Title of Invention

SECURITY ELEMENT AND SECURITY DOCUMENT WITH ONE SUCH SECURITY ELEMENT

Abstract A security element (2; 4) for embedding in or application to a security document (1) is disclosed. The security element has a substrate (S) with at least one reflection layer (R) and one interference element (I1, I2) having a color shift effect, characterized in that the security element has on each side of the reflection layer (R) an interference element (I1, I2) with color shift effect, or has on each side of the substrate (5) both a respective reflection layer (R1, R2) and an interference element (I1, I2) with color shift effect.
Full Text Security element and security document with one such security element

[01] The invention relates to a security element as well as a security document, in
particular document of value as for example a bank note, with such a security element.
The invention also relates to a semifinished product for producing such a security
document. In particular, the invention relates to a security element in the form of a
security thread for embedding in the security document as a so-called window thread
and in the form of a label or transfer element for application to the security document.
[02] Security documents within the terms of the present invention are in particular
bank notes, but also checks, check cards, credit cards, identity cards, passports,
admission tickets, tickets for public transport and the like. As semifinished products
for the production of the aforementioned security document for example unprinted
security paper and other unprinted security document substrates are suitable.
[03] For protection against imitation and as authentication the aforementioned
security documents are typically equipped by means of embedded security threads or
applied security labels or security transfer elements. Security threads in the form of
window threads are widely known, for example, in connection with documents of
value, such as bank notes, but are, in principle, also suitable for the use in check cards
and the like. Window threads are embedded in the base material of the security
document and appear periodically at the surface of the security document, so that they
are visually recognizable in these ā€˛window areas". In translucent substrates a so-called
incident light/transmitted light effect is the result, the security thread viewed in
transmitted light appearing as a dark stripe vis-a-vis the surrounding material. In
incident light, however, the security thread is recognizable only in the window areas.
[04] One distinguishes between simple window threads which appear only on one
surface and two-sided window threads which appear on both surfaces, one special case


of two-sided window threads hereinafter being referred to as lookthrough window
thread which is visible on both sides of the document of value at the same time. A
lookthrough window thread, so to speak, spans a hole or a transparent area in the
document of value. A further two-sided window thread is the security thread referred
to in the following as alternating window thread which is alternately visible on the
front or the back of a document. Apart from security threads there is also the
possibility for using so-called transfer elements as security elements, these usually
spanning gaps, for example a hole, in a document.
[05] The security elements have complex, visually and/or automatically testable
security features which can only be imitated with great efforts. As to additionally
increase the protection against forgery, such security elements often have several
different security features which can also have, when combined, a new common effect.
[06] One security feature which can often be found in security elements is a
multilayer dichroic coating, whose color effect changes depending on viewing angle
and/or the viewing in transmitted light or incident light. This phenomenon is based on
interference effects due to the overlapping of multiple reflections and/or multiple
transmissions of light waves within the layer structure in combination with selective
absorption properties of the layer materials. The change of color from varying viewing
argles is also called color shift effect. The change of color when viewed alternately in
in :ident light and in transmitted light, in contrast, is hereinafter referred to as color
change effect.
[07] Optical interference coatings with color shift effect in connection with security
elements are described in, for example, EP 0 395 410 Bl, EP 0 341 002 Bl, WO
01 / 03945 Al and US 3,858,977. Depending on kind and number of layers in the layer
structure 2, 3, 4 or more color effects depending on the viewing angle can occur. The
reflection and transmission properties of such color shift effect layers depend on
several factors, in particular on refractive indices, absorption coefficients and layer
thicknesses as well as on the number of layers in the layer structure. It is equally
known to integrate the interference layers in a security element all over or, however, as
described for example in WO 00/31571 Al, to break down into tiny flakes and to mix

these with printing ink.
[08] Although security elements with dichroic coating have already been proposed,
there is still a need for security elements improved in contrast to the already existing
security elements.
[09] It is therefore the problem of the present invention to provide security elements,
in particular a security thread or a transfer element, which, compared to prior art, have
an enhanced forgery-proofness.
[10] This problem is solved according to the invention by a security element as well
as a security document or a semifinished product with the features of the independent
claims. In claims dependent on these are specified advantageous developments and
embodiments of the invention.
[11] According to that the multilayer security element has an interferential layer
structure which produces a color shift effect on both the front as well as the back of the
security element when the security element is viewed from different angles. Here the
color shift effect on the front and back of the security element can be designed in the
same way but also differently.
[12] Due to the complex multilayer structure of the security elements and the
therefore only difficultly reproducible color shift and color change effects, they can be
imitated only with great effort.
[13] The interferential layer structure here is composed of at least two multilayer
interference elements (Ib I2) and at least one reflection layer R.
[14] The interference element is formed by absorber and dielectric layers located
one on top of the other, wherein also several absorber and dielectric layers can be
disposed alternately one on top of the other. Instead of alternating absorber and
dielectric layers exclusively dielectric layers can be provided, too, adjoining layers
having strongly different refractive indices so as to produce a color shift effect. The
use of the absorber layers, however, is advantageous, because the color shift effect is
visible better.

[15] In principle, the interference elements I,, I2 can be structured in a multilayer
fashion, but they each comprise preferably at least two layers, namely one absorber
layer A] or A2 located on the outer side and one dielectric layer D] or D2 located
between the respective absorber layer and the inner reflection layer R. As absorber
layers AI? A2 typically serve metal layers of materials such as chromium, iron, gold,
aluminum or titanum of a thickness of preferably 4 nm to 20 nm. Compounds such as
nickel chromium iron or rarer metals such as vanadium, palladium or molybdenum can
also be used as materials for absorber layers. Further suitable materials are specified
for example in WO 01 / 03945 Al, e.g. nickel, cobalt, tungsten, niobium, aluminum,
metal compounds such as metal fluorides, metal oxides, metal sulphides, metal
nitrides, metal carbides, metal phosphides, metal selenides, metal silicides and
compounds thereof, but also carbon, germanium, cermet, iron oxide and the like.
[16] The absorber layers Ai, A2 of the interference elements can have the same or
different thicknesses within the interferential layer structure and/or consist of the same
or different absorber materials.
[17] For the dielectric layer Di, D2 mainly transparent materials with a low refractive
index AI2O3. In principle, nearly all transparent compounds which can be vapor-deposited
are possible, therefore in particular also higher refracting coating materials such as
Zr02, ZnS, Ti02 and indium tin oxides (ITO). Further materials suitable for the
dielectric layers Db D2 are specified for example in WO 01 / 03945 Al. The layer
thickness of the dielectric layers Db D2 is in a range of 100 nm to 1000 nm, preferably
200 nm to 500 nm.
[18] The dielectric layers of the interference elements can have the same or different
thicknesses within the interferential layer structure and/or consist of the same or
different dielectric materials.
[19] Preferably the interference elements are designed differently within the
interferential layer structure, so that they each produce different color shift effects.
[20] Instead of absorber layers Ai, A2also dielectric layers can be used, the


refractive index n of adjoining dielectric layers having to be greatly different, on the
one hand n 1.7 so as to cause a distinct color shift
effect. Since with this structure for a distinct color shift effect several dielectric layers
are necessary and thus the production is very expensive, the use of absorber layers is
preferred.
[21] The absorber layers Ab A2 and dielectric layers Di, D2 of the interference
elements Ils I2 as well as the reflection layer R are preferably produced by means of a
vacuum vapor deposition method on the substrate S which can form a component of
the security element 1, but which can also serve only as an intermediate carrier and is
removed when the security element is applied to or in an object at the latest.
[22] Most different vapor deposition methods are suitable for the production of the
layers. One methodic group is formed by physical vapor deposition (PVD) with
evaporation boat, vapor deposition by resistance heating, vapor deposition by
induction heating or also electron-beam vapor deposition, sputtering (DC or AC) and
electric-arc vapor deposition. Furthermore, the vapor deposition can also be effected
by chemical vapor deposition (CVD) as e.g. sputtering in reactive plasma or any other
plasma activated vapor deposition method. In principle, there is also the possibility
that dielectric layers are printed on.
[23] The reflection layer R is preferably a metal layer for example of aluminum,
silver, nickel, platinum or palladium, preferably of silver or aluminum or of another
strongly reflecting metal. The better the reflection properties of the reflection layer R,
the more striking is the color shift effect and the more brilliant is the possibly present
diffractive effect of the relief structure.
[24] Dependent on the thickness of the reflection layer the latter can be of an opaque
but also semitransparent design. ā€˛Semitransparency" here means translucence, i.e. the
layer shows a light transmission ratio of under 90 %, preferably between 80 % and
20 %.
[25] Preferably, the security element has two interference elements which are
separated from each other by a reflection layer, the interference elements each

producing a color shift effect from different viewing angles. With a semitransparent
reflection layer possibly also a color change effect is recognizable. If the security
element comprises a preferably transparent substrate, then the interference elements
and the reflection layer R in this variation are located on the same side as the substrate.
If it is desired to have the two interference elements on different sides of the substrate,
then two reflection layers have to be used. The security element then consists of the
following layer order interference element (Ii) / reflection layer (Ri) / substrate (S) /
reflection layer (R2) / interference element (I2).
[26] The structure of the interference elements can be identical or different, so that
the interplay of colors depending on the viewing side of the security element is the
same or different. Different color shift effects are preferred. Different effects result, for
example, from a variation of the materials used in the interference elements and
reflection layers and/or from a variation of the layer thicknesses of the individual
layers which form the interference elements or reflection layer. The color intensity of
the color shift effect to be viewed is maximal, which is due to the reflecting metal
layer disposed behind the interference element, so that this security feature is simply
visually testable.
[27] Furthermore, the security element can in particular have diffraction structures,
which overlap at least partly with the reflection layer. For the optical effect of the
diffraction structures, too, the reflection layer has an intensifying effect, so that this
security feature, too, is simply visually testable.
[28] As diffraction structures for example refraction patterns, transmission, volume
or reflection holograms, but also grating structures are considered which are preferably
component of the substrate carrying the interference elements and the reflection layer,
but which can also be placed in every other suitable layer or in an additional layer. The
additional layer can be e.g. a lacquer layer.
[29] Preferably, the diffraction structures are placed, in particular embossed, as a
reflection hologram in the surface of a transparent plastic substrate which forms the
security element, the reflection layer forming the reflective background for the
reflection hologram. The two interference elements with the reflection layer located in

between can both be present on one side of the plastic substrate, either on the surface
in which the relief structure is embossed or on the opposite, flat side of the substrate.
However, the interference layers can also be disposed on opposite sides of the
substrate, then one reflection layer having to be present on the substrate surface with
relief structure and on the opposite, flat surface of the substrate. Thus there arise
several variations which have different visual effects and therefore can be preferred,
depending on the use, to a greater or lesser extend.
[30] From both viewing sides the optical effect of such a security element is
substantially determined by the color effect of the interference elements. If diffraction
structures are additionally used, at least from one viewing side, with a suitable layer
structure also from both viewing sides, the optical appearance can be substantially
determined by the optical effect of these diffraction structures. In this case the effects
of the two security features overlap each other.
[31] Therefore, such a security element is particularly suitable as a two-sided
security thread, since from each viewing side particularly characteristic security
features can be recognized which are visually testable. Such a two-sided security
thread can be used as an alternating security thread which comes to the surface or is at
least visible at different spots on the opposite surfaces of the security document. But it
can also be used as a lookthrough window thread where it is visible from both
document sides in a particularly thin or transparent document area or where it spans a
hole in the document.
[32] Such a security element, however, is also suitable as a transfer element, e.g. in
the form of a label or patch which is put above a hole on a surface of the security
document. Viewed from one side of the document the optical impression arises that it
is a patch with color shift effect. Viewed from the other side through the hole of the
document a part of the patch with another or possibly also an identical color shift
effect is visible, wherein it depends on the exact layer structure of the security element
whether a possibly present diffraction design is visible from both sides or only from
one side.


[33] As "transfer element" within the terms of this invention is described a security
element which is prepared on a separate carrier layer, for example a plastic film, in
reverse order compared to the order later put on the security paper and then is
transferred with the help of an adhesive layer or lacquer layer of the desired outline to
the security paper. The form of the security element is not limited and any outlines are
thinkable up to filigree structures such as guilloches etc. are possible. Frequently, the
security elements are also formed as stripes which run in parallel with the edges of the
document of value. After the transfer the carrier layer can be peeled off from the layer
structure of the security element or remain as a protection layer as firm component of
the security element on the layer structure.
[34] The individual transfer elements can be prepared on the carrier layer as separate
single elements having the outlines to be transferred. Alternatively, the layer order of
the transfer elements is provided in continuous form on the carrier layer. Such carrier
layers with individual transfer elements located at a distance to each other or a
continuous layer structure are hereinafter referred to as "transfer material", and the
layer order of the security element disposed on the carrier layer as "transfer layer".
[35] In case of the continuous transfer layer the transfer material is then connected to
the security paper via an adhesive layer and the adhesive layer is activated via
respective embossing tools, so that the transfer layer only in the activated areas is
bonded to the security paper. All other areas are then peeled off with the carrier layer.
Alternatively, the adhesive layer, too, can have the form of the security element to be
transferred. As adhesives preferably hot-melt adhesives are used. But also any other
adhesives, such as reaction lacquers, can be used.
[36] The security element structured according to the invention can be combined
with further security features, in particular with a negative or positive writing by local
removal of reflection layer and/or the interference element. In a multilayer interference
element structure at least one and up to all layers can be locally removed. With an
interference element which, for example, consists of at least one absorber and at least
one dielectric layer the gaps are preferably in the absorber layer. In case two
interference elements are placed in a security element, each can be of different design.


E.g. in one interference element numbers can be incorporated and also made visible by
means of gaps in the absorber layer, in the other interference element letters by means
of gaps in the absorber layer. Here no limits are set to the design-related possibilities.
The writing preferably represents alphanumeric characters but is not restricted to that.
Within the terms of the invention this can be every pattern, symbol or coding that can
be represented. Due to the gaps in the layer structure an additional incident
light/transmitted light effect is the result. Due to the twofold interference coating this
effect is especially pronounced, since in incident light the patterns, symbols or codings
are substantially more hidden than with an only simple interference coating. In
transmitted light, however, the gaps are recognizable as lighter areas in dark
surroundings.
[37] By local removal of the reflection layer and, optionally, the interference
element, the security element becomes, according to the design of the individual
layers, partially transparent or semitransparent.
[38] These properties and the individual advantages of the particular variations are
described in the following with reference to the accompanying drawings . The
proportions shown in the figures do not necessarily correspond to the dimensions
present in reality and primarily serve for the improvement of clarity.
[39] Figure 1 shows a security document with a security element applied to a
surface above a hole of the security document and with integrated security element as
window thread;
[40] Figure 2 shows a cross-section of the security document of Figure 1 along the
line II - II;
[41] Figure 3 shows a cross-section of the security document according to Figure
1 along the line III - III with lookthrough window thread;
[42] Figure 4 shows a cross-section of the security document according to Figure
1 along the line IV - IV with two-sided, alternating window security thread;
[43] Figure 5 shows the layer structure of a security element according to a first



WE CLAIM:
1. Security element (2; 4) for embedding in or application to a security document (1), in
particular for documents of value, such as e.g. a bank note, wherein the security element has a
substrate (S) with at least one reflection layer (R) and one interference element (I1, I2) having
a color shift effect, characterized in that the security element has on each side of the reflection
layer (R) an interference element (I1, I2) with color shift effect, or has on each side of the
substrate (5) both a respective reflection layer (Rl, R2) and an interference element (I1, I2)
with color shift effect.
2. Security element (2; 4) as claimed in claim 1, wherein the security element has
diffractive effects on one or on both sides.
3. Security element (2; 4) as claimed in claim 1 or 2, wherein the security element has at
least in partial areas diffraction structures (8).
4. Security element (2; 4) as claimed in claim 3, wherein the diffraction structures (8)
overlap at least partially with the reflection layer or layers.
5. Security element (2; 4) as claimed in at least one of the claims 1 to 4, wherein the at
least one reflection layer (R, Rj, R2) is a metal layer.
6. Security element (2; 4) as claimed in at least one of the claims 1 to 5, wherein the at
least one reflection layer (R, Ri, R2) is opaque or semitransparent.
7. Security element (2; 4) as claimed in at least one of the claims I to 6, wherein the at
least one reflection layer (R, Ri, R2) and/or at least one interference element (I1, I2) have gaps
(9) in the form of patterns, symbols or codings.


8. Security element (2; 4) as claimed in at least one of the claims 1 to 7, wherein one or
both of the interference elements (I1, I2) have at least one absorber layer (Ai or A2) and at least
one dielectric layer (Di or D2), which is located between the reflection layer (R) and the
absorber layer (Ai or A2), and wherein, optionally, at least one absorber layer and/or at least
one dielectric layer has gaps in the form of patterns, symbols or codings.
9. Security element (2; 4) as claimed in at least one of the claims 1 to 8, wherein the
interference elements (I1, I2) have a two-layer structure.
10. Security element(2; 4) as claimed in at least one of the claims 1 to 9, wherein the
interference elements (I1, I2) are structured differently.
11. Security element (2; 4) as claimed in at least one of the claims 1 to 10, wherein the
interference elements (I1, I2) and the reflection layer (R) in between are disposed on one side
of the substrate (S).
12. Security element (2; 4) as claimed in at least one of the claims 1 to to, wherein the
interference elements (I1, I2) are disposed on opposite sides of the substrate (S).
13. Security element (2; 4) as claimed in at least one of the claims 3 to 12, wherein the
diffraction structures (8) are present in a separate layer.
14. Security element (2; 4) as claimed in at least one of the claims 3 to 13, wherein the
diffraction structures (8) are embossed in a surface of the substrate (S) or the separate layer in
the form of a relief pattern.
15. Security element (2; 4) as claimed in at least one of the claims 3 to 14, wherein one of
the interference elements (I1, I2) immediately adjoins the diffraction structures (8).


16. Security element(2; 4) as claimed in at least one of the claims 3 to 15, wherein the or
one reflection layer (R) immediately adjoins the diffraction structures (8).
17. Security element (2; 4) as claimed in one of the claims 1 to 16 in the form of a security
thread for embedding in a security document.
18. Security element (2; 4) as claimed in one of the claims 1 to 16 as a label or patch for
the application to a security document.
19. Security element (2; 4) as claimed in one of the claims 1 to 26 or 18 as a transfer
element for the application to a security document by means of the transfer method.
20. Security document, in particular document of value such as bank note, or semi
finished product for the production of the security document with a first and a second surface
located opposite to each other and a security element (2, 4) as claimed in one of claims 1 to
19, characterized in that the security element is connected to the document or semi-finished
product in such a way that it is respectively recognizable when the two surfaces are viewed
and has a color shift effect on both sides.
21. Security document or semi-finished product as claimed in claim 20, wherein the
security element (2) is applied to one of the two surfaces and spans a hole (3) or a transparent
area of the document or semi-finished product.
22. Security document or semi-finished product as claimed in claim 20, wherein the
security element (4) is at least partially embedded in the document and spans a hole or a
transparent area of the document or semi-finished product.


23. Security document or semi-finished product as claimed in claim 20, wherein the
security element (4) is embedded in the document or semi-finished product in such a way that
it is visually recognizable in first areas on the first surface and in second areas on the second
surface different from the first areas.
24. Security element (2; 4) as claimed in one of the claim 1 to 19 having a transfer
material for the application of the security element to a document of value, characterized in
that the transfer material comprises the following layer structure:

- a carrier layer in the form of a substrate (8),
- the reflection layer (R),
- and on each side of the reflection layer (R) on of the interference elements (I i, I2)
with color shift effect,
or the following layer structure;
- a carrier layer,
- the substrate (8),
- and on each side of the substrate (5) both one of the respective reflection layers (Ri,
R2) and one of the interference elements (I1, I2) with color shift effect.
25. Method for producing a security element (2; 4) having a transfer material as claimed in
claim 24 for the application of the security document to a document of value, characterized by
the following steps:
a) providing a carrier layer
b) vapor depositing the reflection layer (R) or reflection layers (R1, R2) and the
interference elements (I1, I2).
26. Method for producing a document of value with a security element as claimed in any
of the claims 1 to 19, wherein to the document of value is partially transferred the security
element (2; 4) having a transfer material as claimed in claim 24 and afterwards, optionally, the
carrier layer is peeled off.

Documents:

1083-KOLNP-2004-ABSTRACT-1.1.pdf

1083-kolnp-2004-abstract.pdf

1083-KOLNP-2004-AMANDED CLAIMS.pdf

1083-KOLNP-2004-AMANDED PAGES OF SPECIFICATION.pdf

1083-kolnp-2004-assignment.pdf

1083-kolnp-2004-assignment1.1.pdf

1083-kolnp-2004-claims.pdf

1083-kolnp-2004-correspondence.pdf

1083-kolnp-2004-correspondence1.1.pdf

1083-KOLNP-2004-DESCRIPTION (COMPLETE)-1.1.pdf

1083-kolnp-2004-description (complete).pdf

1083-KOLNP-2004-DRAWINGS-1.1.pdf

1083-kolnp-2004-drawings.pdf

1083-KOLNP-2004-EXAMINATION REPORT REPLY RECIEVED.pdf

1083-kolnp-2004-examination report.pdf

1083-KOLNP-2004-FORM 1-1.1.pdf

1083-kolnp-2004-form 1.pdf

1083-kolnp-2004-form 18.1.pdf

1083-kolnp-2004-form 18.pdf

1083-KOLNP-2004-FORM 2.pdf

1083-KOLNP-2004-FORM 3-1.1.pdf

1083-kolnp-2004-form 3.1.pdf

1083-kolnp-2004-form 3.pdf

1083-kolnp-2004-form 5.1.pdf

1083-kolnp-2004-form 5.pdf

1083-KOLNP-2004-FORM-27.pdf

1083-kolnp-2004-gpa.pdf

1083-kolnp-2004-gpa1.1.pdf

1083-kolnp-2004-granted-abstract.pdf

1083-kolnp-2004-granted-claims.pdf

1083-kolnp-2004-granted-description (complete).pdf

1083-kolnp-2004-granted-drawings.pdf

1083-kolnp-2004-granted-form 1.pdf

1083-kolnp-2004-granted-form 2.pdf

1083-kolnp-2004-granted-specification.pdf

1083-KOLNP-2004-OTHERS-1.1.pdf

1083-kolnp-2004-others.pdf

1083-KOLNP-2004-PA.pdf

1083-KOLNP-2004-PETITION UNDER RULE 137.pdf

1083-kolnp-2004-reply to examination report.pdf

1083-kolnp-2004-specification.pdf

1083-kolnp-2004-translated copy of priority document.pdf

1083-kolnp-2004-translated copy of priority document1.1.pdf


Patent Number 248925
Indian Patent Application Number 1083/KOLNP/2004
PG Journal Number 37/2011
Publication Date 16-Sep-2011
Grant Date 09-Sep-2011
Date of Filing 29-Jul-2004
Name of Patentee GIESECKE & DEVRIENT GMBH
Applicant Address PRINZREGENTENSTRASSE 159, 81677 MUNCHEN
Inventors:
# Inventor's Name Inventor's Address
1 HEIM MANFRED ALFRED-SCHMIDT-STRASSE 35, 81379 MUNCHEN
PCT International Classification Number B42D15/00
PCT International Application Number PCT/EP2003/01383
PCT International Filing date 2003-02-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102 06 357.5 2002-02-14 Germany