The invention relates to a security paper for the production
of security or value documents with an at least partially
transparent film element, at least in some areas
at least one side of the security paper through the security paper
through freely accessible. The invention further relates
an associated manufacturing method for the
Security paper, a document of value with such a security paper
and a film element for such a security paper
or value document.
Documents of value,
such as banknotes, ID cards and the like, are often used for hedging
provided with security elements that require a review
allow the authenticity of the value documents and at the same time as protection
to prevent unauthorized reproduction.
increasingly gain visibility security features, such as see-through windows
in banknotes, in attractiveness. For window production is
one on one side over the entire surface with an adhesive layer
provided film on a banknote applied to a previously introduced
close through opening. typically,
is the film with a security feature, such as a
Hologram or an optically variable coating provided.
The present invention is based on the object,
a security paper of the type mentioned in terms of
visual appearance of its pane
and at the same time the counterfeit protection of the security paper
The object is achieved by the security paper having the features of the main claim
solved. A value document, a film element and a manufacturing process
for that the security paper is in the sibling
Claims specified. Further developments of the invention are
Subject of the dependent claims.
According to the
Invention is in a generic security paper
provided that the film element over one in the area
the freely accessible subareas highly transparent and
clearly formed adhesive layer connected to the security paper
is. The freely accessible portions of the film element
are often referred to as window areas within the scope of this description
regardless of whether the film element inside
or arranged on a surface of the security paper
is. Is one on a surface of the security paper
arranged film element in a partial area through the security paper
freely accessible, it contains the security paper
in this subarea a reaching to the film element through opening,
where appropriate, often referred to explicitly
Invention is based on the idea, the visual appearance
the window area by an optimized design of the adhesive layer
to improve with which the film element and the security paper
are connected. The result is also the protection against counterfeiting
of the security paper increases, as a visual or machine check
the window area better and more reliable than in the state
the technique can be performed. Due to the required
specific properties in terms of durability, suitability
for certain application procedures and the required
Layer thickness, it is often difficult to apply an adhesive coating
high transparency and low turbidity.
Rather, the present inventors have realized that
the adhesive coating often scatters or matts and thus the
Transparency and clarity of the film element reduced. Known
Review windows in banknotes appear as a result in review
often with low transparency or with a cloudy visual
Appearance, which ultimately reduces the protection against counterfeiting
equals, because the visual or machine verification
the see-through window or arranged in this area
Security element is impaired.
A preferred variant of the invention provides that the adhesive layer
for at least one of the freely accessible subareas
a substantially the region of the portion comprehensive recess
having. Advantageously, the adhesive layer has a recess in
Shape of the freely accessible sub-area, the 1 mm to
2 mm smaller or 1 mm to 2 mm larger than the
Part area is formed. This measure will
on the one hand, a secure connection of film element and security paper
and on the other hand excellent transparency and clarity
the window area ensured, since at most a narrow circumferential
Adhesive edge remains in the region of the opening.
can be provided that the adhesive layer in the area at least
one of the freely accessible partial areas next to the recess
a pattern region in which the adhesive layer in the form of
Patterns, characters or a coding is applied. It can
also a colored adhesive layer with one in the visible,
Infrared and / or ultraviolet recognizable color used
become. The adhesive layer can thereby in the window area as a decorative
Design element, for displaying information and / or as a further security feature
another equally advantageous variant of the invention, the
Adhesive layer in the area of at least one of the freely accessible
Partial areas a thin area with reduced layer thickness,
wherein the layer thickness in particular less than half
the layer thickness is reduced outside the thin area
is. Also by this measure the transparency and
Clarity significantly increased in the window area.
Adhesive layer and the recess or the thin area can
merge into each other along a sharp border, or
can make a smooth, continuous transition
Another advantageous variant of the invention is the adhesive layer
formed from a low refractive index adhesive. A low refractive index
within the meaning of the invention, if it is less than 1.5, especially
preferably less than 1.4.
In some embodiments, it is advisable to use the adhesive of the adhesive layer
in the area of at least one of the freely accessible subareas
to deactivate, so as to reduce the tack of the adhesive layer.
Such deactivation can, for example, by a thermal
Treatment or by UV irradiation.
Another preferred variant of the invention is the adhesive
the adhesive layer in the area of at least one of the freely accessible
Smoothed sections. For this purpose, the adhesive, for example
be treated thermally, in particular by exposure to
Laser radiation, or the adhesive layer is in the window area
calendered the application of the film element.
Smoothing of the adhesive layer can also be by partial or
full-surface application of a lacquer layer in the area at least
one of the freely accessible subareas.
Another advantageous variant of the invention is based on the use
two different adhesives with different properties
side by side. For this purpose, the adhesive layer is in a field of view,
the at least one of the freely accessible subareas
covered by a highly transparent adhesive and in an adhesive area
outside the field of view by an adhesive higher
Adhesive force formed. Because the two adhesives are optimized respectively
their respective task can be selected
creates an adhesive layer with excellent optical properties
in the field of vision and excellent adhesive properties in the detention area.
Yet another advantageous variant of the invention, the film element over
an adhesive layer precisely matched to the through hole
connected to the security paper. This is the adhesive layer
preferably formed multi-layered, wherein a first adhesive layer
an activatable adhesive, in particular a hotmelt adhesive,
is applied to the security paper, and a second adhesive layer
with at least one of the freely accessible subareas
enclosing recess applied to the film element
becomes. Preferably, the recess becomes about 1 mm to 2 mm larger
formed as the subregion. After application of the film element
the activatable adhesive is activated on the security paper
and so the precisely matched, secure connection of foil element
and security paper made. The continuous opening or
The window area can be before or after the application of the activatable
Glue layer are generated.
an advantageous variant of the invention, the security paper
a through opening extending from the film element
is closed. The film element is over a
highly transparent and clear in the area of the through opening
trained adhesive layer connected to the security paper.
The through opening can already be used in papermaking
be generated and characteristic irregularities in the edge region
exhibit. Alternatively, the through opening can also
after papermaking with a sharp edge, e.g. B. by
Punching or cutting, in particular laser beam cutting generated
become. The film element may in particular be a
patch applied to the security paper or an applied one
Foil strips with a width of several millimeters up to
to act on a width of about 30 mm.
In another likewise advantageous variant of the invention, the film element is at least partially embedded in the security paper and freely accessible in window areas on one or both sides of the security paper, wherein the film element is connected to the security paper via a highly transparent and clearly formed adhesive layer in the region of the window areas. In particular, the film element represents a narrow security strip or a wide security band with a width of up to about 30 mm. For example, the film element may be in the form of a window security element, such as a window security thread, which protrudes at certain window areas on one side of the security paper and There is freely accessible. The film element can also form a pendulum security element, such as a pendulum security thread, which alternately emerges at certain window areas on opposite sides of the security paper and is freely accessible there is.
In an advantageous variant, the security paper is single-ply
formed, wherein the film element at least partially in the
a paper layer is embedded. After other likewise advantageous variants,
the security paper is formed two or more layers and the
Foil element is at least partially embedded in one of the paper layers. A
Another advantageous possibility is the film element
in a two- or multi-layered security paper at least
partially embed between two of the paper layers.
Foil element expediently has at least one
Security feature on which preferably in one of the freely accessible
Subareas is arranged. The security feature is particular
from a diffractive structure, such as a hologram or a
hologram-like diffraction structure, a matt structure,
a metallization, a perforation, a lens or micromirror structure,
a micro-optical system, in particular a micro-optical moiré magnification arrangement,
a thin film element, a polarizing filter or
formed a print, the at least one substance with optical
variable, luminescent, electrically conductive or
has magnetic properties.
The invention also includes a value document, such as a banknote, a
ID card and the like, with a security paper described
Art as well as a foil element for a security paper or
a value document of the type described.
The invention further comprises a method for producing a security paper
or value document of the type described, in which a through opening
is inserted in the security paper or document of value
at least partially transparent film element be provided
and provided with an adhesive layer in the region of the through hole
highly transparent and clear, and in which the through opening
is closed with the film element.
The invention includes a method for producing a security paper
or value document of the type described, in which an at least
partially transparent film element is provided, the
Foil element at least partially in a security paper or
Value document is embedded so that it is in one pane
or on both sides of the security paper through the security paper
is freely accessible through, and wherein the film element
is provided with an adhesive layer in the area of the window areas
highly transparent and clear.
If, as described above, the adhesive layer is provided with a recess which essentially surrounds the region of the through opening or one of the window regions, the film element may be provided with a hydrophobic coating in the form of the desired recess before application of the adhesive layer to achieve local repulsion of the adhesive layer. The hydrophobic coating expediently has a surface tension of less than 30 × 10 -3 N / m.
Alternatively, a soluble wash paint in the form of the desired recess can be printed on the film element prior to the application of the adhesive layer, and the wash paint can be washed off with a solvent after application of the adhesive layer together with it. Further details of such a washing process can the document WO 99/13157
are removed, the disclosure of which is included in the present application in this respect.
Adhesive layer can also only after the film application in the field
the through opening or a window area removed
be, for example by means of laser ablation. The adhesive layer
can also already structured with the desired recess
applied to the security paper or document of value, in particular
may be appropriate, the adhesive layer in the area
the continuous opening or a window area in
a pattern area in the form of patterns, characters or an encoding
is also a variant of the method, wherein the adhesive layer in
Area of the continuous opening or a window area
applied as a thin area with a reduced layer thickness
becomes. In this case, the adhesive layer is either with a soft, continuous transition
between adhesive layer and recess or thin area
or with a sharp boundary between the adhesive layer and the recess
or thin area applied.
another variant of the method is the adhesive in the
through opening or a window area deactivated,
in particular by thermal treatment or UV irradiation.
may be the adhesive of the adhesive layer in the area of the through opening
or a window area are smoothed, in particular
by thermal treatment or by calendering.
Another preferred variant of the method is the adhesive layer
in the area of the continuous opening or a window area
partially or completely provided with a varnish layer.
is according to another variant, if in one
Field of view, at least the continuous opening or
a window area comprises a highly transparent adhesive
the film element is applied and in an adhesion area outside
the field of view, an adhesive of high adhesion to the film element
it is preferred if a first adhesive layer of an activatable
Adhesive, in particular a hot melt adhesive, on the security paper
or value document is applied, and a second adhesive layer
with a through opening or a window area
enclosing recess applied to the film element
and the activatable adhesive after application or embedding
of the film element on or in the security paper or document of value
is activated. It is both conceivable, the through opening
or the window area after the application of the activatable adhesive layer
or vice versa, the activatable adhesive layer after
Creating the through opening or the window area
the already mentioned advantages in the visual appearance, the
ultimately an increase in counterfeit protection
can mean, by the design according to the invention
also improved handling of security papers or documents of value
be achieved. Especially with the embodiments with
Recesses, thin spots or deactivated adhesive areas
is the adhesion of dirt on the back of the window
effectively suppressed and the risk of building up
Adhesive on the counterpressure rollers of a printing machine in the window area,
as well as the risk of blocking of substrates or cut
Banknotes in parcels effectively countered.
Embodiments and advantages of the invention will be
explained below with reference to the figures. For better
Clarity is indicated in the figures on a scale
and proportionally true representation omitted.
1 a schematic representation of a banknote according to an embodiment of the invention,
2 a cross section through the banknote of 1 along the line II-II,
3 and 4 Cross-sections through banknotes according to further embodiments of the invention,
5 in (a) a cross-section and in (b) a plan view of an embodiment with additional pattern area,
6 a cross section of a banknote according to a further embodiment of the invention,
7 in (a) a conventional banknote with an applied film element with rough adhesive layer and in (b) a banknote with an adhesive layer smoothed after the film application,
8th an embodiment with a smoothed by a lacquer layer adhesive layer,
9 an embodiment with an adhesive layer with two different adhesives with different specific properties,
10 in (a) to (d) intermediate steps in the production of a banknote with an exact registration of adhesive layer and banknote opening, and
11 in (a) to (e) various designs of security papers according to the invention with applied or embedded foil elements.
The invention will now be explained in more detail using the example of a banknote. Referring first to the 1 and 2 shows 1 a schematic plan view of a banknote according to the invention 10 and 2 a cross section through the banknote 10 along the line II-II of 1 ,
The banknote 10 contains a see-through window 12 that is from a banknote substrate 14 sweeping opening 16 and one the opening 16 closing and at least partially transparent film element 18 is formed.
In addition, the invention will be explained by way of example with reference to embodiments in which a film element 18 like in the 1 and 2 over a continuous opening 16 a banknote is arranged and this closes. The invention is of course not limited to such Ausfüh tion forms, but includes all designs in which a film element is freely accessible at least in some areas on one or both sides of a security paper through this. For illustration are in 11 shown some typical designs.
The representation corresponds to the 11 (a) the in 1 and 2 shown Gestal tion, in which a film element 114 over a continuous opening 112 a security paper 110 is arranged and closes this. In the film element 114 it can not just be a patch with a certain outline, like in 1 but also, for example, a wide film strip extending across the entire width or length of the security paper. The continuous opening 112 can, as in 2 shown having a sharp edge produced by cutting or punching, or also an edge region produced in papermaking 116 with characteristic irregularities, as in 11 (a) shown.
With reference to the representation of 11 (b) and (c) the film element 124 also partially in the security paper 120 be embedded and in window areas 122 on a ( 11 (c) ) or on both sides ( 11 (b) ) of the security paper 120 be freely accessible. For example, the film element may represent a window security thread that protrudes at certain window areas on one side of the security paper, or a pendulum security thread that alternately emerges at certain window areas on opposite sides of the security paper. The film element may also be a wider security tape having a width of up to about 30 millimeters. The window areas may have a sharp edge ( 11 (b) ) or a characteristically irregular border ( 11 (c) ) be formed.
In addition to the embedding in single-ply security paper, an embedding of the film element into two-ply or multi-ply security paper is also possible. In this case, a film element 134 between two paper layers 130-1 . 130-2 a security paper 130 be embedded, as in 11 (d) shown. In the illustrated embodiment, the film element 134 through an opening 132 in the first paper layer 130-1 freely accessible. In other places, the film element 134 also through openings in the second paper layer 130-2 from the opposite side of the security paper 130 be freely accessible.
In another design is, as in 11 (e) shown the foil element 144 in one of the paper layers 140-1 of the security paper 140 embedded and the paper layer 140-1 with the embedded foil element 144 is with another, for example, thinner paper layer 140-2 combined. Again, the foil element 144 through the opening 142 in the first paper layer 140-1 freely accessible.
All described designs come as a substrate material each
Type of paper, especially cotton vellum paper. Of course
It is also possible to use paper which polymerizes a proportion x
Material in the range of 0 <x <100 wt .-% contains.
it is conceivable in principle, if present
not preferred that the substrate material is a plastic film,
z. B. a polyester film is. The film may also be monoaxial
or biaxially stretched. The stretching of the film leads
among other things, that it receives polarizing properties,
which can be used as another security feature.
it may also be when the substrate material of the security paper
is a multilayer composite comprising at least one layer
Paper or a paper-like material. Such a composite
characterized by an extraordinarily large
Stability, what the durability of the security paper
or value document is of great advantage.
But is also, as a substrate material, a multi-layered, paper-free
Use composite material. These materials are also present
not preferred but may be in certain climatic regions
the earth can be used with advantage.
Materials used as substrate material may include additives
which serve as authenticity features. It is first
Line of luminescent substances to think in the visible wavelength range
are preferably transparent and in the non-visible wavelength range
by a suitable tool, for. B. a UV or IR radiation
emitting radiation source, can be excited
to a visible or at least with aids detectable
To produce luminescence. Also other security features can
be used with advantage, provided they consider viewing the imprint
not or only slightly affect.
Film element may be considered as a partial surface of the substrate
covering patch or as one over the entire length
or width of the security paper or value document extending strip
be educated. As materials for the film come
primarily plastics, in particular PET (polyethylene terephthalate),
PBT (polybutylene terephthalate), PEN (polyethylene naphthalate), PP (polypropene),
PA (polyamide), PE (polyethylene), into consideration. The film can also
monoaxially or biaxially stretched.
In some embodiments, the opening becomes 16
of the 2
already in the production of the for the banknote 10
used security paper and has a fibrous, irregular edge. Such an edge is characteristic of already produced during sheet formation openings and can not be created later. Details of the production of the fibrous, irregular edge can the WO 03/054297 A2
be removed. In that regard, the disclosure of the WO 03/054297 A2
included in the present application. In other embodiments, the opening becomes 16
only after paper production by punching or cutting, for example by laser beam cutting produced.
The foil element 18 is with one or more security features 26 provided, for example, with a diffractive structure, such as a hologram or a hologram-like diffraction structure, a matte structure, a metallization, a perforation, a lens or micromirror structure or the like. These security features are known as such and therefore not shown in the following figures.
To be in the banknote 10 a see-through window 12 with excellent transparency and high contrast for the security features 26 to ensure is the film element 18 over one in the area of the continuous opening 16 highly transparent and clearly formed adhesive layer 20 with the banknote substrate 14 connected.
According to the in the 1 and 2 In the embodiment shown, such an attractive visual appearance is achieved in that the adhesive layer 20 on the foil element 18 before the film application with a recess 22 is provided, which is essentially the area of the through opening 16 encloses. The recess 22 is in the form of the through hole 16 in the adhesive layer 20 introduced, but is smaller by 1 mm to 2 mm than the opening 16 designed to tolerate tolerances in the application of the film element 18 catch.
In this way, on the one hand, the film element 18 in the area of the opening 16 safely with the banknote substrate 14 glued, on the other hand, the essential part of the window area 12 excellent transparency and clarity, because of the adhesive layer 20 only a peripheral edge 24 a width of 1 mm to 2 mm in the region of the opening 16 remains. Due to the high transparency and clarity in the area of the opening is the visual and mechanical verification of the security feature 26 significantly improved compared to known film elements without recess of the adhesive and thus increases the protection against forgery of the value document.
As a further advantage of the design according to the invention, improved handling of the banknotes is achieved. Through the window area almost completely registering recess 22 The adhesion of dirt on the back of the window is effectively suppressed. Also, the risk of build-up of adhesive on the counter-pressure rollers of a printing machine in the window area, as well as the risk of blocking of substrates or cut banknotes in packs is effectively countered.
In the embodiment of the 3 became the glue layer 20 before the film application also with a substantially the area of the through opening 16 comprehensive recess 32 in the form of the through opening 16 Mistake. In contrast to the design of the 2 is the recess 32 but not smaller, but 1 mm to 2 mm larger than the opening 16 designed so that when taking into account the tolerances in the application of the film element 18 the area of the opening 16 completely free of adhesive. Because the foil element 18 only in a narrow border area 34 the opening does not interfere with the substrate 14 is glued, yet is a secure connection of foil element 18 and banknote substrate 14 guaranteed.
The transition between the adhesive layer 20 and the recess 22 respectively. 32 can run according to the invention with a sharp boundary, as in the 2 and 3 shown, or even with a smooth and continuous transition 40 as in the embodiment of 4 shown. The layer thickness of the adhesive layer 20 takes for example in a 3 mm wide transition area 42 from the maximum layer thickness continuously down to a layer thickness of zero.
5 shows an embodiment in which the adhesive layer 20 as in the design of the 2 , for the most part 52 the window area is recessed, and in addition a pattern area 56 is provided in the region of the opening, in which the adhesive layer 20 is applied in the form of patterns, characters or a coding.
As best in the supervision on the window area of the 5 (b) can be seen forms the adhesive layer 20 in the area of the opening 16 next to the already at 2 described circumferential edge 54 a pattern of two concentric rings 56 due to the semitransparency of the adhesive layer 20 can be seen in review. The adhesive layer 20 can be so inside the opening 16 purposefully be used as a decorative design element, for displaying a further information and / or as a further security feature.
The area fraction of the pattern area 56 in the area of the opening 16 is kept so small that the disadvantages associated with a full-surface adhesive layer in the region of the opening in the Handling does not occur or at least greatly reduced. Alternatively, the adhesive may be in the pattern area 56 be deactivated thermally or by UV irradiation.
Regarding 6 is according to a further embodiment of the invention in the region of the through opening 16 not a recess with layer thickness zero in the adhesive layer 20 provided, but a thin area 62 with one opposite the detention area 64 in the overlap of film element 18 and substrate 14 reduced layer thickness. The layer thickness may, for example, be less than half or even less than one third of the layer thickness of the adhesive layer in the adhesion region 64 be reduced.
In the thin area 62 As a result, the film element has a significantly increased transparency and reduced scatter compared to a full-surface adhesive layer of normal thickness. The transition from the maximum layer thickness in the adhesion area 64 to the reduced layer thickness in the thin region 62 can be with a sharp border or, as in the illustration of 6 , with a smooth, continuous transition 66 respectively.
With the embodiment of 7 Another approach to increase the transparency and clarity of the adhesive layer is illustrated. 7 (a) first shows a banknote with an applied film element 18 , the one-sided with a full-surface adhesive layer 70 is coated. The roughness 72 the adhesive layer is exaggerated for clarity.
To improve the visual appearance in the window area, the adhesive layer becomes 70 According to the invention after the film application in the region of the through opening 16 smoothed, as in 7 (b) illustrated. Due to the lower roughness 74 a lower light scattering and thus a lower mattness and higher transparency of the smoothed adhesive layer and the window area is achieved in total.
Smoothing the adhesive layer 70 can be done in different ways. For example, the adhesive layer 70 be laser-treated in the region of the through opening, so that the viscosity of the adhesive is reduced, the adhesive flows away and forms a smoother surface. Alternatively, the adhesive layer 70 in the window area are subsequently calendered to obtain a smooth surface texture. Such a calendering step can, for example, with a Teflon-coated tool in the application machine during application of the film element 18 respectively.
At the further in 8th illustrated embodiment of the invention is not the adhesive layer 70 even smoothed, but the rough adhesive layer 70 becomes in the area of the continuous opening 16 with a partial or full varnish layer 80 and thereby the surface scattering of the combined layer structure of adhesive layer 70 and varnish layer 80 reduced.
9 illustrates another approach of the invention based on the use of two different adhesives in the adhesive layer 90 each with different properties. This is the foil element 18 before application in a viewing area 92 that at least the area of the through opening 16 Includes, with a highly transparent adhesive 94 Although under sheds has a lower adhesive force or reduced resistance, but the transparency and clarity of the see-through window particularly little affected.
In a detention area 96 out of sight 92 is an adhesive 98 applied, the predominantly from the viewpoint of a high adhesive force for secure connection of film element 18 and banknote substrate 14 is selected and its transparency and scattering properties are not significant. The two adhesives 94 . 98 can therefore be chosen optimized for their particular task, an adhesive layer 90 which combines high adhesion with excellent transparency and clarity in the window area.
Analogous to the embodiments described above, the viewing area 92 to compensate for tolerances tolerances with advantage about a 1 mm to 2 mm greater extent than the opening to be closed, as in 9 illustrated.
another possibility, impaired transparency
and to avoid clarity in the window area is based on the use
an activatable adhesive, with the help of the film element via
an adhesive layer precisely matched to the through hole
can be connected to the substrate.
Regarding 10 For example, such an exact registration can be achieved by first applying to a banknote substrate 14 at least in the edge region of the intended opening, a first adhesive layer 100 an activatable adhesive, such as a hot melt adhesive, is printed as in 10 (a) shown. Then the banknote substrate becomes 14 together with the not yet activated adhesive layer 100 with the desired opening 16 provided, as in 10 (b) shown. The remaining adhesive layer 100 is then exactly to the outline of the opening 16 gepassert.
At the same time, as in 10 (c) shown, a film element 18 provided and with a second layer of adhesive 102 and a recess 104 provided, which is slightly larger, in the exemplary embodiment, 2 mm larger than the banknote opening 16 is trained. Now the foil element becomes 18 on the substrate 14 applied. During or after the film application becomes the activatable adhesive 100 on the banknote substrate 14 activated so that the film element 18 finally, firmly with the substrate 14 is connected, as in 10 (d) shown. The activation can take place in the case of a hot-melt adhesive, for example by laser application, the necessary heating being produced by the radiation absorbed by the substrate or by the activatable adhesive itself.
an alternative method variant is the activatable adhesive
only after the hole generation in the edge region of the opening
printed. Also, an adhesive layer is on the film element
a recess that is slightly larger than
the banknote opening is and the activatable adhesive
is activated during or after the slide application.
In both variants, the combination of a passivated activatable adhesive layer 100 on the substrate 14 and an adhesive layer recessed further than the opening 102 on the foil element 18 achieved an exact registration of adhesive layer and opening. In both variants, in each case a complete strip-shaped region of activatable adhesive can also be applied to the substrate. It is essential only that the film strip to be applied over it is wider than the adhesive area on the substrate. In its edge region of the film strip is provided with a second adhesive layer to ensure the adhesion of the film strip over its entire width.
Around the tack of the adhesive layer in the area of the through opening 16 In all embodiments, the adhesive may be deactivated after film application, for example by a thermal treatment or by UV irradiation.
In the embodiments with a recessed adhesive layer, the transparency and clarity of the window region is substantially independent of the transparency of the adhesive, so that in these cases, colored adhesive layers can be used. In particular, colored adhesives may be advantageous in embodiments in which the adhesive layer, as in FIG 5 is additionally visible in the form of patterns, characters or a coding inside the window area. This also lends itself to the use of adhesives which are colored exclusively or additionally outside the visible spectral range and, for example, have IR-absorbing or UV-absorbing properties which can be evaluated, for example, in the context of a mechanical authentication test.
already explained in more detail above, the adhesive recess
in all embodiments before the film application
by applying a partial hydrophobic precoating on
the film element or by partial removal of the adhesive layer
using a washing process done.
the film application can the adhesive layer in the region of the through hole
be removed for example by means of laser ablation. Also a direct one
Printing a structured adhesive layer on the film element,
for example by a gravure, flexo, screen, offset or transfer printing method,
Adhesives suitable for the invention are in particular
Hot melt adhesives (hot melts), UV or electron beam curing
Adhesives, solvent or water based systems, hybrid systems,
and 1-component adhesives or 2-component adhesives in question.
QUOTES INCLUDE IN THE DESCRIPTION
The documents listed by the applicant have been automated
generated and is solely for better information
recorded by the reader. The list is not part of the German
Patent or utility model application. The DPMA takes over
no liability for any errors or omissions.
Cited patent literature
- WO 99/13157 
- WO 03/054297 A2 [0061, 0061]