Note: Descriptions are shown in the official language in which they were submitted.
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Data carrier having tactile security feature
100011 This invention relates to a data carrier, in particular a value
document,
such as a bank note, identification card and the like, having a substrate
which has
at least one tactilely detectable security feature.
[0002] The invention also relates to a method for manufacturing such a data
carrier.
[0003] Data carriers, such as security documents, value documents or
identity
documents, but also other objects of value, are often equipped for
safeguarding
purposes with security features that permit a check of the data carrier's
authenticity
and at the same time serve as protection from unauthorized reproduction.
[0004] It is known to equip data carriers, in particular value documents,
with a
tactilely detectable security feature. Studies, as have been carried out by
the Bank
of Canada for instance, have in fact shown that tactility has great importance
in
rating the authenticity of bank notes.
[0005] Further, it is known to equip value documents, in particular bank
notes,
with a substrate material made of paper or polymer. A disadvantage of these
value
documents, however, regardless of the substrate used, is that in particular
value
documents with high circulation are subjected to considerable wear and strong
soiling, so that the circulation periods of these value documents are short.
In
particular, it is known that substrates made of paper become soiled relatively
quickly and become limp through moisture absorption, i.e. the typical sound
and
typical feel of these substrates are largely lost. On the other hand,
substrates made
of a polymer material show very low resistance to tear propagation, which is
why
substrates damaged by initial tears must be replaced.
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[0006] On these premises, the present invention is based on the object of
further improving data carriers of the kind stated at the outset with regard
to their
circulation resistance and their protection from imitation, while at the same
time
preserving as completely as possible the properties important for rating the
authenticity of bank notes.
[0007] This object is achieved by the data carrier and the manufacturing
method having the features of the independent claims.
[0008] Developments of the invention are the subject matter of the
dependent
claims.
[0009] According to the invention, a generic data carrier, in particular a
value
document, such as a bank note, identification card and the like, comprises a
substrate which has at least one tactilely detectable security feature,
wherein the
relief height of the at least one tactilely detectable security feature
amounts to 10
tm to 180 [tm. The substrate having the at least one tactilely detectable
security
feature is covered on both sides respectively over the full area by a
polymeric
cover layer such that the tactility of the at least one tactilely detectable
security
feature is substantially preserved.
[0010] According to the invention, the great relief height of the tactilely
detectable security feature ensures that the consumer can easily check the
authenticity of the bank note according to the invention by the tactile
security
feature. The tactility of the at least one tactilely detectable security
feature is
preserved here according to the invention in spite of the polymeric cover
layer
applied on both sides respectively over the full area to the substrate having
the
tactile security feature. This finding is surprising in that, in hitherto
known data
carriers having a tactile security feature, the both-sided covering of the
substrate
with a cover layer has, sometimes drastically, reduced the tactility of a
security
feature arranged on the substrate.
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=
100111 According to the invention, however, it is now possible to state
data
carriers with a substrate having a tactile security feature and polymeric
cover
layers arranged on both sides on the substrate in which the tactility of the
tactile
security feature is substantially preserved and at the same time the tactile
security
feature, as well as all the other security features and the data-carrier
substrate, are
protected from wear and soiling. Furthermore, the data carrier with the
security-
relevant features is protected from attempts at tampering, thereby making the
security against imitation of the data carriers according to the invention
exceptionally high.
100121 In a preferred embodiment, the tactilely detectable security feature
of
the data carrier has a relief height of 20 gm to 150 gm, preferably 30 gm to
130
gm, and very particularly preferably 35 gm to 90 gm. Security features having
a
relief height of 20 tm to 150 gm enable good haptic perception by the user of
the
data carrier, and can at the same time be made by known manufacturing
processes
for such data carriers. Thus, the data carrier can have a great number of
known
tactile security features, which makes the invention very interesting
economically.
100131 Preferably, the relief height of the tactilely detectable security
feature
covered by the polymeric cover layer has 40% to 100%, preferably 60% to 100%,
and very particularly preferably 80% to 100%, of the relief height of the non-
covered security feature. As mentioned above, preservation of the tactility of
the
security feature to the greatest possible extent is essential to the present
invention.
The surprising finding that the tactility of the security feature is
substantially
preserved through the suitable selection of tactile security features,
covering
polymeric layer and corresponding manufacture parameters will be discussed
hereinbelow in connection with the individual relevant features. Without being
bound to an explanation, it is currently assumed that the tactility of a
security
feature with great relief height is preserved to a greater extent than is the
case with
security features with lesser relief height. For the user of a data carrier
according
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to the invention the complete or substantially complete preservation of
tactility
means ultimately that he can hardly, or not at all, distinguish between a data
carrier with a polymeric cover layer and a data carrier without, at least with
regard
to the haptic detectability of the tactile security feature. Even though this
ideal
case of 100% preservation of the relief height can not always be realized in
practice, an approx. 80% preservation of tactility will be sufficient for most
users
of the data carrier to unambiguously recognize the authenticity of the tactile
security feature.
[0014] The tactilely detectable security feature is advantageously selected
from
the group consisting of watermark, security thread, foil strip, foil patch,
imprint,
embossed structure or relief structure produced by the action of
electromagnetic
radiation. So-called security threads that can be embedded partly or
completely
into a substrate are also suitable as tactile security features. A "foil
strip" will
hereinafter be understood to be an elongate foil element, and a "foil patch" a
non-
elongate foil element having e.g. a circular, elliptical or rectangular
outline.
[0015] An imprint on the substrate of the data carrier, or an embossed
structure
formed by means of a suitable embossing tool, also has a suitable relief for
recognizing authenticity. The relief structure produced by means of
electromagnetic radiation may be e.g. a foamable imprint which expands to form
a
relief structure under the action of heat. It is further conceivable in this
connection
to expose an, in particular paper-based, substrate to form a relief structure
in the
regions exposed to radiation.
[0016] It will be appreciated that the tactile security feature in the form
of a
security thread, foil strip or foil patch can have per se known features, in
particular
a diffractive structure, matt structure, a thin-film arrangement with a color-
shift
effect, micromirrors, microlenses and other optically variable features.
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[0017] Furthermore, it will be appreciated that every imprint with a relief
height greater than 10 gm can be used as a tactile feature, with suitable
printing
processes being in particular offset printing, flexographic printing, screen
printing
or gravure printing. It is possible here e.g. by means of a screen printing
process to
provide a relief on the security substrate that consists only of an ink layer
with a
thickness of approx. 10 inn to 30 gm. Such relief structures can be
manufactured
e.g. with UV-drying inks. The relief produced by screen printing can
fundamentally be configured in color or colorless, i.e. transparent. The
imprint can
comprise effect inks, which can contain in particular magnetically alignable,
metallic or liquid-crystal pigments. It is further conceivable to use
thermochromic
and photochromic materials, whereby all the above-mentioned materials and
pigments can also be enclosed in microcapsules.
[0018] It is especially advantageous when the imprint involves a gravure
printing process, in particular an intaglio printing process. By the gravure
printing
process, in so-called "ink-carrying" gravure printing an embossed structure is
produced congruently with the imprint. Such a security feature, in which the
tactility is formed by the produced embossed structure and the imprint
arranged
congruently with the embossed structure, has a tactile structure with great
stability
and durability, which is further improved with regard to its circulation
resistance
by the cover layer provided according to the invention. The tactile security
features produced by ink-carrying intaglio printing have a typical total
relief
height of approx. 35 gm to 90 gm for the embossed structure and the imprint,
which is especially advantageous for haptic detection and thus proof of
authenticity.
[0019] It is further conceivable to configure the imprint transparent, so
that the
viewer substantially perceives the embossed structure in the color of the
embossed
substrate. At the same time, the embossed structure is well protected by the
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transparent imprint from external influences, which is ensured in even greater
measure through the covering polymeric cover layer.
[0020] It is of course also conceivable to produce, in the region of a
preprint
on the substrate or on a foil element arranged on the substrate, a relief that
is
visually distinguishable from the color of the preprint or of the foil element
by
means of ink-carrying gravure printing or by means of "blind embossing" (see
below).
[0021] It is further advantageous when a gravure printing plate without ink
is
used for producing a so-called "blind embossing". In so doing, the substrate
is
only deformed to form an embossed structure, but no congruent imprint is
produced. Such an embossed structure therefore forms a relief in the color of
the
substrate. If the substrate is colorless, a colorless relief is accordingly
obtained.
Through the blind embossing produced in a preprint or foil element there is
normally produced through shadow effects a structure that is visually
discernible
from the non-embossed region.
[0022] With especially great advantage it is hence possible to produce by
gravure printing tactilely detectable security features in which regions with
imprint and congruent embossed structure as well as blind-embossed regions
having only an embossed structure are produced directly side by side. Such
structures have exceptionally high protection from forgery, because a spatial
succession of embossed structures with and without imprint is especially hard
to
forge.
[0023] In a preferred embodiment, it is further provided that the substrate
has
at least one paper layer. In the simplest case, the substrate is a single- or
multi-ply
security paper, this being advantageously formed of cotton or of cotton with a
polymeric content x, where x is greater than 0% and smaller than 100%. It is
very
advantageous to embed a tactilely detectable security feature at least partly
into the
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paper layer during the paper manufacture. The security feature can be in
particular
a watermark or a security thread. It is further conceivable to use a tactile
security
feature, in particular a fibrous mat or a paper strip, incorporated into the
paper for
producing a thickness modulation in the paper substrate. It will be
appreciated that
further security features can be arranged on the substrate in addition to the
tactile
security features embedded into the substrate. The at least partly embedded
security threads can in turn contain the above-mentioned, in particular
optically
variable, features.
[0024] The substrate may of course also involve a polymeric material, in
particular a plastic foil of PET, PP, PE, PA, PC or PVC. Such polymeric
materials
have an especially long life, but they normally have considerably poorer
embossability and thus normally lower tactility e.g. of an imprint produced
thereon
by intaglio printing.
[0025] The polymeric cover layer which is arranged respectively over the
full
area on the two surfaces of the substrate preferably consists of PET, PP, PE,
LDPE, LLDPE, PA, PC, POPP, PVC, PU, polyurethane actylates, cellophane,
UV-cross-linked lacquer layers (radically cross-linking or cationically cross-
linking) or of natural biopolymers. Conceivable natural biopolymers are in
particular foils made of renewable raw materials, such as starch or polylactic
acids
(PLA). The polymeric cover layer can of course also be a mixture of one or
several of the above-mentioned polymers.
[0026j The polymeric cover layer advantageously has a thickness of 0.8 um
to
20 iiM, preferably 2 gm to 12 'din, and very particularly preferably 2 ilM to
6 gm.
In a special configuration, the thickness of the polymeric cover layer on one
or on
both surfaces of the substrate amounts to only approx. 3.5 fAM. Cover layers
with
such small thicknesses can be produced by the methods described hereinbelow
and
bestow a substantially complete preservation of the tactility of the tactile
security
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=
feature, even after covering through the polymeric cover layer. Furthermore,
such
a thin layer already provides a considerably improved circulation resistance
in
comparison with substrates without a cover layer, and likewise increases the
forgery-proofness of the security features covered by the cover layer.
100271 The polymeric cover layer is advantageously configured transparent
or
translucent. A transparent layer ideally has a transmittance of 100%, whereby
this
value is normally not obtained exactly in practice. Within the framework of
the
present invention, a transparent layer therefore has a transmittance of 90% to
100%. As used in the present application, transmittance designates the
transmissivity to light, in particular to light in the visible wavelength
region
between 400 nm and 800 nm, i.e. to light as is usually perceived by the
viewer. In
other words, within the framework of the present invention transmittance is
the
quotient of the radiant flux transmitted through the material divided by the
radiant
flux irradiated onto the layer. Depending on the application, however,
transmittance can also relate only to a single wavelength or to other
wavelength
regions, for example to the near UV or IR wavelength region adjacent to the
visible spectral region.
100281 A translucent or semi-transparent layer has within the framework
of the
present application a transmittance of 10% to 90%, and particularly preferably
20% to 80%.
[0029] It will be appreciated that a polymeric cover layer applied on a
surface
of the substrate need not have the same transmission properties over its total
area.
In particular, transparent and translucent regions can also alternate or be
arranged
in a certain pattern, in dependence on the manufacturing method.
10030] In a particularly preferred embodiment, it is provided that the
polymeric
cover layer is not equipped with a security feature, preferably not with a
tactilely
detectable security feature, and in particular not with an imprint or an
embossed
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structure. Such an embodiment advantageously enables the substrate to be
equipped with the tactilely detectable security feature and all further
security
features provided for the data carrier, and the substrate having all the
security
features to be covered on both sides with the polymeric cover layers in a
final step.
Such an embodiment is of interest in terms of production engineering and
economically because, after application of the polymeric cover layer, the data
carrier need not be equipped with any further layer, in particular any further
ink-
receiving layer, printed layer or other security-relevant feature.
Furthermore, such
an embodiment has exceptional protection from forgery, because all the
security
features relevant for the authenticity of the data carrier, as well as all
other
information relevant for the recognizability of the data carrier, in
particular
imprints and other design elements, are protected from tampering and forgery
attacks by the polymeric cover layer.
[0031] Although the polymeric cover layer has no security feature, in
particular no tactile security feature and in particular no security thread,
foil patch,
foil strip or imprint, on both sides of the substrate in this preferred
embodiment,
the cover layer might have intrinsic features, such as e.g. polarization
features
resulting from stretching of the cover layer, or fluorescence substances that
are not
visible in the visible wavelength region. Such intrinsic properties of the
polymeric
cover layer are not excluded by the formulation that "the polymeric cover
layer has
no security features". The intrinsic properties are therefore detectable by
machine
and/or visually using suitable auxiliary means or sensors and can act as an
additional authentication feature. Nevertheless, it is particularly preferable
to
configure the cover layer transparent or at least translucent in the visible
wavelength region when such intrinsic features are present in the polymeric
cover
layer.
[0032] The invention also comprises a method for manufacturing a data
carrier
of the above-mentioned kind. In the method according to the invention,
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a) there is made available a substrate having at least one tactilely
detectable
security feature with a relief height of 10 gm to 180 gm, and
b) the substrate having the at least one tactilely detectable security
feature is
covered on both sides respectively over the full area by a polymeric cover
layer such that the tactility of the at least one tactilely detectable
security
feature is substantially preserved.
[0033] The tactilely detectable security feature is advantageously produced
with a relief height of 20 gm to 150 gm, preferably 30 gm to 130 gm, and very
particularly preferably 35 gm to 90 gm.
[0034] It is especially advantageous further to produce the polymeric cover
layer such that the relief height of the covered, tactilely detectable
security feature
amounts to 40% to 100%, preferably 60% to 100%, and very particularly
preferably 80% to 100%, of the relief height of the non-covered security
feature.
[0035] The tactilely detectable security feature can be applied to the
substrate
in the method step a) in particular by means of a transfer method. For
example,
security threads, foil strips or foil patches can be transferred to the
substrate by
such a transfer method. However, the substrate can advantageously also be
provided with an imprint or an embossed structure, there being employable for
this
purpose in particular a gravure printing process, in particular an intaglio
printing
process. It is further conceivable to provide the substrate with a relief
structure by
the action of electromagnetic radiation, which can be done e.g. by exposing a
paper-based substrate to laser radiation, or a foamable imprint to heat.
[0036] In a preferred embodiment, it is further provided that the substrate
is
manufactured with at least one paper layer in a paper machine, and a tactilely
detectable security feature, in particular a watermark or a security thread,
is
embedded at least partly into the paper layer preferably during the paper
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manufacture. Such security features embedded into the substrate are
inseparably
connected to the substrate and hence increase the forgery-proofness of the
data
carrier safeguarded therewith.
[0037] In addition to these security features at least partly embedded into
the
substrate, it is of course possible to apply further, in particular tactile,
security
features to the substrate, for example by means of the above-mentioned
transfer
methods.
[0038] In an advantageous embodiment, it is provided that the substrate is
equipped in the method step a) with all the tactile security features provided
for
the data carrier. In such an embodiment, the substrate of the data carrier is
equipped with all the provided tactile and, where applicable, further,
security
features and/or information relevant for the recognizability of the data
carrier, in
particular imprints and other design elements, so that in a further method
step the
substrate need only be covered by a polymeric cover layer on both sides. In
such
an embodiment, the covering by the polymeric cover layer therefore constitutes
the final method step in the manufacture of the data carrier, apart from
cutting the
data carriers to the desired shape and other minor method steps for finishing
the
data carrier. Advantageously, in such an embodiment all the security elements
and
information of the substrate is protected from forgery attacks by the
polymeric
cover layer.
[0039] In a preferred method, it is further provided that the polymeric
cover
layer is applied to the substrate by a foil laminating method, in particular
pressure-
based laminating, nip laminating or air-assisted laminating method. The stated
methods for foil lamination are suited for manufacturing data carriers in a
process
in which a multiplicity of data carriers yet to be singled have been wound on
rollers (web-fed process) or are present as sheets (sheet-fed process). As the
name
of the laminating method says, in pressure-based lamination the web to be
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laminated is pressed into the carrier web at a defined pressure, while in nip
lamination a predetermined nip width is used so that the desired laminating
pressure can be chosen without changing the thickness of the web to be
laminated.
In air-type lamination, vertically adjustable carrier rollers are used to
ensure a
lamination that is particularly gentle on the substrate for sensitive
substrates. Air-
assisted lamination and, to a certain extent, also nip lamination are
particularly
suitable for preserving the tactility of the tactile security feature.
Furthermore, it
can be expedient to heat the polymeric cover layer to be laminated onto the
substrate, in particular to urge it against the substrate by means of a hot-
air fan, in
order to obtain as complete a preservation of the relief as possible. In so
doing, the
temperature of the hot air should lie in the vicinity of the glass transition
temperature (TG) of the foil.
[00401 According to a preferred embodiment, it is provided to emboss at
least
partial regions of the substrate during the arrangement of the polymeric cover
layer on the substrate and thus to produce a further tactilely detectable
relief. For
example, such an additional embossing of the substrate can be utilized for
producing embossed script and advantageously be arranged in printed or
unprinted
regions of the substrate.
100411 It should further be mentioned that if the polymeric cover layer is
applied in the form of a foil, it is necessary to connect the foil to the
substrate.
There can thus be used for connecting substrate and foil a wet adhesive (wet
lamination process), a dry adhesive (dry lamination process) or no adhesive,
but
the action of heat and/or pressure (thermal lamination process). It is further
conceivable to use the so-called "thermolamination process" by which the
polymeric cover layer is produced by connecting a hot-extruded polymer layer
to
the substrate.
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=
[0042] In an alternative method, it is provided that the polymeric cover
layer is
applied to the substrate by a curtain coating process, an extrusion coating
process
or by means of a flat adhesive metering system. The polymeric cover layer can
furthermore be applied to the substrate by foil transfer, by spraying or by
imprinting. In the curtain coating process, the coating compound provided as a
polymeric cover layer is poured onto the substrate, whereby more than one
layer of
like or different coating substances can be applied simultaneously in this
method.
This manner of coating enables a uniformly thick application of the coating,
in
dependence on the coating material provided for the polymeric cover layer, in
particular the surface tension and viscosity of the cover layer, the substrate
quality,
in particular the surface roughness, the absorbency and the surface tension of
the
substrate, as well as the adjusted machine parameters, in particular the web
speed,
the distance from the substrate and the nozzle design. In this coating
variant, the
tactility of a security feature can be especially well preserved.
[0043] In extrusion coating, flat film extruders are preferably used, the
polymeric material employed being advantageously PE or PP, and the polymeric
material normally being applied directly to the substrate. For flat film
extruders
there are offered for example foils in the thicknesses 4 gm to 60 gm (cast
PP), 4
gm to 50 gm (POPP), 8 gm to 250 gm (PET) as well as PA foils in different
thicknesses.
[0044] Because a curtain coating and extrusion coating process is not
suited
for a sheet-fed process, i.e. not for sheet stock, data carriers according to
the
invention can be equipped with a polymeric cover layer in a sheet-fed process
advantageously by means of a flat adhesive metering system. In such a system a
slot nozzle is advantageously provided in the width of the sheet to be
provided
with the polymeric cover layer, which in turn contains a multiplicity of data
carriers to be singled later. Alternatively, it is also possible, instead of
using one
slot nozzle, to arrange several slot nozzles side by side such that their
width in
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sum corresponds to the sheet width. It is further conceivable to respectively
arrange several slot nozzles side by side in e.g. two rows, so that the end of
a
nozzle is always in the middle region of the nozzle of an adjacent row, with
respect to the running direction of the sheet, thereby avoiding unwanted
"seams"
in the coating process.
100451 In a further embodiment, it is further provided that during the
arrangement of the polymeric cover layers on the two surfaces of the substrate
there are arranged on the outer surface of the polymeric material additional
features, in particular fluorescence substances not visible in the visible
wavelength
region. These features correspond to the above-described intrinsic features
that
might be contained in the polymeric cover layer, but these features are
arranged on
the side of the cover layer facing the substrate or the (outer) side facing
away from
the substrate by a suitable method during the arrangement of the polymeric
cover
layer on the substrate. These features can, in so doing, be arranged on the
polymeric cover layer in a clocked manner and exactly positioned over the
width.
The exact position and the quantity of the additional feature on the polymeric
cover layer of the data carrier can be used as a security-relevant feature for
recognizing the authenticity of the data carrier by means of suitable sensors.
For
manufacturing such an additional feature there is used e.g. a metering unit
which
discharges the feature substance onto the polymeric cover layer in an exactly
positioned manner and synchronized with the process for arranging the
polymeric
cover layer on the substrate. Such a positioned and synchronized metering of
the
additional feature is conceivable in both a web-fed process and a sheet-fed
process.
[0046] In a further method variant, it is provided that the polymeric cover
layers are applied to the substrate in a thickness of 0.8 gm to 20 [im,
preferably 2
gm to 12 [Lin, and very particularly preferably 2 gm to 6 gm, whereby
particularly
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a polymeric cover layer of approx. 3.5 [tm preserves the tactility of the
tactile
security feature exceptionally well.
[0047] It should also be mentioned that the polymeric cover layer arranged
on
both sides of the substrate can be matted at least partly in an advantageous
embodiment. This is advantageous when the polymeric cover layers have a
relatively great luster, which is not always optically attractive to a viewer
and can
impede the machine detection of the data carrier. A high luster might be given
in
those embodiments in which the polymeric cover layers are applied to the
substrate with substantially all security features in a final method step, and
the
polymeric cover layers hence have no matt security features, imprints, etc. In
particular in such embodiments, an at least partial matting of the polymeric
cover
layer can be advantageous in particular for machine detection.
[0048] For reducing the luster of the polymeric cover layers it is
possible, on
the one hand, to arrange on the substrate a polymeric cover layer that is
already
matted, i.e. reduced in its luster. On the other hand, it is also possible,
however, to
at least partly matt the polymeric cover layer already arranged on the
substrate
through suitable matting methods or by means of a coating. Where applicable, a
matted cover layer arranged in the region of a tactile security feature can be
provided with a higher luster partially in the region of the tactile security
feature
e.g. through a lustrous coating, which can be advantageous for visual
detectability,
as to be explained hereinafter.
[0049] Matting can in particular facilitate the machine check of the
authenticity of the tactile security features according to the invention, and
thus
increase forgery-proofness. When the polymeric cover layer is furthermore
unmatted in those regions where the tactile security features according to the
invention are arranged under the polymeric cover layer, the viewer's attention
is
thus positively drawn to the tactile security feature and the possibility of
checking
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authenticity by the lustrous, i.e. unmatted, region in otherwise matted
surroundings. Through the provision of unmatted and matted regions it is thus
possible to emphasize for the viewer the tactile features relevant for the
authenticity check, thus enabling an easier authenticity check. The forgery-
proofness of the data carrier is therefore increased in a synergistic manner
through
the interaction of tactile checkability and easier findability of the tactile
security
features.
[00501 Further embodiment examples as well as advantages of the invention
will be explained hereinafter with reference to the figures, upon whose
representation a true-to-scale and true-to-proportion rendition has been
dispensed
with in order to increase clearness.
100511 There are shown:
Fig. 1 a schematic representation of a data carrier according to the
invention
having tactilely detectable security features in plan view, and
Fig. 2 a cross section through the data carrier of Fig. 1 along the line A-
A'.
[00521 The invention will now be explained by the example of a data carrier
in
the form of a so-called "foil composite bank note". Fig. 1 thus shows in plan
view
a schematic representation of the bank note 1, having several tactilely
detectable
security features 2, 3, 4 and 6 which are arranged on the substrate or
embedded
partly or completely into the substrate. Furthermore, the bank note 1 also has
authentication features, e.g. the imprint marked by reference sign 5, which is
not
necessarily configured so as to be tactilely detectable. The substrate having
the
security features 2, 3, 4, 5 and 6 is covered on both sides respectively over
the full
area by a polymeric cover layer 9a, 9b, which will now be explained more
closely
with reference to Fig. 2.
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A
[0053] The representation according to Fig. 2 shows, on the one hand,
the
security thread 2 partly embedded into the bank-note substrate, which is a so-
called "windowed security thread" with a thickness of approx. 6 pm to 60 pm.
The
windowed security thread 2 has regions 2b which are embedded substantially
completely in the substrate, in the present case a paper-based substrate.
Furthermore, the windowed security thread 2 passes to the surface of the paper
substrate in the regions 2a, so that the features for authentication
assurance, in
particular holograms, diffractive structures, thin-film elements, etc., which
are
arranged on the security thread can be visually checked by the viewer for
checking
authenticity. Fig. 2 shows the cross section through such a region 2a, it also
being
recognizable that the security thread is only partly embedded in the substrate
in the
region 2a and hence protrudes out of the surface of the bank note by the
amount
RO (not drawn in specifically), thus forming a tactile security feature of the
present
invention at least in the regions 2a.
[0054] The security feature 3 shown in Fig. 1 is a haptically detectable
security
feature produced by an intaglio printing process. As to be recognized in Fig.
2, the
data carrier has, on the one hand, relief structures 3b with an imprint 30
arranged
congruently therewith in the region of the security feature 3. For producing
such
tactile structures, the imprint 30 and, congruently therewith, the embossed
structure 3b are produced simultaneously by ink-carrying intaglio printing.
The
relief height RO of the embossed structure 3b amounts, with the imprint 30, to
approx. 35 pm to 110 pin.
[0055] Besides the hereinabove described tactile feature comprising
embossed
structure 3b and imprint 30, there has been produced in the substrate a
tactile
structure 3a which has no inking. Such an embossed structure obtained by blind
embossing of the substrate can likewise be produced with an engraving plate,
whereby no ink is provided in the regions of the engraving plate corresponding
to
the regions 3a, and the plate is pressed into the substrate without ink. As a
result
17
CA 02841862 2014-01-07
there is produced an embossed structure 3a having good haptic detectability.
The
relief height of the embossed structure 3a is designated with the reference
sign RO
in Fig. 2 and amounts to approx. 35 gm to 90 gm. As shown in Fig. 2, embossed
structure 3a and embossed structure 3b with imprint 30 are arranged in
immediate
vicinity and produced in one method step by means of a printing plate. This
procedure makes it possible to produce a tactile security element with great
protection from forgery, because so closely adjacent tactile regions with and
without inking are very hard to imitate. But even if embossed structure 3a and
embossed structure 3b with imprint 30 are slightly spaced apart, e.g. by
approx. 2
mm to 5 mm, the resulting structure is very forgery-proof.
[0056] On the surface of the substrate 7 there has further been applied by
means of a transfer method the foil strip 4, which is arranged as an elongate
foil
element across the total width of the bank note. The foil strip has the relief
height
RO of approx. 20 gm to 50 gm relative to the surface of the substrate.
[0057] The bank note 1 further has a tactilely detectable watermark 6 (see
Fig.
1).
[0058] As shown in Fig. 2, RO is defined as the height of the tactile
security
feature 2, 3, 4, 6 relative to the substrate surface. RO thus states how far
the
security feature 2, 3, 4, 6 projects relative to the substrate surface.
[0059] As can be seen in Fig. 2, the tactile security elements 2, 3 and 4
are
covered on one side of the substrate with the polymeric cover layer 9a. In the
shown exemplary embodiment, a foil 9a has thus been applied to the surface of
the
substrate 7 having the tactile security elements by means of an adhesive 8
with a
thickness of approx. 0.5 um to 8 gm. The application of adhesive can amount to
e.g. 2 g/m2, which corresponds to a thickness of only a few micrometers. On
the
second surface of the substrate, on which further tactile security features
can be
located, as shown by way of example by the windowed security thread 10
18
CA 02841862 2014-01-07
*
embedded in the cross-sectional representation of Fig. 2, there is also
arranged a
foil 9b as a polymeric cover layer by means of an adhesive 8. The foils 9a, 9b
may
each be a PET foil with a thickness of 0.8 Itm to 12 ptm, in particular
approx. 6
ptm. It is also conceivable in such a case that one foil is made of a first
material
and the other foil of a second material, for example POPP or PET, with the
same
or a different thickness. Further, the polymeric cover layers 9a and 9b can
also be
arranged directly on the substrate with security features without adhesive,
e.g.
through extrusion, in contrast to the view in Fig. 2.
[0060] As readily recognized in Fig. 2, the relief height of the embossed
structure 3a has the value R1 after covering through the cover layer 9a. The
foil
strip 4 and the security thread 2 also have a tactilely detectable relief with
the
relief height RI after covering through the polymer cover layer 9a. R1 is
defined
in connection with the tactile security features of the present invention as
the
height of the polymeric cover layer in the region of the covered security
feature
relative to the polymeric cover layer arranged on the substrate surface
(without a
tactile security feature) (see Fig. 2).
[0061] According to the invention, the relief height RO of the tactile
security
features arranged on the substrate 7 is preserved substantially completely
after
covering through the polymeric cover layer 9a, as Fig. 2 illustrates. The
quotient
of R1 and RO amounts to 1 upon complete preservation of tactility,
particularly
preferably lying at least in the range of from 0.8 to 1. In such a case the
user of the
bank note can perceive practically no difference with regard to the relief
height of
the tactile security feature without and with covering through the polymeric
cover
layer. In other words, the tactile detectability of the security feature
covered with
the polymeric cover layer is guaranteed in any case according to the
invention,
while the circulation resistance and the protection from forgery are
simultaneously
increased considerably by the polymeric cover.
19
CA 02841862 2014-01-07
100621 It will be
appreciated that, as an alternative to the polymeric cover
layers 9a, 9b shown in Fig. 2, cover layers can also be provided by likewise
very
advantageous application methods, such as e.g. curtain coating, extrusion
coating,
or by means of a flat adhesive metering system. Such methods can also be used
to
make data carriers according to the invention having security features that
are
readily detectable haptically, great protection from forgery and great
circulation
resistance.
