Note: Descriptions are shown in the official language in which they were submitted.
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Multicolored security element with effect inks
[0001] This application claims priority based on German Patent Application
2015 004 072.3 entitled "MULTICOLORED SECURITY ELEMENT WITH
EFFECT INKS" filed March 30, 2015, which is herein incorporated by reference.
[0002] This invention concerns a multicolored security element for value
documents, bank notes or the like which has a substrate with an upper side, at
least
one color layer on the upper side which has a first printed pattern, at least
one first
effect colorant layer which is arranged over the first printed pattern and
which has
a second printed pattern different from the first printed pattern, and at
least one
second effect colorant layer which is arranged over the first printed pattern
and
which has a third printed pattern different from the first and second printed
patterns, wherein the second printed pattern and the third printed pattern
partly
overlap so that there is an overlap region between second and third printed
patterns.
[0003] For value documents, such as bank notes, etc., printed security
elements
are known. They have the advantage of being applicable upon printing of the
value document. For such printed security elements, effect inks producing an
optically variable effect are known. An example of effect colorants is
colorants
with multilayer interference pigments or LC pigments. Effect colorants are
usually
printed by screen printing. From EP 2185363 BI it is known that effect
colorants
can also be printed one over the other so that there is an overlap region
between
neighboring areas printed with effect colorants. In this manner, more complex
security features can be created. Further, this print portrays it as
advantageous to
print effect colorants on a colored background.
100041 The invention is based on the object of developing a multicolored
security element of the kind stated at the outset, as is known for example
from the
stated EP 2185363 BI, so that a security element that is especially difficult
to
imitate is easier to manufacture.
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[0005] This object is achieved by a security element for value documents,
bank
notes or the like which has a substrate with an upper side, a color layer on
the
upper side which has a first printed pattern, a first effect colorant layer
which is
arranged over the first printed pattern and which has a second printed pattern
different from the first printed pattern, and a second effect colorant layer
which is
arranged over the first printed pattern and which has a third printed pattern
different from the first and second printed patterns, wherein the second
printed
pattern and the third printed pattern partly overlap so that there is an
overlap
region between second and third printed patterns, and the first printed
pattern is
structured in the overlap region, thereby causing the first and second effect
colorant layers to produce in the overlap region a color impression that
differs
from those that the first and second effect colorant layers have outside the
overlap
region.
[0006] The effect colorants are particularly preferably colorants with LC
pigments. Said LC pigments consist for example of liquid crystal polymers as
are
known e.g. from WO 97/19818 Al or EP 0 435 029 A3. Particularly preferably,
cholesteric liquid crystals are employed, with the first effect colorant layer
having
right-handed liquid crystals effect and the second colorant layer having left-
handed liquid crystals, or vice versa.
[0007] According to the invention, the at least one first and the at least
one
second effect colorant layer are so configured that they overlap in an overlap
region. Under the effect colorant layers there is located at least one color
layer. It
interacts with the respective superjacent effect colorant layer, so that the
two
layers define the color impression that is to be seen in plan view. The effect
colorant layers overlap in an overlap region. Under said overlap region the
colorant layer is configured differently, by being structured there. The
structuring
causes the color layer located under the effect colorant layers to have a
different
influence on the color impression in the overlap region from outside the
overlap
region. Thus, the color impression of the effect colorant layers in the
overlap
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region, which would be a mixed color impression, is no longer visible, or much
more weakly. The registration demands on an overlap region that is e.g. as
small
as possible are thus eased. It suffices when the register accuracy is smaller
than
the size of the structuring of the color layer.
[0008] To make the effect especially strong, it is preferred not to
structure the
color layer outside the overlap region, i.e. to keep it uniform.
[0009] The invention achieves the result that the mixed color that the
overlapping effect colorant layers would have in the overlap region is
particularly
little or not at all perceptible, so that the color impression that the effect
colorant
layers have by themselves dominates in the security element. This is due to
the
fact that in the overlap region of the effect colorant layers the subjacent
color layer
is configured differently, since the first printed pattern is structured
there. As soon
as the overlap region of both effect colorants is above a structured or
gridded
background region (i.e. no 100% solid coverage), it is hardly visible. The
structured (e.g. gridded) background region virtually eliminates the
tolerances of
both effect inks relative to each other and camouflages the overlap.
[0010] The structuring of the first printed pattern, i.e. the different
configuration of the color layer under the overlap region can be realized
especially
simply by the first printed pattern of the color layer having under the
overlap
region a gap through which the substrate or a layer located under the color
layer
remains free. Alternatively or additionally, it is possible to structure the
first
printed pattern under the overlap region by a gridding. This allows the
overlap
region to be furnished with a shade of the color that is supplied by the color
layer.
[0011] An especially striking security element is attained when the second
printed pattern surrounds the third printed pattern, so that the overlap
region
frames the third printed pattern. The print with effect colorants is therefore
subdivided into an interior region and an outside region surrounding the
interior
region, and the structuring of the first printed pattern forms the frame
around the
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interior region. Said frame can be configured e.g. asymmetrically in order to
simulate a 3D effect in the manner of a relief contour.
[0012] Effect inks often have a color effect dependent on the angle of
view. To
produce an especially good marking of the overlap region for oblique top
viewing
as well, it is preferable to choose the width of the structured region to be
greater
than that of the overlap region, in which case a manufacturing-based variation
of
the position of the overlap region should also be accommodated. The first
printed
pattern is thus so structured that it projects laterally beyond the overlap
region,
with the width in which the color layer is structured, for example left out or
gridded, preferably being twice as wide as the overlap region.
[0013] An additional security effect can be achieved by providing between
the
two effect colorant layers an additional overlap region under which the
colorant
layer, i.e. the first printed pattern, is not structured, i.e. is uniform.
Such an
additional overlap region then has a different color impression from the
effect
colorants alone and also from the overlap region under which the color layer
is
structured. In plan view there are thus produced, using two effect colorants,
four
different color impressions, namely, the color impressions of the effect
colorants
alone (with the subjacent color layer), the color impression in the overlap
region
(with the structured color layer), and the color impression in the additional
overlap
region (with the subjacent color layer).
[0014] The security element can be configured in particular as a security
thread, pull strip, security band, security strip, patch, foil element or as a
label. In
particular, the security element can used for a security card or an identity
document (e.g. passport). The security element can be part of a precursor, not
yet
fit for circulation, for a value document which can also have, besides the
security
element according to the invention, for example further authentication
features
(such as luminescent substances provided in the volume). Value documents are
understood here to be, on the one hand, documents having the security element.
On the other hand, value documents can also be other documents and objects
that
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can be furnished with the security element according to the invention, in
order for
the value documents to have uncopiable authentication features, thereby making
it
possible to check the authenticity and at the same time preventing unwanted
copies. Chip cards or security cards, such as bank cards or credit cards, are
further
examples of value documents.
[0015] It will be
appreciated that the features mentioned hereinabove and those
to be explained hereinafter are usable not only in the stated combinations but
also
in other combinations or in isolation without going beyond the scope of the
present invention.
100161
Hereinafter the invention will be explained more closely by way of
example with reference to the attached drawings, which also disclose features
essential to the invention. For clarity's sake, the representation in the
figures is not
true to scale or to proportion. There are shown:
Figs. la and lb a
representation of a first embodiment of a security element,
where la shows a plan view and lb an appurtenant sectional
representation,
Figs. 2a and 2b
representations similar to those of Figs. 1 a and lb of a second
embodiment of a security element,
Figs. 3a and 3b
representations similar to those of Figs. la and lb of a third
embodiment of a security element,
Figs. 4a and 4b
representations similar to those of Figs. la and lb of a fourth
embodiment of a security element, and
Fig. 5 a
representation similar to that of Fig. la of a fifth embodiment
of a security element.
[0017] Fig. la
shows a plan view of a security element; Fig. lb shows an
appurtenant sectional representation. The security element is configured on a
substrate 1. On an upper side of the substrate 1 there is located a color
layer 2
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which can be applied for example by conventional offset printing. The color
layer
constitutes a background for effect colorants arranged thereabove. It will
therefore
hereinafter sometimes also be designated as a background layer. Over said
background layer there are located two effect colorant layers 3 and 4 which
are so
applied that they overlap each other in an overlap region 5. The printing
methods
necessary therefor are known from EP 2185363 Bl.
[0018] The plan view of Fig. la shows the corresponding printed patterns,
with the printed pattern of a corresponding layer being designated by the same
reference sign with an added apostrophe. The color layer 2 is applied in a
first
printed pattern 2' which is indicated in the plan view of Fig. 1 a only by
dashed
lines for a gap 6a to be explained hereinafter. The first printed pattern 2'
of the
color layer 2 is covered by the effect colorant layers 3 and 4, since the
color layer
2 forms a background layer, as mentioned hereinabove.
[0019] The first effect colorant layer 3 is applied in a second printed
pattern 3'
which is configured in a frame shape in the described embodiment example. Said
frame-shaped, second printed pattern 3' surrounds an inner region in which the
second effect colorant layer 4 is arranged in a third printed pattern 4'.
Second
printed pattern 3' and third printed pattern 4' are so dimensioned as to
overlap in
an overlap region which has for example a width Bl.
[0020] The color layer 2 acting as a background layer has under said
overlap
region 5 a structuring, in the embodiment example in the form of a gap 6a,
having
in the represented embodiment a width B2 that is greater than the width B1,
particularly preferably exactly twice as wide.
[0021] The overlap region 5 with the width B1 gives rise to an overlap
between the effect colorant layers in the outside region of the second printed
pattern which can be regarded as the main motif. The second printed pattern 3'
supplies a first color tone, which is produced by the interaction of the
effect
colorant of the first effect colorant layer 3 with the colorant of the color
layer 2. In
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the same way, the third printed pattern 4' gives rise to a second color tone
through
the combination of the second effect colorant layer 4 with the color layer 2.
In the
overlap region of the two effect colorant layers 3 and 4, the color impression
that
would otherwise result from the mixture of the effect colorants is hardly
recognizable due to the structuring of the first printed pattern 2', for
example in
the form of the gap 6a. The optional width difference has the advantage,
firstly,
that the masking of the mixed color impression in the overlap region 5 is
retained
upon oblique viewing of the security element. Secondly, the distance between
the
outer dashed line of Fig. 1 a and the outer edge of the overlap region 5 and
between the inner dashed line and the inner edge of the overlap region 5 forms
a
safety margin upon printing. The overlap region 5 is reliably masked even in
the
case of variations in register or alignment. Therefore, the mixed color
impression
in the overlap region 5 is always clearly suppressed or diminished, and the
regions
of the first and second printed patterns 2', 3' which lie outside the overlap
region 5
are clearly visible. The third printed pattern 4' is in addition thus
especially
strikingly framed through the structuring of the base (printed pattern 2' of
the color
layer 2).
100221 Figs. 2a and 2b show a modification of the embodiment or Figs. 1 a
and
lb to the effect that the first printed pattern 2' of the color layer 2 has a
gridding
6b under the overlap region 5. Here, too, the width B2 is optionally greater
than
the width Bl.
100231 The gridding 6b can be a line grid or dot grid, with a preferred
area
coverage of 50%. Employing indirect letterpress printing, positive lines can
be for
example 0.04 mm thick and negative lines 0.08 mm thick. With offset printing,
the
corresponding values amount for example to 0.03 mm and 0.05 mm. The remarks
on the embodiment of Figs. 1 a and lb apply analogously to the embodiments of
Figs. 2a and 2b.
100241 Figs. 3a and 3b as well as 4a and 4b show developments of the
security
element of Figs. 1 a and lb as well as 2a and 2b to the effect that there is
provided
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an additional overlap region 7 between first effect colorant layer 3 and
second
effect colorant layer 4, which forms an information pattern 7' in plan view.
Under
said additional overlap region 7 the color layer 2 acting as a base is not
further
structured, i.e. is configured the same way as under the portions of the
effect
colorant layers 3 and 4 outside the overlap region 5. This deliberately gives
rise
here to the mixed color impression, which is diminished or suppressed in the
overlap region 5 and which makes the information pattern 7' well recognizable.
100251 Fig. 5 shows a modification of the security element to the effect
that the
frame represented in Figs. la, 2a, 3a and 4a that the first printed pattern 2'
forms
around the inner region of the third printed pattern 4' is now configured
asymmetrically. Therefore, the frame produces a 3D effect, by the framed
region
of the third printed pattern 4' standing out in the manner of a relief.
100261 In addition to the hereinabove described embodiments, it is also
possible to structure the color layer 2 by fine negative lines or microprints
in
portions under the second printed pattern 3'.
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List of reference signs
1 Substrate
2 Color layer
2' First printed pattern
3 First effect colorant layer
3' Second printed pattern
4 Second effect colorant layer
4' Third printed pattern
Overlap region
6a Gap
6b Gridding
B 1, B2 Width
7 Additional overlap region
7' Information pattern
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