CN112004897A

CN112004897A - Film-free applique

Info

Publication number: CN112004897A
Application number: CN201980026562.4A
Authority: CN
Inventors: 克里斯·纳伊斯; 安·J·范迪杰克; 德克·科洛弗罗特; 皮埃尔·比伯; 保罗·科瓦尔科夫斯基
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2018-04-19
Filing date: 2019-04-19
Publication date: 2020-11-27
Also published as: WO2019202570A1; EP3781633A1

Abstract

The present invention provides a membraneless decal and a method for manufacturing a membraneless decal.

Description

Film-free applique

Disclosure of Invention

In one aspect, the present application is directed to a filmless decal comprising an adhesive layer having a thickness of 5 to 30 microns and a print layer on at least a portion of the adhesive layer.

In another aspect, the present application is directed to an article comprising a substrate and a filmless decal.

In another aspect, the present patent application is directed to a method for manufacturing a membraneless decal. The method includes providing an adhesive layer, and applying a print layer over at least a portion of the adhesive layer to provide a filmless decal. When the adhesive layer is a UV-cured adhesive layer, the method may further include curing the adhesive layer using ultraviolet radiation to provide a UV-cured adhesive layer, and applying a print layer on at least a portion of the UV-cured adhesive layer to provide a filmless decal.

Drawings

Fig. 1 provides a cross-section of a membrane decal according to the prior art.

Fig. 1a provides a cross-section of the transition region of the decal.

Fig. 2 provides a cross-section of a filmless decal on a substrate.

Fig. 2a provides a cross-section of a transition region for a filmless decal on a substrate.

Fig. 3 provides a cross-section of a stepped ridge decal on a substrate.

Fig. 3a provides a cross-section of the transition region of a stepped ridge decal on a substrate.

Fig. 4 provides a flow chart of a method for manufacturing a membraneless decal.

Fig. 5 a-5 g provide cross-sectional views of a manufacturing process for a membraneless decal.

Detailed Description

The applicant has found that prior art custom manufacturing and painting of bicycle frames involves a complex and time consuming process. Current manufacturers use stencils for each color to be applied, which results in lengthy multi-step manufacturing in view of the drying time of each color layer.

Applicants have discovered that one possible solution is to provide graphics (e.g., logos, multi-tonal colors, stylized designs, etc.) using decals, printed decals, and/or electrotomes. Once these are applied, the manufacturer can apply a topcoat layer. Unfortunately, prior art decal layers are too thick and provide unacceptable distortion in the topcoat layer (e.g., ridges at the transition areas or edges of the decal).

This effect can be suitably observed in fig. 1, which shows a membrane decal 100. In such prior art membrane decals, the decal typically has an adhesive layer 130, a film layer 140, and a print layer 150. Such appliques may be applied to the substrate 120 and encapsulated or covered by a topcoat layer 160. However, such a solution suffers from the problem highlighted in fig. 1a, namely that, due to the height of the membrane decal, unacceptable ridges are formed at the transition area 1 a. This may be slightly smoothed by the topcoat layer 160. However, the ridges provide an aesthetically unacceptable effect due to the height of the decal 100 (shown in fig. 1a as having a ridge height h1, as measured from the top coat layer low point to the top coat layer high point). Furthermore, in applications requiring an elevated level of aerodynamic performance, such as for competitive racing bicycles, it is possible for the ridges to produce an unacceptable increase in technical performance (e.g. due to increased wind resistance).

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

A representative membraneless decal 200 is shown in fig. 2 on a substrate 220. The membraneless decal 200 includes an adhesive layer 230 having a thickness of 5 to 30 microns, or even 5 to 20 microns, and a print layer 250 on at least a portion of the adhesive layer. For simplicity, the membraneless decal 200 is visualized in use, which is shown on substrate 220 in fig. 2, but for clarity, substrate 220 is not itself part of membraneless decal 200.

The adhesive usable in the adhesive layer 230 is not particularly limited, and may include any of well-known classes of UV-curable adhesive materials or any of well-known pressure-sensitive adhesive materials (particularly pressure-sensitive adhesive materials including rubber-based elastomer materials and those including acrylates).

Suitable UV-curable adhesives may be selected, for example, because they have high transparency and/or stability, particularly under conditions to which the final article will be subjected (e.g., sunlight, heat, humidity). They may also be selected based on other considerations, such as rapid cure, flexibility of the adhesive, repositionable nature of the adhesive, and viscosity, which may simplify the manufacturing process or application of the filmless decal. Such UV curable adhesives should also show good properties as substrates for printing. For example, color fastness, the ability to add pigments to the binder (to enhance the color of the printed layer) may be considered.

The UV-curable adhesive in the adhesive layer 230 may be cured by methods known in the art. Generally, UV (or ultraviolet) light is emitted by the source and provides energy to initiate the reactive photoinitiator present in the UV-curable adhesive. Different UV-curable adhesives use photoinitiators that are sensitive to different ranges of UV light. Therefore, it is important to match the material being cured to the light source being used.

Typically, UV-curable adhesives use a broad spectrum of UV light at concentrations in the UVA range to effect curing.

Factors that affect the curing speed of the UV-curable adhesive material include the intensity of light provided on the UV-curable adhesive, the wavelength of light used, the photoinitiator sensitivity to light wavelengths, and the UV-curable adhesive material resin composition.

There are two basic types of UV curable adhesive materials for a wide range of industrial uses: acrylates and epoxies.

The term acrylate refers to a wide range of materials including acrylates, methacrylates, and similar functional groups. Acrylate systems react upon exposure to UV light (especially UVA light) and in many cases also upon exposure to visible light. These materials exhibit a wide range of properties. Depending on the additive package used, such adhesives may be colored (e.g., red, blue, black), opaque, fluorescent (which may be aesthetically desirable in filmless decal applications, or may provide a method for online process detection), or thermally conductive. The physical properties of acrylate systems are generally easier to control than epoxy resins and may include adhesive strength, viscosity, hardness, and appearance.

The curing speed of the acrylate resin depends on formulation details and, of course, also on the intensity and nature of the light used to cure the acrylate resin. The depth of cure may also vary with formulation and process details.

Additionally, surface tack may be controlled with acrylate-containing UV-curable adhesive materials. Surface tack is typically caused by atmospheric oxygen interfering with the free radical cure mechanism on the acrylate resin surface. This surface tack can be controlled by varying the curing process (e.g., light intensity, curing time, wavelength of light used), and can be adjusted as needed to facilitate application of the printed layer 250.

Epoxy materials are the second main type of UV curable adhesive materials. UV curable adhesive materials comprising epoxy resins can be formulated to exhibit some advantageous properties, such as tack-free curing and excellent adhesion to certain substrates. In some cases, developing the full properties of UV curable adhesive materials comprising epoxy resins may take longer than acrylate materials. In such cases, heat is sometimes used to accelerate curing. In addition, the curing of the epoxy resin may be hindered by moisture and/or humidity.

The adhesive layer may comprise a pressure sensitive adhesive, in particular a pressure sensitive adhesive comprising a rubber-like elastomeric material, or a pressure sensitive adhesive comprising an acrylate material.

Pressure Sensitive Adhesives (PSAs) may have one or more of the following properties: (1) strong and durable tack, (2) adhesiveness not exceeding finger pressure, (3) ability to sufficiently hold onto an adherend, and (4) sufficient cohesive strength.

Materials that have been found to function adequately as PSAs include polymers designed and formulated to exhibit the desired viscoelastic properties that achieve the desired balance of initial tack, peel adhesion, and shear holding power. PSAs are characterized as generally tacky at room temperature (e.g., 20 ℃). The compositions need not be considered PSAs simply because they are tacky or adhere to a surface.

These requirements are typically evaluated using tests designed to separately measure tack, adhesion (peel strength), and cohesion (shear holding power), such as the adhesion and adhesive techniques of a.v. pocius as published in 2002 by Hanser Gardner Publication, Cincinnati, OH: as indicated in the Introduction and Adhesives Technology: An Introduction (2 nd edition). These measurements taken together constitute the balance of properties typically used to characterize a PSA.

According to an exemplary aspect, the rubber-based elastomeric material for use herein is selected from the group consisting of: natural rubber, synthetic rubber, thermoplastic elastomeric material, non-thermoplastic elastomeric material, thermoplastic hydrocarbon elastomeric material, non-thermoplastic hydrocarbon elastomeric material, and any combination or mixture thereof.

In one aspect of the present disclosure, the rubber-based elastomeric material for use herein is selected from the group consisting of: halogenated butyl rubbers, specifically bromobutyl rubber and chlorobutyl rubber; halogenated isobutylene-isoprene copolymers; bromo-isobutylene-isoprene copolymer; chloro-isobutylene-isoprene copolymer; a block copolymer; an olefinic block copolymer; butyl rubber; synthesizing polyisoprene; ethylene-octene rubber; ethylene-propylene rubbers; ethylene-propylene random copolymers; ethylene-propylene-diene monomer rubber; polyisobutylene; poly (alpha-olefins); ethylene-alpha-olefin copolymers; ethylene-alpha-olefin block copolymers; a styrene block copolymer; 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 copolymer; olefinic polymers and copolymers; ethylene-propylene random copolymers; ethylene-propylene-diene terpolymers and any combination or mixture thereof.

As described above, when a UV-curable adhesive is used, it may be selected for its high transparency. However, where a filmless decal provides a vivid color on it for application to a colored substrate, such transparency can result in a filmless decal that does not provide sufficient contrast (e.g., the color of the substrate can be seen through the decal).

To overcome the natural transparency of a filmless decal, inorganic pigments or pastes may be added to the uncured UV-curable adhesive. Suitable materials include titanium dioxide, zinc oxide, calcium carbonate and mixtures thereof. However, all of these materials have a relatively high material density. Incorporation of such pigments into UV-curable adhesives can be unstable, and even if they are unstable, they can interfere with the curing process, thereby adversely affecting the adhesion of the filmless decal to the substrate.

In such cases, it may be advantageous to select a pressure sensitive adhesive comprising a rubber-based elastomeric material. Inorganic pigments or pastes such as titanium dioxide, zinc oxide, calcium carbonate and mixtures thereof may be added to such binders. The content of the pigment may be adjusted based on color properties, material handling factors, formulation stability, and the like. Typical loadings may range from 5 to 150 parts per hundred parts rubber (by weight measured relative to the weight of the rubber-like elastomeric material). In particular, from 20 to 100phr, from 10 to 80phr or even from 10 to 50 phr.

The 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 while the printing layer 250 is laid down.

One particular printer that may be used to provide the print layer 250 is a Rho 162TS roll-to-roll flat panel UV inkjet printer (Rho 162TS roll-to-roll flatbed UV inkjet printer) (available from Durst Phototech Digital Technology GmbH, Lienz, Austria) of Ellimetz. Rho 162 is available as a roll-to-roll or flatbed ink jet printer specifically designed for application of UV curable inks available from 3M Company (Saint Paul, Minnesota, USA)) of St.Paul, Minn.Y..

Useful materials for preparing print layer 250 include any printed material (e.g., ink) suitable for the technical and aesthetic effects of the desired end use of the filmless decal.

For example, particularly (but not exclusively) when used in conjunction with the Rho 162 printer in question, the 3M 8800 series of UV curable inks may be particularly useful. Such inks may be dual cured in a single step with a UV curable adhesive layer in Rho 162. The ink was specifically designed as part of a 3m tmmccs (matched part system) for application using Rho 161 or Rho 162 printers.

In the present application, when it is explained that the printing layer 250 is positioned on at least a portion of the adhesive layer 230, this means that the printing layer may completely cover the adhesive layer 230 or may cover only a portion of the 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 imparted by the filmless decal, or any combination of these factors. Furthermore, in the case where the printing layer 250 does not completely cover the adhesive layer 230, the aesthetic effect of such partial covering must be considered. That is, in this case (especially in the case of using a transparent topcoat layer), the adhesive layer 230 will be visible. Thus, in one embodiment, adhesive layer 230 is optically clear. In other embodiments, the adhesive layer 230 may be selected (or, for example, pigments or other additives may be provided) such that the adhesive not covered by the print layer 250 exhibits desired optical properties (e.g., a desired color, finish, etc.).

For example, print layer 250 may stop before the edge of adhesive layer 230 to provide a stepped change in height of the membraneless decal, with transition region 2a showing a more gradual ridge profile, thereby minimizing the aerodynamic and aesthetic effects of the ridge itself. This method is shown in more detail in fig. 3. However, for ease of handling and manufacture, it may also occur that the print layer 250 extends all the way to the edge of the adhesive layer 230, as shown in FIG. 2. As shown in fig. 2a (compared to fig. 1 a), the ridge height h2 is typically less than the ridge height h1, providing a smoother transition, better aesthetics, and potentially better aerodynamics provided by the membraneless decal. The smoothness of the transition is a characteristic determined by both the ridge height h2 and the distance to reach the ridge height (indicated by the ridge depth l 2).

In practice, the membraneless decal 200 may be applied to a substrate 220. Also, for simplicity, the membraneless decal 200 is visualized in use, which is shown on substrate 220 in fig. 2, but for clarity, substrate 220 is not itself part of membraneless 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).

Thus, the substrate for the membraneless decal 200 can be selected according to the desired end use application. For example, while such membraneless decals are discussed herein as being used for bicycle frame customization, they may also be used for customization of automobile or bicycle tire rims for application to the exterior of metal or sheet molded composite industrial equipment such as air compressors or other metal powder coated materials.

In one aspect, the inventors have noted that sheet molding compounds and other plastic compounds (e.g., ABS, particularly ABS as used in industrial and/or farm equipment) tend to outgas. When a calendered or laminated film is applied, this can result in the formation of air bubbles that can affect the aesthetics of the film and/or cause adhesive failure. On the other hand, the use of the filmless decals described herein may allow for outgassing.

Once applied to substrate 220, the article of the present disclosure may further include a 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 region 2 a. Suitable materials for topcoat layer 260 include, but are not limited to, polyurethane materials, powder coating materials, and epoxy enamels.

Efflorescence can occur when the applique is generally applied externally for use (e.g., in industrial and/or agricultural applications), particularly when a topcoat layer is not present on the applique (often avoiding the use of a topcoat layer, such as a film-containing applique, if the applique is too thick). Furthermore, prior art appliques can be sheared off or damaged due to vibration and/or shear forces. In contrast, as described in some embodiments of the present patent application, the combination of a smooth contour with the use of a topcoat layer may provide a more robust decal solution that does not suffer from the same weathering and/or damage in use as a decal comprising a film.

Another representative membraneless decal, stepped ridge membraneless decal 300 is shown in fig. 3. The stepped ridge decal 300 includes an adhesive layer 330 having a thickness of 5 to 30 microns, and a print layer 350 on at least a portion of the adhesive layer 330.

The adhesives that may be used in adhesive layer 330 are the same as those described above with respect to adhesive layer 230.

Print layer 350 may be provided by any printer capable of printing onto adhesive layer 330. When used, the UV-curable resin may be pre-cured before printing or may be cured while laying down the print layer 350.

One particular printer that can be used to provide the print layer 350 is a Rho 162TS roll-to-roll flat panel UV inkjet printer (available from Durst photo Technology Digital Technology GmbH, Lienz, Austria) available from Durst phototech Digital Technology GmbH, Austria). Rho 162 is available as a roll-to-roll or flatbed ink jet printer specifically designed for application of UV curable inks available from 3M Company (Saint Paul, Minnesota, USA)) of St.Paul, Minn.Y..

Useful materials for preparing print layer 350 include any printed material (e.g., ink) suitable for the technical and aesthetic effects of the desired end use of the filmless decal.

In this embodiment, when it is explained that the printed layer 350 is located on at least a portion of the adhesive layer 330, this may mean that the printed layer may cover only a portion of the adhesive layer 330. For example, as shown in fig. 3, print layer 350 may be as shown) stops instead of stopping at the edge of adhesive layer 330 to provide a stepped change in height of the filmless decal. This effect is shown in more detail in the transition region 3a (indicating a more gradual ridge profile, thereby minimizing the aerodynamic and aesthetic effects of the ridge itself). In this embodiment, although the ridge height h3 may be substantially the same as the ridge height h2, the filmless decal on the substrate 320 still provides an even smoother transition, as it covers substantially the same height over the greater ridge depth l 3. This smoother transition effect may result in, for example, better aesthetics and potentially better aerodynamics. Further, when the surface of the substrate 320 is washed (e.g., power washed), scratched, ground, impacted, sandblasted, or otherwise disturbed, it can make such filmless decals more robust and less prone to accidental damage.

As noted above, in such embodiments where the print layer 350 does not completely cover the adhesive layer 330 (e.g., by leaving a stepped ridge configuration as shown in fig. 3), the aesthetic effect of such partial coverage must be considered. That is, in such cases, adhesive layer 330 may be visible (particularly where a transparent topcoat layer is used). Thus, in one embodiment, adhesive layer 330 is optically clear. In other embodiments, adhesive layer 330 may be selected (or, for example, pigments or other additives may be provided) such that the adhesive not covered by print layer 350 exhibits desired optical properties (e.g., a desired color, finish, etc.). More specifically, such stepped profile designs may utilize adhesive layer 330 to provide a decal, highlight the profile of print layer 350, and possibly provide an aesthetically pleasing contrast with the design (in addition to a more gradual ridge profile).

In practice, the stepped ridge decal 300 may be applied to a 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).

Thus, the substrate for the membraneless decal 300 can be selected according to the desired end use application. For example, while such membraneless decals are discussed herein as being used for bicycle frame customization, they may also be used for customization of automobile or bicycle tire rims for application to the exterior of metal or sheet molded composite industrial equipment such as air compressors or other metal powder coated materials.

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

Efflorescence can occur when the applique is typically painted and used externally (e.g., in industrial and/or agricultural applications), particularly when the topcoat is not present on the applique (often avoiding the use of a topcoat, such as a film-containing applique, if the applique is too thick). Furthermore, prior art appliques can be sheared off or damaged due to vibration and/or shear forces. In contrast, as described in some embodiments of the present patent application, the combination of a smooth contour with the use of a topcoat layer may provide a more robust decal solution that does not suffer from the same weathering and/or damage in use as a decal comprising a film.

In general, the manufacture of the filmless decal of the present patent application can be carried out as provided in the generalized process of fig. 4. Specifically, the process may begin at optional step 405 to apply an adhesive layer to the carrier layer. Next, step 410 indicates an optional step of curing the UV-curable adhesive layer to obtain a UV-cured adhesive layer (when such an adhesive is used). Of course, when a PSA is used, such a curing step is not required. A print layer may then be applied to at least a portion of the adhesive layer, per step 420. Next, a transfer tape may optionally be applied to the resulting filmless decal in step 425, and carrier layer 430 removed. The resulting filmless decal with the transfer tape rather than the initial carrier layer (and thus with exposed adhesive) can then optionally be applied to the substrate surface according to step 435, and the optional transfer layer (if present) removed in step 437. Finally, the process may include optionally applying a topcoat layer according to step 440.

In the present application, when discussing curing a UV-curable adhesive layer or a UV-cured adhesive layer, it is to be understood that at least the surface on which the printed layer is applied is cured. Curing may extend more or less into the adhesive layer, but full curing does not extend all the way to the surface opposite the printed layer, as such curing (or at least full curing) will reduce the adhesive ability of the adhesive layer when applied to a substrate, for example. Such UV curing may be performed well before applying the print layer to the UV-cured adhesive layer, or may be performed substantially simultaneously with applying the print layer to a new UV-cured adhesive layer.

A more specific example of manufacturing a filmless decal is shown in fig. 5a to 5 g. Starting with fig. 5a, an optional carrier layer 510 is provided on which an adhesive layer 530 is disposed. Next, in step 5b, a print layer 550 is applied to at least a portion of the adhesive layer 530. Next, in step 5c, a transfer layer 570 is added to the print layer 550 on the side opposite the adhesive layer 530. The optional carrier layer 510 is then removed to expose the surface of the adhesive layer 530 opposite the print layer 550, according to step 5 d. Next, in step 5e, the entire assembly may be applied to the substrate 520 by contacting the exposed surface of the adhesive layer 530 with the substrate 520. Next, in step 5f, the transfer layer 570 may be removed, and in step 5g, a topcoat layer 560 may be applied.

The present disclosure may be exemplified, for example, in the following embodiments.

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

Embodiment 2. the membraneless decal of embodiment 1, wherein the adhesive layer comprises a UV-cured adhesive layer.

Embodiment 3. the membraneless decal of embodiment 2, wherein the UV-cured adhesive layer has a thickness of 5 to 20 microns.

Embodiment 4. the filmless applique of any of embodiments 2-3, wherein the UV-cured adhesive layer comprises an adhesive selected from the group consisting of acrylates and epoxies.

Embodiment 5. the filmless applique of any of embodiments 2-4, wherein the adhesive is an acrylate.

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

Embodiment 7. the filmless applique of any of embodiments 2-6, wherein the first height is less than 30 microns.

Embodiment 8 the filmless decal of embodiment 1 wherein the adhesive layer comprises a pressure sensitive adhesive.

Embodiment 9 the membraneless 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.

Embodiment 10 the membraneless decal of embodiment 9, wherein the rubber-like elastomeric material is selected from the group consisting of: natural rubber, synthetic rubber, thermoplastic elastomeric material, non-thermoplastic elastomeric material, thermoplastic hydrocarbon elastomeric material, non-thermoplastic hydrocarbon elastomeric material, and any combination or mixture thereof.

Embodiment 11. an article comprising a substrate and the filmless decal of any one of the preceding embodiments.

Embodiment 12 the article of embodiment 11, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate define a transition region.

Embodiment 13 the article of 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 region.

Embodiment 14. the article of any of embodiments 11 to 13, wherein the substrate is selected from the group consisting of metal and polymer composites.

Embodiment 15. a method for manufacturing a membraneless decal, the method comprising:

providing an adhesive layer; and

a print layer is applied over at least a portion of the adhesive layer to provide a filmless decal.

Embodiment 16 the method of embodiment 15, further comprising applying the adhesive layer to a carrier layer.

Embodiment 17. the method of any of embodiments 15 to 16, further comprising applying the film-free decal to a surface of a substrate.

Embodiment 18 the method of embodiment 17, wherein the substrate surface is curved.

Embodiment 19 the method of any of embodiments 17-18, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate surface define a transition area.

Embodiment 20. the method of embodiment 19, further comprising applying a topcoat layer covering at least a portion of the membraneless decal, at least a portion of the substrate surface, and at least a portion of the transition region.

Embodiments of the present disclosure are illustrated in more detail by the following non-limiting examples.

Examples

Table 1: materials of examples 1 to 3

Example 1

Printing on adhesives

Transfer belt 467MP on the release liner was printed in various colors using a DURST Rho 162 UV-printer (Durst) using 3M UV 8800 series inks. Application tape SCPS100 is then applied to printed transfer tape 467MP and adhered to ALU36Q panel. The printed layer was measured to be 50 μm.

Example 2

Preparation of filmless decals with UV curable adhesive

A UV curable pressure sensitive adhesive 7555T PCA (3M company) was applied to the liner material using K-bar. The adhesive had a thickness of 6 μm. Then an energy dose of 0.8mJ/cm is used²The 400W UV lamp of (1) cures the adhesive.

After curing, the adhesive was laminated with a release liner (silicone coated release liner available under the trade designation Akrosil from Mondi Akrosil corporation of great Prairie, Wisconsin, USA) for further processing.

After removal of the release liner, a print layer was applied using a DURST Rho 162 UV-printer. The printed adhesive is then transferred to the ALU36Q panel by means of the application tape SCPS 100. The resulting panel had a 16 μm printed layer and 6 μm adhesive, with a total layer thickness of 22 μm.

Example 3

Applied to curved surfaces

A membraneless decal was prepared as described in example 2. Instead of transferring the filmless decal to the ALU36Q panel, the filmless decal of example 3 was transferred to a carbon-treated bicycle frame substrate. The application belt SCPS100 is also used for this transfer. The film-free decal exhibited good adhesion to the substrate.

Example 4

Preparation of filmless decals with PSA

PSA 1 was prepared by adding the materials of table 2 to a 1-liter jar and dissolving overnight until a clear amber and homogeneous solution was obtained.

Table 2: PSA 1 formulations

Various amounts of titanium dioxide were added to PSA 1 and stirred at high speed (3 × 3500rpm) in a high speed mixer. The resulting solution was then coated onto a siliconized liner.

The opacity of these materials was tested for black and white on a Bykochart 2851 using a byk gardener calorimeter D6510 °. The results are shown in Table 3.

Table 3: opacity measurement

Example 5: in the next step, a film-free decal prepared as described in example 4, with a titanium dioxide load of 120phr and applied to a siliconized liner, was printed using a master profile with 250% ink CMYK using a Roland Versa UV print & cut LEC-330. The film was tested for adhesion properties to aluminum substrates before and after printing. Table 4 shows the results of 180 peel strength tests on aluminum substrates with and without primer and with all samples reinforced with IJ180LE print film. The given time is the waiting time between the adhesion time to the substrate and the test time, in hours. The temperature is the temperature (in units of C) at which the sample is held during a given time. Peel strength is given in newtons per inch.

Table 4: peel strength test results

Sample number	Primer coating	Time of day	Temperature of	Peel strength
					1	Y	24	25	17.2
2	Y	72	70	15.3
					3	N	24	25	12.5
4	N	24	25	23.0
					5	N	72	70	32.6

Example 6: in the next step, a film-free decal prepared as described in example 4, having a 120phr titanium dioxide load and applied to a siliconized liner, was printed using a master profile with 250% ink CMYK using a Roland Versa UV print & cut LEC-330, which was analyzed for the same unprinted film. The films were tested for shrinkage in the cross-web and down-web (CW and DW, respectively) directions in both printed and unprinted conditions, as summarized in table 5. The given time is the waiting time between the adhesion time to the substrate and the test time, in hours. The samples were maintained at 70 ℃ for a given period of time. Shrinkage is given in millimeters. The shrinkage reported is the average of the CW and DW measurements.

Table 5: shrinkage property。

Claims

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

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

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

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

5. The membraneless decal of any one of claims 2-4, wherein the adhesive is an acrylate.

6. The membraneless decal of any one of claims 2-5, 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 membraneless decal of any one of claims 2-6, wherein the first height is less than 30 microns.

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

9. The membraneless 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 membraneless applique of claim 9, wherein the rubber-like elastomeric material is selected from the group consisting of: natural rubber, synthetic rubber, thermoplastic elastomeric material, non-thermoplastic elastomeric material, thermoplastic hydrocarbon elastomeric material, non-thermoplastic hydrocarbon elastomeric material, and any combination or mixture thereof.

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

12. The article of 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 of claim 12, further comprising a topcoat layer covering at least a portion of the membraneless decal, at least a portion of the substrate, and at least a portion of the transition region.

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

15. A method for manufacturing a membraneless decal, the method comprising:

providing an adhesive layer; and

16. The method of claim 15, further comprising applying the adhesive layer to a carrier layer.

17. The method of any one of claims 15 to 16, further comprising applying the film-free decal to a substrate surface.

18. The method of claim 17, wherein the substrate surface is curved.

19. The method of any of claims 17-18, wherein the filmless decal has an edge, and the edge of the filmless decal and the substrate surface define a transition region.

20. The method of claim 19, further comprising applying a topcoat layer covering at least a portion of the membraneless decal, at least a portion of the substrate surface, and at least a portion of the transition region.