Method for manufacturing an imaging structure

Abstract

Method for producing an imaging structure, having the steps: providing a printing material; providing a first fluid, which contains at least one metallic pigment and / or interference pigment; applying the first fluid at least in a first region of the printing material by means of a mechanism for the first fluid; shaping the first fluid by means of a mechanism for shaping; characterized by the steps: providing a second fluid, which has a refractive index in the range from 1.4 to 1.6; or applying the second fluid at least in a second region of the printing material by means of a second mechanism for the second fluid, which is arranged directly downstream of the mechanism for shaping, or applying the second fluid first multicolour and then at least in a second region of the printing material by means of a second mechanism for the second fluid, which is arranged downstream of the mechanism for shaping, respectively, said second region at least partially coinciding with said first region. The invention enables imaging structures to be produced and protected cost-effectively in an advantageous manner.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for manufacturing an imaging structure.

[0002] The present invention is in the field of graphic industry technology and here especially in the field of finishing or manufacturing of high-grade finishing and thus high-quality printed products. In particular, the present invention is in the field of producing diffractive structures of the holographic type. BACKGROUND

[0003] US 2019 / 0212697 A1 discloses a method for metallizing an optical element having a surface relief structure.

[0004] EP 1689586 B1 discloses a method for forming a holographic diffraction grating on a substrate. No metallic lacquer is employed here.

[0005] DE 102013016117 A1 discloses a method for producing and transferring diffractive microstructures onto a printing material. No overprint or overvarnish is carried out here.

[0006] EP 2723576 B1 discloses a method for forming a surface relief microstructure on a paper substrate. At the end, the application of a fluid having a high refractive index is carried out.

[0007] EP 3242165 B1 discloses a method for forming a surface relief microstructure on a polymer banknote substrate. At the end, the application of a fluid having a high refractive index is carried out.

[0008] US 2006 / 0272534 A1 discloses a method for printing a surface relief structure. At the end, the application of a fluid having a high refractive index is carried out.

[0009] The prior art discloses so-called HRI materials (HRI: High Refractive Index) which are used as transparent overprint lacquers. The high refractive index of the material relative to transparent UV casting lacquers makes the structures shaped in the lacquer having a lower refractive index underneath it not disappear. But the material is very expensive and difficult to integrate in existing printing process technology. SUMMARY

[0010] It was therefore the task of the present invention to realize an improvement over the prior art which in particular makes it possible to produce and protect imaging structures cost-effectively.

[0011] The solution of the task according to the invention

[0012] According to the invention, the task is solved by a method having the features of the preferred embodiments.

[0013] Advantageous and therefore preferred further embodiments of the present application result from the optional implementation and from the description and the drawings.

[0014] According to the application, a method for producing an imaging structure is proposed, which has the steps: providing a substrate; providing a first fluid, which comprises at least one metallic pigment and / or interference pigment; applying the first fluid at least in a first region of the substrate by means of a mechanism for the first fluid; and shaping the first fluid by means of a mechanism for shaping; characterized by the steps: providing a second fluid, which has a refractive index in the range from 1.4 to 1.6; and either applying the second fluid at least in a second region of the substrate by means of a second mechanism for the second fluid, which is arranged directly downstream of the mechanism for shaping, or first multicolour printing and then applying the second fluid at least in a second region of the substrate by means of a second mechanism for the second fluid, which is arranged downstream of the mechanism for shaping, wherein the second region respectively at least partially coincides with the first region.

[0015] Advantageous configurations and effects of the application

[0016] The application enables imaging structures to be produced and protected cost-effectively in an advantageous manner.

[0017] The second fluid has a regular or low refractive index and not a high refractive index in an advantageous manner. Thereby, the cost-intensive use of a fluid with a high refractive index can be avoided.

[0018] Within the framework of numerous attempts, it has surprisingly been found in the printing of metallic inks (here: first fluid) and their finishing by means of shaping (also referred to as "casting and curing" - C-square technology) to produce holographic diffractive structures that the effect of the structures is retained or can be seen unimpaired upon overprinting (or superimprinting) or varnishing or glossing, even if the second fluid used for overprinting (here: second fluid) does not have a high refractive index. However, it has been assumed hitherto that the fluid used for overprinting must have a high refractive index, that is to say a refractive index greater than 1.6. These attempts show that the metallic pigment in the first fluid allows the use of a second fluid with a low or regular refractive index, but not a high refractive index.

[0019] It is preferred to provide a first fluid, which comprises at least one metallic pigment and in particular does not comprise an interference pigment.

[0020] Since the first fluid comprises a metallic pigment and / or an interference pigment, it is possible in an advantageous manner to avoid having to painstakingly metallize or the like the layer composed of the first fluid in a separate step.

[0021] The second fluid can be a clear lacquer (Klarlack) and / or a glossy lacquer (Glanzlack), in particular a lacquer which can be hardened using UV radiation. The hardened lacquer can effectively protect the sensitive (diffractive) structure lying thereunder from damage, for example scratching or contamination, for example with grease when touched with a finger.

[0022] Embodiments of the application

[0023] Embodiments of the application are described below (for short: embodiments).

[0024] An embodiment can be characterized in that the second fluid has a refractive index in the range from 1.45 to 1.55, or in that the second fluid has a refractive index of 1.5.

[0025] An embodiment can be characterized in that the first fluid is a printing ink or lacquer (or varnish) or ink. An embodiment related thereto can be characterized in that the first fluid is applied in an offset printing method, in a screen printing method or in a gravure printing method.

[0026] An embodiment can be characterized in that the first fluid is a metallic lacquer or metallic varnish. An embodiment related thereto can be characterized in that the first fluid is applied in an offset printing method or in a flexographic printing method.

[0027] An embodiment can be characterized in that the first fluid is UV-hardenable, in particular a UV lacquer or UV varnish.

[0028] An embodiment can be characterized in that the second fluid is a lacquer or varnish, in particular a clear lacquer or clear varnish and / or a glossy lacquer or glossy varnish. An embodiment related thereto can be characterized in that the second fluid is a dispersion lacquer or dispersion varnish. A further embodiment related thereto can be characterized in that the second fluid is a so-called Varnish, in particular an Offset-Varnish (which is printed lithographically), or a so-called Duct-Coat or Duct-Coating (a water-based coating material which is applied planarly without wetting agent by means of an offset mechanism). A further embodiment related thereto can be characterized in that the second fluid is applied in a flexographic printing method or in an offset printing method. An alternative embodiment related thereto can be characterized in that the second fluid is applied in an inkjet printing method, a screen printing method, a gravure printing method, a letterpress printing method or a letterpress offset printing method. A further embodiment related thereto can be characterized in that the second fluid is hardened using UV radiation.

[0029] One refinement can be characterized in that the second fluid cannot be UV-hardened. One refinement associated therewith can be that the second fluid is a solvent-based, oil-based or water-based lacquer or varnish.

[0030] One refinement can be characterized in that the second fluid is applied as a protection against scratching and / or against dirt.

[0031] One refinement can be characterized in that the forming is carried out using a foil. One refinement associated therewith can be that the forming is carried out using a transparent foil. Another refinement associated therewith can be that the forming is carried out using UV radiation, which is shot through the transparent foil onto the substrate. The foil is preferably microstructured and its microstructure is transferred into the first fluid during the forming.

[0032] One refinement can be characterized in that the imaging structure is a diffractive structure. One refinement associated therewith can be that the diffractive structure produces a holographic effect.

[0033] One refinement can be characterized in that the multicolour printing, in particular the multicolour offset printing, is carried out before the application of the first fluid. One alternative or additional refinement can be that the multicolour printing, in particular the multicolour offset printing, is carried out between the forming of the second fluid and the application.

[0034] One refinement can be characterized in that the substrate is provided as a sheet or as a web.

[0035] The features and feature combinations disclosed in the above technical field, summary and refinement paragraphs as well as in the following embodiments paragraph, in any combination with one another, constitute further advantageous refinements of the application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figures 1 to 4 Preferred embodiments and refinements of the application are shown. In the drawings, features corresponding to one another are provided with the same reference symbols. In order to make the drawings clearer, the reference symbols are partially omitted in the drawings.

[0037] Figure 1 A device is shown when carrying out one preferred embodiment of the method of the application;

[0038] Figure 2 Another device is shown when carrying out another preferred embodiment of the method of the application;

[0039] Figure 3 Another device is shown when carrying out another preferred embodiment of the method of the application;

[0040] Figure 4 One preferred embodiment of the method of the application is shown. Detailed Implementation

[0041] Figure 1 The apparatus is shown in a preferred embodiment of the method of the present invention.

[0042] Figure 1 A printing press 1 is shown for printing on a printing substrate 2, which can be provided as a sheet or as a printhead. A fluid 3 containing metallic pigment 3a and / or interference pigment 3a is provided, for example, in an ink cartridge. A second fluid 4 is provided, for example, in another ink cartridge. The printing press 1 has exemplary mechanisms 6, 7, and 9 that follow each other. The first fluid 3 is provided in mechanism 6 and applied to a first region 2a of the printing substrate 2. In mechanism 7, an imaging structure 3b is formed into the first fluid 3 by means of a foil 7a. During forming, radiation 7b can be projected onto the first fluid 3 through the foil. This radiation is used here for curing. The second fluid 4 is provided in mechanism 9 and applied to a second region 2b of the printing substrate 2. Radiation 9a can be projected onto the second fluid 4 behind mechanism 9. This radiation is used here for curing.

[0043] Figure 2 Another apparatus is shown in another preferred embodiment of the method of the invention.

[0044] Figure 2 A printing press 1 is shown for printing on a printing substrate 2, which can be provided as a sheet or as a print. A fluid 3 containing metallic pigment 3a and / or interference pigment 3a is provided, for example, in an ink cartridge. A second fluid 4 is provided, for example, in another ink cartridge. The printing press 1 has exemplary mechanisms 6, 7, a plurality of printing mechanisms 8, and 9 following each other. The first fluid 3 is provided in mechanism 6 and applied to a first region 2a of the printing substrate 2. In mechanism 7, an imaging structure 3b is formed into the first fluid 3 by means of a foil 7a. During the forming process, radiation 7b can be directed onto the first fluid 3 through the foil. This radiation is used here for curing. A printed image is produced on the printing substrate 2, for example, using the CMYK method with the printing mechanism 8. The second fluid 4 is provided in mechanism 9 and applied to a second region 2b of the printing substrate 2. Radiation 9a can be directed onto the second fluid 4 behind mechanism 9. This radiation is used here for curing.

[0045] Figure 3 Another apparatus is shown in another preferred embodiment of the method of the present invention.

[0046] Figure 3A printing press 1 for printing a printing material 2 is shown, which can be provided as a web or as a sheet. A fluid 3 with metal pigments 3a and / or interference pigments 3a is provided, for example in an ink cartridge. A second fluid 4 is provided, for example in another ink cartridge. The printing press 1 has, following one another, exemplary printing mechanisms 5, 6, 7 and 9. A printed image is produced on the printing material 2 with the printing mechanism 5, for example in the CMYK method. The first fluid 3 is provided in the mechanism 6 and applied in a first region 2a of the printing material 2. In the mechanism 7, an imaging structure 3b is shaped into the first fluid 3 by means of a foil 7a. During the shaping, radiation 7b can be shot through the foil onto the first fluid 3. The radiation serves for hardening here. The second fluid 4 is provided in the mechanism 9 and applied in a second region 2b of the printing material 2. Behind the mechanism 9, radiation 9a can be shot onto the second fluid 4. The radiation serves for hardening here.

[0047] Figure 4 A preferred embodiment of the inventive method is shown.

[0048] The method has the following method steps:

[0049] Step 10: Providing a printing material 2.

[0050] Step 11 (optional): Multicolor printing, for example CMYK.

[0051] Step 12: Providing a first fluid.

[0052] Steps 13, 14 and 15: Applying, shaping and hardening the first fluid 3.

[0053] Step 16 (optional): Multicolor printing, for example CMYK.

[0054] Step 17: Providing a second fluid 4.

[0055] Steps 18 and 19: Applying and hardening the second fluid 4.

[0056] List of reference signs

[0057] 1 printing press

[0058] 2 printing material

[0059] 2a first region

[0060] 2b second region

[0061] 3 first fluid

[0062] 3a metal pigments and / or interference pigments

[0063] 3b imaging structure

[0064] 4 second fluid

[0065] 5 printing means

[0066] 6 means for a first fluid

[0067] 7 means for shaping

[0068] 7a foil

[0069] 7b radiation

[0070] 8 printing means

[0071] 9 means for a second fluid

[0072] 9a radiation

[0073] 10 providing a substrate

[0074] 11 multicolour printing

[0075] 12 providing a first fluid

[0076] 13 applying

[0077] 14 shaping

[0078] 15 hardening

[0079] 16 multicolour printing

[0080] 17 providing a second fluid

[0081] 18 applying a second fluid

[0082] 19 hardening.

Claims

1. A method for manufacturing an imaging structure, comprising the steps of: - Provide printing materials (2); - Provide a first fluid (3) comprising at least one metallic pigment (3a) and / or an interference pigment (3a); - The first fluid (3) is applied at least in the first region (2a) of the printing material (2) by means of a mechanism for the first fluid; and -The first fluid is shaped by means of a molding mechanism (3); Its characteristics include the following steps: - A second fluid (4) is provided, the second fluid having a refractive index in the range of 1.4 to 1.6; and - The second fluid (4) is applied at least in the second region (2b) of the printing material (2) by means of a second mechanism for the second fluid arranged directly downstream of the molding mechanism; or first multicolor printing (16) and then the second fluid (4) is applied (18) at least in the second region (2b) of the printing material (2) by means of a second mechanism for the second fluid arranged downstream of the molding mechanism. The second region (2b) at least partially overlaps with the first region (2a).

2. The method according to claim 1, characterized in that, The second fluid (4) has a refractive index in the range of 1.45 to 1.

55.

3. The method according to claim 1, characterized in that, The second fluid (4) has a refractive index of 1.

5.

4. The method according to any one of claims 1 to 3, characterized in that, The first fluid (3) is metallic paint.

5. The method according to any one of claims 1 to 3, characterized in that, The first fluid (3) is capable of UV curing.

6. The method according to any one of claims 1 to 3, characterized in that, The second fluid (4) is capable of UV curing.

7. The method according to any one of claims 1 to 3, characterized in that, The second fluid (4) is a dispersion paint.

8. The method according to any one of claims 1 to 3, characterized in that, The second fluid (4) is varnish.

9. The method according to any one of claims 1 to 3, characterized in that, The second fluid (4) is a solvent-based, oil-based, or water-based paint.

10. The method according to any one of claims 1 to 3, characterized in that, The second fluid (4) is applied as a protective agent against scratches and / or dirt.

11. The method according to any one of claims 1 to 3, characterized in that, The imaging structure (3b) is a diffraction structure.

12. The method according to claim 5, characterized in that, The first fluid (3) is UV paint.

13. The method according to claim 6, characterized in that, The second fluid (4) is UV paint.

14. The method according to any one of claims 1 to 3, characterized in that, The second fluid (4) is a pipe coating, which is a water-based coating material.

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