The invention relates to an optically variable security element for
Securing valuables. The invention relates
Furthermore, a method and an apparatus for producing a
Such security element as well as a security paper and a
Data carrier with such a security element.
like valuables or ID documents, but also other valuables,
such as branded goods, are often hedged with security features
provided a verification of the authenticity of the
Data carrier allow and at the same time as protection against
to serve unauthorized reproduction. The security elements can
for example in the form of a security thread embedded in a banknote,
a cover for a banknote with hole, an applied
Security strip, a self-supporting transfer element or else
in the form of a feature area printed directly on a document of value
special role in the authentication of security play security elements,
show the viewing angle dependent visual effects,
as they do not reproduce even with the latest copiers
can be. The security elements are included
equipped with optically variable elements that underlie the viewer
different viewing angles a different image impression
mediate and, for example, depending on the viewing angle another
Color or brightness impression and / or another graphic
In this context, it is known security elements with multi-layered
Use thin-film elements whose color impression is
for the viewer with the viewing angle changes, and
when tilting the safety feature, for example, from green
blue, blue to magenta or magenta to green
replaced. The occurrence of such color changes in
Tilting a security element is hereafter referred to as a color shift effect
From the publication WO 02/073250 A2
Optically variable thin-film elements are known in whose layer structure at least one magnetic layer is integrated. The magnetic properties of these optically variable thin-film elements can then be used as an additional authenticity mark.
In the publication EP 1 780 040 A2
describes a security element in which in a partial area magnetically oriented pigment particles are present, which produce a kinematic visual effect. The magnetically oriented pigment particles may in particular also have optically variable properties.
It is the object of the invention to provide a security element
of the type mentioned above to improve and in particular
a security element with an attractive visual appearance
and high counterfeit security
intelligent combination with other, in particular underlying
Security features allowed.
Task is characterized by the security element with the characteristics of
Main claim solved. A method and a device
for producing such a security element, a security paper
and a data carrier with such a security element
are given in the independent claims. further developments
The invention is the subject of the dependent claims.
According to the
Invention has a generic security element
an at least partially translucent, optically variable ink layer
on which a motif in the form of patterns, characters or a coding
shows, and in which the color layer of the security element first,
optically variable effect pigments and second, magnetically alignable
Contains effect pigments that are magnetically in the form of the displayed
Motive are aligned.
such security element offers a combination of attractive visual
Effects, namely on the one hand the optically variable effect
the first effect pigments and the other by the magnetic
Alignment of the second effect pigments generated motif, which
a pronounced three-dimensional appearance
having. By their at least partially present translucency
In addition, the optically variable color layer with
other underlying security features, such as a
information-carrying printing layer or a see-through area combined
As used herein, "translucent" means translucent
in the sense of a certain or complete translucency
and thus also includes transparency. A translucent
Layer allows the objects behind or below it
to perceive, even if through the translucent layer the brightness
reduces the objects and / or changes the color of the objects
can be. Is the light transmission of a layer against it
so small that the objects behind or behind them are not
are more recognizable, it is no longer translucent, but will
referred to as opaque or opaque.
Invention is based now on the idea of a color layer with two
different effect pigments with different specifics
To use properties. The first effect pigments are included
optically variable while the second effect pigments are magnetic
are alignable. Essentially only the latter, but not the first
Effect pigments become aligned through an external magnetic field
magnetically oriented in the form of the motif to be displayed.
Decoupling of the optically variable and the magnetic properties
allows a cost-effective production, since effect pigments,
combining optically variable and magnetic properties,
a higher production cost and thus a
require higher costs. In addition, such
Effect pigments typically opaque, leaving an intelligent
Combination with other printing processes or inks only very much
restricted is possible. In addition, the required
Layer structure of the pigments and the associated selective
Reflection stringent requirements for the possible layer thicknesses
of the magnetic material. This leads to limitations
in the magnetic properties, in particular the remanence and
coercive field strength, which is a machine-readable generation
Make security elements difficult.
a preferred embodiment of the invention includes the
Optically variable color coat a pigment mixture with the first and
second effect pigments. Alternatively, the optically variable color layer
also a pure magnetic layer with the second effect pigments and
a pure color layer arranged above the pure magnetic layer
containing the first effect pigments.
The first effect pigments are advantageously based on liquid crystalline polymers prepared pigments or so-called pearlescent pigments, such as those sold by the company Merck KGaA under the designation Iriodin ® or Colorcrypt silver-white, gold luster or metal luster pigments. Both pigments based on liquid-crystalline material and pearlescent pigments are translucent on their own. In other likewise advantageous embodiments of the invention, the first effect pigments are formed by interference layer pigments. Such interference layer pigments typically have a thin-film structure which expediently contains at least one reflection layer, one absorber layer and a dielectric spacer layer arranged between the reflection layer and the absorber layer. Interfacial layer pigments can be translucent per se, although opaque interference layer pigments are also known.
The second effect pigments are preferably formed on the basis of high-purity iron powder and can be prepared, for example, from reducing-treated carbonyl iron powder. Advantageous platelet-shaped iron pigments can in particular the document EP 1 251 152 B1
are taken from the disclosure of the preparation and properties of such pigments in the present description.
an advantageous embodiment of the invention are the second
Effect pigments hard magnetic and thus allow in a particularly reliable manner
a mechanical magnetic readout of the depicted motif.
Preferably, the second effect pigments are in the form of a
machine-readable magnetic coding, such as a barcode
aligned. Of course, the second
Effect pigments also be fundamentally soft magnetic,
although soft magnetic effect pigments for the ma chine
magnetic readings are not as well suited as hard magnetic ones
the second effect pigments are non-spherical, for example
needle-shaped. Particular preference is given to effect pigments,
which have a platelet shape. In addition, the largest
Diameter of a non-spherical pigment as a length
or size of the pigment, while
the thickness of the pigment is referred to as pigment thickness. In general
is the thickness of the pigments with the smallest diameter of the pigment
be identical. In addition, the terms length,
Size and largest diameter
of the pigment and thickness and smallest diameter of the pigment
used synonymously. The ratio of the largest
to the smallest diameter, so the diameter-to-thickness ratio
which is non-spherical second effect pigments
preferably more than 5: 1, preferably more than 10: 1. Especially preferred
this ratio is between 40: 1 and 400: 1. The biggest
Diameter, that is the length of the non-spherical
second effect pigments is advantageously more than 2 μm,
preferably more than 5 microns, more preferably more than 10 microns
and most preferably more than 15 microns.
Use of magnetically orientable effect pigments in the micrometer range
and in particular in said size range
on the one hand the advantage that the particle concentration compared
can be kept lower with nanoparticles. About that
In addition, these pigments are due to the cheaper
Diameter to thickness ratio without external forces
better parallel to the layer surface.
Platelet-shaped effect pigments, in particular in the preferred size range and in the before The preferred diameter-to-thickness range can be oriented as desired by an external magnetic field relative to the layer plane. They then, like the slats of a blind, depending on the orientation of the underlying layers either largely free (approximately vertical orientation relative to the layer plane) or block it partially (oblique orientation relative to the layer plane) or completely (substantially horizontal orientation relative to the layer plane ). With high diameter-to-thickness ratios, high contrasts between translucent and opaque layer areas can be set.
A preferred embodiment of the invention are the second effect pigments
platelet-shaped and are in first
Subareas substantially perpendicular to the plane of the color layer
aligned to form translucent portions of the color layer.
Alternatively or additionally, platelet-shaped
second effect pigments in the second partial areas substantially parallel
be aligned to the layer of color layer to opaque portions
to form the color layer.
optically variable ink layer is preferably by a screen printing layer,
formed in some embodiments by a gravure printing layer.
It can be in addition to all mentioned embodiments
be blind imprinted, especially for reinforcement
the 3D effect of the magnetically oriented effect pigments.
Fixation of the magnetically oriented motif is the color layer
with the pigment mixture, preferably based on a UV-curing color system
formed using pure UV systems, UV / water based systems or
also UV / solvent-based systems come into consideration.
In addition to the first and second effect pigments, the color layer
also other pigments, in particular isotropic pigments and / or soft magnetic
Contain pigments. Of course you can
the other pigments or in general further additives all
have visually and / or machine-detectable properties,
the visual impression of the invention
Do not or only slightly affect security elements.
An advantageous embodiment is the optically variable ink layer
on a banknote paper or on a colored background layer
applied. As substrate material for the banknote paper comes
any type of paper, in particular cotton vellum paper.
Of course, paper can also be used,
which contains a proportion x polymeric material in the range of 0 <x <100 wt .-%.
it is conceivable in principle, if present
not preferred that the substrate material of the banknote or whole
generally a data carrier, a plastic film, for. B.
a polyester film is. The film may also be monoaxial or biaxial
be stretched. The stretching of the film leads among other things
that it receives polarizing properties, the
can be used as another security feature.
it may also be when the substrate material of the banknote 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 out, indicating the durability of the paper
or data carrier 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 the consideration of the invention
Security elements do not or at least not significantly affect.
with dark colors usually lead to a special
high brilliance of the optically variable effects. As a substrate comes
but also a transparent or translucent film in question. In
In this case, the security element can advantageously be in or above
a window area or a through opening of a value document
be used as a see-through security element. The foil can
as a patch covering a partial area of the substrate
or as a 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 the plastics 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 is already in the production of the for the banknote used security paper and has a fibrous, irregular edge. Such an edge is characteristic of openings already made during sheet formation and can not be subsequently produced. 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 is produced only after papermaking by punching or cutting, for example by laser beam cutting.
Optically variable ink layer can in a further development of the invention
on an informative underground, in particular
applied to a screen printing layer or a gravure printing layer
be. As the information in the translucent areas of the paint layer
recognizable, in the opaque areas, however, is hidden, can paint layer
and background layer to produce another authenticity feature
interact, as explained in more detail below.
Substrate layer can also thermochromic properties with advantage
have an interactively influenceable security element
to accomplish. Such a thermochromic background layer can in particular
be designed so that when activated by temperature increase
the optically variable effect of the first effect pigments for the
The invention also encompasses a method for producing an optically variable security element for securing valuables, in which
- - On a substrate, an at least partially translucent, optically variable ink layer is applied, the first, optically variable effect pigments and second, magnetically alignable effect pigments contains, and
- - The second effect pigments are aligned by an external magnetic field to form a motif in the form of patterns, characters or a coding.
In the process, the first and second effect pigments become a pigment mixture
mixed and co-printed, preferably in Siebdruck- or
in intaglio printing.
can on the substrate first a pure magnetic layer
printed with the second effect pigments, and over
the pure magnetic layer then a pure color layer with the first
Effect pigments are printed. Also here is the pure magnetic layer
and / or the pure color layer preferably by screen printing or in
Intaglio printing printed.
The motif produced by the magnetic alignment becomes advantageous
Design by UV curing of the ink layer or the
pure magnetic layer permanently fixed.
The invention further comprises a security paper for the
Production of value documents or the like and a data carrier,
in particular a value document, such as a banknote, a passport, a
Certificate, ID card or the like. The security paper
or the data carrier according to the invention with
equipped a security element of the type described. The
Security element can, especially if it is on a transparent
or translucent substrate, also in or over
a window area or a through opening of the
Security paper or the disk can be arranged.
The invention is further an apparatus for implementation
the described manufacturing method, the means for applying the
optically variable ink layer on a substrate and means for magnetic
Align the second effect pigments, wherein the means
for magnetic alignment, preferably by an arrangement of
Permanent or electromagnet are formed.
The advantage here is the optically variable ink layer with a suitable
Process applied to the intended substrate and the second effect pigments
then aligned, z. B. by a magnetic pressure cylinder.
Subsequently, the optically variable ink layer is complete
the motif formed by the orientation of the second effect pigments
Permanently fixed, what z. B. by the aforementioned
UV curing can be done.
an expedient embodiment are the means
formed for magnetic alignment by a magnetic sieve,
so that the second effect pigments already during the printing of the color layer
or the pure magnetic layer in screen printing magnetically aligned
the second effect pigments or the color layer in intaglio printing
Applied, so can the means for magnetic alignment also
be formed by a magnetic throat plate, so that the second
Effect pigments already when printing the ink layer or the
pure magnetic layer in intaglio printing are magnetically aligned.
Other embodiments and advantages of the invention will be explained below with reference to the figures, in the representation of a Maß bar and proportions faithful reproduction was omitted in order to increase the clarity.
1 a schematic representation of a banknote with a security element according to the invention,
2 the banknote of 1 in the area of the security element in cross section,
3 an interactively influenceable security element according to another embodiment of the invention in cross-section,
4 a security element according to a further embodiment of the invention in cross-section,
5 a banknote having a see-through security element according to the invention, which is arranged over a continuous opening, and
6 a security element according to a further embodiment of the invention with an alternative design of the optically variable ink layer.
The invention will now be explained using the example of a banknote. 1 shows a schematic representation of a banknote 10 that with an in 2 shown in cross-section security element according to the invention 12 is provided.
With reference to the representation of 2 is on the banknote paper 20 in the area of the security element 12 a print layer 22 applied any information, such as a line pattern 24 , an alphanumeric string, a logo or the like. The print layer 22 For example, by screen printing or intaglio printing on the banknote paper 20 be upset.
About the information-bearing print layer 22 is an optically variable ink layer in the screen printing process 26 imprinted with a color shift effect, in which the color impression of the layer 26 for the viewer when tilting the security element 12 z. B. changes from green when viewed perpendicularly to blue when viewed obliquely. It is also conceivable a color change of z. B. coppery green or from gold to green.
Next contains the color layer 26 a motif that in the embodiment of 2 for illustration in the form of a simple stripe pattern 28 . 30 is executed. As explained in more detail below, this motif indicates 28 . 30 due to its formation by the different orientation of platelet-shaped pigments 34 . 36 for the viewer a pronounced 3D effect.
In the field of stripes 30 is the color layer 26 doing translucent, so that in the sub-areas 30 the information 24 through the color layer 26 can be seen through. In the field of stripes 28 is the color layer 26 on the other hand opaque, there is the information 24 the print layer 22 covered.
To this combination of a motif with 3D effect, color shift effect and partial visibility of the background printing layer 22 to produce the color layer 26 using a pigment mixture of first effect pigments 32 and second effect pigments 34 . 36 printed.
At the first effect pigments 32 they are optically variable pigments, for example interference layer pigments with a thin-film structure comprising a reflection layer, an absorber layer and a dielectric spacer layer arranged between the reflection layer and the absorber layer. Also, on the basis of liquid-crystalline polymers produced iridescent pigments or pearlescent pigments, as are marketed, for example from Merck KGaA under the designation Iriodin ® or Colorcrypt come first-effect pigments 32 into consideration.
In addition to these optically variable first effect pigments 32
contains the pigment mixture as a second effect pigments magnetically alignable, platelet-shaped iron pigments 34
, which are made in the embodiment of reducing treated carbonyl iron powder. Such platelet-shaped iron pigments can be produced with a high ratio of platelet diameter to platelet thickness, wherein the (largest) platelet diameter is preferably between 6 .mu.m and 60 .mu.m and the platelet thickness in particular between 40 nm and 250 nm. Details of the preparation and properties of such platelet-shaped iron pigments can be found in the document EP 1 251 152 B1
are removed, the disclosure of which is included in the present description.
For the production of the color layer 26 became the first and second effect pigments 32 . 34 . 36 mixed and jointly screen printed. Then, the magnetically alignable second effect pigments were partially aligned by an external magnetic field. The iron pigments 34 . 36 orient themselves with the platelet expansion along the magnetic field lines, so that the iron pigments 36 in those areas 30 in which the magnetic field lines during the alignment step are substantially perpendicular to the substrate plane, substantially perpendicular to the plane of the color layer be judged, as in 2 shown. In those areas 28 in which the magnetic field lines run essentially parallel to the substrate plane, a corresponding orientation of the iron pigments is obtained which lies essentially in the plane of the ink layer 34 ,
The platy iron pigments 34 . 36 According to the invention in the form of a desired motif, in the embodiment in the form of the stripe motif 28 . 30 aligned. For the human eye, the motifs created in this way appear with an effective, three-dimensional appearance, which in the context of this description is also referred to as a 3D effect or 3D impression of the motif.
In embodiment of the 2 For the sake of simplicity, only two orientations, namely perpendicular (90 °, pigments 36 ) or parallel (0 °, pigments 34 ) to the substrate plane. It is understood, however, that any angle α between the iron pigment platelets and the layer plane can be adjusted by appropriate orientation of the magnetic field lines. In particular, it is also possible to generate continuous, spatially slowly varying transitions in the orientation of the iron pigments.
The non-magnetic first effect pigments 32 are not or hardly influenced by the external magnetic field during the alignment step, their orientation is therefore in the subregions 28 and 30 equal.
After the magnetic alignment of the second effect pigments 34 . 36 becomes the color layer 26 dried. In order to be able to fix the magnetically generated motif permanently, in particular UV-curing color systems are used, pure UV systems, UV / water-based systems or even UV / solvent-based systems being considered.
Like also in 2 to recognize, the aligned effect pigments act 34 . 36 due to its platelike shape like the slats of a blind, which can reveal the view of the underlying layers or block completely or partially. In the fields of 28 in which the iron pigments 34 Aligned substantially parallel to the substrate plane, they limit the view of the underlying printing layer 22 so strong that the color layer 26 appears opaque in this area. It should be remembered that in practice the opaque effect of the pigments 34 Of course, it is caused by a variety of pigments, which are the few pigments 34 the schematic representation of 2 exceeds many times. On the other hand give the iron pigments 36 in the fields of 30 in which they are oriented substantially perpendicular to the substrate plane, the view of the print layer 22 free.
Due to the relatively high ratio of platelet diameter to platelet thickness, a high contrast between opaque partial areas can be achieved 28 and translucent subregions 30 produce. It is understood that a continuous transition of the platelet orientation also provides a smooth, continuous transition between translucent and opaque regions of the color layer 26 can be generated.
The color shift effect of the first effect pigments not substantially influenced by the external magnetic field 32 remains in both areas 28 . 30 visible, noticeable. Due to the superposition with the metallic luster of the second effect pigments oriented parallel to the substrate surface 34 he is, however, in the subarea 28 usually significantly weaker than in the partial area 30 , The brilliance of the color shift effect in the subarea 30 also depends on the design of the background layer, whereby a particularly high brilliance is achieved when using dark colors.
The embodiment of 3 shows a security element 40 , which allows an interactive influence on the visual appearance. This is a substrate 42 with a print 43 , in particular offset printing, in the form of patterns and / or characters 45 Mistake. On the imprint 43 is a thermochromic background layer 44 applied, for example by screen printing or intaglio printing. On this thermochromic layer 44 is then an optically variable ink layer 26 with motive, as related to 2 described, printed and magnetically aligned.
The thermochromic layer 44 is designed so that the color shift effect of the paint layer 26 upon activation of the thermochromic layer 44 for the viewer disappears and only the coarse structure of the aligned magnetic pigments 34 . 36 is visible. Change the thermochromic layer 44 For example, when activated by temperature increase their color of black (or generally a dark appearance) on white (or generally a bright appearance), the brilliance of the color shift effect is significantly reduced during activation, to a degree in which the optical variable effect of the first effect pigments 32 completely disappears for the viewer. At the same time is due to the very light layer 44 the imprint 43 to recognize for the viewer. When cooled, the color of the thermochromic layer changes 44 back to black or to the original dark appearance, and the color shift effect of the color layer 26 reappears. At the same time the dark layer hides 44 then again the under her arranged imprint 43 ,
In this way, 3D information can be deleted interactively by increasing the temperature or reduced to a two-dimensional information. Furthermore, the thermochromic layer acts 44 almost as an interactive switch with which the view of the print 43 or the information 45 can be released to the viewer. The described embodiment therefore has a great recognition value for the viewer and generally a very high security against counterfeiting.
The thermochromic layer 44 can also be formed over the entire surface or with information, such. B. in the form of patterns and / or characters, be provided. It can also have a mixture of different thermochromic colors with different activation temperatures, so that a cascade of changing optically variable effects arises when the temperature increases.
As a further embodiment of the invention shows 4 a security element 50 in which on a substrate 52 a background layer 54 is applied with an image information. Above the background layer 54 is an optically variable ink layer in the screen printing process 56 with a pigment mixture 58 . 60 printed, its first effect pigments 58 based on cholesteric liquid-crystalline polymers. These translucent optically variable effect pigments 58 appear in a vertical view z. Green and tilting blue. Of course, a color change from copper to green or from gold to green can be realized.
The second effect pigments 60 are formed by platelet-shaped iron pigments, which in the embodiment have a mean platelet diameter of 20 microns to 30 microns and a thickness of several tens to several hundred nanometers (nm). Will these second effect pigments 60 through an external point-shaped magnet 66 aligned, so results in a rotationally symmetric orientation pattern, as in 4 is shown schematically in cross section. For clarity, the second effect pigments are 60 in 4 with short strokes and the first effect pigments 58 represented as circular disks, although the latter may also be formed non-spherical, for example in the form of needles or platelets. Because the first effect pigments 58 however, are virtually unaffected by the external magnetic field, their orientation is over the entire area of the printed ink layer 56 essentially homogeneous.
After fixing the magnetic alignment of the second effect pigments 60 arises with the color shift effect of the first effect pigments 58 Combined, ring-shaped 3D motif with smooth continuous transitions. In a central area 62 , in which the second effect pigments 60 are oriented substantially perpendicular to the substrate plane, the color layer 56 when viewed vertically, translucent and the image information of the background layer 54 is for the viewer 64 visible, noticeable. Outside the central area 62 are the second effect pigments 60 increasingly tilted from the vertical, leaving the paint layer 56 In the manner of a closing Venetian blind appears increasingly opaque until the image information for the viewer 64 no longer recognizable.
As in 4 can also be seen, results in oblique viewing of the security element, a slightly shifted area 62 ' , in which the second effect pigments 60 for the viewer 64 ' are vertically oriented and the color layer 56 so that translucent appears. Accordingly, for the viewer 64 ' a slightly shifted section of the image information of the background layer 54 recognizable while the image information is out of range 62 ' is increasingly obscured.
When tilting the security element 50 Therefore, in each case a slightly different area of the image information is recognizable, so that the image information for the viewer "wegzuschwimmen" seems. This movement effect is of course with the already described 3D effect of the subject and the color shift effect of the first effect pigments 58 combined.
the example described simple ring structure, as using
a point magnet can be generated by suitable
Of course, magnetic alignment is also essential
Create more complex motifs.
The optically variable ink layer with the pigment mixture may be printed not only on an opaque or substantially opaque substrate but also on a transparent or translucent film. As in 5 As shown, such a film may have the optically variable ink layer over a window area or through opening 72 a banknote 70 be arranged and a see-through security element 74 form.
In review, only the magnetic orientation of the second effect pigments can be seen, which in 5 exemplified by a ring structure 76 is indicated. The color-shift effect of the first effect pigments is virtually invisible on account of the light background when viewed through. If you put the banknote 70 on a dark background, so in addition to the 3D effect of the mag nicely oriented theme 76 Also, the color shift effect of the first effect pigments in appearance.
Such a dark background can also be on the banknote 70 be provided by yourself. For example, a dark printing area can be arranged on the banknote such that the see-through security element 74 by folding the note on the dark print area comes to rest. For further authenticity assurance, the printing area may contain additional information, from which only the portion lying in the translucent area is visible after folding the banknote.
6 shows a security element according to the invention 80 with an alternative design of the optically variable ink layer 84 , In this embodiment, an arbitrary substrate is used 82 first a screen printing ink with magnetically orientable iron pigments 86 imprinted and the pigments 86 aligned according to the desired motif. Subsequently, over this pure magnetic layer 88 a pure color layer 90 with optically variable effect pigments 92 printed. Due to the magnetic orientation of the iron pigments 86 In some areas, the print pattern appears black, while in non-oriented areas, the metallic impression dominates. Especially when using effect pigments 92 , whose visual impression strongly depends on the background color, show in the overprint interesting optical effects.
all described embodiments, the optical
variable color layer also blind embossed in intaglio
especially to enhance the 3D optical impression.
The platelet-shaped iron pigments preferably used
are hard magnetic, so that their orientation pattern as a machine-readable authenticity mark
can be used.
result from the anisotropic geometry of the iron platelets
and a partially different orientation anisotropic
magnetic properties of the color layer. Let that way
by applying a motivating magnetic field in a homogeneous
Applied color layer areas with different magnetic properties
generate, which can also be read by machine.
It is understood that the first and second effect pigments too
with further pigments, in particular with isotropic pigments and / or
soft magnetic pigments can be combined, the
essentially no modulation of the magnetic
Allow properties of the color layer.
Screen printing can be the orientation of the magnetically alignable
Effect pigments can also be made by using magnetic sieves.
Intaglio printing is used for this purpose
magnetic throat plates into consideration. As already mentioned,
Furthermore, the magnetic alignment of the effect pigments is particularly simple
Way after applying the optically variable ink layer through
a suitable magnetic field possible.
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 02/073250 A2 
- - EP 1780040 A2 
- - EP 1251152 B1 [0016, 0057]
- WO 03/054297 A2 [0030, 0030]