Method for the production of a multilayer element, and multilayer element

Abstract

The invention relates to a method for producing a multilayer element (100), and also to a multilayer element (100) produced by said method. On and/or in a carrier ply (1) a decorative ply (3) is formed. The decorative ply (3) has a first region (8) and a second region (9). Viewed perpendicular to the plane of the carrier ply (1), the decorative ply (3) has in the first region (8) a first transmittance and in the second region (9) a second transmittance greater in comparison to the first transmittance. A layer (5) to be structured and a photoactivatable resist layer are disposed on the first side (11) of the carrier ply (1). On exposure of the resist layer through the decorative ply (3), the decorative ply (3) serves as an exposure mask. The at least one layer (5) to be structured and the resist layer are structured in register to one another by means of structuring operations synchronized with one another.

Claims

1. A multilayer element comprising: a carrier ply which has a first side and a second side; a single-layer decorative ply formed on the first side of the carrier ply, the decorative ply having a first region and a second region and, viewed perpendicular to the plane of the carrier ply, having in the first region a first transmittance and in the second region a second transmittance greater by a ratio of 2:1 in comparison to the first transmittance, said transmittances relating to electromagnetic radiation having a wavelength suitable for photoactivation; a replicating layer disposed on said decorative ply; and at least one metallic layer disposed on a side of said replicating layer opposite said decorative ply, said metallic layer being structured in register to the first region and the second region of the decorative ply.

2. The multilayer element as claimed in claim 1, wherein the multilayer element in the first region or the second region has a resist layer which is photoactivatable by means of said electromagnetic radiation, the at least one structured layer and the resist layer being disposed in in-register orientation to one another in such a way, on the first side of the carrier ply, that the resist layer is disposed on the side of the at least one structured layer that is remote from the carrier ply, and the decorative layer is disposed on the other side of the at least one structured layer.

3. The multilayer element as claimed in claim 2, wherein the resist layer has a thickness in the range from 0.3 to 3 m.

4. The multilayer element as claimed in claim 1, wherein the decorative ply comprises a first coating layer which is disposed in the first region with a first layer thickness and in the second region either not or with a second layer thickness smaller in comparison to the first layer thickness on the carrier ply, so that the decorative ply has said first transmittance in the first region and said second transmittance in the second region.

5. The multilayer element as claimed in claim 1, wherein the decorative ply comprises a first coloration of the carrier ply, which is formed in the first region with a first layer thickness and in the second region either not or with a second layer thickness smaller in comparison to the first layer thickness, so that the decorative ply has said first transmittance in the first region and said second transmittance in the second region.

6. The multilayer element as claimed in claim 1, wherein the decorative ply is at least partly transparent to visible light having a wavelength in a range from approximately 380 to 750 nm.

7. The multilayer element as claimed in claim 1, wherein the decorative ply is colored with at least one opaque and/or at least one transparent colorant which at least in one wavelength range of the electromagnetic spectrum is chromatically colored or chromatically color-generating, and wherein the colorant can be excited outside the visible spectrum and generates a visually perceptible colored impression.

8. The multilayer element as claimed in claim 1, wherein the decorative ply is colored with at least one colorant in the color yellow, magenta, cyan or black (CMYK) or in the color red, green or blue (RGB), and/or is provided with at least one red and/or green and/or blue fluorescent, radiation-excitable pigment or dye and thereby generates an additive color on irradiation.

9. The multilayer element as claimed in claim 1, wherein the first transmittance is greater than zero.

10. The multilayer element as claimed in claim 1, wherein, at least one relief structure is formed on the side of the replicating layer opposite the decorative ply and the at least one structured metallic layer is disposed on the surface of the at least one relief structure.

11. The multilayer element as claimed in claim 10, wherein, the at least one relief structure is embossed into a surface of the replicating layer that is remote from the carrier ply.

12. The multilayer element as claimed in claim 10, wherein the at least one relief structure is disposed at least partly in the first region and/or in the second region.

13. The multilayer element as claimed in claim 1, wherein at least one relief structure is embossed into the carrier ply.

14. The multilayer element as claimed in claim 1, wherein a compensating layer is disposed on the side of the at least one structured layer that is remote from the carrier ply.

15. The multilayer element as claimed in claim 14, wherein the refractive index of the compensating layer in the visible wavelength range is in the range from 90% to 110% of the refractive index of the replicating layer.

16. The multilayer element as claimed in claim 14, wherein the compensating layer is formed as an adhesion layer.

17. The multilayer element as claimed in claim 1, wherein at least one layer of the decorative ply is disposed on the second side of the carrier ply.

18. The multilayer element as claimed in claim 1, wherein the decorative ply comprises at least two coating layers which evoke different color impressions.

19. The multilayer element as claimed in claim 1, wherein the decorative ply comprises a first coating layer, which is applied only regionally on the carrier ply, and a second coating layer, which is applied over the full area of the carrier ply.

20. The multilayer element as claimed in claim 1, wherein the at least one structured layer comprises one or more of the following layers: metal layer, HRI layer, liquid-crystal layer, polymer layer, thin-film layer, pigment layer, semiconductor layer.

21. The multilayer element as claimed in claim 1, wherein the at least one structured layer has a thickness in the range from 20 to 100 nm.

22. The multilayer element as claimed in claim 1, wherein the decorative ply has a thickness in the range from 0.5 to 5 m.

23. The multilayer element as claimed in claim 1, wherein the decorative ply comprises highly disperse pigments.

24. The multilayer element as claimed in claim 1, wherein the decorative ply comprises nanoscaled UV absorbers based on inorganic oxides.

25. The multilayer element as claimed in claim 1, wherein the decorative ply comprises benzotriazole derivatives, having a mass fraction in a range from around 3% to 5%.

26. The multilayer element as claimed in claim 1, wherein the decorative ply comprises organic or inorganic, fluorescent pigments in combination with highly disperse pigments.

27. The multilayer element as claimed in claim 1, wherein the carrier ply is formed as a single-layer or multilayer carrier film.

28. The multilayer element as claimed in claim 1, wherein a detachment layer and/or a protective coating layer, is disposed between the carrier ply and the at least one layer to be structured.

29. The multilayer element as claimed in claim 1, wherein the at least one structured layer has a thickness in the range from 20 to 100 nm, and wherein the decorative ply has a thickness in the range from 0.5 to 5 m.

30. A multilayer element comprising: a carrier ply which has a first side and a second side; a single-layer decorative ply formed on the first side of the carrier ply, the decorative ply having a first region and a second region and, viewed perpendicular to the plane of the carrier ply, having in the first region a first transmittance and in the second region a second transmittance greater in comparison to the first transmittance, said transmittances relating to electromagnetic radiation having a wavelength suitable for photoactivation; a replicating layer disposed on said decorative ply; at least one structured layer disposed on a side of said replicating layer opposite said decorative ply, said structured layer being structured in register to the first region and the second region of the decorative ply; and a compensating layer disposed on a side of the at least one structured layer that is remote from the carrier ply, the compensating layer having a refractive index in the visible wavelength range in the range of from 90% to 110% of the refractive index of the replicating layer.

31. The multilayer element as claimed in claim 30, wherein the ratio between the second transmittance and the first transmittance is greater than two.

32. A multilayer element comprising: a carrier ply which has a first side and a second side; a single-layer decorative ply formed on the first side of the carrier ply, the decorative ply having a first region and a second region and, viewed perpendicular to the plane of the carrier ply, having in the first region a first transmittance and in the second region a second transmittance greater in comparison to the first transmittance, said transmittances relating to electromagnetic radiation having a wavelength suitable for photoactivation; at least one structured layer disposed opposite said decorative ply, said structured layer being structured in register to the first region and the second region of the decorative ply; and a resist layer disposed in the first region or the second region, the resist layer being photoactivatable by means of said electromagnetic radiation, and wherein the at least one structured layer and the resist layer are disposed in in-register orientation to one another in such a way, on the first side of the carrier ply, that the resist layer is disposed on the side of the at least one structured layer that is remote from the carrier ply, and the decorative layer is disposed on the other side of the at least one structured layer.

33. The multilayer element as claimed in claim 32, further comprising a compensating layer disposed on a side of the at least one structured layer that is remote from the carrier ply, the compensating layer encapsulating said resist layer so that the resist layer is left on the structured layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is elucidated by way of example by the drawings, in which

(2) FIG. 1a shows a schematic section through a first manufacturing stage of the multilayer element shown in FIG. 8a;

(3) FIGS. 1b-c show schematic sections through two alternative embodiments of a first manufacturing stage;

(4) FIG. 1d shows a schematic plan view of the first manufacturing stage shown in FIG. 1a;

(5) FIG. 2 shows a schematic section through a second manufacturing stage of the multilayer element shown in FIG. 8a;

(6) FIG. 2a shows a schematic section through an alternative embodiment of a second manufacturing stage;

(7) FIG. 3 shows a schematic section through a third manufacturing stage of the multilayer element shown in FIG. 8a;

(8) FIG. 4 shows a schematic section through a fourth manufacturing stage of the multilayer element shown in FIG. 8a;

(9) FIG. 5 shows a schematic section through a fifth manufacturing stage of the multilayer element shown in FIG. 8a;

(10) FIG. 6 shows a schematic section through a sixth manufacturing stage of the multilayer element shown in FIG. 8a;

(11) FIG. 7 shows a schematic section through a seventh manufacturing stage of the multilayer element shown in FIG. 8a;

(12) FIG. 7a shows a schematic section through an eighth manufacturing stage of the multilayer element shown in FIG. 8a;

(13) FIG. 8a shows a schematic section through a first exemplary embodiment of an inventive multilayer element, formed using a positive resist;

(14) FIG. 8b shows a schematic section through an alternative exemplary embodiment of a multilayer element of the invention;

(15) FIG. 9 shows a schematic section through a further exemplary embodiment of an inventive multilayer element, formed using a negative resist;

(16) FIG. 10 shows a schematic section through a further exemplary embodiment of a multilayer element of the invention;

(17) FIGS. 11a-g show schematic representations of possible designs of the decorative ply;

(18) FIG. 12 shows a schematic section through a further exemplary embodiment of a multilayer element of the invention;

(19) FIG. 13 shows a schematic section through a manufacturing stage of a multilayer element;

(20) FIG. 14 shows a schematic section through a further manufacturing stage of a multilayer element; and

(21) FIG. 15 shows transmission spectra of different UV absorbers.

DETAILED DESCRIPTION OF THE INVENTION

(22) FIGS. 1a to 14 are drawn each schematically and not to scale, in order to ensure a clear representation of the key features.

(23) FIG. 8a shows a multilayer element 100, which comprises a carrier ply 1 having a first side 11 and a second side 12, a functional layer 2 disposed on the first side 11 of the carrier ply 1, a decorative ply 3 disposed on the functional layer 2 and having a first coating layer 31 formed in a first region 8, a replicating layer 4 adjoining the decorative layer 3, a structured layer 5 disposed on the replicating layer 4 and in register with the first coating layer 3, and compensating layer 10 disposed on the replicating layer 4 and the structured layer 5.

(24) The carrier ply 1 comprises a preferably transparent polymeric film with a thickness of between 8 m and 125 m, preferably in the range from 12 to 50 m, more preferably in the range from 16 to 23 m. The carrier film 1 may be formed as a mechanically and thermally stable film made of a translucent material, e.g. of ABS (acrylonitrile-butadiene-styrene), BOPP (biaxially oriented polypropylene), PEN or PC, but preferably of PET. This carrier film 1 may be monoaxially or biaxially oriented. Furthermore, it is also possible for the carrier film 1 to consist not of just one layer but instead of two or more layers. Thus it is possible, for example, for the carrier film 1 to have a detachment layer as well as a polymeric carrier, for example, a polymeric film as described above, said detachment layer allowing the detachment of the layer structure consisting of the layers 2 to 6 and 10 from the polymeric film, as for example when the multilayer element 100 is used as a hot-stamping foil.

(25) The functional layer 2 may comprise a detachment layer, made of hot-melting material, for example, which facilitates detachment of the carrier film 1 from the layers of the multilayer element 100 which are disposed on a side of the detachment layer 2 that is remote from the carrier film 1. This is especially advantageous if the multilayer element 100 is designed as a transfer ply, as employed, for example, in a hot-stamping process or an IMD process. It has been found appropriate, moreover, especially if the multilayer element 100 is used as a transfer film, for the functional layer 2 to have a protective layer, e.g., a protective coating layer, as well as a detachment layer. After the multilayer element 100 has been joined to a substrate and after the transfer film 1 has been detached from the layers of the multilayer element 100 which are disposed on a side of the detachment layer 2 that is remote from the carrier film 1, the protective layer forms one of the upper layers of the layers disposed on the surface of the substrate, and is able to protect underlying layers from abrasion, damage, chemical attacks or the like. The multilayer element 100 may be a section of a transfer film, as for example of a hot-stamping foil, which can be disposed on a substrate by means of an adhesive layer. The adhesive layer is preferably disposed on the side of the compensating layer 10 that is remote from the carrier film 1. The adhesive layer may be a hotmelt adhesive, which melts on thermal exposure and joins the multilayer element 100 to the surface of the substrate.

(26) When the multilayer element 100 is formed as a laminating film, i.e., without a detachment layer for detaching the carrier film 1 from the layers of the multilayer element 100, it is possible, additionally or alternatively to the adhesive layer, for a further carrier film to be provided on the side of the compensating layer 10 that is remote from the carrier film 1. This laminate element, consisting of two outside carrier films and the inside layers of the multilayer element 100, may be used further by being laminated into card assemblies, for example, made of PC, for example. For this purpose it is advantageous if the carrier films are made of the same material as the card assembly layers that adjoin the laminate elementfor example, likewise made of PC.

(27) On the functional layer 2, in the region 8, a transparent, colored coating layer 31 is printed. Transparent means that the coating layer 31 is at least partly pervious to radiation in the visible wavelength range. Colored means that the coating layer 31 exhibits a visible color impression when there is sufficient daylight.

(28) Not only the regions 8 printed with the coating layer 31 but also the unprinted regions 9 of the functional layer 2 are covered by a replicating layer 4 which evens out the relief structure of the decorative ply 3, i.e., the differing levels in the printed regions 8 and unprinted regions 9. In a second zone, zone 42, the replicating layer 4 has a relief structure which is not present in a first zone, zone 41. Disposed on the replicating layer 4, in register and congruent with the coating layer 31 when viewed perpendicular to the plane of the carrier ply 1, is a thin metal layer 5. Not only the regions 8 of the replicating layer 4 that are covered with the metal layer 5 but also the uncovered regions 9 of the replicating layer 4 are covered with a compensating layer 10, which evens out the structures (e.g., relief structure 42, different layer thicknesses, height offset) brought about by the relief structure 42 and by the regionally 8 disposed metal layer 5that is, it covers and fills them, so that the multilayer element, on the side of the compensating layer 10 that is remote from the carrier film 1, has a planar, substantially structureless surface. Where the refractive index of the compensating layer 10 is similar to that of the replicating layer 4, i.e., the refractive index difference is less than about 0.3, those regions of the relief structure 42 that directly adjoin the compensating layer 10 and are not covered by the metal layer 5 are optically extinguished in the replicating layer 4, since there, on account of the similar refractive index of the two layers, there are no longer any optically detectable layer boundaries between the replicating layer 4 and the compensating layer 10.

(29) FIGS. 1a to 7a now show manufacturing stages of the multilayer element 100 shown in FIG. 8a. Components identical to those in FIG. 8a are given the same reference numerals.

(30) FIG. 1a shows a first manufacturing stage 100a of the multilayer element 100, in which a functional layer 2 and a decorative ply 3 are disposed on a first side 11 of a carrier film 1. One side of the functional layer 2 adjoins the carrier film 1; its other side adjoins the decorative ply 3. The decorative ply 3 has a first region 8, in which a coating layer 31 is formed, and a second region 9, in which the coating layer 31 is absent. The coating layer 31 is printed on the functional layer 2, by screen, gravure or offset printing, for example. As a result of the regional formationthat is, the formation confined to the first region 8of the coating layer 31, the decorative ply 3 is given a patterned design.

(31) FIG. 1d shows a plan view of the first manufacturing stage 100a, shown in FIG. 1a, of the multilayer element 100, with a viewing direction perpendicular to the plane of the carrier film 1. Printed on the functional layer 2, disposed over the full area of the carrier film 1, in the first region 8 is the coating layer 31, while the second region, region 9, of the functional layer 2 is not printed with the coating layer 31, i.e., is left bare. In the exemplary embodiment shown in FIG. 1b, the first region 8 consists of two rectangular areas. As well as geometric patterns of this kind, the first region 8, provided with the coating layer 31, may have any desired form, examples being alphanumeric characters, symbols, logos, fine-line patterns, e.g., grids, or ornaments, e.g., guilloches, or geometrical, pictorial or figurative patterns. In FIG. 1b, a sectional plane Ia is indicated; when the sectional plane Ia is viewed in the viewing direction indicated by the arrow, the section shown in FIG. 1a is produced.

(32) FIG. 1b shows an alternative design of a first manufacturing stage of an inventive multilayer element. In contrast to the exemplary embodiment shown in FIG. 1a, the decorative ply 3 in the exemplary embodiment shown in FIG. 1b is formed not on the carrier film 1 but instead in the carrier film 1. The carrier film 1 consists of three layers, 1a, 1b, and 1c. The two outer layers, 1a and 1c, consist of PC. The in-between, middle layer, layer 1b, consists of a polymeric material, e.g., an additized PC, which on exposure to laser radiation of a particular energy exhibits a color change from a transparent, colorless, first state to a transparent, colored, second statei.e., what is called laser blackening. The polymeric material remains in the second state, once it has been achieved, even after the laser radiation has been removed. This means that the carrier film 1 is both decorative ply and carrier.

(33) FIG. 1c shows another alternative design of a first manufacturing stage of an inventive multilayer element. As in the case of the exemplary embodiment shown in FIG. 1b, the decorative ply 3 in the exemplary embodiment shown in FIG. 1c is also formed not on the carrier film 1 but instead in the carrier film 1. The carrier film 1 consists of a polymeric material into which dye/color pigments are able to diffuse. For forming the decorative ply 3, the second surface 12 of the carrier film 1 has been contacted in the first region 8 for a particular time period with a substance from which, color pigments are able to diffuse into the carrier film 1. During this time period, a part of these color pigments diffused into the carrier film 1, and so the colored regions 34 were formed with a particular layer thickness. This means that the carrier film 1 is both decorative ply and carrier.

(34) FIG. 2 shows a second manufacturing stage 100b of the multilayer element 100 formed from the first manufacturing stage 100a in FIG. 1a by application of a replicating layer 4 to the functional layer 2 and to the coating layer 31 disposed thereon regionally, i.e., in such a way as to be confined to the first region 8. Said layer 4 may be an organic layer which is applied by conventional coating techniques, such as printing, pouring or spraying, in liquid form. Here, the replicating layer 4 is applied over the full area. The thickness of the replicating layer 4 varies since it compensates/evens out the different levels of the decorative ply 3, comprising the printed, first region and the unprinted, second region 9; in the first region 8, the thickness of the replicating layer 4 is thinner than in the second region 9, and so the side of the replicating layer 4 that is remote from the carrier ply 1 has a planar, substantially structureless surface before the relief structure is formed in the second zone 42. It is, however, also possible for the replicating layer 4 to be applied only in a subregion of the multilayer element 100. The surface of the replicating layer 4 is structured in a second zone 42, by known methods, whereas it is unstructured in a first zone 41. For this purpose, for example, as replicating layer 4, a thermoplastic replicating coating material is applied by printing, spraying or painting, and a relief structure is impressed in the second zone 42 into the replicating coating material 4, which can be dried/cured thermally in particular, by means of a heated die or a heated replicating roller. The replicating layer 4 may also be a UV-curable replicating coating material, which is structured, for example, by a replicating roller and then cured by means of UV radiation. The structuring may alternatively be brought about by UV radiation through an exposure mask. In this way the second zone 42 may be impressed into the replicating layer 4.

(35) FIG. 2a shows an alternative second manufacturing stage of a multilayer element formed from the first manufacturing stage shown in FIG. 1b by the embossing of a relief structure 42 into the first side 11 of the carrier film 1. This means that the carrier film 1 is decorative ply, carrier and replicating layer all at the same time. Of course there are also alternatives possible in which only one relief structure is embossed into the carrier ply 1, but the carrier ply 1 itself does not serve as a decorative ply.

(36) FIG. 3 a third manufacturing stage 100c of the multilayer element 100 formed from the second manufacturing stage 100b in FIG. 2, by the application to the replicating layer 4 of the layer 5 to be structured. This layer 5 to be structured may be formed, for example, as a metal layer, of silver or aluminum, for example, which is applied by vapor deposition. The application of the layer to be structured here is over the entire area. It is also possible, however, for application to be envisaged only in a subregion of the multilayer element 100, with the assistance, for example, of a regionally shielding vapor deposition mask.

(37) FIG. 4 shows a fourth manufacturing stage 100d of the multilayer element 100 formed from the third manufacturing stage 100c in FIG. 3, by the application to the layer 5 to be structured of a photoactivatable resist layer 6. In the present exemplary embodiment, the resist layer 6 is formed as a positive resist, i.e., as a resist in which the more strongly exposed (i.e., activated) regions are dissolved following exposure. The resist layer 6 may be an organic layer applied by conventional coating techniques, such as printing, pouring or spraying, in liquid form. Provision may also be made for the resist layer 6 to be applied by vapor deposition or to be laminated on as a dry film.

(38) The photoactivatable layer 6 may be, for example, a positive photoresist BAZ 1512 or AZ P 4620 from Clariant or S1822 from Shipley, which is applied to the layer 5 to be structured in a density per unit area of 0.1 g/m.sup.2 to 10 g/m.sup.2, preferably of 0.1 g/m.sup.2 to 1 g/m.sup.2. The layer thickness is guided by the desired resolution and by the operation. Application here is envisaged over the entire area. Also possible, however, is application only in a subregion of the multilayer element 100.

(39) FIG. 5 shows a fifth manufacturing stage 100d of the multilayer element 100, in which the multilayer element 100, present after the fourth manufacturing stage 100d, is irradiated. Electromagnetic radiation 7, having a wavelength suitable for activating the photoactivatable resist layer 6, is radiated from the second side 12 of the carrier film 1, i.e., the side of the carrier film 1 that is opposite the carrier film 1 side coated with the resist layer 6, through the multilayer element 100d. The irradiation serves for activating the photoactivatable resist layer 6 in the second region 9, in which the decorative ply 3 has a higher transmittance than in the first region 8. The strength and duration of the exposure with the electromagnetic radiation 7 is tailored to the multilayer element 100e in such a way that in the second region 9 the radiation 7 causes activation of the photoactivatable resist layer 6, while in the first region 8 printed with the coating layer 31 it does not cause activation of the photoactivatable resist layer 6. It has been found appropriate if the contrast brought about by the coating layer 31 between the first region 8 and the second region 9 is greater than two. Moreover, it has been found appropriate if the coating layer 31 is designed such that the radiation 7, after passing through the entire multilayer element 100e, exhibits a ratio of the transmittances, i.e., a contrast ratio, of approximately 1:2 between the first region 8 and the second region 9.

(40) FIG. 6 shows a developed sixth manufacturing stage 100e of the multilayer element 100 formed from the fifth manufacturing stage 100d in FIG. 5, by the action of a developer solution, e.g., solvents or alkalis, more particularly a sodium carbonate solution or a sodium hydroxide solution, having taken place on the surface of the exposed photoactivatable resist layer 6 that is remote from the carrier film 1. As a result of this, the exposed resist layer 6 has been removed in the second region 9. In the first region 8, the resist layer 6 is intact, since the amount of radiation absorbed in these regions has not led to sufficient activation. As already mentioned, therefore, the resist layer 6 is formed from a positive photoresist in the exemplary embodiment shown in FIG. 6. With a photoresist of this kind, the more strongly exposed regions 9 are soluble in the developer solution, e.g., in the solvent. In the case of a negative photoresist, in contrast to this, the unexposed or less strongly exposed regions 8 are soluble in the developer solution, as set out below in the exemplary embodiment shown in FIG. 9.

(41) FIG. 7 shows a seventh manufacturing stage 100f of the multilayer element 100 formed from the sixth manufacturing stage 100e in FIG. 6, by the removal of the layer 5 to be structured in the second region 9 by means of an etchant. This is possible by virtue of the fact that, in the second region 9, the layer 5 to be structured is not protected against the attack of the etchant by the developed resist layer 6, which acts as an etch mask. The etchant may be, for example, an acid or an alkali. In this way, the regions of the structured layer 5 that are shown in FIG. 7 are formed.

(42) FIG. 7a shows an eighth manufacturing stage 100g of the multilayer element 100 formed from the seventh manufacturing stage 100f in FIG. 7, by further removal, likewise, of the regions of the resist layer 6 that remained intact (this removal being referred to as stripping). Generally speaking, the resist of the resist layer 6 has only low chemical stability, since it must be amenable to attack by the developer solution in the present method. If the intact regions of the resist layer 6 were left on the multilayer element, therefore, it would be possible for the intact regions of the resist layer 6 to have weakened the stability and resistance of the security element, in the case, for example, of a counterfeiting attack on the multilayer element using solvents or acids or alkalis. As a result of the complete removal of the resist layer 6, therefore, this disadvantage is avoided. The fact that certain resists have only low chemical stability, i.e., are sensitive, toward solvents, however, may also be exploited to advantage in some cases. Following application of the multilayer element 100 to a substrate, more particularly to the surface of a security document, the resist is washed off by means of solvent, together with a dye that colors the resist, in the event of attempted manipulations. The attempted manipulation is made visible by a change in the coloredness of the resist.

(43) In this way, therefore, the layer 5 to be structured can be structured in register with the first and second regions 8 and 9 defined by the coating layer 31 without additional technical cost and complexity. In conventional methods for producing an etch mask by means of mask exposure, the mask being present either as a separate unit, e.g., as a separate film or as a separate glass plate/glass roller, or in the form of a layer applied subsequently by printing, the problem occurs that linear and/or nonlinear distortions in the multilayer element 100, brought about by prior operating steps, more particularly those involving thermal and/or mechanical stress, as for example when the replicating structure 42 is produced in the replicating layer 4, cannot be compensated entirely over the entire area of the multilayer element 100, despite the fact that mask orientation takes place to register marks that are present in disposition preferably on the horizontal and/or vertical edges of the multilayer element. The tolerance here fluctuates within a comparatively large range over the entire area of the multilayer element 100.

(44) With the method of the invention, the first and second regions 8 and 9 defined by the coating layer 31 are utilized as a mask, with the coating layer 31 being applied in an early operational step in the production of the multilayer element 100 as described above. As a result of this, there can be no additional tolerances and also no additional tolerance fluctuations over the area of the multilayer element 100, since the subsequent generation of a mask and the resultant requirement for extremely in-register subsequent positioning of this mask independent of the operational profile so far are avoided. The tolerances and register accuracies in the case of the method of the invention have their basis only in the not absolutely precise profile of the color edge of the first and second regions 8 and 9, defined by the coating layer 31, the quality of these regions being determined by the printing technique employed in each case, and are situated, for instance, in the micrometer range, and hence well below the resolution capacity of the eye; in other words, the naked human eye is no longer able to perceive tolerances present.

(45) The multilayer element 100 shown in FIG. 8a is formed from the manufacturing stage 100g of the multilayer element 100, shown in FIG. 7a, by the application of a compensating layer 10 to the exposed structured layer 5 disposed in the first region 8 and also to the replicating layer 4 disposed in the second region 9, and exposed by removal of the layer 5 to be structured and of the photoresist layer 6. Here, the compensating layer 10 is applied over the full area.

(46) It is possible for the compensating layer 10 to be applied in a different layer thickness in each of the first and second regions 8 and 9 respectively, by means of knifecoating, printing or spraying, for example, so that the compensating layer 10 has a planar, substantially structureless surface on its side remote from the carrier ply 1. The layer thickness of the compensating layer 10 varies, since it compensates/evens out the different levels of the structured layer 5 disposed in the first region 8, and the replicating layer 4 exposed in the second region 9. In the second region 9, the thickness of the compensating layer 10 is selected greater than the thickness of the structured layer 5 in the first region 8, and so the side of the compensating layer 10 that is remote from the carrier ply 1 has a planar surface. Also possible, however, is the application of the compensating layer 10 only in a subregion of the multilayer element 100. It is possible for one or more further layers, such as an adhesion layer or adhesive layer for example, to be applied to the planar compensating layer 10. In an advantageous way it is also possible for the adhesion layer or adhesive layer to take on the level-compensating effect of the compensating layer 10, with the consequence that there is no need for a separate compensating layer 10.

(47) FIG. 8b shows an alternative design of the multilayer element 100 shown in FIG. 8a, formed from the manufacturing stage 100f of the multilayer element 100, shown in FIG. 7a, by the application of a compensating layer 10 to the regions of the resist layer 6 that were retained in the first region 8, and also to the replicating layer 4 disposed in the second region 9 and exposed by removal of the layer 5 to be structured and of the photoresist layer 6. In contrast to the multilayer element 100 shown in FIG. 8a, therefore, the multilayer body shown in FIG. 8b comprises the retained regions of the resist layer 6.

(48) FIG. 9 shows an alternatively formed multilayer element 100 of the invention, in which, in contrast to the multilayer element 100 shown in FIG. 8, a negative resist layer 6 rather than a positive resist layer 6 has been used. As a result, the structured layer 5 and the resist layer 6 are disposed not like the coating layer 31 in the first region 8, but instead in the second region 9. The structured layer 5 and the resist layer 6 of the alternative multilayer element 100 are indeed disposed in register with the regional boundaries of the regions 8, 9 of the coating layer 31, like the multilayer element 100 shown in FIG. 8, but are not disposed congruently with the coating layer 31, but instead are disposed in the unprinted interstices 9 of the coating layer 31.

(49) FIG. 10 shows a multilayer element 100, in which the decorative ply 3 consists of a regionally formed coating layer 31, which is disposed on the second side 12 of the carrier film 1, with the second side 12 being opposite the first side 11 of the carrier film 1, on which the structured layer 5 is disposed.

(50) FIG. 11a to FIG. 11g show in schematic representation different inventive designs of the decorative ply 3. Shown in each case is a carrier film 1 having a bottom side and a top side, on which is disposed a decorative ply 3 comprising a first region 8 and/or a second region 9 in different dispositions. In all of the designs shown, the top side may be either the first side or the second side of the inventive multilayer element.

(51) When reference is made below to a first coating layer and a second coating layer, what this means is that there are two differently formed coating layers, with, for example, different optical properties such as color and/or different mechanical properties such as elasticity modulus, having different transmittances. Two first coating layers, explicitly described as having a different layer thickness from one another, likewise have a different transmittance. Absent an explicit description to the effect that two layer elements of a first coating layer have differing layer thicknesses, the assumption shall be that they are of equal thickness and have the same transmittance.

(52) FIG. 11a shows the version already depicted in FIG. 10, in which the decorative ply 3 consists of a first coating layer 31 which is disposed in the first region on the top side of the carrier film 1 and is not present in the second region 9.

(53) FIG. 11b shows a version in which the decorative ply 3 consists of a first coating layer 31 disposed over the full area of the top side of the carrier film 1 and having a greater thickness in the first region 8 than in the second region 9.

(54) FIG. 11c shows a version in which the decorative ply 3 consists of a first coating layer 31 disposed in the first region 8 on the top side of the carrier film 1, and of a second coating layer 32 disposed in the second region 9 likewise on the top side of the carrier film 1. The coating layers 31 and 32 may, for example, be two different colored coating layers or two coating layers each having different optical effects.

(55) FIG. 11d shows a version in which the decorative ply 3 consists of a first coating layer 31 which is disposed in the first region 8 and which is not present in the second region 9. The first coating layer comprises two layer components, a first layer component being disposed on the top side of the carrier film 1 and a second layer component being disposed on the bottom side of the carrier film 1.

(56) FIG. 11e shows a version in which the decorative ply 3 from a first coating layer 31 which is disposed in the first region 8 on the top side of the carrier film 1 and has a first thickness, and from a first coating layer 31 which is disposed in the second region 9 on the bottom side of the carrier film 1 and has a second thickness, which is lower than the first thickness.

(57) FIG. 11f shows a version in which the decorative ply 3 consists of a first coating layer 31, which is disposed in the first region 8 on the top side of the carrier film 1, and of a second coating layer 32, which is disposed in the second region 9 on the bottom side of the carrier film 1.

(58) FIG. 11g shows a version in which the decorative ply 3 consists of a first coating layer 31, which is disposed in the first region 8 on the top side of the carrier film 1, and of a second coating layer 32, which is disposed over the full area of the bottom side of the carrier film 1.

(59) FIG. 12 shows a multilayer element 100, in which the decorative ply 3 is formed by a first coating layer 31, which generates a first color impression, and a second coating layer 32, which generates a second color impression, both coating layers 31, 32 being disposed on the same side of the carrier ply 1 between the functional layer 2 and the replicating layer 4.

(60) FIG. 13 shows a multilayer element 100a in which the decorative ply 3 is formed from a first, regionally applied coating layer 31 and from a second coating layer 32, applied over the full area of said first layer 31, with both coating layers 31, 32 being disposed on the same side of the carrier ply 1.

(61) FIG. 14 shows a multilayer element 100a, in which the decorative ply 3 consists of a first coating layer 31, which is applied over the full area of the second side 12 of the carrier film 1, and of a second coating layer 32, which is applied regionally on the first side 11 of the carrier film 1.

(62) FIG. 15 shows transmission spectra of four different classes of UV absorbers which may be present in the first region 8 of the decorative ply 3, in order to form a different transmittance in the first region 8 and in the second region 9. The UV absorbers are present at a concentration of 0.00014 mol/l in chloroform. The plot shows the transmittance % T, measured as a percentage, over the wavelength in the range from 280 to 410 nm. The dash-dot line A shows the transmission of oxalanilide, the dash-dot-dot line B the transmission of hydroxybenzophenone, the dash-dash line C the transmission of hydroxyphenyl-S-triazine, and the continuous line D the transmission of benzotriazole.

LIST OF REFERENCE NUMERALS

(63) 1 carrier ply 1a, 1b, 1c layers (of 1) 2 functional layer 3 decorative ply 4 replicating layer 5 layer to be structured, or structured layer 6 resist layer 7 radiation 8 first region 9 second region 10 compensating layer 11 first side (of 1) 12 second side (of 1) 31 first coating layer (of 3) 32 second coating layer (of 3) 33, 34 coloration 40 surface (of 4) 41 first zone, unstructured (of 4) 42 second zone, structured (of 4) 100 multilayer element