, for example a transparent or opaque lacquer with a UV blocker. Benzophenone derivatives or highly disperse titanium dioxide are particularly suitable for this purpose. The second layer 12 is then preferably printed overlapping with the border areas of the color layers of the first layer 11. After exposure over the entire surface in a wavelength range of preferably 320 nm to 430 nm, a preferred exposure dose of 10 mJ/cm.sup.2 to 500 mJ/cm.sup.2 and etching with for example 0.3% NaOH at a preferred temperature of approximately 50 C. for a period of preferably 10 seconds to 30 seconds, only the colored components of the first layer 11 then remain where they were covered by the second layer 12 and thus form a multi-colored decoration. If e.g. the second layer 12 is present in the form of guilloche lines, the finished multi-layer body 10 therefore displays guilloche lines in which color transitions can be seen, i.e. so-called rainbow printing.

(33) The multi-layer body 10 shown in FIG. 2 is produced analogously to FIG. 1. Only in the second production step according to FIG. 2b, the second layer 12 is formed as a layer system by printing two different-colored lacquers 121, 122. The two lacquers 121, 122 can overlap in places and are preferably printed in register with a tolerance of preferably less than 0.5 mm and particularly preferably of less than 0.2 mm.

(34) After the etching, which is carried out as described in FIG. 1, the multi-layer body 10 according to FIG. 2c is obtained. The rays of the star-shaped motif shown, formed by the second layer 12, now appear alternately in the colors of the lacquers 121, 122. As well as print colors visible in the visible range, here as in the other embodiment examples shown, lacquers can also be used which are UV active or can be excited by IR radiation or display optically variable effects, such as for example OVI inks, or which are electrically or magnetically detectable, for example by adding appropriate metallic nanoparticles.

(35) Here too, as explained with reference to FIG. 1, a rainbow printing effect can again be created.

(36) FIGS. 3 to 5 show the production steps of an alternative multi-layer body 10, the basic structure of which, however, corresponds to that shown in FIG. 2. The essential difference lies in the fact that the second layer 12 in this case is not already structured when printed, but is first applied over the entire surface or at least in large areas of the surface and is then structured.

(37) For this, a release layer 14 and a replication layer 15 of for example a thermoplastic material or a radiation- or heat-curing replication lacquer are first applied to a carrier layer 13 of polyester, in particular PET, wherein these layers can in turn consist of several plies. In the replication layer 15, diffractive structures 151 are then formed, for example by stamping with a metallic stamping tool. The first layer 11, which in this case is formed as a layer of a transparent highly refractive material (HRI=High Refractive Index), for example of zinc sulfide or titanium dioxide, is then applied to the replication layer 15. The second layer 12, which again consists of two different-colored lacquers 121, 122, which adjoin one another, is then applied to the first layer 11 over the entire surface or at least in large areas of the surface. The lacquers 121, 122 are UV-sensitive photoresists, such as for example AZ 1518 from AZ Electronic Materials based on phenolic resin/diazoquinone. A mask layer 16 is then printed partially onto the second layer 12. The mask layer 16 simultaneously serves as an etching lacquer and a protective lacquer. An etch resist lacquer, for example based on PVC/PVAc (polyvinyl acetate) copolymer, can be provided for example with UV-absorbing titanium dioxide particles or other UV blockers for this. This is followed by exposure to UV light from the side of the mask layer 16. The exposure preferably takes place at a wavelength of 365 nm with a dose of 25 mJ/cm.sup.2 to 500 mJ/cm.sup.2. The intermediate product shown in FIG. 3 is then exposed to an alkaline bath, which simultaneously functions as a developing and etching bath.

(38) NaOH in a preferred concentration of 0.05% to 2.5%, which preferably acts on the intermediate product for a period of 2 seconds to 60 seconds at a temperature of 20 C. to 65 C., is for example suitable for this.

(39) In the areas not protected by the mask layer 16, the photoresist 121, 122 of the layer 12 was exposed during the UV irradiation and therefore now dissolves in the developing bath. The intermediate product represented in FIG. 4 is obtained. However, this is not isolated. Rather, the etching operation is continued, wherein the HRI layer 11 is now attacked where it is not protected by the remaining layer 12. The lacquers 121, 122 therefore act simultaneously here as an etch resist. After the etching operation, the finished multi-layer body 10 represented in FIG. 5 is obtained. An adhesive layer can also be applied to this, which fills in the exposed diffractive structures 151 where these are not covered by the first layer 11. The diffractive structures 151 are then only visible where the HRI material of the first layer 11 acts as a reflective layer.

(40) In FIG. 6, a further multi-layer body 10 is represented. The application of the layers 11 and 12 takes place analogously to the embodiment example shown in FIG. 1. A further transparent HRI layer 17 is then applied over the entire surface, so that a diffractive element 18 not covered by the first layer 11 becomes visible.

(41) Diffractive structures are thus visible in the opaque metallic areas of the first layer 11 and in the areas of the transparent HRI layer 17, but typically not in the printing areas of the second layer 12, because the diffractive structures are obliterated by the colored lacquer of the second layer 12 printed directly onto the diffractive structures, because the colored lacquer preferably has a similar refractive index (approximately 1.5) to the replication layer and therefore no optically active boundary layer is formed between colored lacquer and replication layer. The refractive indices of the two adjacent layers should preferably differ from one another by no more than 0.1.

(42) The embodiment example according to FIG. 7a-c again corresponds to the embodiment example according to FIG. 1. The only difference lies in the fact that, for the first layer 11, two different metals 113, 114, such as for example Al and Cu, are used. The two metals 113, 114 can be spatially separated, adjacent or also partially overlapping.

(43) FIG. 7b again shows how the second layer 12 is printed onto the first layer 11, viewed from the printing side.

(44) FIG. 7c shows the finished multi-layer body viewed from the metal side. Because of the opaque metal layers, the printing of the layer 12 is not visible under the metal areas of the layer 11.

(45) The structuring of the first layer 11 can take place in two steps since, for example, different etching agents have to be utilized for the two metals or metal alloys used. Where Al and Cu are used for the first layer 11, these are for example NaOH and FeCl.sub.3. However, since the same printed mask, namely the second layer 12, is used for the structuring, the transitions of the two metals 113, 114 of the first layer 11 take place in perfect register, in other words in an exact relative position to the printing of the second layer 12.

(46) The embodiment example according to FIG. 8 again corresponds to the embodiment example according to FIG. 1. In addition, only a further transparent HRI layer 17 is applied. For this, in a first step an opaque metal 113, for example aluminum, is applied in the manner already described. In a further step, the HRI layer 17 of ZnS or TiO.sub.2 is applied, which can also take place by vapor deposition or sputtering, so that a layer arrangement according to FIG. 8a is present. The HRI layer 17 can likewise be only partially present, can adjoin the metal layer 113 or can also at least partially overlap it. The metal layer 113 and the HRI layer 17 together form the first layer 11.

(47) Overprinting is then carried out with for example a red-colored layer as the second layer 12, so that the situation according to FIG. 8b is obtained. The view is from the printing side.

(48) In another process step, the areas of the two reflective layers 113, 17 that have not been overprinted are removed, optionally also in two process steps with chemicals adapted corresponding to the layers to be removed, e.g. two different alkaline solutions. While NaOH can be used to remove the aluminum parts under the conditions described, to remove an HRI layer of ZnS, NaOH or also Na.sub.2CO.sub.3 is preferably likewise used at a temperature of 20 C. to 60 C. for a period of 5 seconds to 60 seconds.

(49) The finished multi-layer body is seen in FIG. 8c from the side of the first layer 11. Compared with FIG. 1, the effect of the diffractive structures in the substrate is also visible in the non-metallic areas in which the HRI layer 17 is present, while at the same time the colored printing of the second layer 12 is visible because between the print and the diffractive structures the HRI layer 17 is also arranged as an optical boundary layer. The colored lacquer here can be transparent, translucent or else largely opaque.

(50) The embodiment according to FIG. 9 again corresponds to the one according to FIG. 1. The difference lies only in the fact that the first layer 11 is present in finely structured form, here as repetitions of the number 50. The production process comprises a first step, in which the finely structured first layer 11 is produced according to FIG. 9a. Correspondingly finely structured metal layers can be produced for example in the following manner: by structuring a photoresist layer by means of a high-resolution mask exposure, which layer is in turn then utilized for structuring the metal layer, or by using a method for tolerance-free partial metalizing as known for example from WO 2006/084685 A2. The layer 11 consists of a fine grid, which consists for example of a microscopically fine text.

(51) The colored printing of the second layer 12 then takes place according to FIG. 9b. The second layer 12 in this example is a comparatively coarsely structured motif in the form of the large number 50. However, the second layer 12 can likewise be very finely structured.

(52) In the last step, the colored printing of the layer 12 serves as a mask for the removal of the first layer 11 in accurate register, so that the multi-layer body 10 shown in FIG. 9c is obtained. This takes place analogously to the etching methods already described.

(53) If, for example, first layer 11 and second layer 12 are finely structured line grids, depending on their relative position to one another, overlay effects occur and the structure ultimately formed is a finely structured overlay structure of the first layer 11 and second layer 12. The overlay structure can produce for example a desired moir effect.

(54) The fine structuring of the first layer 11 can also be designed for example as a guilloche of a large number of fine lines, preferably as a metallic reflective layer in combination with optically diffractive structures, for example with a KINEGRAM, as shown by FIG. 17A.

(55) The colored printing of the second layer 12 then takes place according to FIG. 17B. The colored printing can exhibit several different-colored areas, for example in the form of a national flag (as shown here) and/or a geographic contour of a country or in the form of a coat of arms or of another multi-colored motif.

(56) In the last step, the colored printing of the layer 12 serves as a mask for the removal of the first layer 11 in accurate register, so that the multi-layer body 10 shown in FIG. 17C is obtained. This takes place analogously to the etching methods already described.

(57) In the embodiment shown in FIG. 17, the observer recognizes as forgery-proof and independent features, the facts that the finely structured lines are present only in the colored areas and that the finely structured lines visible in one colored area continue in register in a further adjacent colored area.

(58) Another embodiment with a finely structured first layer 11 is shown in FIG. 18. Here too, the fine structuring of the first layer 11 can also be designed for example as a guilloche composed of a large number of fine lines, preferably as a metallic reflective layer in combination with optically diffractive structures, for example with a KINEGRAM, as shown by FIG. 18A.

(59) The printing of the second layer 12 then takes place according to FIG. 18B. A colorless, preferably transparent etch resist with a UV absorber is utilized. This etch resist is then intended to perform a dual function: the etch resist serves on the one hand for the further substructuring of the finely structured first layer 11 by means of etching and on the other hand subsequently as an exposure mask for structuring a colored area.

(60) Corresponding to the surface of the first layer 11 coated with etch resist, the fine structure of the first layer 11 is removed by means of etching in the areas where the etch resist is not provided.

(61) A colored photoresist is then printed on, which comprises at least the area that is not covered by the colorless etch resist. The photoresist can also, however, overlap with the etch resist. By exposure of the colored photoresist using the colorless etch resist with the UV absorber as an exposure mask, the colored photoresist is cured in those areas that do not have any transparent etch resist and can be removed in the other areas in accurate register with the etch resist and with the areas of the finely structured first layer 11 that are protected and defined by the etch resist.

(62) In the embodiment shown in FIG. 18, the observer recognizes as forgery-proof and independent features the facts that the fine structures of the first layer 11 are only present in the colorless areas and end in accurate register with the colored area of the photoresist, and that the fine structures of the first layer 11 virtually continue over the colored area in an adjacent transparent area while remaining in register.

(63) FIGS. 10 to 13 show the production steps of an alternative multi-layer body 10, which, however, corresponds in its basic structure to that shown in FIG. 9. The essential difference lies in the fact that the second layer 12 in this case is not already structured when printed, but is first applied over the entire area or at least in large areas and is then structured.

(64) For this, a release layer 14 and a replication layer 15 are initially applied to a carrier layer 13 of polyester or PET. Diffractive structures 151 are then formed in the replication layer 15. The first layer 11, which in this case is present as a finely structured metal layer, for example in the form of a grid, is then applied to the replication layer 15.

(65) As shown in FIG. 11, the second layer 12, which again consists of two different-colored lacquers 121, 122, which adjoin one another, is then applied to the first layer 11 over the entire surface. The lacquers 121, 122 are UV-sensitive colored photoresists. A mask layer 16 is then printed partially onto the second layer 12 so that the intermediate product represented in FIG. 12 is obtained. The mask layer 16 can take the form of a further grid. The mask layer 16 simultaneously serves as an etching lacquer and a protective lacquer. For this, an etch resist lacquer can be provided for example with UV-absorbing titanium dioxide particles or other UV blockers. This is followed by exposure to UV light from the side of the mask layer 16. The exposure parameters and lacquers used correspond to those already described above.

(66) Instead of a mask layer 16, a film mask can also be utilized which lies in contact with the layers 121 and 122 only during the exposure process and is then removed again.

(67) The intermediate product shown in FIG. 12 is then exposed to an alkaline bath, for example 0.3% NaOH at 50 C., which simultaneously functions as a developing and etching bath. In the areas not protected by the mask layer 16, the photoresist 121, 122 of the layer 12 was exposed during the UV irradiation and therefore it now dissolves in the developing bath. In the further course of the etching operation, the first layer 11 is attacked where it is not protected by the remaining layer 12. The lacquers 121, 122 therefore simultaneously act as an etch resist here. After the etching operation, the finished multi-layer body 10 represented in FIG. 13 is obtained.

(68) Examples of possible gridded forms of the first layer 11 and the second layer 12 are shown in FIG. 14. Apart from the line and motif grids shown, other structures, for example dot grids, are of course also possible. Furthermore, the first layer 11 and/or the second layer 12 can be provided with a further grid of diffractive structures on the respective replication layer of the first and/or second layer. This can result not only in overlay effects through the overlaying of the fine grids of the first and second layers 11, 12, but also a further, additional overlaying with the diffractive grid or grids of the first and/or second layer or their optically variable effects. The overlay effects can prove very different depending on how similar or different the grid spacings and/or grid shapes of the grids involved in the overlay are. In particular, the viewing angle and/or lighting angle dependency of the diffractive grids can lead to surprising optical effects in this complex overlay.

(69) The embodiment examples discussed up to now are based on the fact that a partial reflective layer of opaque metal or transparent HRI material (first layer 11) is first produced and then a print (second layer 12) is applied. The print of the second layer 12 serves as a mask layer, for example analogous to an etch resist print, for the further structuring of the partial metal layer 11.

(70) In the embodiment example according to FIG. 15, a print (second layer 12) is first introduced into the input material, into which material a diffractive structure that is not represented is then formed (see FIG. 15a).

(71) In a further step, a first partial metal area (first layer 11) is produced, as represented in FIG. 15b.

(72) In the next step, the print that is already present in the input material is utilized as an exposure mask for a photoresist layer applied thereon in order to structure the first layer 11 in perfect register with the print of the second layer 12. The materials and process parameters used correspond to those already described above.

(73) The second layer 12 is therefore produced completely independently of the first layer 11 in terms of time and location. The second layer 12 can also, for example, be arranged on the reverse of the substrate, which is not shown, and the first layer 11 on the front thereof. For specific purposes, the second layer 12 could optionally be removed when it has served its purpose as a structuring aid for the first layer 11.

(74) In top view, therefore, both colored metallic areas with the diffractive structures and only colored areas with no diffractive effect can be recognized, wherein these areas, corresponding to the layers 11, 12, blend into one another in perfect register.

(75) FIG. 16 shows a further alternative embodiment example of a multi-layer body 10. Here, as shown in FIG. 16a, the first layer 11 is first produced as a metal layer with recessed lettering 19. The second layer 12, as illustrated in FIG. 16b, is printed as a gridded wavy lacquer layer onto the first layer 11 and then serves as an etch resist mask for the further structuring of the first layer 11 in an alkaline bath. After the etching, the multi-layer body 10 shown in FIG. 16c is obtained, in which the colored lines of the second layer 12 in the area of the recessed lettering continue in perfect register with the remaining metallic lines of the first layer 11 outside the lettering 19.

(76) The line widths do not have to be constant but can additionally be modulated, resulting in different local surface densities of the grid, forming an additional piece of information. The line widths are preferably from 25 m to 150 m. The grid spacing can also be modulated and is preferably less than 300 m and preferably less than 200 m, and preferably more than 25 m.