Process for producing a multilayer body, and multilayer body

Patent metadata

Field	Value
Publication number	US-9969203-B2
Application number	US-201414455521-A
Country	US
Kind code	B2
Filing date	Aug 8, 2014
Priority date	Aug 9, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

In a process for producing a multilayer body, an HRI layer made of a material having a high refractive index is applied to at least part of the surface area of a substrate. At least one partial region of the HRI layer is then physically removed from the substrate again by treatment with an alkaline solution. Additionally specified is a multilayer body that can be obtained by such a process.

First claim

The invention claimed is:

1. A process for producing a multilayer body comprising:
applying a High Refractive Index (HRI) layer which consists of a material having a high refractive index over an entire surface area of a substrate;
applying an alkaline solution on at least one partial region of the HRI layer such that the alkaline solution does not chemically dissolve the HRI layer in the at least one partial region, but, instead, causes the HRI layer in the at least one partial region to flake off from the surface area of the substrate; and
completely removing the flaked off HRI layer in the at least one partial region by a mechanical process,
wherein the alkaline solution has a pH value of at least 10, and
wherein the treatment with the alkaline solution is effected at a temperature of from 10° C. to 80° C.

2. A process according to claim 1 , wherein the material having a high refractive index is selected from the group zinc sulfide, niobium pentoxide, titanium oxide.

3. A process according to claim 1 , wherein the alkaline solution is selected from the group sodium hydroxide, potassium hydroxide, sodium bicarbonate, tetramethylammonium hydroxide, sodium ethylenediaminetetra-acetate.

4. A process according to claim 1 , wherein, to aid the separation of the HRI layer, a mechanical treatment of the HRI layer is effected during and/or after the treatment with the alkaline solution.

5. A process according to claim 4 , wherein the mechanical treatment comprises brushing, and/or wiping with a sponge and/or a wiping roller, and/or an ultrasonic treatment, and/or application of a flowing and/or sprayed liquid to the HRI-layer.

6. A process according to claim 1 , wherein, a mask layer, to protect at least one partial region not to be removed of the HRI layer, is applied to the HRI layer before the treatment with the alkaline solution.

7. A process according to claim 6 , wherein the mask layer is applied by gravure printing, offset printing, flexographic printing, screen printing or inkjet printing of a protective varnish on to the HRI layer.

8. A process according to claim 7 , wherein the protective varnish is a varnish that dries physically or undergoes chemical cross-linking or radiation curing.

9. A process according to claim 7 , wherein a protective varnish is used, which comprises pigments and/or dyes and/or pigments that can be UV-activated and/or nanoparticles and/or upconverters and/or thermochromic dyes and/or photochromic dyes.

10. A process according to claim 7 , wherein the protective varnish is removed again, at least regionally, after the treatment with the alkaline solution.

11. A process according to claim 6 , wherein the mask layer is formed by full surface-area or partial application of a positive photoresist, light exposure of the partial region to be removed of the HRI layer, and removal of the light-exposed photoresist.

12. A process according to claim 6 , wherein the mask layer is formed by full surface-area or partial application of a negative photoresist, light exposure of the partial region not to be removed of the HR1 layer, and removal of the photoresist not exposed to light.

13. A process according to claim 11 , wherein a photoresist is used that contains dyes and/or pigments and/or pigments that can be UV-activated and/or nanoparticles and/or upconverters and/or thermochromic dyes and/or photochromic dyes.

14. A process according to claim 11 , wherein the photoresist is removed, at least regionally, after the treatment with the alkaline solution.

15. A process according to claim 11 , wherein the exposure to light is effected over the full surface area and/or over part of the surface area by means of a laser or a controllable mask.

16. A process according to claim 1 , wherein the alkaline solution is printed on to the partial region to be removed of the HR1 layer.

17. A process according to claim 16 , wherein the alkaline solution is printed on by flexographic printing or gravure printing.

18. A process according to claim 16 , wherein an alkaline solution is used that contains at least one additive to increase the viscosity, and/or at least one wetting agent.

19. A process according to claim 18 , wherein calcium carbonate, kaolin, titanium dioxide, Aerosil or silicon dioxide is used as an additive.

20. A process according to claim 1 , wherein before the application of the HRI layer, at least one relief structure is molded at least in a partial region of the substrate.

21. A process for producing a multilayer body according to claim 1 , in which, in at least one first region of a or the substrate, at least one first relief structure is molded into a first surface of the substrate, then an HRI layer or the HRI layer, which consists of a material having a high refractive index, is applied to at least part of the surface area of the first surface of the substrate, in such a manner that the HRI layer covers, at least regionally, the at least one first region and at least one second region of the substrate, in which the first relief structure has not been molded into the first surface of the substrate, and then a partial region of the HRI layer is physically removed from the substrate again by treatment with an alkaline solution, in such a manner that the HRI layer is removed in the partial region covering the at least one second region and remains on the substrate in the partial region covering the at least one first region.

22. A process according to claim 21 , wherein the first relief structure is realized with a depth-to-width ratio of the individual structural elements of more than 0.15.

23. A process according to claim 21 , wherein in the at least one second region no relief structure is molded into the substrate, or at least one second relief structure, which differs from the first relief structure, is molded into the substrate.

24. A process according to claim 23 , wherein the first relief structure and the second relief structure are realized such that, owing to the relief structures, the adhesion of the layer to the substrate is greater in the at least one first region than in the at least one second region, wherein the spatial frequency of the first relief structure is greater than the spatial frequency of the second relief structure, the depth-to-width ratio of the structural elements of the first relief structure is greater than the depth-to-width ratio of the structural elements of the second relief structure, and/or the product of spatial frequency and the depth-to-width ratio of the structural elements of the first relief structure is greater than that of the second relief structure.

25. A process according to claim 21 , wherein the at least one first relief structure and/or second relief structure is realized as a one-dimensional or two-dimensional diffractive grating structure having a spatial frequency of more than 1000 lines/mm.

26. A process according to claim 25 , wherein the diffractive grating structure of the second relief structure is realized with a period of less than 3 μm.

27. A process according to claim 21 , wherein the at least one first and/or second relief structure is realized as a light-diffracting and/or light-refracting and/or light-scattering and/or light-focusing microstructure or nanostructure, as an isotropic or anisotropic matte structure, as a binary or continuous Fresnel lens, as a micro-prism structure, as a blazed grating, as a

Assignees

• Ovd Kinegram Ag
• Leonhard Kurz Stiftung & Co Kg
• Leohnard Kurz Stiftung & Co Kg

Inventors

• Staub René
• Brehm Ludwig
• Attner Juri
• Hoffmann Michael
• Seeholzer Peter

Classifications

• B42D25/445

  using chemical means, e.g. etching · CPC title

• B42D25/45

  Associating two or more layers · CPC title

• B42D25/425

  by deformation, e.g. embossing · CPC title

• B41M7/0045

  using protective coatings or film forming compositions cured by mechanical wave energy, e.g. ultrasonics, cured by electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams, or cured by magnetic or electric fields, e.g. electric discharge, plasma · CPC title

• B42D25/36

  comprising special materials · CPC title