Adhesive security tape
View Patent ↗An adhesive security tape comprises a polymer film whose refractive index and/or interface structure can be changed locally by heating. Disposed below the polymer film is an absorber layer comprising an absorber dye set up at least partly to absorb a write beam directed onto the absorber layer, to emit at least some of the generated heat to the polymer film locally, and in doing so to undergo local change itself. Below the absorber layer there is an adhesive layer. The adhesion between the adhesive layer and the absorber layer is greater than the adhesion to the polymer film. There is preferably a partly transparent reflection layer between the polymer film and the absorber layer.
1. An adhesive security tape comprising:
a polymer film whose refractive index and/or interface structure can be changed locally by heating,
an absorber layer disposed below the polymer film and comprising an absorber dye which is set up at least partly to absorb a write beam directed onto the absorber layer, to transfer at least some of the heat generated to the polymer film locally, and in doing so to undergo local change itself, and
an adhesive layer disposed below the absorber layer,
wherein at least the polymer film is less strongly adhered to the absorber layer than at least the absorber layer is adhered to the adhesive layer.
2. The tape of claim 1 , wherein the interface structure of the polymer film can be changed locally by heating, holographic information being writable via the local interface structure of the polymer film.
3. The tape of claim 2 , wherein the absorber layer is set up to adopt an interface structure which corresponds to the local interface structure of the polymer film, when a write beam is absorbed.
4. The tape of claim 1 , wherein the refractive index of the polymer film can be changed locally by heating.
5. The tape of claim 1 , wherein the absorber dye is set up to undergo local change in its optical properties when a write beam is absorbed.
6. The tape of claim 5 , wherein the absorber dye undergoes local changes in its absorption capacity when a write beam is absorbed.
7. The tape of claim 1 , wherein disposed between the polymer film and the absorber layer there is a partly transparent reflection layer, the adhesion between the polymer film and the reflection layer being greater than the adhesion between the reflection layer and the absorber layer.
8. The tape of claim 1 , wherein the reflection layer has a thickness in the range from 1 nm to 50 nm.
9. The tape of claim 7 , wherein the reflection layer comprises aluminum.
10. The tape of claim 7 , wherein the polymer film is oriented.
11. The tape of claim 10 , wherein the polymer film is biaxially oriented.
12. The tape of claim 1 , wherein the polymer film comprises a material selected from the following group: polypropylene, polyvinyl chloride, polyester, polyethylene terephthalate, polyethylene naphthalate, polymethylpentene, and polyimide.
13. The tape of claim 1 , wherein the absorber layer comprises a binder and has a thickness in the range from 0.1 μm to 10 μm.
14. The tape of claim 1 , wherein the polymer film is set up as the outer layer and as a bearing structure of the tape.
15. The tape of claim 1 , comprising written holographic information.
16. A process for entering holographic information into an adhesive security tape as claimed in claim 1 , where holographic information present in a hologram of a storage object is calculated as a two-dimensional array and a write beam of a write device is directed onto the absorber layer and is controlled in accordance with the two-dimensional array in such a way that the local refractive index and/or interface structure of the polymer film is adjusted in accordance with the holographic information and the absorber layer is locally changed in accordance with the holographic information.
17. The process of claim 16 , the tape having a partly transparent reflection layer disposed between the polymer film and the absorber layer, wherein the write beam is focused by evaluating its reflection returned from the reflection layer.
18. The process of claim 16 , wherein the holographic information is entered in the form of pits of predetermined size.
19. The process of claim 18 , wherein the holographic information is stored in binary-encoded form in a pit.
20. The process of claim 18 , wherein the holographic information is stored in continuously encoded form in a pit, the local properties of the polymer film being adjusted in the pit in accordance with a value from a predetermined range of values.
21. The process of claim 16 , wherein the write device comprises a laser lithography device.
22. An adhesive security tape, comprising:
an adhesive layer having a first surface for adhering the tape to a substrate, and a second surface; and
an absorbing layer and a polymer film disposed in this order on the second-surface-side of the adhesive layer, wherein
the absorbing layer undergoes local changes when heated and transfers at least some of the heat to the polymer film to effect corresponding local changes therein, and
the adhesion of the adhesive layer to a layer contacting the second surface thereof is greater than the adhesion of the polymer film to a layer contacting the locally-changed surface thereof.
23. The tape of claim 22 , wherein the layer contacting the second surface of the adhesive layer comprises the absorbing layer.
24. The tape of claim 22 , wherein the layer contacting the second surface of the adhesive layer comprises a partly transparent reflecting layer.
25. The tape of claim 24 , wherein one surface of the partly transparent reflecting layer contacts the adhesive layer and another surface contacts the absorbing layer.
26. The tape of claim 22 , wherein the layer contacting the locally-changed surface of the polymer layer comprises a partly transparent reflecting layer.
27. The tape of claim 22 , wherein the layer contacting the locally-changed surface of the polymer layer comprises the absorber layer.
28. The tape of claim 22 , wherein the local changes of the polymer film comprise refractive index changes.
29. The tape of claim 22 , wherein the local changes of the polymer film comprise interface structure changes.
30. The tape of claim 22 , wherein the local changes of the absorber layer comprise absorption capacity changes.
31. The tape of claim 22 , wherein the polymer layer is removable from the tape while at least the adhesive layer and the absorbing layer of the tape remain on the substrate.
32. An adhesive security tape, comprising:
an adhesive layer;
an absorber layer;
a polymer layer; and
information formed partly in the absorber layer and partly in the polymer layer.
33. The tape of claim 32 , wherein the information comprises a hologram.
34. The tape of claim 32 , wherein the adhesive layer adheres the tape to a substrate and the polymer layer is removable from the tape while at least the adhesive layer and the absorber layer of the tape remain on the substrate.
35. The tape of claim 32 , further comprising:
a partly transparent reflecting layer provided between the absorber layer and the polymer layer film.
36. The tape of claim 32 , further comprising:
a partly transparent reflecting layer provided between the absorber layer and the adhesive layer.