METHOD FOR PRODUCING A MULTILAYER BODY, AND A MULTILAYER BODY

Abstract

Methods for producing a multilayer body (1), and a multilayer body (1). The method for producing a multilayer body includes: —providing a carrier layer (10); —applying a first replication varnish layer (11) to the carrier layer (10); —molding a plurality of microlenses (12) arranged in the form of a grid into the first replication varnish layer (11a); —applying at least one layer (14) to be structured to the side of the carrier layer (10) opposite the plurality of microlenses; —structuring the at least one layer (14) to be structured using a separate high-resolution mask (23) such that a plurality of microimages (15) arranged in the form of a grid are formed by removal in areas of the at least one layer (14) to be structured. A multilayer body (1) has a carrier layer (10) and a first replication varnish layer (11a), applied to the carrier layer (10), into which a plurality of microlenses (12) arranged in the form of a grid are molded, and with a plurality of microimages (15) arranged in the form of a grid arranged on the side of the carrier layer (10) opposite the plurality of microlenses (12) arranged in the form of a grid.

Claims

1. A method for producing a multilayer body, wherein the method comprises the following steps: a) providing a carrier layer; b) applying a first replication varnish layers to the carrier layer; c) molding a plurality of microlenses arranged in the form of a grid into the first replication varnish layer; d) applying at least one layer to be structured to the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid; e) structuring the at least one layer to be structured using a separate high-resolution mask such that a plurality of microimages arranged in the form of a grid are formed by removal in areas of the at least one layer to be structured.

2. The method according to claim 1, wherein the at least one layer to be structured applied in step d) and structured in step e) comprises or is a first photoresist layer.

3. The method according to claim 2, wherein a positive photoresist, or a negative photoresist, is used to form the at least one first photoresist layer.

4. The method according to claim 2, wherein the at least one layer to be structured applied in step d) and structured in step e) comprises at least one first colored varnish layer, which is applied to the at least one first photoresist layer.

5. The method according to claim 4, wherein the at least one first colored varnish layer is structured in step e) registration-accurately with the at least one first photoresist layer.

6. The method according to claim 2, wherein the at least one layer to be structured applied in step d) and structured in step e) comprises or is at least one second colored varnish layer and/or at least one first metal layer and/or at least one layer made of a transparent dielectric and/or at least one thin film layer system.

7. The method according to claim 6, wherein the at least one second colored varnish layer and/or the at least one first metal layer and/or the at least one layer made of a transparent dielectric and/or the at least one thin film layer system is structured in step e) registration-accurately with the at least one first photoresist layer.

8. The method according to claim 2, wherein the at least one first photoresist layer is removed.

9. The method according to claim 2, wherein the at least one first photoresist layer applied in step d) and structured in step e) further contains UV-blocking additives.

10. The method according to claim 9, wherein the method further comprises the following steps: applying at least one second photoresist layer to the at least one first photoresist layer; exposing the at least one second photoresist layer to light from the side of the carrier layer having the plurality of microlenses arranged in the form of a grid; structuring the at least one second photoresist layer.

11. The method according to claim 10, wherein a positive photoresist is used to form the at least one first photoresist layer and a negative photoresist is used to form the at least one second photoresist layer, or vice versa.

12. The method according to claim 9, wherein the method further comprises the following steps: applying at least one second metal layer to the at least one first photoresist layer; applying at least one third photoresist layer to the at least one second metal layer; exposing the at least one third photoresist layer to light from the side of the carrier layer having the plurality of microlenses arranged in the form of a grid; structuring the at least one third photoresist layer and the at least one second metal layer.

13. The method according to claim 2, wherein the at least one first photoresist layer is developed.

14. The method according to claim 1, wherein at least one third colored varnish layer and/or at least one partially transparent metal layer and/or at least one dielectric spacing layer is applied to the carrier layer before step d).

15. The method according to claim 1, wherein after step e) at least one fourth colored varnish layer and/or at least one third metal layer and/or at least one further replication varnish layer is applied to the at least one layer to be structured.

16-17. (canceled)

18. The method according to claim 1, wherein the layers selected from the group: at least one first photoresist layer, at least one second photoresist layer, at least one first colored varnish layer, at least one second colored varnish layer, at least one third colored varnish layer, at least one fourth colored varnish layer, at least one first metal layer, dyed carrier layer have in each case a total ink holdout dE from each other in the CIELAB color space of from 50 to 270.

19. The method according to claim 1, wherein of the layers selected from the group: at least one first photoresist layer, at least one second photoresist layer, at least one first colored varnish layer, at least one second colored varnish layer, at least one third colored varnish layer, at least one fourth colored varnish layer, at least one first metal layer, dyed carrier layer, the layer that faces the first replication varnish layer has a darker color, and the layer that, when viewed from the side of the plurality of microlenses arranged in the form of a grid, is arranged behind has the lighter color.

20. The method according to claim 1, wherein the at least one layer to be structured applied in step d) and structured in step e) comprises at least two layers selected from the group: at least one first photoresist layer, at least one first colored varnish layer, at least one second colored varnish layer, at least one first metal layer.

21. The method according to claim 14, wherein the at least one third colored varnish layer and/or the at least one fourth colored varnish layer, has a total ink holdout dE from the at least one layer to be structured in the CIELAB color space of from 50 to 270, and/or wherein, of the at least one third colored varnish layer, and/or of the at least one fourth colored varnish layer, and the at least one layer to be structured, the layer that faces the first replication varnish layer has a darker color, and the layer that, when viewed from the side of the plurality of microlenses arranged in the form of a grid, is arranged behind has the lighter color.

22. The method according to claim 1, wherein the method further comprises at least one of the following steps: generating the separate high-resolution mask by means of electron-beam lithography and/or by means of laser-beam lithography; contact-locking joining of the separate high-resolution mask with the at least one layer to be structured applied to the carrier layer.

23. The method according to claim 1, wherein step e) further comprises at least one of the following steps: exposing the at least one layer to be structured to light from the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid; aligning the separate high-resolution mask.

24. The method according to claim 1, wherein a separate high-resolution mask with structures smaller than 10 μm, is used in step e).

25. A method for producing a multilayer body, wherein the method comprises the following steps: a) providing a carrier layer; b) applying a first replication varnish layer to the carrier layer; c) molding a plurality of microlenses arranged in the form of a grid into the first replication varnish layer; f) printing a control structure onto the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid by means of a first high-resolution digital printer; g) detecting the control structure by means of a detection device from sides of the plurality of microlenses arranged in the form of a grid such that the control structure is detected by means of the detection device through the plurality of microlenses arranged in the form of a grid; h) applying a printed layer in areas to the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid by means of a second high-resolution digital printer using the detected control structure such that a plurality of microimages arranged in the form of a grid are formed by the printed layer.

26. The method according to claim 25, wherein an angular misalignment and/or a distortion is further detected in step g) with reference to the control structure.

27. The method according to claim 26, wherein with reference to the detected angular misalignment and/or the detected distortion, the plurality of microimages arranged in the form of a grid formed of the printed layer in step h) are applied registered relative to the plurality of microlenses arranged in the form of a grid.

28. The method according to claim 25, wherein after step h) at least one fourth metal layer and/or at least one layer made of a transparent dielectric and/or at least one fifth colored varnish layer is applied to the printed layer.

29. A method for producing a multilayer body, wherein the method comprises the following steps: a) providing a carrier layer; b) applying a first replication varnish layer to the carrier layer; c) molding a plurality of microlenses arranged in the form of a grid into the first replication varnish layer; i) applying a second replication varnish layer to the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid; j) molding a subwavelength plasmonic structure in areas into the second replication varnish layer such that a plurality of microimages arranged in the form of a grid are formed by the molded subwavelength plasmonic structure; k) applying a metal layer to the second replication varnish layer.

30. The method according to claim 29, wherein in step k) the metal layer is applied such that plasmonic colors are generated by an interaction of the subwavelength plasmonic structure molded into the second replication varnish layer and the metal layer.

31. The method according to claim 29, wherein before step i), at least one color filter layer is applied to the carrier layer.

32. The method according to claim 29, wherein in step a), a dyed carrier layer is provided and/or a carrier layer pre-coated with an adhesion-promoter layer is provided.

33-35. (canceled)

36. The method according to claim 29, wherein the plurality of microimages arranged in the form of a grid are formed in step e) by the areas in which the at least one layer to be structured is removed or is not removed, and/or wherein the plurality of microimages arranged in the form of a grid are formed in step h) by the areas of the printed layer in which the printed layer is applied or is not applied, and/or wherein the plurality of microimages arranged in the form of a grid are formed in step j) by the areas in which the subwavelength plasmonic structure is molded or is not molded.

37. The method according to claim 29, wherein in step e) and/or step h) and/or step j) the plurality of microimages arranged in the form of a grid in each case consist of one or more pixels.

38. A multilayer body with a carrier layer and a first replication varnish layer, applied to the carrier layer, into which a plurality of microlenses arranged in the form of a grid are molded, and with a plurality of microimages arranged in the form of a grid arranged on the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid.

39. The multilayer body according to claim 38, wherein the plurality of microimages arranged in the form of a grid are formed of at least one structured layer, which is removed in areas such that the plurality of microimages arranged in the form of a grid are formed.

40. The multilayer body according to claim 39, wherein the at least one structured layer comprises or is at least one first photoresist layer.

41. The multilayer body according to claim 40, wherein at least one structured layer further comprises at least one first colored varnish layer.

42. The multilayer body according to claim 39, wherein the at least one structured layer further comprises or is at least one second colored varnish layer and/or at least one first metal layer and/or at least one layer made of a transparent dielectric and/or at least one thin film layer system which is arranged in particular on the side of the at least one first photoresist layer facing the plurality of microlenses arranged in the form of a grid and is arranged registration-accurately with the at least one first photoresist layer and/or which are arranged registration-accurately with each other.

43. The multilayer body according to claim 40, wherein the structured at least one first photoresist layer further contains UV-blocking additives.

44. The multilayer body according to claim 43, wherein the multilayer body further comprises at least one second photoresist layer and wherein the at least one second photoresist layer is arranged register-accurately next to the at least one first photoresist layer.

45. The multilayer body according to claim 44, wherein the at least one first photoresist layer is formed of a positive photoresist, and the at least one second photoresist layer is formed of a negative photoresist.

46. The multilayer body according to claim 43, wherein the multilayer body further comprises at least one second metal layer and/or at least one third photoresist layer, and wherein the at least one second metal layer and/or the at least one third photoresist layer is arranged registration-accurately with the at least one first and/or third photoresist layer.

47-49. (canceled)

50. The multilayer body according to claim 38, wherein the multilayer body further comprises at least one third colored varnish layer and/or at least one partially transparent metal layer and/or at least one dielectric spacing layer.

51. The multilayer body according to claim 38, wherein the multilayer body further comprises at least one fourth colored varnish layer and/or at least one third metal layer and/or at least one further replication varnish layer.

52. The multilayer body according to claim 51, wherein a relief structure is stamped into the further replication varnish layer at least in areas.

53. (canceled)

54. The multilayer body according to claim 52, wherein the plurality of microimages and microlenses arranged in the form of grids arranged overlapping at least in areas overlap with the relief structure stamped into the further replication varnish layer at least in areas, overlap with it completely or do not overlap with it.

55-56. (canceled)

57. The multilayer body according to claim 38, wherein the layers selected from the group: at least one first photoresist layer, at least one second photoresist layer, at least one first colored varnish layer, at least one second colored varnish layer, at least one third colored varnish layer, at least one fourth colored varnish layer, at least one first metal layer and dyed carrier layer have in each case a total ink holdout dE from each other in the CIELAB color space of from 50 to 270.

58. The multilayer body according to claim 38, wherein of the layers selected from the group: at least one first photoresist layer, at least one second photoresist layer, at least one first colored varnish layer, at least one second colored varnish layer, at least one third colored varnish layer, at least one fourth colored varnish layer, at least one first metal layer and dyed carrier layer, the layer that faces the first replication varnish layer has a darker color, and the layer that, when viewed from the side of the plurality of microlenses arranged in the form of a grid, is arranged behind has the lighter color.

59. The multilayer body according to claim 39, wherein the at least one structured layer comprises at least two layers selected from the group: at least one first photoresist layer, at least one first colored varnish layer, at least one second colored varnish layer, at least one first metal layer.

60. The multilayer body according to claim 50, wherein the at least one third colored varnish layer and/or the at least one fourth colored varnish layer has a total ink holdout dE from the at least one layer (14) to be structured in the CIELAB color space of from 50 to 270 and/or wherein, of the at least one third colored varnish layer and/or of the at least one fourth colored varnish layer and the at least one layer to be structured, the layer that faces the first replication varnish layer has a darker color and the layer that, when viewed from the side of the plurality of microlenses arranged in the form of a grid, is arranged behind has the lighter color.

61-63. (canceled)

64. The multilayer body according to claim 38, wherein the at least one first and/or second and/or third photoresist layer is dyed, and/or the at least one first and/or second and/or third photoresist layer contains fluorescent substances, and/or wherein the at least one first and/or second and/or third photoresist layer is transparent.

Description

[0192] Embodiment examples of the invention are explained below by way of example with the aid of the accompanying figures, which are not true to scale.

[0193] FIG. 1 a schematically shows a sectional representation of a multilayer body

[0194] FIG. 1b to FIG. 1d schematically show methods for producing a multilayer body

[0195] FIG. 2 schematically shows a method for generating a separate high-resolution mask

[0196] FIG. 3a to FIG. 3c show schematic sectional representations of multilayer bodies

[0197] FIG. 4a and FIG. 4b show a method for producing a multilayer body, and a multilayer body

[0198] FIG. 5 schematically shows a sectional representation of a multilayer body

[0199] FIG. 6 schematically shows a representation of the CIELAB color space

[0200] FIG. 7 to FIG. 10 schematically show sectional representations of multilayer bodies

[0201] FIG. 11a to FIG. 11c schematically show sectional representations of multilayer bodies

[0202] FIG. 12a and FIG. 12b schematically show sectional representations of multilayer bodies

[0203] FIG. 1a schematically shows a sectional representation of a multilayer body 1.

[0204] The multilayer body 1 is preferably a multilayered security element for protecting security documents.

[0205] The multilayer body, as shown in FIG. 1a, comprises a carrier layer 10 and a replication varnish layer 11a, applied to the carrier layer 10, into which a plurality of microlenses 12 arranged in the form of a grid are molded. The multilayer body further has a plurality of microimages 15 arranged in the form of a grid arranged on the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid, in particular wherein the plurality of microimages 15 arranged in the form of a grid are arranged registered relative to the plurality of microlenses 12 arranged in the form of a grid.

[0206] The carrier layer 10 is preferably a mono- or multilayered film, the one or more layers of which consist in particular of the following materials or combinations thereof: polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyethylene naphthalate (PEN), polycarbonate (PC), polyvinyl chloride (PVC), poly-oxydiphenylene-pyromellitimide (Kapton) or other polyimides, polylactide (PLA), polymethyl methacrylate (PMMA) or acrylonitrile butadiene styrene (ABS).

[0207] The layer thickness of the carrier layer 10 is preferably between 1 μm and 500 μm, further preferably between 6 μm and 75 μm, still further preferably between 12 μm and 50 μm.

[0208] The carrier layer 10 shown in FIG. 1a is for example a carrier layer made of PET with a layer thickness of 12 μm. With respect to further possible designs of the carrier layer 10, reference is made here to the above statements.

[0209] Furthermore, the multilayer body 1 has an adhesion-promoter layer 13, which is arranged between the plurality of microlenses 12 arranged in the form of a grid and the carrier layer 10. For this purpose, a carrier layer 10 pre-coated on one side with the adhesion-promoter layer 13 is expediently provided.

[0210] Preferably, the layer thickness of the adhesion-promoter layer 13 is preferably between 0.01 μm and 15 μm, particularly preferably between 0.1 μm and 5 μm.

[0211] The adhesion-promoter layer 13 advantageously consists of polyester, epoxide, polyurethane, acrylate and/or copolymer resins or mixtures thereof. It is further possible for the adhesion-promoter layer to be designed thermoplastic, UV-curable, as a hybrid variant (thermoplastic and UV-curable), as a cold glue or as a self-adhesive adhesion-promoter layer.

[0212] The adhesion-promoter layer 13 shown in FIG. 1a is for example an adhesion-promoter layer made of epoxide with a layer thickness of 1 μm. With respect to further possible designs of the adhesion-promoter layer 13, reference is made here to the above statements.

[0213] The plurality of microlenses 12 arranged in the form of a grid are molded into the replication varnish layer 11a.

[0214] The replication varnish layer 11a is preferably a functional layer, into which structures, in particular surface structures, are introduced and/or fixed, preferably by means of thermal replication and/or UV replication.

[0215] It is further possible for the replication varnish layer 11a to be a hybrid replication varnish layer, which is for example thermally replicated and then cured by means of radiation, in particular by means of UV radiation and/or by means of at least one electron beam. In particular in the case of UV molding, the replication varnish layer 11a is replicated at room temperature and then cured by means of UV radiation.

[0216] It is further preferred if the layer thickness of the replication varnish layer 11a lies between 0.1 μm and 50 μm, preferably between 0.1 μm and 30 μm, further preferably between 0.3 μm and 20 μm, still further preferably between 0.5 μm and 20 μm, moreover preferably between 0.5 μm and 10 μm.

[0217] It is further conceivable that the replication varnish layer 11a contains fluorescent substances, which are excited in particular by means of UV radiation, preferably from the wavelength range between 200 nm and 380 nm.

[0218] The replication varnish layer 11a shown in FIG. 1a is for example a UV-curable layer, which has been applied in a layer thickness of 30 μm. With respect to further possible designs of the replication varnish layer 11a, reference is made here to the above statements.

[0219] It is also advantageous if the plurality of microlenses 12 arranged in the form of a grid in each case have a lens focal length of between 10 μm and 50 μm, preferably between 15 μm and 40 μm.

[0220] It is further expedient if the grid of the plurality of microlenses 12 arranged in the form of a grid has a period of between 5 μm and 70 μm, preferably between 5 μm and 50 μm, further preferably between 10 μm and 40 μm, and/or if the plurality of microlenses 12 arranged in the form of a grid have a lens diameter of between 5 μm and 70 μm, preferably between 5 μm and 50 μm, further preferably between 10 μm and 40 μm.

[0221] The plurality of microlenses 12 arranged in the form of a grid preferably have a hemispherical geometry and/or a flattened hemispherical geometry and/or a geometry similar thereto.

[0222] It is also conceivable that the grid of the plurality of microlenses 12 arranged in the form of a grid is a one- or two-dimensional grid. It is further conceivable that, in particular in the case of a two-dimensional grid, the microlenses 12 are arranged offset line by line, preferably are offset by half a lens diameter and/or lens spacing.

[0223] The plurality of microlenses 12 arranged in the form of a grid shown in FIG. 1a are for example flattened hemispherical microlenses with a lens diameter of in each case 25 μm and a lens focal length of 30 μm, which are arranged according to a two-dimensional grid. With respect to further possible designs of the plurality of microlenses 12 arranged in the form of a grid, reference is made here to the above statements.

[0224] The plurality of microimages 15 arranged in the form of a grid preferably consist in each case of one or more pixels, wherein in particular the shortest edge length or the smallest diameter of a pixel is smaller than 10 μm, preferably smaller than 5 μm, particularly preferably smaller than 2.5 μm.

[0225] Methods for producing a multilayer body, such as the multilayer body 1 shown in FIG. 1a, will be explained below with reference to FIGS. 1b to 1 d, wherein the generation of the plurality of microimages 15 arranged in the form of a grid is in particular also set out:

[0226] Thus, FIG. 1b to FIG. 1d schematically show methods for producing a multilayer body 1.

[0227] FIG. 1b shows a method for producing a multilayer body 1, in particular a multilayered security element for protecting security documents, wherein the method comprises the following steps, which are performed in particular in the following order: [0228] a) providing a carrier layer 10; [0229] b) applying a replication varnish layer 11a to the carrier layer 10; [0230] c) molding a plurality of microlenses 12 arranged in the form of a grid into the replication varnish layer 11a; [0231] d) applying a layer 14 to be structured to the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid; [0232] e) structuring the one layer 14 to be structured using a separate high-resolution mask 23 such that a plurality of microimages 15 arranged in the form of a grid are formed by removal in areas of the one layer 14 to be structured.

[0233] It is advantageous if the one layer 14 to be structured applied in step d) and structured in step e) is a photoresist layer 16a, which in particular remains in the multilayer body 1 produced. Further preferably, the photoresist layer 16a is dyed, in particular dyed with dyes and/or pigments, contains fluorescent substances and/or is formed transparent.

[0234] Still further preferably, the photoresist layer 16a is first applied over the whole surface in particular in a layer thickness of between 0.5 μm and 1.5 μm.

[0235] It is further expedient if step e) further comprises at least one of the following steps: [0236] exposing the photoresist layer 16a to light from the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid, preferably by means of an exposure light source, through the separate high-resolution mask, in particular in a step-and-repeat method; [0237] aligning the separate high-resolution mask, in particular by means of register marks, which preferably make an angular misalignment and/or a distortion detectable, wherein the angular misalignment is further preferably smaller than 0.5°, preferably smaller than 0.3°, further preferably smaller than 0.1°, still further preferably smaller than 0.05°.

[0238] A contact-locking joining of the separate high-resolution mask with the photoresist layer 16a applied to the carrier layer 10, and in particular then an exposure of the photoresist layer 16a to light through the mask, is advantageously effected. The photoresist layer 16a is preferably thereby exposed to light in the areas of surface in which the mask is permeable to or transparent for the respective exposure radiation.

[0239] The photoresist layer 16a is then in particular developed and structured.

[0240] Thus, it is possible for in the plurality of microimages 15 arranged in the form of a grid shown in FIG. 1a to be formed of the photoresist layer 16a.

[0241] Furthermore, it is advantageous that a separate high-resolution mask with structures smaller than 10 μm, preferably smaller than 5 μm, further preferably smaller than 2.5 μm, is used in step e). With respect to the further possible design of the separate high-resolution mask, reference is made here to the above statements.

[0242] A positive photoresist, the solubility of which in particular increases when activated by exposure to light, or a negative photoresist, the solubility of which in particular decreases when activated by exposure to light, is preferably used to form the photoresist layer 16a.

[0243] In particular, a positive photoresist is characterized in that, when sufficiently exposed to light with a suitable wavelength, such as for example by means of UV radiation, this photoresist becomes soluble in a particular solvent, for example in acidic or basic aqueous solutions, in the exposed areas. In particular through an exposure to light using the separate high-resolution mask, dyed areas with defined shape and size, which preferably form the plurality of microimages 15 arranged in the form of a grid, can therefore preferably be achieved.

[0244] A positive photoresist preferably comprises for example condensation polymers of m- and p-cresol and formaldehyde (novolac resin), diazonaphthoquinone derivative (DNQ) and solvent or solvent mixture, such as for example 1-methoxy-2-propyl acetate.

[0245] Here, in particular, novolac resins are hydrophilic (OH groups) and soluble in aqueous base. In particular if the novolac resins are mixed with DNQ, the solubility of the novolac in a base is greatly reduced. In particular, an exposure of the inhibitor (DNQ) to light leads to the acid, which makes it possible for the exposed locations (A) of the photoresist to be able to be dissolved selectively by aqueous base (developer). In particular after the exposure to light, DNQ is converted to the indene carboxylic acid (ICA). The latter is in particular hydrophilic and ionizable.

[0246] In particular, a negative photoresist is characterized in that, when sufficiently exposed to light with a suitable wavelength, such as for example by means of UV radiation, this varnish cures, and thereby becomes insoluble in a particular solvent, for example in acidic or basic aqueous solutions, in the exposed areas. In particular through an exposure to light using the separate high-resolution mask, dyed areas with defined shape and size, which preferably form the plurality of microimages 15 arranged in the form of a grid, can therefore preferably be formed.

[0247] A negative photoresist is preferably based on epoxy resins and contains low-molecular-weight organic compounds, which have in particular more than one epoxide group per molecule. Epoxy resins based on bisphenol A, epoxidized phenol novolac, and/or resorcinol diglycidyl are further preferably used to generate negative photoresists.

[0248] In particular in conjunction with a crosslinker (curing agent), a so-called resin/curing agent system provides a macromolecular network through polymerization of the epoxide group. Here, in particular, different curing agents can be used, which are distinguished by the ring opening reaction of the oxirane groups. Acid anhydrides, amines or phenol-containing compounds are preferably used, or triarylsulfonium salts are used as photoactive component.

[0249] Furthermore, catalysts, such as e.g. Lewis bases and acids, are preferably used. The curing agent is preferably incorporated in the three-dimensional network structure. In particular, a catalyst promotes the network formation via ester bridges in the case of a basic accelerator. Preferably, g-butyrolactone is used in particular as solvent in the printing ink of such epoxy-resin-based photoresists. Additives, such as e.g. long-chain epoxy resins, are further preferably used in order to act on the one hand as adhesion promoter, reactive diluent or as an augmentation or lowering of the viscosity.

[0250] For example, the photoresist SU-8 epoxy novolac based on bisphenol A; triarylsulfonium hexafluoroantimonate; g-butyrolactone, MicroChem Corporation, Newton, USA, is used as negative photoresist.

[0251] For example, a negative photoresist further consists in particular of the following combination of solvent, binders and curing agent: [0252] solvent: 1-methoxy-2-propanol proportion: 75%, [0253] binder: urethane acrylate oligomer 15%, [0254] binder: pentaerythritol tetraacrylate 2.5%, [0255] binder: pentaerythritol triacrylate 1%, [0256] binder: ethoxylated trimethylolpropane triacrylate 1%, [0257] binder: acrylated oligomer 2.5%, [0258] curing agent: Genocure ITX 3%.

[0259] FIG. 1c shows a method for producing a multilayer body 1, in particular a multilayered security element for protecting security documents, wherein the method comprises the following steps, which are performed in particular in the following order: [0260] a) providing a carrier layer 10; [0261] b) applying a replication varnish layer 11a to the carrier layer 10; [0262] c) molding a plurality of microlenses 12 arranged in the form of a grid into the replication varnish layer 11a; [0263] f) printing a control structure onto the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid by means of a first high-resolution digital printer; [0264] g) detecting the control structure by means of a detection device from sides of the plurality of microlenses 12 arranged in the form of a grid such that the control structure is detected by means of the detection device through the plurality of microlenses 12 arranged in the form of a grid; [0265] h) applying a printed layer in areas to the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid by means of a second high-resolution digital printer using the detected control structure such that a plurality of microimages 15 arranged in the form of a grid are formed by the printed layer.

[0266] The high-resolution digital printer used here, in particular the first and/or the second high-resolution digital printer, advantageously has a resolution of at least 6,000 dpi, preferably at least 12,000 dpi, further preferably of at least 24,000 dpi.

[0267] It further also makes sense if the detection device is an optical sensor, such as for example a CMOS and/or CCD sensor.

[0268] It is further preferred that an angular misalignment and/or a distortion is further detected in step g) with reference to the control structure.

[0269] Here, it is further preferred if, with reference to the detected angular misalignment and/or the detected distortion, the plurality of microimages 15 arranged in the form of a grid formed of the printed layer in step h) are applied registered relative to the plurality of microlenses 12 arranged in the form of a grid, wherein the angular misalignment is further preferably smaller than 0.5°, preferably smaller than 0.3°, further preferably smaller than 0.1°, still further preferably smaller than 0.05°.

[0270] It is also possible if the method further comprises the following step, which is carried out in particular between steps g) and h): [0271] compensating for the angular misalignment and/or the distortion such that the plurality of microimages 15 arranged in the form of a grid formed of the printed layer in step h) are applied registered relative to the plurality of microlenses 12 arranged in the form of a grid.

[0272] Furthermore, it is expedient that after step h) a metal layer and/or a layer made of a transparent dielectric and/or at least one colored varnish layer is applied to the printed layer.

[0273] FIG. 1d shows a method for producing a multilayer body 1, in particular a multilayered security element for protecting security documents, wherein the method comprises the following steps, which are performed in particular in the following order: [0274] a) providing a carrier layer 10; [0275] b) applying a first replication varnish layer 11a to the carrier layer 10; [0276] c) molding a plurality of microlenses 12 arranged in the form of a grid into the first replication varnish layer 11a; [0277] i) applying a second replication varnish layer to the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid; [0278] j) molding a subwavelength plasmonic structure in areas into the second replication varnish layer such that a plurality of microimages 15 arranged in the form of a grid are formed by the molded subwavelength plasmonic structure; [0279] k) applying a metal layer to the second replication varnish layer.

[0280] In step k) the metal layer is advantageously applied such that plasmonic colors are generated by an interaction of the subwavelength plasmonic structure molded into the second replication varnish layer and the metal layer.

[0281] The subwavelength plasmonic structure preferably comprises grating structures selected from the group two-dimensional gratings, cross gratings, hexagonal gratings. Such grating structures further preferably have a grating period of between 150 nm and 400 nm and further preferably between 200 nm and 350 nm, and a relief depth of between 50 nm and 400 nm and further preferably between 150 nm and 350 nm.

[0282] It is further conceivable that before step i) at least one color filter layer is applied to the carrier layer 10 in particular over the whole surface, preferably applied to the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid.

[0283] FIG. 2 schematically shows a method for generating a separate high-resolution mask 23.

[0284] As shown in FIG. 2, a glass substrate 23a coated with a chromium layer 23b, in particular made of high-purity quartz glass or calcium fluoride, is provided, wherein a photoresist layer 16d is further applied to the chromium layer 23b. In a first step the photoresist layer 16d is exposed to light by means of a laser or an electron beam to structure the chromium layer 23b on the glass substrate 23a. In a further step the photoresist layer 16d is developed, wherein, in particular when a positive photoresist is used, the exposed areas are removed. The chromium layer 23b is then etched, wherein the areas covered by the photoresist layer 16d, as shown in FIG. 2, are protected from the etchant and are thus not removed. In the subsequent step the photoresist 16d is in particular completely removed. In the last step a so-called pellicle, by which is meant in particular a thin, transparent membrane which covers the separate high-resolution mask, is applied.

[0285] The separate high-resolution mask 23 is advantageously generated by means of electron-beam lithography methods. However, it is also possible for the separate high-resolution mask 23 to be generated by means of laser-beam lithography methods, wherein here lower resolutions are typically achieved than in the case of electron-beam lithography methods. With these methods, structures smaller than 10 μm, preferably smaller than 5 μm, further preferably smaller than 2.5 μm, are preferably generated.

[0286] The thus-generated separate high-resolution mask 23 thus preferably comprises the following layers: a glass substrate 23a, in particular made of high-purity quartz glass or calcium fluoride, a chromium layer 23b, in particular an optically dense chromium layer, optionally an adhesion-promoter layer and optionally a pellicle 23c.

[0287] FIG. 3a to FIG. 3c schematically show sectional representations of multilayer bodies.

[0288] Thus, a multilayer body 1 is shown in FIG. 3a comprising a replication varnish layer 11a with a plurality of microlenses 12 arranged in the form of a grid molded therein, an adhesion-promoter layer 13, a carrier layer 10, a photoresist layer 16a, which is shaped such that it forms a plurality of microimages 15 arranged in the form of a grid, and a primer layer.

[0289] With respect to the design of the layers 10, 11a, 12, 13, 15 and 16a, reference is made here to the above statements.

[0290] As shown in FIG. 3a, the primer layer 24 is applied to the side of the plurality of microimages 15 arranged in the form of a grid facing away from the carrier layer 10. The primer layer 24 is preferably a thermally activatable layer, which further preferably has a layer thickness of between 0.3 μm and 25 μm and is preferably deposited over the whole surface. The primer layer 24 can in particular be constructed monolayered or multilayered. Furthermore, the primer layer 24 can in particular be constructed on an aqueous, solvent-containing or radiation-curing basis and/or combinations thereof. The following can in particular be used as binder for the primer layer 24: polyacrylates, polyurethanes, epoxides, polyesters, polyvinyl chlorides, rubber polymers, ethylene acrylic acid copolymers, ethylene vinyl acetates, polyvinyl acetates, styrene block copolymers, phenol formaldehyde resin adhesives, melamines, alkenes, allyl ether, vinyl acetate, alkyl vinyl ether, conjugated dienes, styrene, acrylates and the mixtures of the above raw materials and their copolymers. In particular, water, aliphatic (benzine) hydrocarbons, cycloaliphatic hydrocarbons, terpene hydrocarbons, aromatic (benzene) hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, glycols, glycol ethers, glycol ether acetates can be used as solvent.

[0291] Furthermore, in particular, curing agents, crosslinkers, photoinitiators, fillers, stabilizers, inhibitors, additives such as e.g. flow additives, defoamers, deaerators, dispersing additives, wetting agents, lubricants, matting agents, rheology additives, pigments and dyes or waxes can be added to the primer layer 24.

[0292] The primer layer 24 is preferably applied by means of a printing method such as e.g. gravure printing, screen printing, flexographic printing, inkjet printing, pouring or by means of a doctor-blade method. With respect to the further production of such a multilayer body 1, reference is made here to the above statements.

[0293] The primer layer 24 shown in FIG. 3a is for example a thermally activatable layer made of binder and optionally further auxiliary agents, which further has a layer thickness of from 0.3 μm to 25 μm.

[0294] The multilayer body 1 shown in FIG. 3b corresponds to the multilayer body shown in FIG. 3a with the difference that it further comprises the edge emitter layer 21. As shown in FIG. 3b, the edge emitter layer 21 is arranged on the side of the plurality of microlenses 12 arranged in the form of a grid facing the plurality of microlenses 12 arranged in the form of a grid, in particular on the side facing an observer. It is also possible for the edge emitter layer 21 to cover the whole plurality of microlenses 21 arranged in the form of a grid, in particular wherein the layer thickness of the edge emitter layer 21 is smaller, in particular much smaller, than the lens height. Here, it is further possible for more material of the edge emitter layer 21 to accumulate in the intermediate spaces between the microlenses 12.

[0295] The edge emitter layer 21 shown in FIG. 3b is for example a layer made of a binder with auxiliary agents, for example additives, wherein the edge emitter layer 21 further contains fluorescent substances. With respect to the binders and the fluorescent substances and further possible designs of the edge emitter layer 21, reference is made here to the above statements.

[0296] The multilayer body 1 shown in FIG. 3c corresponds to the multilayer body 1 shown in FIG. 3b with the difference that the edge emitter layer 21 is arranged on the side of the carrier layer opposite the plurality of microlenses arranged in the form of a grid. Thus, the edge emitter layer 21 in the multilayer body 1 shown in FIG. 3c is arranged between the carrier layer 10 and the primer layer 24.

[0297] It is further possible for the total thickness of the multilayer body 1 to be smaller than 50 μm, preferably to be smaller than 35 μm, still further preferably smaller than 25 μm.

[0298] FIG. 4a and FIG. 4b show a method for producing a multilayer body 1, and a multilayer body 1.

[0299] The multilayer body shown in FIG. 4a and FIG. 4b is preferably produced with the method explained with reference to FIG. 1b with the difference that the layer 14 to be structured applied in step d) and structured in step e) comprises a colored varnish layer 17a, which is applied to the photoresist layer 16a in particular over the whole surface. The colored varnish layer 17a is then structured registration-accurately with the photoresist layer 16a in step e).

[0300] The colored varnish layer 17a shown in FIG. 4a and FIG. 4b is a layer which, unlike the photoresist layer 16a, is itself not able to be exposed to light or structured. As shown in FIG. 4a, the colored varnish layer 17a is structured in the same step in which the photoresist layer 16a is structured. In other words, the colored varnish layer 17a is removed together with the photoresist layer 16a. With respect to the further possible design of the colored varnish layer 17a, reference is made here to the above statements.

[0301] Thus, the following method steps are shown in particular in FIG. 4a: —structuring and removing the photoresist layer 16a, wherein the colored varnish layer 17a arranged underneath, in particular when the multilayer body 1 is viewed from sides of the plurality of the microlenses 12 arranged in the form of a grid, is removed registration-accurately together with the photoresist 16a.

[0302] The removal of photoresist layers, such as here the photoresist layer 16a, is generally also referred to as so-called stripping.

[0303] As shown in FIG. 4b, the multilayer body is then also vapor-coated with a metal layer 18c, in particular to increase the contrast, with the result that a multilayer body 1 is obtained which comprises the following layers:

a replication varnish layer 11a with a plurality of microlenses 12 arranged in the form of a grid molded therein, an adhesion-promoter layer 13, a carrier layer 10, a structured layer 14 comprising a photoresist layer 16a and a colored varnish layer 17a, wherein the structured layer 14 is shaped such that it forms a plurality of microimages 15 arranged in the form of a grid, and a metal layer 18c.

[0304] The metal layer 18c is expediently a layer made of aluminum, silver, chromium, copper, tin, indium, gold, zinc or an alloy of the above-named metals. It is further also possible for the metal layer 18c to be a layer made of aluminum or silver blackened by oxidation, such as for example substoichiometric Al.sub.xO.sub.y. It is further useful if the layer thickness of the of the metal layer lies between 1 nm and 500 nm, preferably between 5 nm and 100 nm.

[0305] The metal layer 18c shown in FIG. 4b is for example a metal layer made of aluminum with a layer thickness of 20 nm. With respect to further possible designs of the metal layer, reference is made here to the above statements.

[0306] FIG. 5 schematically shows a sectional representation of a multilayer body 1.

[0307] The multilayer body 1 shown in FIG. 5 comprises a replication varnish layer 11a with a plurality of microlenses 12 arranged in the form of a grid molded therein, an adhesion-promoter layer 13, a carrier layer 10, a photoresist layer 16a, which is shaped such that it forms a plurality of microimages 15 arranged in the form of a grid, a colored varnish layer 17d and a metal layer 18c.

[0308] With respect to the design of the layers 10, 11a, 12, 13, 16a and 18c, reference is made here to the above statements.

[0309] The multilayer body 1 shown in FIG. 5 is preferably produced with the method explained with reference to FIG. 1b with the difference that the colored varnish layer 17d is preferably applied in particular over the whole surface after step e).

[0310] The photoresist layer 16a is preferably dyed, in particular dyed with dyes and/or pigments. The dyes preferably generate a color from the RGB color space (R=red; G=green; B=blue) or the CMYK color space (C=cyan; M=magenta; Y=yellow; K=black). However, it is also possible for the dyes to generate a color from a special color space, such as for example the RAL, HKS or Pantone® color space. The dyes further preferably generate a color from the CIELAB color space.

[0311] Thus, it is possible for example for the photoresist layer 16a to be dyed with Orasol dyes and/or Microlith color pigments and/or Luconyl.

[0312] It is further possible for the photoresist layer 16a to be transparent, in particular for the photoresist layer 16a to have a transmittance for visible light, preferably from the wavelength range between 380 nm and 780 nm, of more than 50%, preferably more than 70%, further preferably of more than 85%, still further preferably of more than 90%.

[0313] The photoresist layer shown in FIG. 5 is for example a dyed photoresist layer which has a transmittance of more than 50%. With respect to further possible designs of the photoresist layer 16a, reference is made here to the above statements.

[0314] The colored varnish layer 17d preferably generates a color from the RGB color space (R=red; G=green; B=blue) or the CMYK color space (C=cyan; M=magenta; Y=yellow; K=black). However, it is also possible for the colored varnish layer 17d to generate a color from a special color space, such as for example the RAL, HKS or Pantone® color space. The colored varnish layer 17d further preferably generates a color from the CIELAB color space.

[0315] It is advantageous if the layer thickness of the color layer is between 0.1 μm and 10 μm, preferably between 0.1 μm and 5 μm. Thus, the colored varnish layer 17d shown in FIG. 5 has for example a layer thickness of 2.5 μm. With respect to possible designs of the colored varnish layer 17d, reference is made here to the above statements.

[0316] The colored varnish layer 17d is advantageously applied by printing, in particular by means of offset printing and/or gravure printing and/or flexographic printing and/or inkjet printing.

[0317] In particular in order to achieve a sufficient contrast, the colors of the corresponding layers, here the photoresist layer 16a and the colored varnish layer 17d, are preferably chosen as follows:

[0318] The photoresist layer 16a, which faces the replication varnish layer 11a, preferably has a darker color, in particular with a low lightness value L, and the colored varnish layer 17d, which, when viewed from the side of the plurality of microlenses 12 arranged in the form of a grid, is arranged behind, has the lighter color, in particular with a higher lightness value L.

[0319] It is further preferred if the photoresist layer 16a and the colored varnish layer 17d have in each case a total ink holdout dE from each other in the CIELAB color space of from 50 to 270, preferably from 100 to 270, further preferably from 130 to 270.

[0320] In particular, a particularly good contrast is achieved hereby, which is preferably determined in the CIELAB color space by the total ink holdout dE. According to the CIELAB system, as represented schematically in FIG. 6, the color space is in particular represented by a sphere K, wherein this is defined by the three axes lightness L, red-green axis a and yellow-blue axis b. In particular, here, L=100 corresponds to white, L=0 corresponds to black and L=50 corresponds to the achromatic point. The total color distance dE is further determined as follows:

dE=((dL).sup.2+(da).sup.2+(db).sup.2).sup.1/2,

wherein in particular dL is the lightness difference, da is the color difference on the red-green axis and db is the color difference on the yellow-blue axis between two colors.

[0321] If the value ranges lie for example between −100 and 150 for the red-green axis a and yellow-blue axis b and between 0 and 100 for the lightness axis L, with the result that a, b∈(−100; 150) and L∈(0; 100), then the following results for example for a very light yellow (100L, 0a, 150b) and a very dark blue (0L, 0a, −100b) as total color distance between the two colors: dE=((100−0).sup.2+(0−0).sup.2+(150−(−100)).sup.2).sup.1/2=((100).sup.2+(0).sup.2+(250).sup.2).sup.1/2=269.26. For example in the case of a dark photoresist layer 16a (30L, 0a, −70b) and a light colored varnish layer 17d (80L, 0a, 70b), the following further results as total color distance dE=((80−30).sup.2+(0−0).sup.2+(70+70).sup.2).sup.1/2=148. As a still further example, in the case of a dark photoresist layer 16a (40L, 0a, −50b) and a light colored varnish layer 17d (50L, 0a, 50b), the following results as total color distance dE=((50−40).sup.2+(0−0).sup.2+(100).sup.2).sup.1/2=100.5.

[0322] FIG. 7 to FIG. 10 schematically show sectional representations of multilayer bodies 1.

[0323] A multilayer body 1 with a carrier layer 10 and a replication varnish layer 11a, applied to the carrier layer 10, into which a plurality of microlenses 12 arranged in the form of a grid are molded, is shown in FIG. 7. The multilayer body shown in FIG. 7 further also comprises the photoresist layers 16a and 16b as well as the metal layer 18c. With respect to the design of the layers 10, 11a, 12, 13 and 18c, reference is made here to the above statements.

[0324] The photoresist layer 16a here comprises UV-blocking additives, which in particular absorb light from the ultraviolet wavelength range, preferably from the wavelength range between 200 nm and 380 nm. Such UV-blocking additives further preferably have no or only a very low absorption in the wavelength range visible to the human eye from 380 nm to 780 nm.

[0325] The UV-blocking additives are advantageously for example benzotriazole derivatives, which are used in the corresponding layers in particular with a proportion by mass in a range of from approx. 3% to 5%. Suitable organic UV absorbers are sold for example under the trade name Tinuvin® by BASF, Ludwigshafen, Germany.

[0326] In addition to the photoresist layer 16a, the multilayer body 1 shown in FIG. 7 also comprises the photoresist layer 16b, wherein the photoresist layer 16b has an exposure principle that complements the photoresist layer 16a and/or wherein the solubility of the photoresist layer 16b is alterable at a different exposure wavelength than in the case of the photoresist layer 16a, and wherein the photoresist layer 16b is further arranged register-accurately next to the photoresist layer 16a.

[0327] Such a multilayer body 1 is preferably produced with the method explained with reference to FIG. 1b with the difference that the method further comprises the following steps, which are carried out in particular after step e): [0328] applying the photoresist layer 16b to the photoresist layer 16a, in particular wherein the photoresist layer 16b has an exposure principle that complements the photoresist layer 16a and/or wherein the solubility of the photoresist layer 16b is altered at a different exposure wavelength than in the case of the photoresist layer 16a; [0329] exposing the photoresist layer 16b to light from the side of the carrier layer 10 having the plurality of microlenses 12 arranged in the form of a grid, in particular by means of an exposure light source; [0330] structuring the photoresist layer 16b, in particular such that the photoresist layer 16b is arranged register-accurately next to the photoresist layer 16a.

[0331] By a complementary exposure principle is meant here in particular the use of an exposure principle that counteracts the exposure principle of the photoresist layer 16a. Thus, it is by a complementary exposure principle is preferably meant that a positive photoresist, the solubility of which in particular increases when activated by exposure to light, is used to form the photoresist layer 16a and a negative photoresist, the solubility of which in particular decreases when activated by exposure to light, is used to form the photoresist layer 16b, or vice versa.

[0332] In other words, the photoresist layer 16a applied first, as described with reference to FIG. 1b, is first developed and structured by means of the separate high-resolution mask. The photoresist layer 16b is then applied, which has an exposure principle that complements the photoresist layer 16a, as set out above. The photoresist layer 16b is then exposed to light from the side of the microlenses 12 through the microlenses 12, wherein the photoresist layer 16a acts as a mask for the structuring of the photoresist layer 16b because of the UV-blocking additives. Finally, the photoresist layer 16b is developed and structured.

[0333] The photoresist layers 16a and 16b are preferably dyed differently, with the result that a multilayer body 1 is generated, in which the photoresist layer 16b is arranged in exact register next to the photoresist layer 16b, with the result that for example colored microimages with very high resolution are generated, which are surrounded by a differently colored background. With respect to further possibilities for dyeing the photoresist layers 16a and 16b, reference is made here to the above statements.

[0334] FIG. 8 shows a multilayer body 1 with a carrier layer 10 and a replication varnish layer 11a, applied to the carrier layer 10, into which a plurality of microlenses 12 arranged in the form of a grid are molded. The multilayer body shown in FIG. 8 further also comprises the photoresist layer 16a and the metal layer 18b.

[0335] As shown in FIG. 8, the metal layer 18b is applied to the photoresist layer 16a on the side of the photoresist layer 16a facing away from the plurality of microlenses 12 in the form of a grid and is further also arranged registration-accurately with the photoresist layer 16a.

[0336] As already explained in connection with FIG. 7, the photoresist layer 16a here also comprises UV-blocking additives here, which in particular absorb light from the ultraviolet wavelength range, preferably from the wavelength range between 200 nm and 380 nm. In this respect, reference is also made here to the above statements.

[0337] With respect to the design of the layers 10, 11a, 12, 13, 16a and 18b, reference is also made here to the above statements.

[0338] Such a multilayer body 1 is preferably produced with the method explained with reference to FIG. 1b with the difference that the method further comprises the following steps, which are carried out in particular after step e): [0339] applying the metal layer 18b to the photoresist layer 16a; —applying a further photoresist layer to the metal layer 18b; [0340] exposing the further photoresist layer to light from the side of the carrier layer 10 having the plurality of microlenses 12 arranged in the form of a grid, in particular by means of an exposure light source; [0341] structuring the further photoresist layer and the metal layer 18b, in particular with the result that the metal layer 18b is arranged registration-accurately with the photoresist layer 16a and the further photoresist layer. The further photoresist layer is then preferably removed again.

[0342] The exposure light source is preferably for example a UV lamp or UV LED.

[0343] The layer thickness of the photoresist layer 16a and of the further photoresist layer is advantageously less than 15 μm, preferably less than 5 μm.

[0344] In other words, the photoresist layer 16a, as described with reference to FIG. 1b, here is also first developed and structured by means of the separate high-resolution mask. Then the metal layer 18b is applied, for example vapor-deposited. In a further step, metal layer 18b is coated with the further photoresist layer in particular over the whole surface. The further photoresist layer is then exposed to light from the side of the microlenses 12 through the microlenses 12, wherein the photoresist layer 16a acts as a mask for the structuring of the further photoresist layer because of the UV-blocking additives. Finally, the further photoresist layer is developed and structured together with the metal layer 18b lying underneath.

[0345] The metal layer 18b here is preferably formed transparent or at least partially transparent, with the result that in particular the light emitted by the exposure light source passes through the metal layer 18b to the further photoresist layer. For this purpose, the metal layer 18b preferably has a layer thickness of less than 15 nm.

[0346] FIG. 9 shows a multilayer body 1 with a carrier layer 10 and a replication varnish layer 11a, applied to the carrier layer 10, into which a plurality of microlenses 12 arranged in the form of a grid are molded. The multilayer body shown in FIG. 9 further also comprises the colored varnish layers 17c and 17d, the photoresist layer 16a and the metal layer 18a.

[0347] As shown in FIG. 9, the metal layer 18a, which is arranged on the photoresist layer 16a on the side facing the plurality of microlenses 12 in the form of a grid, is further also arranged registration-accurately with the photoresist layer 16a.

[0348] The colored varnish layers 17c and 17d, as shown in FIG. 9, however, are applied over the whole surface, wherein the colored varnish layer 17c, when viewed from the side of the plurality of microlenses 12 arranged in the form of a grid, is arranged in front of the structured metal layer 18a and the photoresist layer 16a and the colored varnish layer 17d is arranged behind the structured metal layer 18a and the photoresist layer 16a. The metal layer 18a and the photoresist layer 16a therefore form the structured layer 14 here.

[0349] It also makes sense here to choose the color values of the colored varnish layers 17c and 17d as well as the color value of the photoresist layer 16a and of the metal layer 18a according to the above-explained details, with the result that reference is made in this respect to the above statements.

[0350] Thus, it is advantageous if the colored varnish layer 17c and/or the colored varnish layer 17d has a total ink holdout dE from the structured layer 14, preferably in the CIELAB color space, of from 50 to 270, preferably from 100 to 270, further preferably from 130 to 270, in particular wherein the structured layer 14, as shown in FIG. 9, comprises the photoresist layer 16a and the metal layer 18a.

[0351] Furthermore, it is alternatively or additionally advantageous if, of the colored varnish layers 17c and/or 17d and the structured layer 14, which in particular comprises the photoresist layer 16a and the metal layer 18a, the layer that faces the microlenses 12 has a darker color, in particular with a low lightness value L, and the layer that, when viewed from the side of the plurality of microlenses 12 arranged in the form of a grid, is arranged behind has the lighter color, in particular with a higher lightness value L.

[0352] With respect to the design of the layers 10, 11a, 12, 13, 16a, 17a, 17d and 18a, reference is also made here to the above statements.

[0353] Such a multilayer body 1 is preferably produced with the method explained with reference to FIG. 1b with the difference that the colored varnish layer 17c is first applied over the whole surface before step d). The layer 14 applied in step d) and structured in step e) here also further comprises the metal layer 18a, which is first applied over the whole surface before the application of the photoresist layer 16a to the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid. Here too, it is advantageous if the metal layer 18a is then structured registration-accurately with the at least one first photoresist layer in step e). It is also possible for the photoresist layer 16a to be removed again in particular after step e). The photoresist layer 17d, as shown in FIG. 9, is then applied over the whole surface.

[0354] In other words, here, as described in particular in principle with reference to FIG. 1b, in addition to the photoresist layer 16a the metal layer 18a previously vapor-deposited first over the whole surface for example is structured together with the photoresist layer 16a using the separate high-resolution mask. The colored varnish layers 17c and 17d were further additionally applied beforehand or afterwards, in order to generate mixed colors or a colored background.

[0355] Here too, it is advantageous if the colored varnish layer 17c, in particular applied before step d), and/or the colored varnish layer 17d, in particular applied after step e), has a total ink holdout dE from the structured layer 14, which in particular, as shown in FIG. 9, comprises the metal layer 18a and the photoresist layer 16a, preferably in the CIELAB color space, of from 50 to 270, preferably from 100 to 270, further preferably from 130 to 270.

[0356] It is alternatively or additionally advantageous if, of the colored varnish layer 17c, in particular applied before step d), and/or of the colored varnish layer 17d, in particular applied after step e), and the structured layer 14, which in particular, as shown in FIG. 9, comprises the metal layer 18a and the photoresist layer 16a, the layer that faces the microlenses 12 has a darker color, in particular with a low lightness value L, and the layer that, when viewed from the side of the plurality of microlenses 12 arranged in the form of a grid, is arranged behind has the lighter color, in particular with a higher lightness value L.

[0357] The multilayer body 1 shown in FIG. 10 corresponds to the multilayer body shown in FIG. 9 with the difference that the whole-surface colored varnish layer 17c is not present. The multilayer body 1 shown in FIG. 10 is produced analogously to the multilayer body shown in FIG. 9. It is also possible for example to replace and/or supplement the metal layer 18a with a colored varnish layer 17b. Such a multilayer body is also produced analogously to the multilayer body shown in FIG. 9, with the result that reference is made in this respect to the above statements.

[0358] FIG. 11a to FIG. 11c schematically show sectional representations of multilayer bodies 1.

[0359] FIG. 11a shows a multilayer body 1 with a carrier layer 10 and a replication varnish layer 11a, applied to the carrier layer 10, into which a plurality of microlenses 12 arranged in the form of a grid are molded. The multilayer body shown in FIG. 11a further also comprises the thin film layer system 20, which comprises the partially transparent metal layer 20a, the dielectric spacing layer 20b and the opaque metal layer 20c, and is formed of the structured layer 14. The thin film layer system 20 further forms the plurality of microimages 15 arranged in the form of a grid.

[0360] The partially transparent metal layer 20a here preferably has an optical density OD of approximately 0.6 and the opaque metal layer has an optical density OD of approximately 1.9. For example, the metal layers 20a and 20c here are formed of aluminum.

[0361] With respect to the design of the layers 10, 11a, 12 and 13, reference is also made here to the above statements.

[0362] Such a multilayer body 1 is preferably produced with the method explained with reference to FIG. 1b with the difference that the layer 14 applied in step d) and structured in step e) here further contains the thin film layer system 20, which comprises the partially transparent metal layer 20a, the dielectric spacing layer 20b and the opaque metal layer 20c. Before the application of the photoresist layer 16a to the side of the carrier layer 10 opposite the plurality of microlenses 12 arranged in the form of a grid, the thin film layer system 20 is first applied over the whole surface, in particular by means of sputtering, physical vapor deposition (PVD), chemical vapor deposition (CVD) or gravure printing. The thin film layer system 20 is then structured registration-accurately with the photoresist layer 16a in step e) and the photoresist layer 16a is in particular removed again after step e).

[0363] In other words, here, as described in particular in principle with reference to FIG. 1b, in addition to the photoresist layer 16a, the thin film layer system previously brought over the whole surface first is structured together with the photoresist layer 16a using the separate high-resolution mask.

[0364] The multilayer body 1 shown in FIG. 11b corresponds to the multilayer body shown in FIG. 11a with the difference that the layers 20b and 20c of the thin film layer system 20, unlike the multilayer body shown in FIG. 11a, are formed over the whole surface. The plurality of microimages 15 arranged in the form of a grid or the shape and/or contour thereof are formed here in particular by the structured partially transparent metal layer 20a.

[0365] The multilayer body shown in FIG. 11b is produced like the multilayer body shown in FIG. 11a with the difference that the layer 14 applied in step d) and structured in step e) here has only the partially transparent metal layer 20a. The further layers 20b and 20c of the thin film layer system 20 are then applied over the whole surface. Here, it is further possible for the dielectric spacing layer 20b further to function as a replication layer, into which microstructures with a relief depth of less than 200 nm are preferably molded.

[0366] The multilayer body shown in 11c corresponds to the multilayer body shown in FIG. 11a with the difference that the layers 20a and 20b of the thin film layer system 20, unlike the multilayer body shown in FIG. 11a, are formed over the whole surface. The multilayer body 1 shown in FIG. 11c further also comprises the colored varnish layer 17d applied over the whole surface. The plurality of microimages 15 arranged in the form of a grid or the shape and/or contour thereof are formed here in particular by the structured opaque metal layer 20c. With respect to the design of the layers 10, 11a, 12, 13, 17d, 20a, 20b and 20c, reference is made here to the above statements.

[0367] The multilayer body shown in FIG. 11c is produced like the multilayer body shown in FIG. 11a with the difference that the layers 20a and 20b are first applied over the whole surface. Further, there is the difference that the layer 14 applied in step d) and structured in step e) here has only the opaque metal layer 20c. The colored varnish layer 17d is then further applied over the whole surface.

[0368] FIG. 12a and FIG. 12b schematically show sectional representations of multilayer bodies 1.

[0369] The multilayer body 1 shown in FIG. 12a corresponds for example to the multilayer body 1 shown in FIG. 3a with the difference that the plurality of microlenses 12 arranged in the form of a grid are only applied in areas. As shown in FIG. 12a, the plurality of microlenses 12 arranged in the form of a grid are present here only in the area 25b. The same applies the to the plurality of microimages 15 arranged in the form of a grid, with the result that the optically variable effect generated by the interaction of the microlenses 12 and the microimages 15 is only generated in the area 25b. The multilayer body 1 shown in FIG. 12a further also comprises the replication varnish layer 11c, which is applied over the whole surface and is arranged on the side of the plurality of microimages 15 arranged in the form of a grid facing away from the carrier layer 10. A relief structure 22 is further stamped into the replication varnish layer 11c in areas. The metal layer 18c is further also applied to the replication varnish layer 11c at least in the area 25a.

[0370] The relief structure 22 here is preferably a diffractive grating, a Kinegram® or hologram, a blazed grating, a binary grating, a multi-step phase grating, a linear grating, a cross grating, a hexagonal grating, an asymmetrical or symmetrical grating structure, a retroreflective structure, in particular a binary or continuous free-form surface, a diffractive or refractive macrostructure, in particular a lens structure or microprism structure, a microlens, a microprism, a zero-order diffraction structure, a moth-eye structure or anisotropic or isotropic matte structure, or a superimposition or combinations of two or more of the above-named relief structures. Thus, the relief structure shown in FIG. 12a is for example a Kinegram®.

[0371] With respect to the design of the layers 10, 11a, 12, 13, 15, 11c, 18c and 24, reference is made here to the above statements.

[0372] The multilayer body 1 shown in FIG. 12b corresponds to the multilayer body 1 shown in FIG. 12a with the difference that the plurality of microlenses 12 arranged in the form of a grid and the plurality of microimages 15 arranged in the form of a grid are applied over the whole surface. The multilayer body shown in FIG. 12b, unlike the multilayer body shown in FIG. 12a, further comprises no primer layer 24.

[0373] As shown in FIG. 12b, the plurality of microimages 15 and microlenses 12 arranged in the form of a grid completely overlap with the relief structure 22 stamped into the replication varnish layer 11c.

LIST OF REFERENCE NUMBERS

[0374] 1 multilayer body [0375] 10 carrier layer [0376] 11a, 11c replication varnish layers [0377] 12 microlenses [0378] 13 adhesion-promoter layer [0379] 14 structured layer, layer to be structured [0380] 15 microimages [0381] 16a, 16b, 16d photoresist layers [0382] 17a, 17b, 17c, 17d colored varnish layers [0383] 18a, 18b, 18c, 20c metal layers [0384] 20 thin film layer system [0385] 20a partially transparent metal layer [0386] 20b dielectric spacing layer [0387] 21 edge emitter layer [0388] 22 relief structure [0389] 23 separate high-resolution mask [0390] 23a glass substrate [0391] 23b chromium layer [0392] 23c pellicle [0393] 24 primer layer [0394] 25a, 25b areas