Transfer Film, Method for Producing a Transfer FIlm, Use of a Transfer Film, and Method for Coating a Component

Abstract

A transfer film includes a carrier film and a transfer ply, wherein the transfer film is provided for transferring the transfer ply to a component. A deep-drawing membrane is arranged between the carrier film and the transfer ply. A method for producing a transfer film as well as the use of a transfer film and a method for coating a component with a transfer film.

Claims

1. A transfer film, comprising a carrier film and a transfer ply that can be detached from the carrier film, wherein the transfer film is provided for transferring the transfer ply to a three-dimensional component, and wherein a deep-drawing membrane is arranged between the carrier film and the transfer ply.

2. The transfer film according to claim 1, wherein the deep-drawing membrane is formed as a varnish layer with a layer thickness in the range of from 10 m to 200 m.

3. The transfer film according to claim 1, wherein the deep-drawing membrane is formed of polyurethane.

4. The transfer film according to claim 1, wherein the deep-drawing membrane is formed transparent, translucent or opaque.

5. The transfer film according to claim 1, wherein the deep-drawing membrane has a decoration or a motif.

6. The transfer film according to claim 1, wherein the deep-drawing membrane is not formed over the whole surface.

7. The transfer film according to claim 6, wherein the deep-drawing membrane is not formed in an edge area of the transfer film.

8. The transfer film according to claim 1, wherein, in its edge area, the deep-drawing membrane has a handling aid for peeling off the deep-drawing membrane.

9. The transfer film according to claim 1, wherein the deep-drawing membrane is formed stretchable by 200%.

10. The transfer film according to claim 1, wherein the deep-drawing membrane is formed as a printed layer.

11. The transfer film according to claim 1, wherein the deep-drawing membrane is formed of several layers.

12. The transfer film according to claim 1, wherein the deep-drawing membrane is formed as a homogeneous total layer.

13. The transfer film according to claim 1, wherein the transfer ply is formed as a multilayer body formed of transfer layers.

14. The transfer film according to claim 1, wherein the transfer ply comprises a first transfer layer facing the deep-drawing membrane, a second transfer layer and a third transfer layer.

15. The transfer film according to claim 14, wherein the first transfer layer is formed as a protective layer.

16. The transfer film according to claim 15, wherein the protective layer is formed as a protective varnish made of a PMMA-based varnish with a layer thickness in the range of from 2 m to 50 m.

17. The transfer film according to claim 15, wherein the protective layer is formed as a protective varnish made of a varnish based on PMMA (PMMA=polymethyl methacrylate) or a varnish based on a mixture of PVDF (PVDF=polyvinylidene fluoride) and PMMA, with a layer thickness in the range of from 2 m to 50 m.

18. The transfer film according to claim 14, wherein the second transfer layer is formed as a single- or multi-layered decorative layer.

19. The transfer film according to claim 18, wherein the second transfer layer is formed as a color layer.

20. The transfer film according to claim 19, wherein the color layer is formed of a varnish based on PMMA with a layer thickness in the range of from 1 m to 10 m.

21. The transfer film according to claim 14, wherein the third transfer layer is formed as a base coat.

22. The transfer film according to claim 21, wherein the base coat is formed with a layer thickness in the range of from 1 to 5 m.

23. The transfer film according to claim 1, wherein a first detachment layer is arranged between the carrier film and the deep-drawing membrane and wherein a second detachment layer is arranged between the deep-drawing membrane and the transfer ply.

24. The transfer film according to claim 23, wherein the first detachment layer and/or the second detachment layer comprises a wax.

25. The transfer film according to claim 23, wherein the first detachment layer and/or the second detachment layer are/is formed of montanic acid ester or polyethylene.

26. The transfer film according to claim 23, wherein the first detachment layer and/or the second detachment layer have/has a layer thickness smaller than 0.1 m.

27. The transfer film according to claim 23, wherein the force for detaching the carrier film from the deep-drawing membrane, because of the first detachment layer arranged between carrier film and deep-drawing membrane, is 5 to 10 times smaller than the force for detaching the deep-drawing membrane from the transfer ply, because of the second detachment layer arranged between deep-drawing membrane and transfer ply.

28. The transfer film according to claim 27, wherein the first detachment layer is formed of polyethylene wax and the second detachment layer is formed of montanic acid ester.

29. The transfer film according to claim 23, wherein the detachment force of the deep-drawing membrane, because of the second detachment layer arranged between deep-drawing membrane and transfer ply, is 30 to 70% smaller than the adhesive force between two neighboring transfer layers.

30. A use of a transfer film according to claim 1, in an IMD method.

31. A use of a transfer film according to claim 1, in an insert molding method.

32. A use of a transfer film according to claim 1, in a TOM.

33. A method for producing a transfer film according to claim 1, having a carrier film, a transfer ply that can be detached from the carrier film and a deep-drawing membrane arranged between the carrier film and the transfer ply, wherein the deep-drawing membrane is produced or applied by means of casting methods or by means of screen printing, gravure printing, flexographic printing or inkjet printing.

34. The method according to claim 33, wherein, the deep-drawing membrane is produced in several successive passes or from several layers.

35. The method according to claim 34, wherein to form the deep-drawing membrane, an applied layer is at least partially made surface-dry, before a further layer is applied to it to form the deep-drawing membrane.

36. The method according to claim 34, wherein, to form the deep-drawing membrane, an applied layer is completely dried or is dried through before a further layer is applied to it to form the deep-drawing membrane.

37. The method according to claim 34, wherein, to form the deep-drawing membrane, a following layer is applied in such a way that it etches the previously applied layer at least on the surface, with the result that a homogeneous total layer is formed.

38. The method according to claim 34, wherein a layer is applied in one pass with a thickness of 0.1 m to 50 m.

39. A method for coating a component with a transfer ply of a transfer film according to claim 1.

40. The method according to claim 39, wherein the method is formed as an IMD method, which comprises inserting the transfer film into an injection mold and back-injection molding the transfer film with a plastic, wherein the carrier film of the transfer film is peeled off after the back-injection molding and wherein the deep-drawing membrane is peeled off together with the carrier film or at a later point in time, shortly before or not until the component is used.

41. The method according to claim 39, wherein the method is formed as an insert molding method, which comprises laminating a substrate, deep-drawing the laminated substrate and back-injection molding the deep-drawn substrate with a thermoplastic, wherein the carrier film of the transfer film is peeled off the substrate after the lamination of the substrate, and wherein the deep-drawing membrane is peeled off the back-injection-molded substrate after the back-injection molding.

42. The method according to claim 39, wherein the method is formed as a TOM, which comprises laminating a substrate, coating the back of the substrate with a TOM base coat and applying the laminated and base-coated substrate to a three-dimensional component, wherein the carrier film of the transfer film is peeled off before or after the coating of the substrate, and wherein the deep-drawing membrane is peeled off the transfer ply after the application of the laminated and base-coated substrate to the component.

43. The method according to claim 39, wherein the method is formed as a TOM, which comprises applying the transfer film to a three-dimensional component, wherein the carrier film is peeled off the deep-drawing membrane before the application of the transfer film to the component, and wherein the deep-drawing membrane is peeled off the transfer ply after the application of the transfer film to the component.

Description

[0058] The invention is now explained in more detail with reference to embodiment examples. There are shown in:

[0059] FIG. 1 a first embodiment example of the transfer film according to the invention in a schematic sectional representation;

[0060] FIG. 2 a first method step for producing an insert using the transfer film in FIG. 1 in a schematic sectional representation;

[0061] FIG. 3 a second method step for producing an insert using the transfer film in FIG. 1 in a schematic sectional representation;

[0062] FIG. 4 a method step for forming a TOM laminating film using the transfer film in FIG. 1 in a schematic sectional representation;

[0063] FIG. 5 the coating of a component with the TOM laminating film in FIG. 4 in a schematic sectional representation;

[0064] FIG. 6 a second embodiment example of the transfer film according to the invention in a schematic sectional representation;

[0065] FIG. 7 a first method step of a TOM for coating a component with the transfer film in FIG. 1 in a schematic sectional representation;

[0066] FIG. 8 a second method step of a TOM for coating a component with the transfer film in FIG. 1 in a schematic sectional representation.

[0067] FIG. 1 shows a transfer film 1, which comprises a carrier film 11, a first detachment layer 12, a deep-drawing membrane 13, a second detachment layer 14 and a transfer ply 15 with several transfer layers 151, 152, 153.

[0068] The further details describe the embodiment example represented in FIG. 1.

[0069] The carrier film 11 is formed as a PET film with a layer thickness in the range of from 12 to 100 m.

[0070] The deep-drawing membrane 13 is formed as a varnish layer made of polyurethane with a layer thickness in the range of from 10 m to 200 m, preferably in the range of from 20 m to 100 m, further preferably of from 25 m to 75 m. The polyurethane can be solvent-based or an aqueous dispersion. The polyurethane must be sufficiently deformable and can be composed of different polymers. These include polyurethanes made of e.g. polyester polyols, polyether polyols, polycarbonate polyols, polyacrylate polyols and combinations of these polymers. Polyurethane made of polyester polyols can preferably be used. These polymers form the basis for varnish formulations from which the deep-drawing membrane 13 is produced.

[0071] In order to achieve a sufficient layer thickness, these layers can preferably be produced in the casting method, for example by means of application with a slit die, or also by means of screen printing, gravure printing, flexographic printing or inkjet printing. The named production methods can be applied in one pass or in several successive passes.

[0072] The first-applied varnish layer is preferably at least partially dried between the successive passes, with the result that the varnish layer is at least surface-dry. However, the varnish layer can in particular also be dried through. After this drying the following varnish layer is deposited, wherein the following varnish layer etches the previously deposited varnish layer in particular at least on the surface such that both varnish layers together form a homogeneous total varnish layer. In the case of more than two successive varnish layers, the procedure is performed a corresponding number of times in order that all successive varnish layers together form a homogeneous total varnish layer.

[0073] In a preferred embodiment a varnish layer is applied in one pass with a layer thickness in the range of from 0.1 m to 50 m, preferably in the range of from 0.1 m to 35 m, further preferably in the range of from 1 m to 25 m. By means of such comparatively thin partial varnish layers, as described above, total varnish layers with greater layer thicknesses can then be built up.

[0074] The deep-drawing membrane 13 is formed stretchable by 200%, preferably by 500% to over 1500% at a deep-drawing temperature in the rance of from 130 C. to 160 C.

[0075] The first detachment layer 12 is arranged between the carrier film 11 and the deep-drawing membrane 13, is formed of a wax, which can be e.g. carnauba wax, montanic acid ester, polyethylene wax, polyamide wax or PTFE wax, and has a layer thickness in the range of less than 0.1 m. Moreover, surface-active substances such as silicones are suitable as first detachment layer. Thin layers of varnishes crosslinked with melamine formaldehyde resin can also act as first detachment layer.

[0076] A second detachment layer 14 is arranged between the deep-drawing membrane 13 and the transfer ply 15. The second detachment layer 14, like the first detachment layer 12, is formed of a wax, which can be e.g. carnauba wax, montanic acid ester, polyethylene wax, polyamide wax or PTFE wax, and has a layer thickness in the range of less than 0.1 m. Moreover, surface-active substances such as silicones are suitable as second detachment layer 14. Thin layers of varnishes crosslinked with melamine formaldehyde resin can also act as second detachment layer 14.

[0077] The force for detaching the carrier film 11 from the deep-drawing membrane 13, because of the first detachment layer 12 arranged between carrier film 11 and deep-drawing membrane 13, is 5 to 10 times smaller than the force for detaching the deep-drawing membrane 13 from the transfer ply 15, because of the second detachment layer 14 arranged between deep drawing membrane 13 and transfer ply 15. For this, the first detachment layer 12 can, for example, be made of polyethylene wax and the second detachment layer 14 can, for example, be made of montanic acid ester.

[0078] The transfer ply 15 is formed as a multilayer body which has three transfer layers 151 to 153.

[0079] The first transfer layer 151 faces the second detachment layer and is formed as a protective layer. The first transfer layer can be formed, for example, as a protective varnish made of acrylate with a layer thickness of 4 m to 8 m or of polyurethane with a layer thickness of 15 m to 30 m.

[0080] The second transfer layer 152 is formed as a color layer made of acrylate with a layer thickness of 4 m to 20 m.

[0081] The third transfer layer 153 is formed as a base coat with a layer thickness of 1 m to 5 m. Raw materials coming into consideration for the base coat are PMMA, PVC, polyester, polyurethanes, chlorinated polyolefins, polypropylene or epoxy resins or polyurethane polyols in combination with deactivated isocyanates. The base coats can moreover contain inorganic fillers.

[0082] The force for detaching the deep-drawing membrane 13 from the transfer ply 15, because of the second detachment layer 14 arranged between deep-drawing membrane 13 and transfer ply 15, is approximately 30% to 70% smaller than the adhesive force of the neighboring transfer layers 151 to 153 with respect to each other.

[0083] FIGS. 2 and 3 show method steps for producing an insert using the transfer film 1 described in FIG. 1.

[0084] FIG. 2 shows the application of the transfer film 1 under the action of temperature and pressure (indicated by directional arrows in FIG. 2) to a substrate 2 as well as the detachment of the carrier film 11 after the lamination of the substrate 2.

[0085] The substrate 2 can be formed, for example, as a film made of ABS (acrylonitrile-butadiene-styrene copolymer) with a layer thickness in the range of from 100 m to 1000 m.

[0086] It has proved to be worthwhile to apply a linear load in the range of from 0.1 kN/cm to 1.0 kN/cm, preferably in the range of from 0.3 kN/cm to 0.4 kN/cm, at a temperature in the range of from 120 C. to 300 C., preferably in the range of from 180 C. to 220 C., in order to join the transfer film 1 to the substrate.

[0087] FIG. 3 shows a further method step, in which the substrate 2 laminated with the transfer film 1 is vacuum-formed using a mold 3 at a temperature in the range of from 130 C. to 160 C., wherein the deep-drawing membrane 13 is then removed from the transfer ply 15. During the deep-drawing, the deep-drawing membrane 13 absorbs the tensile forces of the strains occurring and at the same time defines the surface quality of the protective layer of the transfer ply 15 lying underneath it. There is thus a finished decorated insert 4, which is trimmed by die cutting in the following steps and back-injection-molded with a thermoplastic.

[0088] FIGS. 4 and 5 show method steps for coating a component 5 with a TOM laminating film.

[0089] In a first method step the transfer film 1 is laminated onto a smooth, flat substrate 2 and after the lamination the carrier film 11 is removed, as described further above in FIG. 2.

[0090] Thereafter, to form a TOM laminating film on the back of the substrate 2, a TOM base coat with layer thicknesses of 5 m to 20 m is applied, as represented in FIG. 4. Such base coats for the TOM usually consist of polypropylene, of a combination of polyurethane polyols with deactivated isocyanates, polyurethanes or epoxy resins. If epoxy resins are used it is advantageous to apply a suitable spray base coat to the component in addition to the base coat. These spray base coats typically contain various raw materials containing amino groups. The other types are heat-activated.

[0091] A further method step is represented in FIG. 5, in which in the TOM a three-dimensional component 5 is coated with the TOM laminating film described in FIG. 4 and then the deep-drawing membrane 13 is removed.

[0092] In a further method step the coating of the component 5 is trimmed by die cutting, milling or laser trimming.

[0093] FIG. 6 shows a second embodiment example of the transfer film. A transfer film 1 is formed like the transfer film described in FIG. 1, with the difference that the third transfer layer 153 is formed as a TOM base coat. The TOM base coat has a comparatively large layer thickness and is preferably formed as a combination of polyurethane polyols with deactivated isocyanates. The TOM base coat is already activatable at the low process temperatures of approximately 100 C. to 180 C. and the low process pressures of 0.1 bar to 2 bar and, because of the crosslinking reaction effected by the activation, can have a higher temperature resistance on the finished component. The transfer film 1 is used in the TOM. In the case of the transfer film, the trimming by die cutting, milling or laser trimming is dispensed with.

[0094] FIG. 7 shows a first method step, in which the carrier layer 11 is peeled off the transfer film 1.

[0095] FIG. 8 shows a second method step, in which in the TOM a component 5 is coated with the layer composite described in FIG. 7.

[0096] The deep-drawing membrane 13 is peeled off after the coating of the component 6, wherein residues 15r of the transfer ply 15 remaining on the deep-drawing membrane 13 are also removed. The transfer ply 15 here has the necessary mechanical brittleness in order that a clean separation of the transfer ply 15 between the parts thereof applied to the component 5 and the residues 15r can be effected at the edge of the component 5. The transfer ply 15 is finally trimmed with edges flush with the component 5.

LIST OF REFERENCE NUMBERS

[0097] 1 transfer film

[0098] 2 substrate

[0099] 3 mold

[0100] 4 insert

[0101] 5 component

[0102] 11 carrier film

[0103] 12 first detachment layer

[0104] 13 deep-drawing membrane

[0105] 14 second detachment layer

[0106] 15 transfer ply

[0107] 15r residual portion of the transfer ply

[0108] 16 TOM base coat

[0109] 151 first transfer layer

[0110] 152 second transfer layer

[0111] 153 third transfer layer