Transfer film and method for producing a transfer film
10427446 ยท 2019-10-01
Assignee
Inventors
- Rene Staub (Hagendorn, CH)
- Christina Streb (Abtwil, CH)
- Michael Hoffmann (Walchwil, CH)
- Reto Gnos (Attinghausen, CH)
Cpc classification
B42D25/328
PERFORMING OPERATIONS; TRANSPORTING
B42D25/387
PERFORMING OPERATIONS; TRANSPORTING
B42D25/369
PERFORMING OPERATIONS; TRANSPORTING
B41M3/12
PERFORMING OPERATIONS; TRANSPORTING
B42D25/425
PERFORMING OPERATIONS; TRANSPORTING
B42D25/382
PERFORMING OPERATIONS; TRANSPORTING
International classification
B42D25/328
PERFORMING OPERATIONS; TRANSPORTING
B41M3/12
PERFORMING OPERATIONS; TRANSPORTING
B42D25/369
PERFORMING OPERATIONS; TRANSPORTING
B42D25/382
PERFORMING OPERATIONS; TRANSPORTING
B42D25/387
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The invention relates to a transfer film (1), in particular hot-stamping film, the use of a transfer film (1), a film, a security document (2), and a method for producing a transfer film (1). Here, it is provided that the transfer film (1) comprises a transfer layer (20) detachably arranged on a carrier layer (10). The transfer layer (20) further has at least one first color layer (30) and the at least one first color layer (30) comprises at least one binder and at least first pigments, the color appearance of which changes depending on the observation angle.
Claims
1. A transfer film comprising a transfer layer detachably arranged on a carrier layer, wherein the transfer layer has at least one first color layer, and wherein the at least one first color layer comprises at least one binder and at least first pigments, the color appearance of which changes depending on the observation angle, wherein the at least one first color layer is present in at least one first area of the transfer layer and no color layer is present in at least one second area of the transfer layer, wherein the transfer layer has a first compensation layer which covers the at least one first area of the transfer layer and covers the at least one second area of the transfer layer, and wherein the transfer layer further comprises: at least one replication varnish layer disposed between the first color layer and the carrier layer; a primer layer disposed between the first color layer and the at least one replication varnish layer; and at least one first stabilizing layer disposed between the at least one replication varnish layer and the carrier layer.
2. The transfer film according to claim 1, wherein the at least one first area represents a first item of information in the form of a pattern, motif or a logo.
3. The transfer film according to claim 1, wherein the first compensation layer has a layer thickness between 3 m and 50 m.
4. The transfer film according to claim 1, wherein the first compensation layer is transparent and/or colorless.
5. The transfer film according to claim 1, wherein the first compensation layer is formed as a bonding layer.
6. The transfer film according to claim 1, wherein the at least one first color layer has a thickness between 3 m and 30 m.
7. The transfer film according to claim 1, wherein the at least one first stabilizing layer mechanically stabilizes the transfer layer.
8. The transfer film according to claim 7, wherein the at least one first stabilizing layer has a layer thickness between 0.2 m and 7.5 m.
9. The transfer film according to claim 7, wherein the at least one first stabilizing layer is cross-linked chemically and/or by irradiation with UV light and/or irradiation with electron beams.
10. The transfer film according to claim 7, wherein the at least one first stabilizing layer is a layer cured by electromagnetic radiation.
11. The transfer film according to claim 7, wherein the at least one first stabilizing layer is transparent or translucent.
12. The transfer film according to claim 1, wherein the carrier layer has a layer thickness between 12 m and 50 m.
13. The transfer film according to claim 1, wherein the transfer layer comprises a detachment layer which allows the separation of the transfer layer from the carrier layer.
14. The transfer film according to claim 13, wherein the detachment layer has a layer thickness between 0.2 m and 4 m.
15. The transfer film according to claim 1, wherein the carrier layer comprises a separating layer curable by means of UV light or electron beams, which allows the separation of the transfer layer from the carrier layer.
16. The transfer film according to claim 1, wherein the at least one first color layer is applied to the primer layer.
17. The transfer film according to claim 16, wherein the primer layer has a layer thickness between 0.01 m and 0.5 m.
18. The transfer film according to claim 1, wherein a surface structure is molded into the surface of the replication varnish layer.
19. The transfer film according to claim 18, wherein the surface structure is not molded into the surface of the replication varnish layer in the at least one first area of the transfer layer.
20. The transfer film according to claim 18, wherein the refractive index of the replication varnish layer differs from the refractive index of the binder by less than 0.2.
21. The transfer film according to claim 18, wherein the surface structure is selected from the group of diffractive surface structures, Kinegram or holograms, zero-order diffraction structures, blazed gratings, linear or crossed sinusoidal diffraction gratings, linear or crossed single- or multi-step rectangular gratings, asymmetrical saw-tooth relief structures, light-diffracting and/or light-refracting and/or light-focusing micro- or nanostructures, binary or continuous Fresnel lenses, binary or continuous Fresnel freeform surfaces, diffractive or refractive macrostructures, structures or microprism structures, mirror surfaces and mat structures, anisotropic or isotropic mat structures, or combinations of these structures.
22. The transfer film according to claim 18, wherein the surface structure of the transfer layer represents a second item of information in the form of a pattern, motif or a logo.
23. The transfer film according to claim 1, wherein the replication varnish layer is thermoplastically deformable and/or is cross-linked by irradiation with UV light.
24. The transfer film according to claim 1, wherein the replication varnish layer has a layer thickness between 0.2 m and 4 m.
25. The transfer film according to claim 1, wherein the transfer layer has a reflecting layer, wherein the surface coverage of the reflecting layer is less than 30% of the total surface area of the transfer layer.
26. The transfer film according to claim 25, wherein the reflecting layer represents a third item of information in the form of a pattern, motif or a logo.
27. The transfer film according to claim 1, wherein the transfer layer contains at least one mark for determining the at least one first area of the transfer layer.
28. The transfer film according to claim 1, wherein the first pigments have a diameter between 1 m and 100 m and a thickness between 0.1 m and 5 m.
29. The transfer film according to claim 1, wherein the at least one first color layer contains second pigments.
30. The transfer film according to claim 29, wherein the at least one first color layer contains third pigments which, in the case of irradiation with electromagnetic radiation emit light from the wavelength range visible to the human eye.
31. The transfer film according to claim 1, wherein the proportion of the at least first pigments in the at least one binder of the at least one first color layer is less than 50%.
32. The transfer film according to claim 1, wherein the at least one first color layer contains soluble dyes in the at least one binder.
33. The transfer film according to claim 1, wherein the first pigments are formed as flakes and exhibit a substantially similar orientation to each other with respect to the surface normal established by the plane spanned by the transfer layer.
34. The transfer film according to claim 1, wherein the orientation of the first pigments with respect to the surface normal established by the plane spanned by the transfer layer and a coordinate system spanned by the transfer layer is locally varied.
35. The transfer film according to claim 1, wherein the first pigments are magnetic and/or have one or more metal layers.
36. The transfer film according to claim 1, wherein the transfer layer is present in at least one first zone and is not present in at least one second zone, wherein the first zones of the transfer layer are formed patterned.
37. A method for applying a transfer film to a film with a first surface and a second surface, the method comprising: applying one or more transfer films according to claim 1 to the second surface of the film with the side of the carrier layers facing away from the transfer layers of the one or more transfer films, and; applying a bonding layer between the one or more transfer films and the film, the bonding layer connecting the one or more transfer films to the film, wherein the bonding strength of the bonding layer exceeds the bonding strength between the one or more transfer layers and the one or more carrier layers of the one or more transfer films or vice versa.
38. A security document comprising one or more transfer films according to claim 1.
39. The security document according to claim 38, wherein one or more transfer layers of the one or more transfer films are arranged on a surface of a first carrier substrate made of paper or plastic.
40. The security document according to claim 39, wherein the one or more transfer layers arranged on the surface of the first carrier substrate are laminated or adhesively bonded, to a polycarbonate layer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Embodiment examples of the invention are explained below by way of example with the aid of the attached figures.
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DETAILED DESCRIPTION OF THE INVENTION
(10)
(11) The carrier layer 10 is preferably a PET, PEN, OPP, BOPP, PE or cellulose acetate film with a thickness between 12 m and 50 m. The carrier layer 10 shown in
(12) The wax layer 22 and the transfer layer 20 are now applied to the carrier layer 10 successively, by applying further layers. The wax layer 22 here has a thickness of 10 nm. Typical layer thicknesses for the wax layer 22 lie in the range of from 1 nm to 100 nm. A detachment layer 24 with a thickness of from 0.2 m to 2 m is applied to the wax layer 22. The detachment layer 24 shown in
(13) The color layer 30 is preferably an OVI layer with a thickness between 3 m and 30 m. The color layer 30 thus comprises a binder and pigments, the color appearance of which changes depending on the observation angle and in particular generates a color-change effect.
(14) The pigments in the color layer 30 preferably have a diameter between 1 m and 100 m. The color-change effect of the pigments can appear for a human observer for example from green to brown or from green to violet. The pigments of the color layer 30 which produce such a color-change effect, are here preferably substantially similarly oriented to each other, with respect to the surface normal established by the plane spanned by the transfer layer 20. The orientation of the pigments with respect to each other can however be locally varied; for this the pigments can for example be magnetic.
(15) It is also possible that the color layer 30 contains further pigments such as preferably flakes, charms, taggants, reflective pigments or pigments formed as flakes, which have a diffractive structure.
(16) Furthermore, it is possible that the color layer 30 contains pigments which, in the case of irradiation with electromagnetic radiation, in particular irradiation with UV or IR light, emit light from the wavelength range visible to the human eye, in particular in the wavelength range from 400 nm to 800 nm. The color layer 30 can also contain for example soluble dyes which for example stain the color layer 30 corresponding to the added dyes. The color layer 30 shown in
(17) The bonding layer 92 is then applied with a layer thickness of from approximately 2 m to 8 m. The bonding layer 92 shown in
(18) The transfer layer 20 can for example be transferred onto a target substrate by means of hot stamping. Furthermore, it is possible to transfer the transfer layer 20 by means of cold transfer. A UV-curable adhesive can for example be used as bonding layer here. In the case of cold transfer, but also in the case of hot stamping, the bonding layer can preferably either be part of the transfer layer or also alternatively or additionally thereto be applied to the target substrate. The curing of the UV-curing adhesive can take place through the color layer, if the color layer exhibits sufficient transmission for UV light, or through the target substrate, if the target substrate is at least partially transparent to UV light. The latter applies in particular in the case of polymer substrates such as for example polycarbonate, polyester, polyethylene or polypropylene.
(19) The bonding layer 92 can also be applied patterned to the target substrate, for example by a printing process. This process is suitable in particular in the case of application by means of cold transfer. However, it can also be used with thermally activatable adhesives in the case of hot stamping.
(20)
(21) In the embodiment example of
(22) The compensation layer 90 is preferably a layer made of acrylate, PVC, polyurethane or polyester with a layer thickness between 2 m and 50 m. The compensation layer 90 in
(23) It is however also possible that the compensation layer 90 is also present in a smaller layer thickness, in particular in a layer thickness smaller than the color layer 30, whereby the areas 40 and 42 are overlapped, and the areas 42 are only covered, but not filled in.
(24) Furthermore, it is possible that the compensation layer 90 is a layer made of polymethyl acrylate, dipentaerythriol pentaacrylates or polysiloxane resin, which comprises a photoinitiator such as for example Irgacure and can be cross-linked by means of UV light. Alternatively, the compensation layer can consist of acrylate, polyester, polyvinyl alcohols or alkyd resins and be chemically cross-linked by means of isocyanate. In such a case, the transfer layer would in addition have a bonding layer which is applied to the compensation layer 90. With respect to the embodiment of such a bonding layer, reference is made here to the statements of
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(26) With respect to the embodiment of the carrier layer 10, the wax layer 22, the detachment layer 24 and the color layer 30 reference is made here to the statements of
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(29) In the embodiment example shown in
(30) The stabilizing layer 60 is preferably a layer made of acrylate, polyester, polyvinyl alcohols or alkyd resins, which is chemically cross-linked for example by means of isocyanate. Furthermore, layers made of polymethyl acrylate, dipentaerythriol pentaacrylates or polysiloxane resin, which are provided with a photoinitiator such as for example Irgacure, can for example be used. Such a stabilizing layer can be cross-linked through the photoinitiator by irradiation by means of UV light. The stabilizing layer 60 preferably has a layer thickness between 0.2 m and 5 m. The stabilizing layer shown in
(31) The replication varnish layer 70 consists of a thermoplastic lacquer into which a surface structure is molded by means of heat and pressure by the action of a stamping tool. It is further also possible that the replication varnish layer 70 is formed by a UV-cross-linkable lacquer and the surface structure is molded into the replication varnish layer 60 by means of UV replication. The surface structure is molded onto the uncured replication varnish layer by the action of a stamping tool and the replication varnish layer is cured directly during or after the molding by irradiation with UV light.
(32) The replication varnish layer 70 preferably has a layer thickness between 0.2 m and 2 m. The layer thickness of the replication varnish layer 70 in
(33) It is further possible that a reflecting layer is applied to the replication varnish layer 70. The reflecting layer is preferably a metal layer made of chromium, gold, copper, silver or an alloy of such metals, which is vapor-deposited in a layer thickness of from 0.01 m to 0.15 m under vacuum. It is further also possible that the reflecting layer is formed by a transparent reflecting layer, for example a thin or finely structured metallic layer or an HRI (high refraction index) or LRI (low refraction index) layer. Such a dielectric reflecting layer consists, for example, of a vapor-deposited layer made of a metal oxide, metal sulfide, titanium oxide etc. of a thickness of from 10 nm to 150 nm.
(34) The primer layer 80 is a layer which preferably comprises acrylates, PVC, polyurethane or polyester and has a layer thickness between 0.01 m and 0.5 m. The primer layer shown in
(35) With respect to the embodiment of the further layers in
(36) The transfer film 1 of the embodiment example of
(37) The transfer film 1 of the embodiment example of
(38) The transfer film 1 of the embodiment example of
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(40) It can also be provided that the arrangement of the bonding layer between the carrier layers 10 and the film 12 as well as of the detachment layer 24 between the carrier layers 10 and the transfer layers 20 is reversed. Thus, a detachment layer is arranged in each case between the film 12 and the carrier layers 10, and the carrier layers 10 are connected to the transfer layers 20 in each case by a bonding layer. This has the effect that, during application to a target substrate, the carrier layers 10 of the film 12 are transferred together with the transfer layers 20, and thus the carrier layers 10 become part of the transfer layers 20. Consequently self-supporting small areas are transferred through the carrier layers 10. The mechanical stability of the transfer layers 20 is increased by the carrier layers 10 also transferred.
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(44) The transfer film 1 of the embodiment example of
(45) The transfer film 1 of the embodiment example of
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LIST OF REFERENCE NUMBERS
(48) 1 transfer film 2 security document 10 carrier layer 12 film 14 carrier substrate 16 plastic layer 20 transfer layer 22 wax layer 24 detachment layer 30 color layer 40, 42, 43, 44, 45 47, 49 areas 46,48 zones 50 mark 60 stabilizing layer 70 replication varnish layer 80 primer layer 90 compensation layer 92 bonding layer