EP1509404B1 - Multilayer body with a layer having at least one laser-sensitive material - Google Patents

Abstract

The present invention relates to a multi-layer body which is a paper document with a hot stamping film embossed thereon. The hot stamping film has a laser-sensitive layer in which a laser-induced color image is produced by laser treatment. Arranged on the document are further security identifications such as a security print, which is in the form of guilloche patterns, fluorescent threads, and a security strip. Water marks are also provided in the paper document.

Description

The invention relates to a multilayer body consisting of a layer composite formed with a substrate with at least one layer comprising laser-sensitive material - referred to below as the laser-sensitive layer.

Such multilayer bodies are producible, e.g. using a transfer film, preferably hot stamping foil. It is known to apply such films on a plastic body to form an identity card or code card and make the individualization of the card via a laser treatment of the applied film. In laser treatment, laser-induced markings are produced on the laser-sensitive layer.

The publication EP 1 022 625 describes a transfer film that allows transfer of a hologram to a substrate.

The publication DE 10047450 A1 discloses a product having a security element, wherein transparent cover films and laser-sensitive ink layers are applied to, for example, an opaque core film or another security product for forming a security element in an alternating sequence.

The invention has for its object to provide a multi-layer body of the type mentioned, which makes a particularly accurate and diverse laser-induced marking possible. In particular, the unwanted impairments occurring in the laser treatment should be reduced or eliminated in further layers or on the substrate of the multilayer body. It should also Substrates can be used on the paper material.

The invention solves this problem with the subject matter of claim 1.

Characterized in that the laser-sensitive layer is associated with a background layer, which preferably reflects to a high degree or at least substantially not transparent to the laser radiation in the laser treatment of the laser-sensitive layer, ie when generating the laser-induced markers for this laser radiation or at least substantially not transparent is for the non-reflected portion of the incident laser radiation, it is achieved that in layers below the background layer no laser radiation or at least very little laser radiation is incident. Additionally or alternatively it can be provided that the background layer for the laser radiation is absorbent, so that at least a large part of the non-reflected radiation is absorbed in the background layer. The background layer thus forms a protective layer for underlying layers or the substrate. This means that even very laser-sensitive substrates, ie also substrates made of paper material can be used without further ado. It has indeed been found that the laser-sensitive layer itself already acts as a protective layer for the underlying layers and the substrate and a large part of the laser radiation acting on the laser treatment does not completely penetrate the laser-sensitive layer or does not reach the underlying layer and thus substantially destroy the laser Substrate is prevented. However, the background layer brings significantly increased security, so that a particularly precisely limited and varied laser-marked marking is possible and also much greater freedom of design for the design of the layer composite can be obtained.

Alternatively or additionally, the background layer can also be used to obtain a color enhancement or lightening of the laser-induced marking formed in the overlying laser-sensitive layer. In the background layer and special brightener substances can be introduced, which provide this effect.

Preferably, the background layer under the laser-sensitive layer is arranged only in a partial area, advantageously only below the area in which the arrangement of the laser-indexed marking is provided, i. in the limited portion of the laser-sensitive layer in which the laser-induced marking is to be positioned.

In particularly advantageous embodiments, a plurality of laser-sensitive layers arranged one above the other are provided in the layer composite. In these cases, it is advantageous if in particular a background layer is formed between the laser-sensitive layers.

In preferred embodiments, it is provided that a transfer or laminating film is applied to the substrate and in the film one or more layers are formed, wherein at least one layer is formed as the laser-sensitive layer. The background layer can likewise be formed in the film, but alternatively also as a constituent of the substrate, for example as a surface layer of the substrate. In other embodiments, it is provided that the multi-layer body is laminated from a plurality of overlay films and inlets. At least one of the overlay films may be formed as the laser-sensitive layer or comprise the laser-sensitive layer. It may be formed, for example, as a laminating film, the application of a hot stamping foil with the is provided laser-sensitive layer.

In the following preferred embodiments are explained in more detail with reference to the accompanying figures.

Figur 1

eine Schnittansicht eines Ausführungsbeispiels eines Mehrschichtenkörpers bestehend aus einem Papiermaterialsubstrat, auf dem bereichsweise eine mehrschichtige Folie aufgebracht ist;

Figur 2

eine Draufsicht auf das Ausführungsbeispiel in Figur 1;

Figur 3

eine Draufsicht entsprechend Figur 2 von einem abgewandelten Ausführungsbeispiel;

Figuren 4 bis 6

Schnittdarstellungen von Ausführungsbeispielen von Transferfolien mit lasersensitiver Schicht und zugeordneter Hintergrundschicht;

Figuren 7 bis 9

Schnittdarstellungen von Ausführungsbeispielen von Laminierfolien mit lasersensitiver Schicht und zugeordneter Hintergrundschicht;

Figur 10

Explosionsdarstellung einer aus diversen Overlay-Folien und Inlets laminierten Kartenkörpers.

Showing:

FIG. 1

a sectional view of an embodiment of a multi-layer body consisting of a paper material substrate on which a multi-layered film is partially applied;

FIG. 2

a plan view of the embodiment in Figure 1;

FIG. 3

a plan view corresponding to Figure 2 of a modified embodiment;

FIGS. 4 to 6

Sectional views of embodiments of transfer films with laser-sensitive layer and associated background layer;

FIGS. 7 to 9

Sectional views of embodiments of laminating with laser-sensitive layer and associated background layer;

FIG. 10

Exploded view of a card body laminated from various overlay foils and inlets.

In the embodiment shown in Figures 1 and 2, it is an identity card with various markings and individualizations, as can be seen from the top view in Figure 2. The card body - hereafter called card 8 - is made of paper material. On its surface, as can be seen in Figure 1, a multilayer film is applied. The film has as layers a protective layer 3, a laser-sensitive material having layer 4, a background layer 5 and an adhesive layer 6, with which it is bonded to the surface of the card 8. The film is arranged exclusively in a partial area of the card 8. It has a rectangular plan, as can be seen in Figure 2. The film may be transferred via a transfer process, e.g. be applied by hot stamping a hot stamping foil on the card 8. Such a transfer film is shown in section in FIG. 4. The release layer 2 and the carrier film 1 shown above the protective layer 3 have been removed during the transfer process, which is usually carried out under elevated pressure and elevated temperature.

As can be seen in FIG. 2, a laser-induced color image 10y is formed in the laser-sensitive layer. This color image 10y can be made by laser-induced bleaching of the layer 4 laser-sensitive material. The process of laser-induced bleaching will be described later in detail. Under the entire region of the laser-sensitive layer 4, the background layer 5 is formed. This background layer 5 is not transparent in the visible spectral range, so that the substrate 8 is covered in this area. As can be seen in FIGS. 1 and 2, a marking 81 (see FIG. 1) is formed on the surface of the substrate 8, which is recognizable exclusively in the area outside the color image 10 y or outside the background layer 5 when viewed from above (see Figure 2). The marking 81 consists of a security pressure 81 d, which is formed in the embodiment in the manner of guilloches. Further, fluorescent threads 81f are disposed in the substrate and on its surface, which reflect upon exposure to UV light and appear as black threads in the visible spectral range. In addition, a watermark 81w is formed as a further identification in the substrate 8 and a security strip 81s. The security strip 81s may have various identification and individualization elements, such as a diffraction and / or hologram structure, laser-induced markings, etc. The security strip 81s is incorporated in the substrate 8 in the illustrated embodiment. It also passes through the substrate below the laser-induced color image 10 y and is not visible there due to the non-transparent background layer 5. The security strip 81f is visible only in the area in which it extends beyond the laser-induced image 10y.

In the embodiment shown in Figure 3 is a modification of the embodiment in Figures 1 and 2. In this embodiment in Figure 3, the background layer 5 is formed only in the left half of the laser-induced color image 10y, so that only in this left part in which the background layer 5 is formed, the identification 81 is covered on the substrate 8 and is not visible. In the remaining area of the laser-induced image 10y, no background layer 5 is arranged, so that the surface of the substrate 8 and thus the marking 81 are visible in this area through the color-tinted transparent laser-induced color image. This exemplary embodiment results in particularly increased protection against counterfeiting, since the laser-induced image 10y interacts in a particularly versatile manner with the other identification elements optically.

In modified embodiments, diffraction and / or hologram structures may also be formed in the film layers. FIGS. 5 and 6 show transfer foils which have such a diffraction and / or hologram structure 5b in their layer structure. The film in FIG. 5 corresponds in its construction to the film in FIG. 4, with only an additional resist layer 5c and a reflection layer 5r being additionally formed between the protective layer 3 and the laser-sensitive layer 4. The diffraction and / or hologram structure 5b is formed in the region of the resist layer 5c, the reflection layer 5r and the laser-sensitive layer 4. In the exemplary embodiment in FIG. 6, the additional lacquer layer 5c is designed as a laser-sensitive layer 4c. Thus, in this embodiment, in addition to the laser-sensitive layer 4, there is the laser-sensitive layer 4c between which the reflection layer 5r extends. The laser-sensitive layers 4 and 4c can each be formed from the same laser-sensitive material, but alternatively also from two different laser-sensitive materials. In all of the exemplary embodiments illustrated in FIGS. 4 to 6, the background layer 5 is formed underneath the laser-sensitive layer 4 on the side facing the substrate, which, as in connection with the exemplary embodiments illustrated in FIGS. 1 to 3, acts as a protective layer during laser treatment and as a brightener and color amplifier of the laser-induced image can act.

In the figures 7 to 9 laminating films are shown, which correspond in their layer structure of the transfer sheets of Figures 5 to 6. The overlay film 30 corresponds to the protective layer 3. The remaining layers: the laser-sensitive layer 40, the background layer 50, the reflective layer 50r, and the adhesive layer 60 correspond to the laser-sensitive layer 4, the background layer 5, the reflective layer 5r, and the adhesive layer 6, respectively appropriate way is also at 8 and 9, a diffraction and / or hologram structure 50b corresponding to the diffraction and / or hologram structure 5b of FIGS. 5 and 6 is provided.

In the embodiment in FIG. 10, the multilayer body is formed as a body laminated from various overlay foils and inlets. The overlay film 30 arranged on top has a plurality of layers on its underside which are applied by applying a transfer film to the overlay film. These layers are a lacquer layer 5c, a reflection layer 5r, a laser-sensitive layer 4, a background layer 5 and an adhesive layer 6. In the region of the lacquer layer 5c, the reflection layer 5r and the laser-sensitive layer 4 is a diffraction and / or hologram structure 5b formed.

Underneath this film dressing is an overlay film 32 consisting of material doped with carbon and / or carbon black. This doped overlay film is a second laser-sensitive layer. In this layer takes place with appropriate laser action a carbonization, which can be obtained with appropriate adjustment of the laser conditions, a grayscale marker.

Below this doped overlay film 32 inlets 90 are arranged, which may consist of paper material in the illustrated embodiment. On the lower side of the lower inlet, an overlay film 30 and thereon another overlay film 30 are arranged.

In order to generate the laser-induced marking in the laser-induced layer, the laser irradiation is preferably carried out when applied to the substrate film or coating. Alternatively, however, the laser irradiation can also be carried out before application, ie, directly by irradiation of the film alone. Full-color image formation, ie, the generation of a laser-induced mark as a full-color image, may be performed in embodiments in which the laser-sensitive material is formed from a mixture of a cyan pigment component, a magenta pigment component, and a yellow pigment component. For such an embodiment, the formulation of the layers is given a hot stamping foil at the end of the description.

In bleaching, in a first step, a blue or green or red color mark is produced in which this spot is irradiated with a certain laser wavelength, with which a certain pigment component is bleached.

To make the color blue, only the yellow pigment component should be bleached. For this purpose, blue laser light is used. Bleaching requires a certain minimum intensity. Furthermore, a certain pulse duration must not be exceeded. To get a green color mark in the first step, only the magenta pigment component should be bleached. For this purpose, green laser light is used. To get a red color mark in the first step, only the cyan pigment component should be bleached. For this purpose, red laser light is used.

In order to produce at this point a color marking in the color cyan or magenta or yellow, this point is laser-treated in a second step, with a laser wavelength with which one of the not yet bleached at this point pigment components is bleached. If a blue color mark has been generated in the first step, the cyan pigment component is at this point and the magenta pigment component unbleached. To make the color cyan at this point, the magenta pigment component must be bleached in this second step. This is done with green laser light. This results in a cyan mark at this point.

If, in the second step, a magenta mark is to be obtained instead of this cyan mark, the blue mark produced in the first step must be treated with red laser light. As a result, the cyan pigment is bleached at this point, so that the magenta pigment remains unbleached at this point. This results in the magenta marking at this point.

In a corresponding manner, a green color marking produced in the first step, which is formed from unbleached cyan pigment and yellow pigment remaining there, can produce a cyan-colored marking or a yellow-colored marking by treatment with blue laser light or red laser light.

In a corresponding manner, a red color marking produced in the first step can be converted into a yellow or magenta marking in the second step by laser treatment in the second step with green laser light or blue laser light.

In order to obtain a transparent spot at the point treated in the first and second step, ie to obtain a white spot when the background layer 5 is white, in a third step this point must be treated with a laser beam whose wavelength is adjusted so that at this point after the second step unbleached pigment component is bleached, ie the yellow color marking must be bleached with blue laser light, the magenta green light mark and the cyan mark with red laser light.

In the same way, further adjacent points are then treated in the laser-sensitive layer 4 in order to produce further color markings in the layer 4 of the stamping foil. In this way, a full-color image can be produced.

Laser treatment can also be used to produce color markers or a full-color image in the colorant or the colorants in the laser-sensitive layer by color change. The laser treatment can be carried out in a corresponding manner with successive process steps. As a colorant, i. Coloring substances are pigments in question. These are usually insoluble and are usually inorganic substances. As a colorant but also mostly soluble, organic colorants in question. The color change takes place in each case under specific laser conditions, which are then used in the laser treatment in the individual steps.

Similarly, the bleaching and color conversion process described can also be used if the laser-sensitive material consists of only one or two colorant components. Also, other colorant components and other laser wavelength ranges can be used in the laser treatment.

Alternatively, the laser treatment of the transfer film to produce the color markings may also take place before the application of the film, and in particular, if the protective layer 3 is formed as a layer which is not or only partially transparent to laser radiation or a layer which is not transparent for laser radiation in the specific wavelength range or if an additional UV-absorbing protective layer is provided. The laser treatment is then carried out before the application of the film in which the laser beam is directed to the back of the film, ie on the background layer 5 or the adhesive layer 6 and thus the laser-sensitive layer 4 is thus treated from the other side to therein To produce color markings in the same way. The background layer 5 and the adhesive layer 6 are transparent or at least partially transparent or applied only in partial areas in these applications for the laser radiation in question.

The layers 2 to 6 can be produced according to the following recipes:

Release Layer 2 (Release Layer):

toluene 99.5 parts Ester wax (dropping point 90 ° C) 0.5 parts

Protective layer 3 (protective lacquer layer):

methyl ethyl ketone 61.0 parts Diaketonalkohol 9.0 parts Methyl methacrylate (Tg = 122 ° C) 18.0 parts Polyethylene dispersion (23% in xylene) (softening point 140 ° C) 7.5 parts High molecular weight dispersing additive (40%, amine number 20) 0.5 parts Extender (aluminum silicate) 4.0 parts

Laser-sensitive layer 4 (first color coat layer):

methyl ethyl ketone 34.0 parts toluene 26.0 parts ethyl acetate 13.0 parts Cellulose nitrate (low viscosity, 65% in alcohol) 20.0 parts Linear polyurethane (mp> 200 ° C) 3.5 parts High molecular weight dispersing additive (40%, amine number 20) 2.0 parts For example: Pigment Blue 15: 4 0.5 parts Pigment Red 57: 1 0.5 parts Pigment Yellow 155 0.5 parts

Background layer 5 (second color coat layer):

methyl ethyl ketone 40.0 parts toluene 22.0 parts Ethylene-vinyl acetate terpolymer (mp = 60 ° C) 2.5 parts Polyvinyl chloride (Tg: 89 ° C) 5.5 parts Polyvinyl chloride (Tg: 40 ° C) 3.0 parts Dispersing additive (50%, acid number 51) 1.0 parts Titanium dioxide (d = 3.8-4.2 g / cm ³ ) 26.0 parts

Adhesive layer 6:

methyl ethyl ketone 55.0 parts toluene 12.5 parts ethanol 3.5 parts Polyvinyl acetate (softening point 80 ° C) 6.0 parts Butyl / methyl methacrylate (Tg: 80 ° C) 8.0 parts Ethyl methacrylate resin (Tg: 63 ° C) 3.0 parts Methacrylate copolymer (Tg: 80 ° C) 5.0 parts Unsaturated polyester resin (softening point 103 ° C) 3.5 parts silica 3.5 parts

Claims (16)

1. Multilayer body comprising a layer composite formed with a substrate and having at least one layer with laser-sensitive material - called a laser-sensitive layer below
   characterized in that
   the layer composite has at least one background layer which is reflective and/or non-transparent and/or absorbent to the laser radiation used and which is assigned to the at least one laser-sensitive layer, by the background layer being arranged, at least in one subregion, on the side of the laser-sensitive layer facing the substrate, and which has the effect that, in layers underneath the background layer, no laser radiation or at least very little laser radiation is incident, so that substantial destruction of the substrate by the laser radiation used is prevented.
2. Multilayer body according to Claim 1,
   characterized in that
   a plurality of layers of the layer composite, preferably the laser-sensitive layer and the background layer assigned to the latter, and preferably one or more further laser-sensitive layers, preferably with associated background layer, are arranged in a common overlay film or in a plurality of overlay films.
3. Multilayer body according to one of the preceding claims, characterized in that the substrate is formed from at least one inlay.
4. Multilayer body according to one of the preceding claims, characterized in that the substrate or at least one of the inlays is or are formed from paper material.
5. Multilayer body according to one of the preceding claims, characterized in that the multilayer body is formed as a body laminated from a plurality of films, for example one or more overlay films and one or more inlays, preferably inlay films.
6. Multilayer body according to Claim 1, characterized in that the multilayer body is formed as a transfer film, preferably a hot embossing film, or as a laminating film.
7. Multilayer body according to Claim 6, characterized in that the background layer is transparent to light in the visible spectral range and/or is transparent or non-transparent to laser radiation only under specific laser conditions, in particular only specific laser wavelengths and/or angles of incidence, is preferably transparent or non-transparent to the laser radiation used which is used to produce a laser-induced marking in the laser-sensitive layer.
8. Multilayer body according to one of the preceding Claims 1 to 7, characterized in that the background layer under the laser-sensitive layer is arranged only in one subregion or in the entire region of the laser-sensitive layer, preferably under the region in which the arrangement of a laser-induced marking is envisaged.
9. Multilayer body according to one of the preceding Claims 1 to 8, characterized in that the background layer is arranged immediately adjacent to and lying on the laser-sensitive layer assigned to it.
10. Multilayer body according to one of the preceding Claims 1 to 9, characterized in that at least one intermediate layer is arranged between the background layer and the laser-sensitive layer assigned to it.
11. Multilayer body according to one of the preceding Claims 1 to 10, characterized in that a plurality of laser-sensitive layers are formed at least partly over one another and a background layer is arranged, at least in some regions, between two laser-sensitive layers arranged above one another.
12. Multilayer body according to one of the preceding Claims 1 to 11, characterized in that a laser-induced marking can be produced in the laser-sensitive material of the laser-sensitive layer under the action of laser radiation, preferably by means of laser-induced bleaching and/or a laser-induced colour change and/or laser-induced blackening.
13. Multilayer body according to Claim 12, characterized in that the laser-sensitive material is formed as a mixture of different laser-sensitive components.
14. Multilayer body according to Claim 13, characterized in that at least two, preferably three, different laser-sensitive components are contained in the mixture and can be changed, preferably bleached, by means of a laser under laser conditions that are respectively specific to the components, it being true of each of the two or three components that, under the laser conditions specific to one component, the other or the two other components cannot or substantially cannot be changed, preferably bleached.
15. Multilayer body according to one of Claims 12 to 14, characterized in that the laser-sensitive material has a cyan colorant, preferably a cyan pigment, and/or a magenta colorant, preferably a magenta pigment, and/or a yellow colorant, preferably a yellow pigment.
16. Multilayer body according to Claim 15, characterized in that the cyan pigment is formed as a colorant that can be bleached with red laser light, and/or in that the magenta colorant is formed as a colorant that can be bleached with green laser light, and/or in that the yellow colorant is formed as a colorant that can be bleached with blue laser light.

Images