EP1771307A1

EP1771307A1 - Stock comprising a masking field for hiding a confidential information pattern

Info

Publication number: EP1771307A1
Application number: EP05754456A
Authority: EP
Inventors: Jules Fischer
Original assignee: Fofitec AG
Current assignee: Fofitec AG
Priority date: 2004-07-07
Filing date: 2005-07-07
Publication date: 2007-04-11
Also published as: US20080012288A1; AU2005259752A1; WO2006002571A1

Abstract

The invention relates to stock comprising a masking field on which an information pattern can be printed in such a way that it can be recognised in front of the background of the masking field only once certain manipulations have been carried out. The aim of the invention is to increase the security of the confidential information. To this end, the following measures are carried out individually or as a combination: the masking field contains irregularly distributed colour points of between 50 and 400 µm, amounting to an entire surface area of between 0.3 and 0.5 cm<SUP>2</SUP> per cm<SUP>2</SUP>; and/or the masking field consists of a plurality of superimposed printed layers; and/or the masking field is printed with a printing ink, of which at least 50 % is concentrated in a masking field layer; and/or the masking field can be removed, at least partially and/or together with other layers, using an adhesive strip, with a peeling force of between 0.5 N / 50 mm and 2 N / 50 mm according to the Finat test method no. 1; and/or the stock is provided with a thermochromatic reagent which changes colour irreversibly under the effect of heat, from a temperature of 140°; and/or the stock is provided with a solvent-reactive reagent which changes colour irreversibly in a solvent atmosphere.

Description

DESCRIPTION

TITLE

Print carrier with camouflage field for hiding a confidential information pattern

TECHNICAL AREA

The present invention relates to a print carrier with camouflage field on which with normal printing ink, in particular using today's conventional laser or inkjet printer, a e.g. Information pattern consisting of characters can be imprinted in such a way that, against the background of the camouflage field, it can only be recognized by the naked eye after certain manipulations have been carried out. Accordingly, the term "normal printing ink" is also intended to include the toner used by laser printers or the ink used by ink-jet printers.

Such print media are used to PIN codes of bank or credit cards, passwords or similar sensitive information by mail to their

To provide recipients without unauthorized third parties having the opportunity to at least readily Only the authorized recipient makes them recognizable by performing the specific manipulations for the naked eye. The manipulations are such that they leave irreversible traces, so that attempts by unauthorized third parties to read the information, at least with the naked eye, are recognizable. One also speaks in this context of manipulation indicator.

STATE OF THE ART

A print carrier of the type mentioned is known from WO 99/24267 A1. Here, a transparent film on another substrate such as a paper sheet is arranged in the area of a previously printed on it camouflage field. The confidential information is printed on the upper surface of the film. Against the background of the camouflage field visible through the film, it can not be read, at least with the naked eye if suitably executed. It only becomes recognizable when the film and the substrate are separated, this separation leaves the irreversible traces necessary for the Maniplationsindativativity.

According to another embodiment known from EP 1 120 291 A2, the confidential information becomes readable by decoloration of an ink used for the camouflage field under the action of heat. However, EP 1 120 291 A2 does not contain any details of a suitable printing ink. It is questionable whether the apparently desired thermochromatic effect can be sufficiently irreversibly realized in order to make manipulations clearly recognizable.

In order to visualize the confidential information, however, WO 2004/106085 A1 proposes to irreversibly decolorize the printing ink of the camouflage field by the action of a chemical reagent.

In all previously known print media, the contrast of the confidential imprint after canceling the effect of the camouflage field is rather weak and in any case in need of improvement.

The Tarnfeld is in the prior art embodiments, a so-called sea of numbers, which is made by overprinting different characters and forms a disorderly, dark background in which the characters of the confidential information pattern for the naked eye are no longer visible or disappear into it. With the use of technical aids, however, it is still possible in the known embodiment to read the confidential information without this being subsequently recognizable.

It is known from EP 1 001 884 B1 to improve this type of camouflage by printing the areas forming the confidential information pattern with an overlap of less than 100%, which is achieved, for example, by screening with resolution of the characters into a multiplicity of small dots can be. In order to further improve the camouflage of the characters printed in this way, EP 1 001 884 B1 additionally proposes to also apply a grid of small dots in the camouflage field. Even if, for example, with the help of a microscope, the individual points should be recognizable, in this case there is the difficulty of assigning them to the confidential information on the one hand or the camouflage field on the other hand. As far as the mentioned applications for the transmission of PIN codes etc. are concerned, it is usually sufficient to ensure the security during printing in the printing house until the most automatic inserting. The persons involved in the printing should not be able to simply read the confidential information especially if it is printed on the same document together with the personal data of the recipient The possibilities for manipulation or the possibilities to use technical aids are relatively small in this phase and can be further restricted by suitable organizational measures in the printing house

Recently, however, applications have been envisaged in which the legitimate recipient makes the confidential information transmitted to him with the substrate for certain reasons unrecognized and identifiable and also proves this by presenting the unmanipulated substrate if necessary. It is understood that that here in the area of the receiver if necessary, much more time available and also technical aids could be used to read the confidential information and thereby allfalhg caused traces to eliminate again, without this would be at least easily recognizable for a third party

PRESENTATION OF THE INVENTION

Among other things, with regard to the last-mentioned applications, the present invention has the object of further improving the security of the confidential information in the case of a printing carrier with camouflage field of the type mentioned at the outset

This object is achieved by at least one of the features specified in claim 1 Preferred embodiments are specified in the dependent claims

The first of the features of the invention is that the camouflage field contains irregularly distributed color dots with irregular diameters in the large range between 20-400 μm and with a total area between 0 3 - 0 5 cm ² per cm ² This feature further improves the camouflage improvement already known from EP 1 001 884 B1 by screening the confidential information as well as by halftone dots even in the camouflage field. It has been shown that the halftone dots of the confidential information in EP 1 001 884 B1 alone due to their geometric arrangement of the yes also geometrically arranged halftone dots in the camouflage field with sufficient magnification can be discriminated for example under a microscope. By irregular arrangement of color dots with irregular diameters of said variable type in the camouflage field and with greater density than the density with which the halftone dots of confidential information are usually printed, this discrimination is, however, as good as no longer possible.

The density of the color points may be chosen to for example, that the number of color dots in the size range between 50-100 microns 2000-5000 per cm ^2, in the size range 100 - 200 microns 500 - 1000 per cm ^2, and in the size range between 200-400 microns 200 - 500 per cm ² .

Preferably, the camouflage field is printed with a liquid ink, wherein the color dots are formed by the ink mixed particles. This takes into account the fact that it is difficult or at least complicated and / or expensive to print irregularly arranged dots with irregular diameters in the specified size range and in the specified density.

For the purposes of the invention, a liquid printing ink for camouflage printing can be used as described in WO 2004/106085, which, in contrast to normal printing ink, in particular the toner of a laser print or the ink of an inkjet printer, can be irreversibly bleached using a chemical decolorizing agent is.

The special printing ink may e.g. by reaction of the products CB and CF as used for copying papers and well known to those skilled in the art.

As a chemical decolorizing suitable in this case is a

Desensitizing printing ink for the product CF, as used in printing technology Also suitable as chemical decolorizing agents are bleaching agents such as those used for bleaching paper and textiles, including commercial Javel water or the product DIRAXON S12 from CECA (F -92062 LA DEFENSE), CAS No. 61790-85-0

The particles admixed for the production of the color dots in the camouflage field of the printing ink are preferably porous and have an approximately corresponding color due to the absorption of ink. Suitable particles are known from so-called matting agents and can consist of amorphous silica, for example. These particles, however, have only one grain size between them 5 - 7 microns on color dots with diameters in the desired range between 50-400 microns are still formed by agglomeration of these particles By not all the particles used to agglomerate the desired color dots in the specified large area resulting in larger numbers and smaller color dots, resulting in the desired camouflage effect but hardly contribute

The use of smaller particles and their agglomeration has in comparison to the use of larger particles with diameters directly in the specified large range the advantage that the agglomerations form rather flat and thereby fit well into the camouflage layer, while larger particles were protruding from the camouflage layer and therefore as such were recognizable again

The second of the inventive features of the solution is then that the camouflage field is made up of a plurality of layers printed one above the other

As the layer thickness of the camouflage field increases, its so-called opacity value increases, as is the case, for example, with that customary in the graphics industry

Densitometer is measurable The color intensity of the camouflage field is thereby larger and it is better to hide a confidential information The confidential information could alternatively or additionally be printed even more intense, which then their readability after removal of their camouflage was improved by the camouflage However, the layer thickness of the camouflage field layer are subject to technical limitations due to the application quantity, drying and undesired imprinting or doubling of the pressure in the stack or on the roll. By constructing the camouflage field layer of a plurality of layers printed on top of each other, nevertheless a sufficiently large layer thickness can be achieved. By means of the multiple partial layers, it is also possible to achieve a camouflage-enhancing appearance of the camouflage field with a better distribution of the particles producing the color points mentioned. In particular, the "white" areas in the camouflage field decrease, ie those areas which are not covered with printing ink in the manner of a sea of numbers when the camouflage field is generated and on which no particles producing color dots are present.

The color intensity of the camouflage field can alternatively or additionally also be increased according to the third of the inventive solution features by concentrating at least 50% of the printing ink with which the camouflage field is printed in a camouflage field layer. Preferably even at least 90% of the printing ink is concentrated in the camouflage field layer.

This is e.g. this is not the case when plain, uncoated paper is used as the carrier for the printing of the camouflage field. This has the property of absorbing ink at least predominantly in itself and thus to quickly make the imprint smudge-proof. In this context, one speaks in the technical language of offset printing of putting away the printing ink, this effect being particularly pronounced in the case of papers with only slight fiber sizing, as have hitherto been preferred in the context of printing media of the type considered in the prior art.

The desired concentration of the printing ink can be achieved in one

Camouflage layer itself on per se absorbent paper through a barrier layer, which is dense for the ink at least in the said percentage. The barrier layer may for example consist of a material, as it is commonly used for the coating of so-called coating base papers. These coatings applied, for example, by brushing also serve to obtain a surface that is as closed as possible and also smooth, and consist, for example, of China Clay, chalk, casein or plastic dispersion Despite their tightness and smoothness, they still have good anchoring properties for printing inks

Due to the concentration of the printing ink, when using a special, chemically decolorizable printing ink, there is the additional advantage that it is more quickly achieved by the decolorizing agent. The decoloration is thus also faster and, if necessary, only a few seconds. Moreover, it is considerably more effective and complete

The printing ink for the camouflage printing is preferably optically matted in order to avoid the recognizability of a printed information pattern by gloss effects. It is particularly advantageous to adapt the ink in color and in terms of its gloss to conventional toner as used by laser printers

According to the fourth of the inventive solubility features, the camouflage field can be at least partially and / or together with other layers with a Ablosekraft between 0 5 N / 50 mm and 2 N / 50 mm according to the Finat Test Method Nr 1 remove (using the Finat test method No. 1 see also www finat com) Preferably the Ablosekraft amounts to about 1 N / 50 mm

As has been shown by experience with already known print carriers of the type considered, it is quite possible to lift the printing ink or the toner used for printing the confidential information pattern at least partially with an adhesive strip from the camouflage field, so that the pattern can be recognized on the adhesive strip As a result of the aforementioned training, the camouflage field was at least partially and / or together with other layers of the print carrier with, whereby the print carrier was destroyed and the manipulation was made visible the aforementioned training is unnecessary, of course, if it succeeds, the to apply color to the camouflage field sufficiently strong enough to print the confidential information pattern

In order to achieve the stated values, the camouflage pressure or the camouflage field layer can be arranged on an intermediate layer which, if subjected to a corresponding load, has a cohesive failure in itself or an adhesion break to an adjacent one Suffers interface As an intermediate layer, the above-mentioned barrier layer may optionally be used in combination with a release layer

According to the fifth of the inventive solubility features of the print carrier is provided with a thermochromatic reagent which irreversibly discolored when exposed to heat from a temperature of 140 ° Suitable reagents are state of the art and commercially available

This feature takes into account the fact that it is possible in the known print carriers of the type considered with the aid of an iron to read the confidential information, provided that it is printed with toner of a laser printer For this purpose, it is sufficient to put a thin smooth paper over the print and rub it with the iron until a readable impression is made on the paper. The impression results from the fact that toner is thermoplastic and begins to soften again at a certain temperature. The characteristic according to the invention became the reagent in such a manipulation attempt discolour and make it recognizable The specified limit temperature of 14O ⁰ C for the reagent used results from the fact that this just barely discolored at the usual fixing temperature for the toner in a laser printer

In accordance with a preferred embodiment of the invention, the thermochromatic reagent is arranged on the back of a carrier layer carrying the camouflage field on the front and can thus not impair the camouflage pressure and the ink used therefor and, if preferred, chemically decolonable ink

According to the sixth of the inventive solubility features, the print carrier is alternatively or additionally provided with a solvent reactive reagent which irreversibly discolors in a solvent atmosphere. Suitable reagents are state of the art and commercially available

This feature takes into account the fact that certain printing inks, such as the chemically decolonable printing ink preferably used for the camouflage field, reversibly decolorize in cold solvent vapor, for example in acetone vapor, and thereby temporarily make the confidential information visible By irreversible discoloration of the reagent used, such a manipulation attempt would also be recognizable later

Like the thermochromatic reagent, the solvent-reactive reagent can also be arranged on the back of a carrier layer bearing the camouflage field on the front side

In the context of the embodiments in which the camouflage field is printed with a special printing ink which decolorizes with a chemical decolorizing agent, the decolorizing agent can advantageously be kept ready on the printing substrate and / or even integrated in its structure

BRIEF EXPLANATION OF THE FIGURES

Embodiments of the invention will now be explained with reference to the drawings

1 is a greatly enlarged photographic image of a printed with a confidential information pattern camouflage according to the invention,

2 shows a correspondingly enlarged photographic illustration of the confidential information pattern of FIG. 1 in front of a uniformly light background in the form of the number "2", FIG.

3 shows a basic embodiment of a printing carrier according to the invention,

4 an embodiment of an inventive print carrier with a two-layered camouflage field,

5 shows an embodiment of a printing carrier according to the invention with a barrier layer adjacent to the camouflage field layer,

6 shows an embodiment of FIG. 5 with a torn barrier layer, FIG.

7 shows an embodiment of a printing carrier according to the invention with a barrier layer and a separating layer adjacent thereto, FIG. An embodiment of an inventive print carrier with a coating which irreversibly discolored under the action of heat and / or in a solvent atmosphere,

A further embodiment of an inventive print carrier with a coating which irreversibly discolors under the action of heat and / or in a solvent atmosphere,

Yet another embodiment of an inventive

Print carrier with a coating which irreversibly discolors under the action of heat and / or in a solvent atmosphere,

a print carrier according to FIG. 5, additionally provided with a protective layer on the front side and additionally provided on the back with a pressure-sensitive adhesive layer and a cover layer for the pressure-sensitive adhesive layer,

an embodiment of a print carrier with integrated

Decoating agent, back pressure-sensitive adhesive layer and a covering layer for this pressure-sensitive adhesive layer,

the print carrier according to FIG. 12, after removal of the cover layer, adhered to a substrate and provided with a printed information pattern,

FIG. 13 shows the print carrier after detachment of an upper complex with the information pattern;

13 after turning and reincorporation of the complex shown in FIG. 14 on the remaining lower complex with the integrated decoupling agent, FIG.

a) in plan view of a printing substrate in the form of a substrate according to the invention with herauslobarem camouflage part and a reactive label in

Oπginalzustand,

FIG. 16 shows the substrate of FIG. 16 with the camouflaged part part slipped out and pushed under the reactive label, FIG. FIG. 18 shows the substrate of FIG. 17 after decoupling of the camouflage field and FIG

Making recognizable a confidential information pattern printed on the camouflage field,

19 shows in section (A-A) the substrate of FIG. 16, FIG.

Figure 20 in section (B-B), the substrate of Figure 17, and

21 in a representation corresponding to FIG. 19, an embodiment expanded by further layers

WAYS OF IMPLEMENTING THE INVENTION

The photographic image of Figure 1 shows a small, but greatly enlarged section of a formed in the manner of a numerical camouflage field according to the invention on which in Fig. 2 in front of a uniformly bright background shown and resolved into individual, spaced apart grid points digit "2" in the same However, due to the camouflage, the figure "2" in Fig. 1 is not visible. The good small camouflage is clearly illustrated by the many small dots of varying size distributed unevenly over the camouflage field in FIG

In a basic embodiment, the print carrier, as shown in section in FIG. 3, can simply have a carrier layer 30 which is printed on one side with a camouflage field 10 using a printing ink which can be bleached with a chemical decolorizing agent and mixed with particles of the type described above schematically represented also a directly on the camouflage field z B with toner of a laser printer printed confidential information pattern M. This can be seen by fading the ink of the camouflage The carrier layer 30 may be, for example, a paper or foil layer In Figure 3, the individual layer thicknesses shown greatly exaggerated thick, which also applies to all other sectional views

4 shows an embodiment of a print carrier in which the camouflage field 10 is constructed from two layers 11 and 12 printed on top of one another. Before the application of the layer 12, the layer 11 was dried In the embodiment of FIG. 5, the carrier layer 30 consists, for example, of absorbent paper. A barrier layer 20, however, prevents the printing ink of the camouflage field layer from penetrating into the carrier layer during printing. The ink thus remains substantially concentrated in the camouflage field layer, producing a pressure-intensive image there and There is also good and quickly accessible there for the required for their Decoloπerung chemical Decoloπerungsmittel

At least one of the layers of the print carrier according to the invention is advantageously designed so that it has only a small inner cohesion and suffers a cohesive failure, if it should be attempted to lift the confidential information pattern z B by means of an adhesive strip

Cohesion failure is shown in FIG. 6 by the example of the barrier layer 20 which is torn in two in FIG. 6. Instead of a cohesive failure, an adhesion break z B at a separation layer 31, as shown in FIG. 7, also serves the same purpose

In the figures 6 and 7, the print carrier is otherwise still formed in the manner of a self-adhesive label on the back of the carrier layer 30, he is provided with a pressure-sensitive adhesive layer 60 and adhered to a larger substrate 70 by means of this with the substrate 70 may in particular a standard paper sheet z B in A4 format act

FIGS. 8-10 show a print carrier in such a configuration on a substrate 70, wherein additionally a coating 40 or 50 is additionally provided on the back side of the carrier layer 30. The coating 40 is a thermochromatic reagent, which starts from a temperature of about 140 ⁰ C irreversibly changes color when coating 50 is it is a solvent-reactive reagent which in a Losungmittelatmospare such B in acetone vapor irreversibly changes color through the Verfarbungseffekt experiments are seen partly reflect the confidential information by Bugein on another transmitter or by reversible Decoloπeren of the ink briefly to make the two reagents may alternatively be present next to each other or mixed with each other It could also be used reagent that has both properties simultaneously

In order for the discoloring effect of the coating 40/50 to be clearly visible despite the camouflage field 10, the camouflage field layer 10 is in the embodiment of FIG For this same reason, the pressure-sensitive adhesive layer 60 is flat-shaped somewhat smaller than the carrier layer, whereby its edge strip can be raised and the coating 40/50 can be viewed directly In Fig. 10, a punched-out portion 71 is mounted in the substrate 70 below the print carrier, whereby the view of a portion of the coating 40/50 is also released

As a result of the presence of the intermediate layer 20, the printing ink used for the printing of the camouflage field can hardly be knocked downwards, as was explained above for normal paper. In particular, the higher-boiling, more volatile constituents of the printing ink remain in the camouflage field layer as a result Wiping and scratching resistance of this layer may be impaired. As a result, unwanted effects such as the so-called ghost effect can occur during further processing. The ghosting effect is a technical term for a print in which no printing form is present and where by the

Abklatsch the actual pressure due to insufficient abrasion resistance results in more than one image, which is increasingly weak and has a very disturbing effect

To achieve sufficient resistance to wiping and scratching, the following measures are suitable either individually or in combination with one another

The print carrier can be actively dried immediately after the application of the ink, whereby especially the higher-boiling components of the printing ink used can be effectively removed A particularly effective and intensive drying results, for example, using high-speed hot air For this purpose, if the order of special Printing ink in a continuous process on a running Drucktragerbahn takes place, so-called

Floating dryers are used, which build from both sides of the web high-speed hot air cushion and keep the web without Walzenfuhrung in suspension

The printing ink is formulated with very low-boiling organic solvents or water, or a reactive ink is additionally used, such as a two-component system with resin and hardener. It could also be a 100% solids Solid-body formulation can be chosen as a radiation-curing system with or without photoinitiators (UV or EB radiation hardening)

The camouflage field layer 120 is provided on the surface with a transparent protective layer 110 increasing the abrasion and scratch resistance of the printing ink, as shown in FIG. 11. The layers 130, 140 and 150 correspond to the layers

The layer 190 is a masking paper z B in the form of a silicone paper. In the case where the printing ink is chemically decolonizable with a decolorizing agent, the protective layer 110 must, of course, be sufficiently transparent to the decolorizing agent This may be due to a porous or lattice-like

In addition, the thickness of this layer should be very small and, for example, only 1 - 2 microns

The upper four layers 110-140 correspond to those of FIG. 11 In addition, the layers 130 and 140 are transparent here. The carrier layer 140 may, for example, comprise a plastic film, in particular a preferably slightly matt, stretched polyester film a thickness of about 50 microns

Below the carrier layer 140, a further carrier layer 170 is provided in the embodiment of FIG. 12, and between the two carrier layers 140 and 170 are two outer, preferably strip-shaped pressure-sensitive adhesive layers 151 and 152 which in turn enclose a preferably strip-shaped layer 160 between them, which encloses the decoupling agent z B encapsulated in liquid form in microcapsules which can be destroyed under pressure The further carrier layer 170 is preferably a film layer of only a very small thickness, such as 12 μm

Between the two carrier layers 140 and 170 and the two

Pressure-sensitive adhesive layers 151 and 152, the Decoloπerungsmittel is tightly embedded, especially if the support layers 140 and 170 are film layers, which is indeed preferred A loss of decolorizing over time, for example by evaporation, is thus virtually eliminated

On the back side of the further carrier layer 170, a further pressure-sensitive adhesive layer 180 is present, which in turn is provided with a removable cover layer 190 The cover layer 190 is selected to be the same size as other layers of the print carrier

The print carrier of FIG. 12 (as with all other print carriers described) could also be a stripe-shaped material with a uniform structure that extends endlessly perpendicular to the plane of the paper, from which individual print carriers could be obtained by stitching, which is then transferred to a so-called Web-Fιnιshιng plant could be mounted on a running paper web or on running sheets or forms From such a Endlosmateπal could be produced by a lattice punching a label material The respective Endlosmateπalien are in any case by the cover 190 on itself aufrollbar and are preferably on roll produced and processed

The handling of the print carrier of FIG. 12 will now be explained with reference to FIGS. 13-15

FIG. 13 shows the print carrier of FIG. 12 after the covering layer 190 has been removed and pasted on a substrate in the form of a paper sheet 200, a confidential information pattern M (reversed page) already being printed on its upper side

In FIG. 14, an upper complex of the print carrier with the information pattern M and the layers 110-140 is removed from the remaining layers 151, 151 and 160-180 and glued back to these layers in FIG. 15 after turning. As a result, the camouflage field layer 120 is at least indirectly through the permeable protective layer 110, come into contact with the decoating agent-containing layer 160

For Decoloπerung the special printing ink of the camouflage field layer, it is sufficient to exert rubbing with the finger of a certain pressure (arrows P) on the entire complex and thereby release the Decoloπerungsmittel contained in the layer 160 in encapsulated form By far the largest share of special, decolorable ink is concentrated in the adjacent Tarnfeldschicht 120, the Decoloπerung takes place after release of Decoloπerungsmittels quickly and effectively accordingly quickly and with good contrast becomes the confidential In addition, an extremely small amount of decolorizing agent of z B only suffices for 10-20 g / m ²

The detachment of the upper complex with the layers 1 10 - 140 as shown in FIG. 14 is facilitated by the fact that the two pressure-sensitive adhesive strips 151 and 152 are each arranged at some distance from the edge of the complex to be detached, resulting in narrow grip tabs on both sides Of course, the adhesive properties of the adhesive strips 151 and 152 on the underside of the support layer 140 also play a role in this detachment

Use of a polyester film for the support layer 140 satisfies this requirement

The fact that the pressure-sensitive adhesive layers 151 and 152 and the layer 160 with the Decoloπerungsmittel are strip-shaped is advantageous in their production They can be produced efficiently by continuous coating by coating a moving web (support layer 170)

If the print carrier of FIG. 12 is intended to be glued to a plastic substrate instead of z B, the two layers 170 and 180 may also be omitted, because then the layer 160 containing the decolorizing agent is already protected against evaporation by the plastic substrate the Decoloπerungsmittels is protected

In the following, still another embodiment is described, in which a Decoloπerungsmittel is kept ready on the print carrier for use

The print carrier in the form of a substrate 210, which is only partially illustrated in FIGS. 16-18, is, for example, a sheet of A4-sized paper, as can be processed, in particular, in commercially available laser or inkjet printers

In accordance with FIG. 16, the substrate 210 is provided with a camouflage field 220 and with a reactive label 230

The camouflage field layer 222 of the camouflage field 220 is printed using a special ink which, in contrast to normal ink under Use of a chemical Decoloπerungsmittels in an irreversible manner bleachable

The camouflage field 220 is arranged on a part 212 of the substrate 210 which is delimited by a perforation 21 1 from the rest of the substrate 210. The perforation 21 1 may be, for example, a land or a micro-perforation by severing the perforation 211 The part 212 comprises a first area 214 substantially corresponding to the camouflage field 220 and a second area 15 which can be used as a grip area and having a somewhat larger width. The contours of the part 212 are rounded, see FIG that the release of the part 212 does not lead to undesirable cracking

The reactive label 230 comprises a transparent carrier layer 232, made of polyester, which carries on its underside, ie its side facing the substrate 210, a layer 233 which contains a liquid decolorizing agent for bleaching the special printing ink of the tamse field 222, eg in microencapsulated form the support layer 232 on both sides of the layer 233 on the substrate 210 by two strip-shaped adhesive layers 234 and 235 However, the layer 233 itself is not connected to the substrate 210. The adhesive of the adhesive layers 234 and 235 is selected and / or adjusted so that the Carrier layer 232 non-destructive leave not detach from the substrate 210

In order to make detectable a confidential information pattern M printed on the camouflage field 220, which in FIG. 1 is not discernible against the background of the camouflage field, the part 212 with the camouflage field 220 is removed from the composite with the remaining substrate 210 and then pushed under the carrier layer 232 of the reactive label 230 in that the camouflage field 220 or the tamfield layer 222 with which the

Decoating agent-containing layer 233 comes into direct overlap At the location of the substrate 210, at which the part 12 was herausgelost, remains a relatively large hole 213 back

FIG. 17 shows the substrate of FIG. 16 with part 21 stripped out and subsequently with its region 214 between the support layer 232 of the reactive label 230 and the substrate 210. Insertion is possible because the layer 233, as already mentioned, is not connected to the substrate 210 is also the is The distance between the two pressure-sensitive adhesive layers 234 and 235 is slightly larger than the width of the region 214. The insertion of the region 214 of the part 212 between the support layer 232 and the substrate 210 is also simple and convenient, because the part 212 at its region 215 according to Art By the region 215 has a slightly larger width than the region 214, it is more advantageous at the upper end of the two pressure-sensitive adhesive layers 234 and 235 each a stop, by which it is ensured that the camouflage field 220 in exact overlap with the layer 233 comes to cher

In order to make the information pattern M printed on the camouflage field 220 visible, only pressure has to be exerted on the carrier layer 232 in order to destroy the microcapsules and release the decolorizing agent contained in them to bleach the special printing ink of the camouflaging layer 222. FIG. 18 shows the state after a deflection of the camouflage field and with an information pattern M which has become recognizable in the bleached area

Preferably, a very thin film with a thickness in the range of only 36 microns is used for the support layer 232. In this case, a comparatively low pressure on the surface of the film is sufficient to release the decolorizing agent. The use of such a thin film is possible because it after bonding on the substrate 10 no longer needs to be handled freely

FIG. 19 illustrates, in a section A - A, the layer structure of the substrate of FIG. 16 as described above. The confidential information pattern M, which is not recognizable in the plan view of FIG. 16, is printed on the surface of the camouflage field 222

FIG. 20 shows the layer structure of the substrate according to FIG. 17 in a section B - B, ie how it results after detaching the part 212 with the camouflage field 220 from the composite with the remaining substrate 210 and then inserting the part 212 under the support layer 232 of the reactive label 230

21 shows in a representation corresponding to that of FIG. 19 still another preferred embodiment of a substrate according to the invention in which both the camouflage field 220 and the reactive label 230 are widened by further layers, which make it possible, inter alia, to completely prefabricate the two units and to apply as dispenser parts z B with a label dispenser on the substrate 210. This and the attachment of the perforation 211 can be particularly efficient in an endless process, in which the substrate 210 forms a continuous web, the For example, B is subdivided into individual sheets

In the embodiment of FIG. 21, the structure of the camouflage field 220, in addition to the aforementioned camouflage field layer 222, also comprises a transparent protective layer 221 and below this an intermediate layer 223, a carrier layer 224 and a pressure-sensitive adhesive layer 225. The pressure-sensitive adhesive layer 225 is preferably adjusted again so that Abloding the entire Tarnfeldaufbaus from the substrate 210 is not possible nondestructively

The carrier layer 224 may be a paper or a film layer, the latter in particular with a thickness of about 60 microns It must allow the cohesion of the entire camouflage structure and its "handling" during dispensing

By means of the intermediate layer 223, the camouflage field layer is anchored on the carrier layer 224 without the ink of the camouflage field layer 222 being able to penetrate to a greater extent into the intermediate layer 223 or even into the underlying carrier layer 24 used ink are concentrated in the camouflage field layer 22

To avoid the above-described ghost effect and to

Achieving sufficient wiping and scratch resistance of the camouflage field layer 222 serves the protective layer 210. In order for it to be sufficiently transparent for the decolorizing agent, it is designed as a porous or lattice-like structure with a thickness of only 1-2 μm

Reactive label 230 according to FIG. 21 includes, in addition to those already mentioned

Layers 232-235 on the upper side of the carrier layer 232 still have a transparent sliding layer 231 and below the adhesive layers 234 and 235 another carrier layer 236 and a pressure-sensitive adhesive layer 237. The latter establishes the connection of the reactive label to the substrate 210 and is again of the type that a Ablosen the entire structure of the reactive label 230 from the substrate 210 is non-destructive not possible. The further carrier layer 236 is preferably like the carrier layer 232 a Foil layer z B made of polyester and also preferably only very thin z B with a thickness of 12 microns

The sliding layer 231 advantageously reduces the sliding resistance of the surface of the support layer 232 that is noticeable when rubbing with a finger to make confidential information visible, thus simplifying scratching. The sliding resistance is preferably reduced by the sliding layer 231 to such an extent that the peel force required to move a 5 x 7 cm ² piece of the overlayer coated with the overlay on a similar horizontal surface under load of 416 g at a constant rate of 138 to 8 cm / min, less than 1 N, and is preferably only about 0 5 N amounts

Films which are already provided with a suitable overlay are available on the market ready-made, for example under the name LUMIRROR 50 12 from Toray Plastics SA, St Maurice de Beynost, F-01708 Miπbel Cedex On the other hand, the sliding layer 41 also under Using a

Protective varnish formulation are prepared, as offered by various manufacturers of paint and varnish. In these, the lubricity is adjusted by adding special lubricating waxes, for example for paints as wassπge basic dispersion with LUBA-pπnt wax dispersion 138, available from LP Bader & Co GmbH, PF 1137, D-7861 Rottweil

Between the two support layers 232 and 236 and the two pressure-sensitive adhesive layers 234 and 235, the Decoloπerungsmittel the layer 233 is tightly embedded, especially if both support layers are film layers, which is indeed preferred A loss of Decoloπerungsmittel with time, for example by evaporation, is so good as excluded

In addition to the decolorizing agent in microencapsulated form, the layer 233 preferably also contains a binder which contains wood glue and / or an odorizing agent and / or a liquid-absorbing agent and / or a dye

Finally, it should be mentioned that individual solution or design features of the invention and as far as they are described above only in

Frame of individual or special exemplary embodiments occur and explained could be used in other embodiments as well as in other combinations with each other. All the features described can be used in particular in embodiments of the type of Fig. 21, wherein multi-layer complexes with the camouflage field on the one hand and / or a Decolorierungsmittel on the other hand are completely prefabricated as such and need, for example, only be placed on a form sheet.

NAME LIST

10 Tarnfeld or Tarnfeldschicht

11 partial layer of the camouflage field

12 partial layer of the camouflage field 20 barrier layer

30 carrier layer

31 separating layer

40 Coating with thermochromatic reagent

50 Coating with solvent-reactive reagent 60 pressure-sensitive adhesive layer

70 substrate / paper sheet

71 Cutout 110 Protective Layer 120 Tarnfeldschicht 130 Interlayer

140 carrier layer

150 pressure-sensitive adhesive layer

151, 152 pressure-sensitive adhesive layers

160 Decoloration center! containing layer 170 further carrier layer

180 pressure-sensitive adhesive layer

190 cover layer

200 substrate, paper sheet

210 substrate 211 perforation punching

212 herauslosbarer part of the substrate

213 hole

214 range of 12

215 area of 12 220 Tarnfeld

221 protective layer

222 Tarnfeldschicht

223 interlayer

224 carrier layer 225 adhesive layer

230 reactive label

231 sliding layer

232 carrier layer

233 decolorant-containing layer 234 adhesive layer

235 adhesive layer

236 further carrier layer

237 pressure-sensitive adhesive layer

M Confidential Information Pattern P Arrows regarding pressure

Claims

1 Drucktrager with camouflage field on which an information pattern is imprinted so that it can be recognized against the background of the camouflage field only after execution of certain manipulations, characterized by at least one of the following features

the Tarnfeld contains irregularly distributed color dots in the large range between 50-400 microns and with a total area between 0 3 - 0 5 cm ² per cm ² , and / or

the camouflage field is constructed of several layers printed on top of each other, and / or

the camouflage field is printed with a printing ink of which at least 50% is concentrated in a camouflage field layer, and / or

the camouflage field can be at least partially and / or together with other layers with a Abselkraft between 0 5 N / 50 mm and 2 N / 50 mm according to the Finat test method no

1 remove, and / or

the print carrier is provided with a thermochromatic reagent which irreversibly discolors when exposed to heat from a temperature of 140 °, and / or

- The Drucktrager is provided with a solvent-reactive reagent which irreversibly discolored in a solvent atmosphere

2 Drucktrager according to claim 1 and in which the camouflage unevenly distributed color dots in the large range between 20 - 400 microns and with a total area of 0 3 - 0 5 cm ² per cm ² contains, characterized in that the camouflage field is printed with a liquid ink and that the color dots are formed by particles mixed with the printing ink

3 Drucktrager according to claim 2, characterized in that the number of color dots in the large range between 50 - 100 microns 2000 - 5000 per cm ² , im Large range between 100 - 200 microns 500 - 1000 per cm ² , and in the large range between 200 - 400 microns 200 - 500 per cm ² , amounts

4 print carrier according to one of claims 2 or 3, characterized in that the particles admixed with the printing ink are porous and have assumed by absorption of ink one of these about corresponding color

5 printing carrier according to claim 4, characterized in that the particles admixed with the printing ink consist of amorphous silicic acid

6 Drucktrager according to any one of claims 2-5, characterized in that the particles admixed with the ink have a particle size between 5 - 7 microns and that the color dots are formed by agglomeration of these particles

The print carrier of any one of claims 1-6, and wherein the camouflage field is printed with a printing ink of which at least 50% is concentrated in a tamper field layer, characterized in that at least 90% of the ink is concentrated in the tamper field layer

8, and wherein the camouflage field is printed with a printing ink, of which at least 50% are concentrated in a Tamfeldschicht, characterized in that it has adjacent to the Tamfeldschicht a barrier layer, which for the ink at least in the denominated percentage is dense

9 Drucktrager according to one of claims 1-8 and in which the Tarπfeld using an adhesive strip at least partially or together with other layers with a Ablosekraft between 0 5 N / 50 mm and 2 N / 50 mm according to the Finat test method Nr 1 let remove , characterized in that the camouflage field can be removed with a Ablosekraft of about 1 N / 50 mm

10 printing carrier according to one of claims 1 - 9 and which is provided with a thermochromatic reagent which is irreversibly discolored when exposed to heat from a temperature of 140 °, characterized in that the thermochromatic reagent on the back of a front side of the camouflage bearing carrier layer is arranged 11 print carrier according to one of claims 1 - 10 and which provided with a solvent-reactive reagent which irreversibly discolored in a solvent atmosphere, characterized in that the solvent releasing agent is arranged on the back of a front side carrying the camouflage carrier layer

12 Drucktrager according to any one of claims 1- 1 1, characterized in that it is designed in the manner of a self-adhesive label and provided with a back pressure-sensitive adhesive layer, if necessary in strip form

13 print carrier according to any one of claims 1-12, characterized in that the camouflage field is made with a special ink, which unlike normal printing ink, in particular the toner of a laser printing or the ink of an ink jet printer using a chemical Decoloπerungsmittels is irreversible bleachable

14 printing carrier according to claim 13, characterized in that the Tamfeldschicht surface is provided with a the abrasion and scratch resistance of the special printing ink increasing, for a Decoloπerungmittel however permeable protective layer

15 Drucktrager according to any one of claims 13 or 14, characterized in that it is on the back of a front side, at least indirectly, the Tamfeldschicht bearing first carrier layer with a Decoloπerungmittel, preferably in strip form provided

16 printing carrier according to claim 15, characterized in that the Decoloπerungsmittel between the front side, at least indirectly, the camouflage field bearing first carrier layer and a second carrier layer is embedded

17 Drucktrager according to claim 16, characterized in that the second

Carrier layer is a plastic film

18 print carrier according to one of claims 16 or 17, characterized in that the second carrier layer is provided on the back with a pressure-sensitive adhesive layer 19 print carrier according to one of claims 12 or 18, characterized in that the pressure-sensitive adhesive layer is provided with a removable cover, preferably in an endless form

20 Drucktrager according to claim 12, characterized in that it is non-detachably attached non-destructively on him a reactive label with a transparent support layer which carries on its drucktragerseitigeπ surface a chemical Decoloπerungsmittel for irreversible bleaching of the special ink, and that part of the print carrier with the camouflage field the Verbund with the rest Drucktrager herauslosbar and then slid so under the support layer of the reactive label that the camouflage field comes with the Decoloπerungsmittel in direct overlap

21 Drucktrager according to claim 20, characterized in that the part of the print carrier is connected to the camouflage via a particular designed as a web or micro perforation perforation perforation with the rest of the print carrier

22 Drucktrager according to claim 20 or 21, characterized in that the herauslosbare from the composite with the rest of Drucktrager part of the print carrier with the camouflage field has a first, the camouflage field substantially corresponding area and a second, serving as a grip tab area

23 Drucktrager according to any one of claims 20 - 22, characterized in that the Decoloπerungsmittel is embedded in a binder which contains wood glue and / or an odorant and / or a liquid absorbing agent and / or a dye