TRANSFER FILM, USE THEREOF AND METHOD FOR PRODUCING A TRANSFER FILM AS WELL AS METHOD FOR PRODUCING AN INJECTION-MOLDED ARTICLE DECORATED WITH A TRANSFER PLY OF A TRANSFER FILM

Abstract

A transfer film, in particular hot-stamping film, which includes a carrier film and a transfer ply with a top coat arranged on the carrier film and detachable from the carrier film, wherein a master structure is molded on the carrier film on its side facing the transfer ply, and wherein the top coat includes a structuring which has a structure complementary to the master structure.

Claims

1. A transfer film which comprises a carrier film and a transfer ply with a top coat arranged on the carrier film and detachable from the carrier film, wherein a master structure is molded on the carrier film on its side facing the transfer ply, and the top coat comprises a structuring which has a structure complementary to the master structure.

2. The transfer film according to claim 1, wherein a structured varnish comprises the master structure.

3. The transfer film according to claim 2, wherein the carrier film consists of a self-supporting structured varnish.

4. The transfer film according to claim 2, wherein the carrier film comprises a carrier layer and structured varnish arranged on the carrier layer in the direction of the transfer ply.

5. The transfer film according to claim 1, wherein the master structure or the structured varnish and/or the top coat have a homogeneous surface structure at least in areas.

6. The transfer film according to claim 1, wherein the master structure or the structured varnish has a structural depth of from 1 m to 10 m.

7. The transfer film according to claim 1, wherein the master structure or the structured varnish has a chemically inert surface.

8. The transfer film according to claim 1, wherein the structured varnish comprises at least one UV-curable and/or at least one isocyanate component and/or at least one melamine component.

9. The transfer film according to claim 1, wherein the top coat is formed from long-chain polymers.

10. The transfer film according to claim 1, wherein the top coat is formed from polyurethane, with a molecular weight between 2000 and 8000.

11. The transfer film according to claim 10, wherein the polyurethanes are formulated into a soft-touch varnish via a cobinder or with an isocyanate binder.

12. The transfer film according to claim 9, wherein the polymers are formed cross-linked.

13. The transfer film according to claim 1, wherein the top coat comprises fillers, made of PMMA, silicones, polyurethanes, different copolymers and/or mineral compounds.

14. The transfer film according to the top coat comprises silicone-containing acrylates, silicone-containing polyurethanes, oils, waxes and/or wax dispersions.

15. The transfer film according to claim 1, wherein the top coat comprises silicones.

16. The transfer film according to claim 1, wherein the top coat comprises UV-curable components.

17. The transfer film according to claim 1, wherein the top coat has a gloss level of between 20 and 60.

18. The transfer film according to claim 1, wherein the top coat comprises matting agents.

19. The transfer film according to claim 1, wherein the top coat has an elongation of at least 50%.

20. The transfer film according to claim 1, wherein the top coat has a temperature resistance of up to 200 C.

21. The transfer film according to claim 1, wherein the top coat is formed such that it has a soft-touch effect.

22. The transfer film according to claim 1, wherein the top coat has a pencil hardness HB.

23. The transfer film according to claim 1, wherein a detachment layer is arranged between the top coat and the master structure or the structured varnish.

24. The transfer according to claim 1, wherein an intermediary layer is arranged on the side of the top coat facing away from the carrier film.

25. The transfer film according to claim 24, wherein the intermediary layer comprises cross-linkable acrylates.

26. The transfer film according to claim 24, wherein the intermediary layer has a layer thickness between 0.1 m and 10 m.

27. The transfer film according to claim 1, wherein the transfer film comprises a decorative layer, a metallization and/or an adhesive layer or a primer layer.

28. The transfer film according to claim 1, wherein a haptic varnish is arranged at least in areas on the side of the carrier layer facing away from the top coat or on the side of the structured varnish facing away from the top coat.

29. A method for producing a transfer film for use as IMD soft-touch film, which comprises a carrier film and a transfer ply with a top coat arranged on the carrier film and detachable from the carrier film, wherein a master structure, is incorporated or produced in the carrier film, and the top coat is applied to the master structure, wherein a structure complementary to the master structure of the carrier film is molded into the top coat.

30. The method according to claim 29, wherein the master structure is produced by applying a structured varnish to a carrier layer.

31. The method according to claim 30, wherein the structured varnish is printed.

32. The method according to claim 30, wherein the structured varnish is applied over the whole surface of the carrier layer.

33. The method according to claim 30, wherein the structured varnish is applied partially to the carrier layer.

34. The method according to claim 33, wherein a further varnish is applied at least in areas to the carrier layer in areas where no structured varnish is arranged.

35. The method according to claim 29, wherein the carrier layer is pre-treated to improve the adhesion between carrier layer and structured varnish.

36. The method according to claim 29, wherein the top coat is cured by means of UV curing or thermally during the production of the transfer film.

37. The method according to claim 29, wherein an intermediary layer or adhesion promoter, a decorative layer and/or an adhesive layer are applied, on the top coat.

38. The method according to claim 29, wherein a metallization is applied, by means of vapor deposition.

39. The method according to a haptic varnish is applied at least in areas on the side of the carrier layer facing away from the top coat or on the side of the structured varnish facing away from the top coat.

40. (canceled)

41. (canceled)

42. A method for producing an injection-molded article decorated with a transfer ply of a transfer film with the following steps: arranging a transfer film according to claim 1 in an injection mold, back injection molding the transfer film with a plastic injection-molding composition, removing the carrier film together with the master structure from the transfer ply of the transfer film.

43. The method according to claim 42, wherein the top coat is cured during the production of the transfer film by means of UV curing and/or thermally.

44. The method according to the curing of the top coat as post-cure film is carried out.

Description

[0076] In the following the invention is explained with reference to several embodiment examples utilizing the attached drawings by way of example. There are shown in:

[0077] FIG. 1 a schematic sectional representation of a transfer film.

[0078] FIG. 2 a schematic sectional representation of a further transfer film.

[0079] FIG. 3 a schematic sectional representation of a further transfer film.

[0080] FIG. 4 a schematic sectional representation of a further transfer film.

[0081] FIG. 5 a schematic sectional representation of a further transfer film.

[0082] FIG. 6 a schematic sectional representation of a further transfer film.

[0083] FIG. 7 a schematic sectional representation of an injection-molded article decorated with a transfer ply.

[0084] FIG. 1 shows a schematic sectional representation of a transfer film 10. The transfer film 10, in particular hot-stamping film, comprises a carrier film 12 and a transfer ply 14 arranged on the carrier film 12 and detachable from the carrier film 12. The transfer ply 14 comprises a top coat 16. A master structure is molded on the carrier film 12 on its side facing the transfer ply 14, wherein the top coat 16 comprises a structuring which has a structure complementary to the master structure. It is advantageous if a structured varnish 18 comprises the master structure.

[0085] The structure incorporated into the top coat 16 provides in particular the soft-touch effect of the transfer film 10. Depending on the structuring of the surface of the top coat 16 by means of the master structure, the functional properties of the top coat 16 can be controlled, as a result of which in particular the tactile or hapticaily perceptible properties of the surface, the fingerprint sensitivity, dirt-repellent and/or liquid-repellent functions and/or the level of matting can be controlled.

[0086] The carrier film 12 shown in FIG. 1 preferably comprises a carrier layer 20 and the structured varnish 18 arranged on the carrier layer 20 in the direction of the transfer ply 14. The carrier layer 20 is preferably formed from ABS, ABS/PC, PET, PC, PMMA, PE and/or PPP. The layer thickness of the carrier layer 20 is advantageously between 5 m and 500 m, in particular between 6 m and 100 m.

[0087] The structured varnish 18 is arranged over the whole surface of the carrier layer 20 in FIG. 1. Advantageously, the structured varnish 18 is formed from melamine, polyurethane (PU), polyacrylates, polyol, isocyanate and/or polyvinyl chloride.

[0088] Ideally, the structured varnish 18 has a layer thickness of from 0.1 m to 10 m, in particular from 0.5 m to 7 m. It is advantageous if the structured varnish 18 has a structural depth between 1 m and 10 m, preferably between 2 m and 4 m, in particular between 3 m and 4 m. A particularly good soft-touch effect of the top coat 16 can be achieved as a result of such a structural depth. However, it is also possible for the structural depths to be larger. This is preferably achieved in that the master structure or the structured varnish 18 has larger particles. Through the selection of particles of corresponding size, the structural depth of the master structure or of the structured varnish 18 can be optimally adapted to the respective use. Ideally, the master structure or the structured varnish 18 comprises fillers with a particle size of approximately 6 m, preferably 8 m. In principle, particles with a size of 15 m can also be used.

[0089] Advantageously, the top coat 16 is formed from long-chain polymers. The polymers can be formed cross-linked. The cross-linking is preferably based on UV curing and/or on chemical reactions. The top coat 16 is particularly preferably formed from polyol, polyurethane (PU), copolymers of polyurethane (PU) and polyol and/or to copolymers of polyurethane (PU) and polyacrylates. Ideally, the top coat 16 is formed from polyurethane (PU), in particular with a molecular weight between 2000 and 8000. The polyurethanes are preferably formulated into a soft-touch varnish via a cobinder, for example via polyols and/or via melamine resins, or with an isocyanate binder.

[0090] The layer thickness of the top coat 16 is advantageously between 0.5 m and 100 m, in particular between 0.2 m [ . . . ] 50 m, particularly preferably between 5 m and 30 m.

[0091] The top coat 16, in particular the binder matrix of the top coat 16, can comprise fillers, preferably spherical fillers made of PMMA, silicones, polyurethanes (PU), different copolymers and/or mineral compounds. Furthermore, the top coat 16, in particular the binder matrix of the top coat 16, can comprise silicone-containing acrylates, silicone-containing polyurethanes, oils, waxes and/or wax dispersions. Through the use of such additives or fillers, the elasticity of the top coat 16 and the tactile or haptic properties associated with it, as the so-called feel, can be strengthened.

[0092] The top coat 16 advantageously comprises silicones. Through the use of silicones, the scratch resistance, the grip as well as the surface quality of the top coat 16 can be improved. In addition, the detachment properties between top coat 16 and structured varnish 18 can be controlled through the use of silicone.

[0093] Ideally, the top coat 16 has an elongation of at least 50%, preferably of at least 100%, in particular preferably of at least 200%. This makes a deformable top coat 16 possible. As a result of such an elongation behavior of the top coat 16, the transfer film 10 is particularly suitable for use in the IMD method.

[0094] A detachment layer 22 is preferably arranged between the top coat 16 and the structured varnish 18. The detachment layer 22 ensures a reliable detachment of the transfer ply 14 from the carrier film 12 by preventing too strong an adhesion between the top coat 16 and the structured varnish 18. Instead of or in addition to a detachment layer 22, it is advantageous if the structured varnish 18 and/or the top coat 16 comprise additives such as for example silicones, aliphatic hydrocarbons etc., which reduce the adhesion between top coat 16 and structured varnish 18.

[0095] The detachment layer 22 preferably has a layer thickness of from 0.001 m to 2 m, in particular from 0.05 m to 1 m. The detachment layer 22 can consist of a wax or comprise a wax. This can be e.g. a camauba wax, a montanic acid ester, a polyethylene wax, a polyamide wax or a PTFE wax. In addition, however, surface-active substances such as silicones are also suitable as detachment layer 22. Thin layers made of melamine-formaldehyde resin-cross-linked varnishes can also serve as detachment layer 22.

[0096] Advantageously, an intermediary layer 24, in particular an adhesion promoter, is arranged on the side of the top coat 16 facing away from the carrier film 12. The intermediary layer 24 ensures in particular that a very good adhesion is produced between the top coat 16 and the other layers of the transfer ply 14. Moreover, the intermediary layer 24 advantageously serves as a barrier layer. In particular, it prevents substances penetrating from outside into the top coat 16 from being able to penetrate into the other layers of the transfer ply 14.

[0097] The intermediary layer 24 preferably comprises cross-linkable acrylates, in particular polyacrylates, polyester resins, alkyd resins as well as their modifications, amino resins, amido resins or phenolic resins. Isocyanate can be used as cross-linking component. In principle, all current cross-linkings are conceivable here. A UV cross-linking as well as a dual cure system, i.e. in particular a cross-linking based on external radiation energy and in addition based on chemical reactions can be used.

[0098] Ideally, the intermediary layer 24 has a layer thickness between 0.1 m and 10 m, preferably between 0.5 m and 5 m, particularly preferably between 0.3 m and 4 m.

[0099] Furthermore, the transfer film 10, in particular the transfer ply 14, preferably has a decorative layer 26. The decorative layer 26 is in particular a color layer. The layer thickness of the decorative layer 26 is preferably 0.1 m to 10 m, in particular 0.5 m to 5 m. The decorative layer 26 is formed over the whole surface. However, it is also conceivable that the decorative layer 26 is applied only partially or in areas.

[0100] The decorative layer 26 can comprise one or more partial or full-surface color layers to generate a pattern and/or a motif, which [have] also in particular in register with the partial areas of the soft-touch varnish with their different optical properties, in particular with respect to reflection, absorption and/or refractive index. The layer thickness of the decorative layer 26 is preferably 0.1 m to 10 m, in particular 0.5 m to 5 m.

[0101] The decorative layer 26 can comprise a replication layer into which diffractively and/or refractively acting micro- or macrostructures are molded. This replication layer is preferably provided with a reflective layer which can consist of a metallization 28 and/or an HRI layer with a high refractive index (HRI=High Refractive Index). Here, the reflective layer can be opaque, semi-transparent or transparent.

[0102] One or more of the following structures can be molded in the replication layer: a diffractive structure, a zero-order diffraction structure, a blazed grating, a macrostructure, in particular a lens structure or microprism structure, a mirror surface, a matte structure, in particular an anisotropic or isotropic matte structure.

[0103] The structures in the replication layer can represent a pattern and/or a motif which can also be arranged in particular in register with the color layers of the decorative layer 26 and/or in register with the partial areas of the soft-touch varnish.

[0104] The metallization 28 is preferably produced by means of vapor deposition. Cr, Sn and/or Al are suitable in particular as metal. Through the use of a layer made of metal, a soft-touch film with metallic appearance is obtained. The vapor-deposited metallization 28 can be effected over the whole surface and either retained over the whole surface or else structured with known demetallization methods such as etching, lift-off or photolithography and thus be only partially present. The metallization 28 can also consist of a printed layer made of metallic pigments in a binder. These printed metallic pigments can be applied over the whole surface or to partially and have different colorings in different surface areas. The metallization 28 can represent a pattern and/or a motif which can also be arranged in particular in register with the color layers of the decorative layer 26 and/or with the structures of the replication layer and/or in register with the partial areas of the soft-touch varnish.

[0105] In addition, the transfer film 10, in particular the transfer ply 14, preferably has an adhesive layer 30 or a primer layer. The adhesive layer 30 or the primer layer ensures in particular that there is a good adhesion between the transfer film 10 or between the transfer ply 14 of the transfer film 10 and a plastic injection-molding composition 36 or a plastic body. The adhesive layer 30 can be applied here over the whole surface as well as only partially or in areas. The adhesive layer 30 or the primer layer preferably has a layer thickness of from 0.1 m to 10 m, in particular from 0.1 m to 3 m.

[0106] FIG. 2 shows a schematic sectional representation of a further transfer film 10. The structured varnish 18 is arranged partially, i.e. in areas, on the carrier layer 20 in FIG. 2. Ideally, the structured varnish 18 is arranged in the pattern on the carrier layer 20. Because the structured varnish 18 is arranged only in areas on the carrier layer 20, in particular surface areas with different levels of gloss or different mattings can be realized. In addition to the different optical properties, the different surface areas are characterized in particular with respect to reflection, absorption and/or refractive index, in particular by different friction and different tactile properties.

[0107] If the structured varnish 18 is arranged in the pattern or in areas on the carrier layer 20, then preferably areas 40 are present which have a matte effect, namely in particular areas in which the structured varnish 18 is located, and areas 38 are present which remain glossy. The glossy areas 38 can be the surface of the carrier layer 20. However, it is also possible to apply a further varnish layer, in particular a smooth varnish, to the carrier layer 20 in areas where no structured varnish 18 is present.

[0108] FIG. 3 shows a schematic sectional representation of a further transfer film 10. The carrier film 12 shown in FIG. 3 consists of the structured varnish 18. Here, preferably a self-supporting structured varnish 18 is involved. The structured varnish 18 is preferably formed from silicone. The structured varnish 18 advantageously has a Shore A hardness of from 10 to 50.

[0109] The thickness of the self-supporting structured varnish 18 is preferably between 10 m and 5000 m, in particular between 10 m and 500 m, in particular preferably between 10 m and 250 m. Advantageously, the master structure is incorporated into the structured varnish 18 by means of stamping.

[0110] The transfer ply 14 shown in FIG. 3 corresponds substantially to the transfer ply 14 shown in FIG. 1.

[0111] FIG. 4 shows a schematic sectional representation of a further transfer film 10. The transfer ply 14 of the transfer film 10 has a metallization 28. The metallization 28 is preferably produced by means of vapor deposition. Cr. Sn and/or Al are suitable in particular as metal. Through the use of a layer made of metal, in particular a soft-touch film with metallic appearance is obtained. The metallization 28 is formed over the whole surface in FIG. 4. However, it is also possible for the metallization 28 to be arranged only in areas, in particular in the pattern.

[0112] In order to obtain a good adhesion between the metallization 28 and the decorative layer 26, an adhesion promoter 24 is arranged between these layers.

[0113] The carrier film 12 represented in FIG. 4 corresponds substantially to the carrier film 12 represented in FIG. 1. It comprises a carrier layer 20 and a structured varnish 18 arranged over the whole surface thereof. However, the structured varnish 18 can also be arranged only in the pattern on the carrier layer 20.

[0114] FIGS. 5 and 6 each show a schematic sectional representation of a further transfer film 10, wherein a haptic varnish 32 is arranged at least in areas on the side of the carrier layer 20 facing away from the top coat 16. Haptic varnish 32 is substantially dimensionally stable. If a film with a haptic varnish 32 is processed further, for example in an IMD method or during hot stamping, then the haptic varnish 32 does not deform or deforms only negligibly. The use of a transfer film 10 with haptic varnish 32 for IMD or hot pressing makes it possible to form spatial structures in the area of the transfer ply 14 on a plastic article 34 decorated with same.

[0115] The haptic varnish 32 preferably has a layer thickness between 1 m and 500 m, in particular between 5 m and 100 m. In order to achieve a haptically detectable, spatial structuring, a haptic varnish 32 in particular at least 5 m, preferably at least 10 m thick is necessary which cannot be deformed or can be deformed only to a small extent under the processing conditions for the transfer film 10.

[0116] The transfer ply 14 represented in FIG. 5 corresponds substantially to the transfer ply 14 represented in FIG. 1. The transfer ply 14 represented in FIG. 6 corresponds substantially to the transfer ply 14 represented in FIG. 2.

[0117] FIG. 7 shows a schematic sectional representation of an injection-molded article 34 decorated with a transfer ply 10. The injection-molded article 34 is preferably produced by means of an IMD method. For this, the transfer film 10 is arranged in an injection mold. The transfer film 10 is then back injection molded with a plastic injection-molding composition 36. In a further step, the carrier film 12 together with the master structure is removed from the transfer ply 14 of the transfer film 10. As a result, the top coat 16 together with the further layers remains on the plastic injection-molding composition 36 and together with same forms the injection-molded article 34. The top coat 16 represents the outer layer of the injection-molded article 34. As a result, the injection-molded article 34 has a soft-touch effect.

LIST OF REFERENCE NUMBERS

[0118] 10 transfer film [0119] 12 carrier film [0120] 14 transfer ply [0121] 16 top coat [0122] 18 structured varnish [0123] 20 carrier layer [0124] 22 detachment layer [0125] 24 intermediary layer/adhesion promoter [0126] 26 decorative layer [0127] 28 metallization [0128] 30 adhesive layer/primer layer [0129] 32 haptic varnish [0130] 34 injection-molded article [0131] 36 plastic injection-molding composition [0132] 38 glossy area [0133] 40 matte area