WO2019202570A1

WO2019202570A1 - Filmless decal

Info

Publication number: WO2019202570A1
Application number: PCT/IB2019/053277
Authority: WO
Inventors: Kris Nuyts; An J. VAN DIJCK; Dirk Kolowrot; Pierre BIEBER; Paul KOWALKOWSKI
Original assignee: 3M Innovative Properties Company
Priority date: 2018-04-19
Filing date: 2019-04-19
Publication date: 2019-10-24
Also published as: CN112004897A; EP3781633A1

Abstract

Provided is a filmless decal and a process for making a filmless decal.

Description

FILMLESS DECAL

Summary

[0001] In one aspect, this application relates to a filmless decal, the filmless decal comprising an adhesive layer having a thickness of from 5 to 30 microns and a print layer on at least a portion of the adhesive layer.

[0002] In another aspect, this application relates to an article comprising a substrate and the filmless decal.

[0003] In yet another aspect, this application relates to a process for making a filmless decal. The process comprises providing an adhesive layer and applying a print layer on at least a portion of the adhesive layer to provide a filmless decal. When the adhesive layer is a UV-cured adhesive layer, the process may also include curing the adhesive layer using ultra-violet radiation to provide a UV-cured adhesive layer, and applying the print layer on at least a portion of the UV-cured adhesive layer to provide the filmless decal.

Brief Description of the Drawings

[0004] Figure 1 provides a cross section of a film decal according to the state of the art.

[0005] Figure la provides cross section of the transition area for a film decal.

[0006] Figure 2 provides a cross section of a filmless decal on a substrate.

[0007] Figure 2a provides a cross section of the transition area for a filmless decal on a substrate.

[0008] Figure 3 provides a cross section of a stepped ridge filmless decal on a substrate.

[0009] Figure 3a provides a cross section of the transition area for a stepped ridge filmless decal on a substrate.

[0010] Figure 4 provides a flow chart for a process for making a filmless decal.

[0011] Figures 5a-5g provide a cross section view of a manufacturing process for a filmless decal.

Detailed Description

[0012] The applicants have found that state of the art custom manufacturing and painting of bicycle frames involves a complicated and time-consuming process. Current manufacturers use a stencil for each color to be painted, which, considering the drying time for each color layer, leads to long, multi-step manufacturing. [0013] The applicants have found that one potential solution is the use of decals, printed and/or electrocut, to provide graphics (e.g., logos, multi-toned colors, stylized designs, and the like). Once these are applied, the manufacturer can apply a topcoat layer. Unfortunately, state of the art film decals are too thick and provide an unacceptable deformation in the topcoat (e.g., a ridge at the transition area, or the edge, of the film decal).

[0014] This effect can be aptly observed in Figure 1, where film decal 100 is shown. In such state of the art film decals, the decals typically have adhesive layer 130, film layer 140, and print layer 150. Such decals may be applied to substrate 120 and encased or covered by topcoat layer 160. Such solutions, however, suffer from the issue, highlighted in Figure la, that at transition area la, because of the height of the film decal, there is an unacceptable ridge formed. This can be somewhat smoothed out by topcoat layer 160. However, due to the height of film decal 100, the ridge provides an aesthetically unacceptable effect (shown in Figure la as having ridge height hi, as measured from the topcoat low point to topcoat high point). Further, it is possible that in applications that demand an elevated level of aerodynamic performance, such as for competitive racing bicycles, the ridges produce an unacceptable increase in technical

performance (e.g., from increased wind resistance).

[0015] A potential solution to this problem of custom manufacturing and painting in a technically and aesthetically advanced manner, which may be applied more broadly than just for bicycle frames, involves the use of a filmless decal.

[0016] Representative filmless decal 200 is shown in Figure 2 on substrate 220. Filmless decal 200 comprises adhesive layer 230 having a thickness of from 5 to 30 microns, or even from 5 to 20 microns, and print layer 250 on at least a portion of the adhesive layer. For the sake of simplicity in visualizing filmless decal 200 in use, it is shown in Figure 2 on substrate 220, but to be clear, substrate 220 is not itself part of filmless decal 200.

[0017] The adhesives useful in adhesive layer 230 are not particularly limited and may include any of the well-known classes of UV-curable adhesive materials or any of the well- known pressure sensitive adhesive materials, particularly pressure sensitive adhesive materials that comprise a rubber-based elastomer material, as well as those that comprise acrylates.

[0018] Suitable UV-curable adhesives may be chosen, for instance, for their high

transparency and/or stability, especially in the conditions to which the final article will be subjected (e.g., sunlight, heat, humidity). They may also be chosen based on other considerations that may ease the manufacturing process or application of filmless decals, such as fast curing, flexibility of the adhesive, repositionable nature of the adhesive, and viscosity. Such UV-curable adhesive should also show good properties as a substrate for printing. For instance, the color- fastness, ability to add pigments to the adhesive (in order to enhance the colors of the printed layer) may be taken into consideration.

[0019] UV-curable adhesives in adhesive layer 230 may be cured by processes known in the art. Generally, UV (or ultraviolet) light is emitted by a source and provides the energy to begin a reaction photoinitiator present in the UV-curable adhesive. Difference UV-curable adhesives use photoinitiators that are sensitive to different ranges of UV light. It is therefore important to match the material being cured with the light source being used.

[0020] Typically, a UV-curable adhesive uses a broad spectrum of UV light with a concentration in the UVA range to achieve curing.

[0021] Factors that influence the cure speed of UV-curable adhesive materials include light intensity provided on the UV-curable adhesive, the light wavelength being used, the

photoinitiator sensitivity to the light wavelength being used, and the UV-curable adhesive material resin composition.

[0022] There are two basic types of UV-curable adhesive materials in widespread industrial use, acrylates and epoxies.

[0023] The term acrylate refers to a broad range of materials including acrylates,

methacrylates, and similar functional groups. Acrylate systems react when exposed to UV-light (specifically UVA light) and in many cases also visible light. These materials exhibit a broad range of properties. Depending upon the additive packages being used, such adhesives may be colored (e.g., red, blue, black), opaque, fluorescing (which may be aesthetically desirable in the filmless decal application, or may provide a means for in-line process inspection), or thermally conductive. The physical properties of acrylate systems are generally easier to control than for epoxies and can include adhesion strength, viscosity, durometer, and appearance.

[0024] Cure speeds for acrylate resins depend on formulation specifics, and of course, on the intensity and nature of the light used to cure them. Cure depth can also be varied with formulation and process specifics.

[0025] Further, surface tack can be controlled with acrylate containing UV-curable adhesive materials. Surface tack is generally caused by the interference of atmospheric oxygen with the free radical cure mechanism on the surface of the acrylate resins. This surface tack can be controlled by altering the curing process (e.g., light intensity, cure time, wavelength of light used) and can be adjusted as necessary to facilitate the application of print layer 250.

[0026] Epoxy materials are the second main type of UV-curable adhesive materials. UV- curable adhesive materials containing epoxy resins may be formulated to exhibit some advantageous properties such as a tack free cure and superior adhesion to certain substrates. In some cases, the development of the full properties of UV-curable adhesive materials containing epoxy resins may take longer than for acrylate materials. In such cases, heat is sometimes used to accelerate the curing. Further, curing of epoxy resins can be impeded by moisture and/or humidity.

[0027] The adhesive layer may comprise a pressure sensitive adhesive, particularly a pressure sensitive adhesive comprising a rubber-based elastomeric material, or a pressure sensitive adhesive comprising an acrylate material.

[0028] Pressure sensitive adhesives (PSAs) may possess one or more of the following properties: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength.

[0029] Materials that have been found to function well as PSAs include polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. PSAs are characterized by being normally tacky at room temperature (e.g., 20°C). Compositions are not necessarily considered to be PSAs merely because they are sticky or adhere to a surface.

[0030] These requirements are assessed generally by means of tests which are designed to individually measure tack, adhesion (peel strength), and cohesion (shear holding power), as noted in A.V. Pocius in Adhesion and Adhesives Technology: An Introduction, 2^nd Ed., Hanser Gardner Publication, Cincinnati, OH, 2002. These measurements taken together constitute the balance of properties often used to characterize a PSA.

[0031] According to an exemplary aspect, the rubber-based elastomeric material for use herein is selected from the group consisting of natural rubbers, synthetic rubbers, thermoplastic elastomeric materials, non-thermoplastic elastomeric materials, thermoplastic hydrocarbon elastomeric materials, non-thermoplastic hydrocarbon elastomeric materials, and any

combinations or mixtures thereof.

[0032] In one aspect of the disclosure, the rubber-based elastomeric material for use herein is selected from the group consisting of halogenated butyl rubbers, in particular bromobutyl rubbers and chlorobutyl rubbers; halogenated isobutylene-isoprene copolymers; bromo- isobutylene-isoprene copolymers; chloro-isobutylene-isoprene copolymers; block copolymers; olefmic block copolymers; butyl rubbers; synthetic polyisoprene; ethylene-octylene rubbers; ethylene-propylene rubbers; ethylene-propylene random copolymers; ethylene-propylene-diene monomer rubbers; polyisobutylenes; poly(alpha-olefm); ethylene-alpha-olefm copolymers; ethylene-alpha-olefm block copolymers; styrenic block copolymers; styrene-isoprene-styrene block copolymers; styrene-butadiene-styrene block copolymers; styrene-ethylene/butadiene- styrene block copolymers; styrene-ethylene/propylene-styrene block copolymers; styrene- butadiene random copolymers; olefmic polymers and copolymers; ethylene-propylene random copolymers; ethylene-propylene-diene terpolymers, and any combinations or mixtures thereof.

[0033] As mentioned above, when a UV-curable adhesive is used, they may be chosen for their high transparency. In situations where vibrant colors are provided on a filmless decal to be applied onto a colored substrate, however, such transparency can result in filmless decals that do not give sufficient contrast (e.g., the color of the substrate can be seen through the decal).

[0034] In order to overcome the natural transparency of the filmless decal, one may add inorganic pigments or pastes into the uncured UV-curable adhesives. Suitable materials include titanium dioxide, zinc oxide, calcium carbonate, and mixtures thereof. However, all of these materials have relatively high material density. Incorporation of such pigments into a UV- curable adhesive may not be stable and, even when they are, they may interfere with the curing process and thus negatively affect the adhesion of the filmless decal to the substrate.

[0035] In such situations, it may be beneficial to choose instead a pressure sensitive adhesive comprising a rubber-based elastomeric material. Into such adhesives, inorganic pigments or pastes, such as titanium dioxide, zinc oxide, calcium carbonate, and mixtures thereof may be added. The level of the pigment can be adjusted based upon color performance, material handling factors, formulation stability, and the like. Typical loadings may range from 5 to 150 parts per hundred rubber (by weight as measured against the weight rubber-based elastomeric material). In particular, from 20 to 100 phr, from 10 to 80 phr, or even from 10 to 50 phr.

[0036] Print layer 250 may be provided by any printer capable of printing onto the adhesive layer 230. When a UV-curable adhesive is used, the UV-curable resin may be pre-cured before printing or may be cured simultaneous to the laying of print layer 250.

[0037] One specific printer that may be useful in providing print layer 250 is the Rho 162 TS roll-to-toll flatbed UV inkjet printer (available from Durst Phototechnik Digital Technology GmbH, Lienz, Austria). The Rho 162 is available as a roll-to-roll or flatbed inkjet printer designed specifically to apply UV-curable inks available from 3M Company (Saint Paul, Minnesota, USA).

[0038] Useful materials for preparing print layer 250 include any print materials (e.g., inks) that are suitable to the technical and aesthetic effects of the desired end use of the filmless decal.

[0039] For instance, especially (but not only) when used in conjunction with the Rho 162 printer discussed, 3M 8800 series UV curable inks may be especially useful. Such inks which may dual cure in the Rho 162 in one single step with the UV-curable adhesive layer. This ink was specifically designed as part of the 3MTMMCS (Matched Component System) for application using the Rho 161 or Rho 162 printer.

[0040] In the present application, when it is explained that print layer 250 is on at least a portion of adhesive layer 230, it is meant that the print layer may completely cover adhesive layer 230 or may cover only a portion of adhesive layer 230. The choice here will generally depend on considerations such as the weight of the filmless decal, the thickness of the filmless decal, the aesthetic design to be imparted by the filmless decal, or any combination of these factors. Furthermore, in situations where print layer 250 does not completely cover adhesive layer 230, consideration must be given to the aesthetic effect of such partial covering. That is, it may be that adhesive layer 230 will be visible in such an instance (especially where a clear topcoat layer is used). Thus, in one embodiment, adhesive layer 230 is optically clear. In other embodiments, adhesive layer 230 may be chosen (or, e.g., pigments or other additives may be provided) such that the adhesive that is not covered by print layer 250 demonstrates a desired optical characteristic (e.g., a desired color, finish, or the like).

[0041] For instance, print layer 250 may stop before the edge of adhesive layer 230, in order to provide a stepped changed in height of the filmless decal, where transition area 2a shows a more gradual ridge profile, thus minimizing the aerodynamic and aesthetic effects of the ridge itself. This approach is shown in more detail in Figure 3. However, for handling and

manufacturing simplicity, it may also occur that print layer 250 extends all the way to the edge of adhesive layer 230, as shown in Figure 2. As shown in Figure 2a (comparing to Figure la), ridge height h2 is generally smaller than ridge height hi, providing for a smoother transition provided by the filmless decal, better aesthetics, and potentially better aerodynamics. The smoothness of the transition is a property determined by both ridge height h2 and the distance over which the ridge height is achieved, indicated by ridge depth 12

[0042] In practice, filmless decal 200 may be applied to substrate 220. Again, for the sake of simplicity in visualizing filmless decal 200 in use, it is shown in Figure 2 on substrate 220, but to be clear, substrate 220 is not itself part of filmless decal 200. Suitable materials for substrate 220 include, but are not limited to filled polymer composites (e.g., carbon fiber composites, glass fiber filled composites), metals (e.g., aluminum and aluminum alloys, steel, and titanium).

[0043] Thus, substrates for filmless decal 200 may be chosen according to the desired end use application. For instance, while it is discussed herein to use such filmless decals for bicycle frame customization, they may also be used for the customization of car or bike tire rims, to apply to the outside of metal or sheet molded composite industrial equipment such as air compressors or other metal powder coated materials. [0044] In one aspect, the inventors have noticed that sheet molded compounds and other plastic compounds (e.g., ABS, especially as used in industrial and/farm equipment) tends to outgas. This can result, when a calendared film or laminate film is applied, to forming bubbles which can affect the aesthetics of the films and/or cause adhesive failure. On the other hand, with the use of filmless decals described herein may allow outgassing.

[0045] Once applied to substrate 220, articles of the present invention may further include topcoat layer 260 covering at least a portion of filmless decal 200, at least a portion of substrate 220, and at least a portion of transition area 2a. Suitable materials for topcoat layer 260 include, but are not limited to polyurethane materials, powder coating materials, and epoxy enamels.

[0046] When decals generally are applied used outside (e.g., in industrial and/or agricultural applications) weathering can occur, especially when there is not a topcoat on a decal (which topcoats are often avoided if the decal is too thick, such as with a film containing decal). Further, because vibration and/or shear forces, prior art decals can be sheared off or damaged. In contrast, the combination of a smooth profile and the use of a topcoat, as described in some embodiments of this application, can provide for a more robust decal solution that does not suffer the same weathering and/or damage in use as film containing decals.

[0047] Another representative filmless decal, stepped ridge filmless decal 300, is shown in Figure 3. Stepped ridge filmless decal 300 comprises adhesive layer 330 having a thickness of from 5 to 30 microns, and print layer 350 on at least a portion of adhesive layer 330.

[0048] The adhesives useful in adhesive layer 330 are the same as those described above with regard to adhesive layer 230.

[0049] Print layer 350 may be provided by any printer capable of printing onto the adhesive layer 330. When used, a UV-curable resin may be pre-cured before printing, or may be cured simultaneous to the laying of print layer 350.

[0050] One specific printer that may be useful in providing print layer 350 is the Rho 162 TS roll-to-toll flatbed UV inkjet printer (available from Durst Phototechnik Digital Technology GmbH, Lienz, Austria). The Rho 162 is available as a roll-to-roll or flatbed inkjet printer designed specifically to apply UV-curable inks available from 3M Company (Saint Paul, Minnesota, USA).

[0051] Useful materials for preparing print layer 350 include any print materials (e.g., inks) that are suitable to the technical and aesthetic effects of the desired end use of the filmless decal.

[0052] For instance, especially (but not only) when used in conjunction with the Rho 162 printer discussed, 3M 8800 series UV curable inks may be especially useful. Such inks which may dual cure in the Rho 162 in one single step with the UV-curable adhesive layer. This ink was specifically designed as part of the 3MTMMCS (Matched Component System) for application using the Rho 161 or Rho 162 printer.

[0053] In this embodiment, when it is explained that print layer 350 is on at least a portion of adhesive layer 330, it may be that the print layer covers only a portion of adhesive layer 330. For instance, as shown in Figure 3, print layer 350 may stop, as shown, other than at the edge of adhesive layer 330, to provide a stepped changed in height of the filmless decal. This effect is shown in more detail in transition area 3a (indicating a more gradual ridge profile, thus minimizing the aerodynamic and aesthetic effects of the ridge itself). In this embodiment, while ridge height h3 may be substantially the same as ridge height h2, there is provided yet an even smoother transition by the filmless decal on substrate 320, because substantially the same height is covered over a larger ridge depth 13. This smoother transition effect may lead, for instance, to better aesthetics, and potentially better aerodynamics. Furthermore, it may make such filmless decals more robust and less prone to accidental damage when the surface of substrate 320 is washed (e.g., power washed), scraped, abraded, impacted, sand blasted, or otherwise disturbed.

[0054] As discussed above, in such embodiments as these, where print layer 350 does not completely cover adhesive layer 330 (e.g., by leaving a stepped ridge configuration as shown in Figure 3), consideration must be given to the aesthetic effect of such partial covering. That is, in such instances, adhesive layer 330 may be visible (especially where a clear topcoat layer is used). Thus, in one embodiment, adhesive layer 330 is optically clear. In other embodiments, adhesive layer 330 may be chosen (or, e.g., pigments or other additives may be provided) such that the adhesive that is not covered by print layer 350 demonstrates a desired optical characteristic (e.g., a desired color, finish, or the like). More specifically, such a stepped profile design may take advantage of adhesive layer 330 to provide an outline of the decal, accentuating print layer 350, and possibly providing aesthetically pleasing contrast to the design (in addition to the more gradual ridge profile).

[0055] In practice, stepped ridge filmless decal 300 may be applied to substrate 320. Suitable materials for substrate 320 include, but are not limited to filled polymer composites (e.g., carbon fiber composites, glass fiber filled composites), metals (e.g., aluminum and aluminum alloys, steel, and titanium).

[0056] Thus substrates for filmless decal 300 may be chosen according to the desired end use application. For instance, while it is discussed herein to use such filmless decals for bicycle frame customization, they may also be used for the customization of car or bike tire rims, to apply to the outside of metal or sheet molded composite industrial equipment such as air compressors or other metal powder coated materials. [0057] In one aspect, the inventors have noticed that sheet molded compounds and other plastic compounds (e.g., ABS, especially as used in industrial and/farm equipment) tends to outgas. This can result, when a calendared film or laminate film is applied, to forming bubbles which can affect the aesthetics of the films and/or cause adhesive failure. On the other hand, with the use of filmless decals described herein may allow outgassing.

[0058] Once applied to substrate 320, articles of the present invention may further include topcoat layer 360 covering at least a portion of stepped ridge filmless decal 300, at least a portion of substrate 320, and at least a portion of transition area 3a. Suitable materials for topcoat layer 360 include, but are not limited to polyurethane materials, powder coating materials, and epoxy enamels.

[0059] When decals generally are applied with a topcoat layer and used outside (e.g., in industrial and/or agricultural applications) weathering can occur, especially when there is not a topcoat on a decal (which topcoats are often avoided if the decal is too thick, such as with a film containing decal). Further, because vibration and/or shear forces, prior art decals can be sheared off or damaged. In contrast, the combination of a smooth profile and the use of a topcoat, as described in some embodiments of this application, can provide for a more robust decal solution that does not suffer the same weathering and/or damage in use as film containing decals.

[0060] In general, manufacturing of the filmless decals of the present application can be carried out as provided in the generalized process of Figure 4. In particular, the process may begin with the optional step 405 to apply an adhesive layer to a carrier layer. Next, step 410 indicates an optional step of curing of a UV-curable adhesive layer to give a UV-cured adhesive layer (when such adhesives are used). Of course, when a PSA is used, no such curing step is necessary. Then a print layer may be applied to at least a portion of the adhesive layer per step 420. Next, one may optionally apply a transfer tape to the resulting filmless decal in step 425 and remove carrier layer 430. The resulting filmless decal with a transfer tape instead of the initial carrier layer (thus with adhesive exposed) may then optionally be applied to a substrate surface per step 435, and the optional transfer layer removed, if present, in step 437. Finally, the process may include optionally applying a topcoat layer per step 440.

[0061] In the present application, when it is discussed to cure a UV-curable adhesive layer or a UV-cured adhesive layer is discussed, it is understood that at least the surface upon which the print layer is applied is cured. Curing may extend more or less into the adhesive layer, but complete curing does not extent all the way to the surface opposite the print layer, as such curing (or at least complete curing) would reduce the adhesive capacity of the adhesive layer when applied, for instance, to a substrate. Such UV curing may take place well before the print layer is applied to the UV-cured adhesive layer, or may take place essentially simultaneous to applying the print layer to the newly UV-cured adhesive layer.

[0062] A more specific example of manufacturing of a filmless decal is shown in Figures 5a to 5g. Starting in Figure 5a, provided is optional carrier layer 510 with adhesive layer 530 disposed thereon. Next, in step 5b, to at least a portion of adhesive layer 530 is applied print layer 550. Next, in step 5c, transfer layer 570 is added to the face of print layer 550 that is opposite adhesive layer 530. Per step 5d, optional carrier layer 510 is then removed to expose the surface of adhesive layer 530 opposite print layer 550. Next, in step 5e, the entire assembly may be applied to substrate 520 by making contact between the exposed surface of adhesive layer 530 and substrate 520. Next, in step 5f, transfer layer 570 can be removed, and in step 5g, topcoat layer 560 may be applied.

[0063] The present disclosure may be exemplified, for instance, in the following

embodiments.

[0064] Embodiment 1. A filmless decal comprising an adhesive layer having a thickness of from 5 to 30 microns and a print layer on at least a portion of the adhesive layer.

[0065] Embodiment 2. The filmless decal of embodiment 1, wherein the adhesive layer comprises a UV-cured adhesive layer.

[0066] Embodiment 3. The filmless decal of embodiment 2, wherein the UV-cured adhesive layer has a thickness of from 5 to 20 microns.

[0067] Embodiment 4. The filmless decal of any of embodiments 2 to 3, wherein the UV-cured adhesive layer comprises an adhesive selected from the group consisting of an acrylate and an epoxy.

[0068] Embodiment 5. The filmless decal of any of the embodiments 2 to 4, wherein the adhesive is an acrylate.

[0069] Embodiment 6. The filmless decal of any of embodiments 2 to 5, wherein the UV-cured adhesive layer and the print layer define a first height, and the first height is less than 50 microns.

[0070] Embodiment 7. The filmless decal of any of embodiments 2 to 6, wherein the first height is less than 30 microns.

[0071] Embodiment 8. The filmless decal of embodiment 1, wherein the adhesive layer comprises a pressure sensitive adhesive.

[0072] Embodiment 9. The filmless decal of embodiment 8, wherein the pressure sensitive adhesive is selected from the group consisting of a rubber-based elastomeric material, and an acrylate material. [0073] Embodiment 10. The filmless decal of embodiment 9, wherein the rubber-based elastomeric material is selected from the group consisting of natural rubbers, synthetic rubbers, thermoplastic elastomeric materials, non-thermoplastic elastomeric materials, thermoplastic hydrocarbon elastomeric materials, non-thermoplastic hydrocarbon elastomeric materials, and any combinations or mixtures thereof.

[0074] Embodiment 11. An article comprising a substrate and the filmless decal of any of the preceding embodiments.

[0075] Embodiment 12. The article according to embodiment 11, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate define a transition area.

[0076] Embodiment 13. The article according to embodiment 12, further comprising a topcoat layer covering at least a portion of the filmless decal, at least a portion of the substrate, and at least a portion of the transition area.

[0077] Embodiment 14. The article according to any of embodiments 11 to 13, wherein the substrate is selected from a metal and a polymer composite.

[0078] Embodiment 15. A process for making a filmless decal, the process comprising:

[0079] providing an adhesive layer, and

[0080] applying a print layer on at least a portion of the adhesive layer to provide a filmless decal.

[0081] Embodiment 16. The process according to embodiment 15, further comprising applying the adhesive layer onto a carrier layer.

[0082] Embodiment 17. The process according to any one of embodiments 15 to 16, further comprising applying the filmless decal onto a substrate surface.

[0083] Embodiment 18. The process according to embodiment 17, wherein the substrate surface is curved.

[0084] Embodiment 19. The process according to any one of embodiments 17 to 18, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate surface define a transition area.

[0085] Embodiment 20. The process according to embodiment 19, further comprising applying a topcoat layer covering at least a portion of the filmless decal, at least a portion of the substrate surface, and at least a portion of the transition area.

[0086] Embodiments of the present disclosure are explained in more detail with the following non-limiting examples. Examples

[0087] Table 1. Materials Examples 1-3

[0088] Example 1

[0089] Printing on an adhesive

[0090] Transfer tape 467MP on a release liner, was printed with various colors using a DEIRST Rho 162 ETV-printer (Durst) (using 3M ETV 8800 series inks). Application tape

SCPS100 was then applied to the printed transfer tape 467MP and adhered to an ALET36 Q Panel. The printed layer was measured as 50 pm.

[0091] Example 2

[0092] Preparation of a Filmless Decal with a ETV-curable adhesive

[0093] ETV-curable pressure sensitive adhesive 7555T PCA (3M Company) was applied to a liner material using a K-bar. The adhesive had a thickness of 6 pm. The adhesive was then cured using a UV-lamp of 400 W having an energy dose of 0.8 mJ/cm².

[0094] After curing, the adhesive was laminated with a release liner (silicone coated release liner available under the tradename Akrosil from Mondi Akrosil, Pleasant Prarie, Wisconsin, ETSA) for further handling. [0095] After removal of the release liner, a print layer was applied using a DURST Rho 162 UV-printer. This printed adhesive was then transferred with the aid of application tape SCPS100 onto an ALU36 Q panel. The resulting panel had a print layer of 16pm and an adhesive of 6pm for a total layer thickness of 22 pm.

[0096] Example 3

[0097] Application to a curved surface

[0098] A filmless decal was prepared as described in Example 2. Instead of transferring the filmless decal to an ALU36 Q panel, the filmless decal of Example 3 was transferred onto a carbon treated bike frame substrate. Application tape SCPS100 was also used for this transfer. The filmless decal demonstrated good adhesion to the substrate.

[0099] Example 4

[00100] Preparation of a Filmless Decal with a PSA

[00101] PSA 1 was prepared by adding, to a 1 liter jar and dissolving overnight until a clear amber and uniform solution was obtained, the materials of Table 2.

[00102] Table 2. PSA 1 Formulation

[00103] To PSA 1, various levels of titanium dioxide were added and stirred under high speed (3 x 3500 rpm) in a highspeed mixer. The resulting solutions were then coated onto a siliconized liner.

[00104] The opacity of these materials was tested against black and white on a Bykochart 2851 using a BykGardener Calorimeter D65 10°. The results are shown in Table 3.

[00105] Table 3. Opacity Measurements

[00106] Example 5. In a next step, a filmless decal prepared as described in Example 4, having a titanium dioxide loading of 120 phr and coated onto a siliconized liner, was printed with a Roland Versa ETV Print & Cut LEC-330 using a master profile with 250% ink CMYK. The film adhesion properties to an aluminum substrate were tested before and after printing. The results of 180° peel strength testing on an aluminum substrate with and without primer, and with all samples reinforced with IJ180LE print film, are shown in Table 4. Times given are the waiting time, in hours, between the time of adhesion to the substrate and the time of testing. The temperatures are the temperatures (in C) at which the samples were held during the times given. Peel strengths are given in Newtons per inch.

[00107] Table 4. Peel Strength Testing Results

[00108] Example 6. In a next step, a filmless decal prepared as described in Example 4, having a titanium dioxide loading of 120 phr and coated onto a siliconized liner was printed with a Roland Versa ETV Print & Cut LEC-330 using a master profile with 250% ink CMYK was analyzed against an identical unprinted film. Film shrinkage in cross-web and down-web (CW and DW, respectively) direction under printed and unprinted conditions was tested as summarized in Table 5. Times given are the waiting time, in hours, between the time of adhesion to the substrate and the time of testing. The samples were held at 70 °C during the times given. Shrinkage is given in millimeters. The shrinkage reported is the average of CW and DW measurements.

[00109] Table 5. Shrinkage performance.

Claims

What is claimed is:

1. A filmless decal comprising an adhesive layer having a thickness of from 5 to 30 microns and a print layer on at least a portion of the adhesive layer.

2. The filmless decal of claim 1, wherein the adhesive layer comprises a UV-cured adhesive layer.

3. The filmless decal of claim 2, wherein the UV-cured adhesive layer has a thickness of from 5 to 20 microns.

4. The filmless decal of any of claims 2 to 3, wherein the UV-cured adhesive layer comprises an adhesive selected from the group consisting of an acrylate and an epoxy.

5. The filmless decal of any of the claims 2 to 4, wherein the adhesive is an acrylate.

6. The filmless decal of any of claims 2 to 5, wherein the UV-cured adhesive layer and the print layer define a first height, and the first height is less than 50 microns.

7. The filmless decal of any of claims 2 to 6, wherein the first height is less than 30 microns.

8. The filmless decal of claim 1, wherein the adhesive layer comprises a pressure sensitive adhesive.

9. The filmless decal of claim 8, wherein the pressure sensitive adhesive is selected from the group consisting of a rubber-based elastomeric material, and an acrylate material.

10. The filmless decal of claim 9, wherein the rubber-based elastomeric material is selected from the group consisting of natural rubbers, synthetic rubbers, thermoplastic elastomeric materials, non-thermoplastic elastomeric materials, thermoplastic hydrocarbon elastomeric materials, non-thermoplastic hydrocarbon elastomeric materials, and any combinations or mixtures thereof.

11. An article comprising a substrate and the filmless decal of any of the preceding claims.

12. The article according to claim 11, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate define a transition area.

13. The article according to claim 12, further comprising a topcoat layer covering at least a portion of the filmless decal, at least a portion of the substrate, and at least a portion of the transition area.

14. The article according to any of claims 11 to 13, wherein the substrate is selected from a metal and a polymer composite.

15. A process for making a filmless decal, the process comprising:

providing an adhesive layer, and

applying a print layer on at least a portion of the adhesive layer to provide a filmless decal.

16. The process according to claim 15, further comprising applying the adhesive layer onto a carrier layer.

17. The process according to any one of claims 15 to 16, further comprising applying the filmless decal onto a substrate surface.

18. The process according to claim 17, wherein the substrate surface is curved.

19. The process according to any one of claims 17 to 18, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate surface define a transition area.

20. The process according to claim 19, further comprising applying a topcoat layer covering at least a portion of the filmless decal, at least a portion of the substrate surface, and at least a portion of the transition area.