DE19836503A1 - Security marking for document and banknote paper - Google Patents

Abstract

The security markings for special papers, as proof of validity, uses electrically conductive materials added to the paper pulp or applied to the surface of the paper web. The marking materials are taken from a supply container (26) for delivery through a tube (17) to the web surface, or the marking material is applied to a watermark embossing roller for transfer to the paper. The marking material is an electrically conductive and transparent polymer, or conductive pigments or a combination of both. The marking material is used as a dispersion, suspension, solution or as a monomer with a polymerization agent bonded to the paper. It is applied partially or homogeneously into or on the paper, and is pref. mixed with pulp in the paper making machine vat. The container (26) for the marking material is pumped (20) into the delivery tube (17), fitted with a valve (19) and a control (18). The delivery tube (17) is set to deliver the marking material in equidistant droplets on the moving paper surface, or as lines in a continuous flow. The marking material can also be applied to all or part of the embossing surface of a watermark embossing roller, to be transferred to the paper as part of the watermark. At the paper processing stage, monitors register that the marking material is correctly in place, with control links to the marking material feed system. An Independent claim is included for an electrically conductive marking material, as a conductive polymer which can be with a film in the paper web bonded to the security marking. Preferred Features: The electrically conductive polymer can be at least partially in a printed image to be applied to the paper. The film structure is composed of a carrier film layer with a metallized surface, with partial metal removal to the edge of the carrier film. It has a further layer of electrically conductive polymer. The film structure is integrated into the paper web. A further adhesive layer can be between the carrier and the metallized surface, which also gives adhesion to the film structure within the paper. The carrier film can be metallized on one side and carry the electrically conductive polymer film on the other side, or the polymer film can be over the metal layer. A second carrier film can be used in the film structure, to carry the conductive polymer film layer. The conductive polymer film has a greater stretch than the carrier film and the metal coating. The marking material has a specific surface resistance, which is set by the application method, the integration technique and/or its composition and/or specific formulation. The conductive polymer has a resistance of 20-40 kOhm/sq. The polymer has a conductive grid structure, or contains conductive additives with at least a pigment visible to the human eye, which can be activated and deactivated for scanning by an optical monitor. The polymer additives have magnetic characteristics which can be neutralized. The paper can be given an optical or magnetic coding in addition to the conductive marking material. The conductive polymer is applied to the carrier film by transfer printing, printing, spraying or immersion. The carrier is the paper web itself, or a film integrated into the paper. The carrier can be a primer or adhesive applied to the base. The carrier can be a packaging or a product, or a visible security marking. The conductive polymer is transparent or virtually transparent, or has a metallic appearance. The polymer can be opaque to light passing through. It does not become detached from its environment, and is at least a surface which is bonded to the carrier, and it can be intermittent on the carrier. The conductive polymer can be applied as continuous or intermittent lines, or as local points. Before the conductive polymer is bonded to the paper web, it can be fitted with a film, a hardening varnish layer, a reflection layer and a protective layer. A further Independent claim is included for a scanning system which detects the marking material according to the data for its electrical conductivity and/or other physical values and/or chemical characteristics to give a multiple test operation. Preferred features: The scanning sensor has optical, magnetic and/or mechanical sensors to detect the electrical conductivity from a number of channels which scan the conductivity. The conductivity is scanned across the whole paper width, by capacitive sensors. To reduce the scatter coupling, on the first scan even number channels are used, followed by the odd number channels on subsequent scanning, with a scanning frequency of preferably 200 kHz. The gap is adjusted between the transmitter and receiver electrodes, according to the test structure and plane. The conductive marking material has a characteristic used as a reference value, as a double test for the conductivity. A retaining roller or sliding rail is near the scanning sensor, for a good paper movement through the scanning zone. Functional sensor electrodes are on both sides of the paper, and across the whole paper width, to test that the required parameters are present throughout. The scanning sensors are linked to a control, to set the feed of the marking materials.

Description

The invention relates to methods for integrating electrically conductive memory materials in paper webs for documents, securities and banknotes and Method for testing such integrated electrically conductive Feature substances.

Special papers are known, which identification features for Protection against counterfeiting. These are used during the Integrated paper manufacturing process. For example, they become light-active Feature substances incorporated. Some light-active feature substances are on the market today available so that counterfeiters are able to use these already known Recreate security features. There are e.g. B. Security features in UV Adjusted spectral range. These reenactments have a significant impact on counterfeit protection.

Furthermore, there are optical features in the form of watermarks Papers introduced. The watermark is currently becoming insignificant adjusted. Known counterfeits relate to the printing of the papers with representations similar to watermarks. However, these are with aids or recognizable in transmitted light or in the UV range.  

Another way of securing paper is to integrate Security threads or security tapes. This security thread Security tapes are generally electrically conductive. The security threads or Security tapes mainly consist of a metallized film, which partially demetallized or punched out with letters or numbers or symbols were. These additional features are designed as optical features and serve as optical security and as a technological hurdle for the counterfeiter. The threads themselves are detected using known capacitive sensors. Here is the electrical conductivity for a specific section of the thread measured. This is the determination of the presence.

These security threads are currently being re-enacted by Frischer. These re-enactments are made by applying hot adhesive film or by Apply metallic inks. For the viewer quickly These reenactments are difficult to detect in banknote transactions. Also are such reenactments for the ATMs are not always detectable Highly sensitive capacitive sensors can operate within small measurement tolerances however, detect some of these counterfeits.

The object of the invention is to provide methods for integrating electrically conductive Feature substances in paper webs for documents, securities and banknotes and method for testing such integrated electrically conductive Propose feature substances that increase the security against counterfeiting.

Furthermore, it is an object of the invention for electrically conductive security threads or electrically conductive security features as user-active security features an additional reference test and or independent test zones using Integration of electrically conductive feature substances within the paper and Testing the same, using capacitive scanner sensors.  

The invention is described below with reference to the drawings Exemplary embodiments explained and described in more detail. The drawings and features to be extracted from the description can be found in others Embodiments of the invention individually for themselves or for several in any Use combination.

The drawings show

Fig. 1 wire (1) of a paper machine in schematic side and top view with illustrated method of partial integration of the feature substance in line form or in sections of a line,

Fig. 2 the cylinder mold (2) of a paper machine in schematic side and top view with illustrated method of partial integration of the feature substance in line form or in sections of a line,

Fig. 3 cylinder mold (2) of a paper machine in a schematic side view with CONNECTING forming watermark embossing roller (5), which takes over the material density change and thus the change in electrical conductivity,

Fig. 3a schematic plan view of a sheet material during the test and signal image of a sheet material with homogeneously incorporated of feature substance and then embossed watermark,

Fig. 4 cylinder mold (2) of a paper machine in schematic side view with a stock inlet (4) for the homogeneous integration of the feature substance,

Fig. 5 wire (1) of a paper machine in a schematic side view of the headbox (3) for the homogeneous integration of the feature substance,

Fig. 6 signal image when slipping of the sensor of a bank note with a homogeneous feature substance equipment (6) and security threads (15),

Fig. 7 shows signal image history when slipping of a bank note with a homogeneous characteristic cloth interior (6) and watermark (24)

Fig. 7a signal linkage of the arranged sensors.

Fig. 8 schematic side view of the watermark embossing roll (5) with feature substance transfer roller (7),

FIG. 8a image signal of an electrically conductive water mark in conventional paper,

Fig. 9 schematic representation with partial feature substance application or feature substance integration into the paper web and

Fig. 10 signal images of the partial feature substance detection.

Feature substances with electrical conductivity usually consist of solids, like pigments in rod form or irregular form. Furthermore, are electrical Conductive polymers known in different designs.

The presence of these different manifestations enables a variety of technological possibilities for the integration of the feature substance in the paper.  

example 1

In this embodiment, the production of special paper with represented electrically conductive pigments as a feature substance.

The paper stock is mixed with the feature stock in the machine chest ( 8 ) and kept under constant stirring as a homogeneous suspension. For solid feature substances, 10% of the paper solids content is preferably used as the addition amount. This proportionate amount can vary depending on the age of detection.

When using electrically conductive polymers there is the advantage that a good There is compatibility with other materials. The integration into the paper stock is much more straightforward than with solid materials because of the electrically conductive polymers also occur as a dispersion. The required concentration almost allows one transparent electrically conductive marking.

The detection of homogeneously introduced feature substances ( 6 ) is realized by means of capacitive scanner sensors ( 11 ). The capacitive scanner sensor is a series of individual capacitive sensors to form a sensor line, which are interconnected so that the individual channels are measured one after the other. The resulting individual signal images are processed using a controller. With a homogeneously integrated feature substance, the signal images in the individual scanner channels are the same, so that the presence is determined.

If this homogeneous version is used as a reference feature for the electrically conductive security thread ( 15 ), it is necessary that a feature substance with a conductivity of greater or less than 35% of 100% of the conductivity of the security thread is preferably used. The majority of the scanner sensor channels detect the same signal images in the area of the homogeneously integrated feature substance. Corresponding to the security thread width, scanner sensor channels emit a typical signal image.

FIG. 6 shows how the sheet material passes the scanner sensor ( 11 ) and the electrical signal is generated on the scanner sensor channel. The sheet material first passes through optical sensors ( 13 ) which activate the capacitive scanner sensor ( 11 ).

The homogeneously introduced feature substance ( 6 ) now generates a signal image ( 23 ) in the time sequence t = 1. .3, at time t = 4 the security thread ( 15 ) slips over the capacitive scanner sensor ( 11 ). The security thread ( 15 ) produces a much larger signal, since in this case the security thread ( 15 ) has a higher conductivity than the printed feature substance. The same signal pattern as in the time sequence t = 1. .3 is generated in the time sequence t = 5. .7. The signal images are compared and evaluated using a controller.

Example 2

In this exemplary embodiment, a further possibility of homogeneous feature integration ( 6 ) in the paper stock is shown. Here, further coding is achieved by changing the density of the watermark ( 24 ). The technological process is identical to the first embodiment until the paper web is formed. The paper web is further processed by embossing watermarks.

The process of watermark production takes place via mechanical processing of the paper web as shown schematically in FIG. 8, with the omission of the feature substance transfer roller ( 7 ) and with the omission of the feature storage container ( 16 ). An impression is made on the paper web by means of embossing roller ( 5 ). This embossing roller ( 5 ) consists of a carrier roller with embossed segments ( 25 ). These embossed segments correspond to the pictorial representation of the watermark. The impression of the embossing segments ( 25 ) on the paper web corresponds to the pictorial representation on the embossing roller ( 5 ). Such a mechanical partial treatment of the paper web causes a change in stock density in the area of the watermark ( 24 ) with an electrically conductive structure typical of the impression.

This change in the electrical conductivity in the stamping area corresponds to the pictorial representation of the stamping segment ( 25 ).

If the sheet material produced in this way is then passed over a capacitive scanner sensor ( 11 ), a signal image ( 23 ) for the embossing area ( 24 ) is recovered in accordance with the visual representation and the scanner resolution.

In Fig. 7 it is shown: how a banknote in landscape format passes the scanner sensor ( 11 ) and how the signal image ( 23 ) is created when the sheet material is streaked with homogeneously introduced feature substance ( 6 ) and subsequently generated watermarks ( 24 ). In the illustration of FIG. 7a optical sensors (13) activate the capacitive scanner sensor (11). When the sheet material is slipped over the scanner sensor, a uniform signal pattern is created on channels 1-3, 5-6, 8-9, 11-14 at the time of the banknote check. A signal image is generated on the scanner channels 4, 7 and 10 in accordance with the partial material change and the associated change in the partial electrical conductivity.

If barium sulfate is used as a feature substance, additional coding is achieved in the optical field, because this substance is infrared absorbing. The sensor arrangement is shown schematically in FIG. 7. The sensor arrangement of the capacitive scanner sensor is combined with an optical scanner sensor ( 10 ). In Fig. 7, the signal images of the capacitive scanner sensor (11) are shown with its plurality of sensor channels and the optical scanning sensor (10) with its plurality of sensor channels during testing of a watermark (24), which was generated in the homogeneous selected paper stock. The signals obtained are fed to a controller in which a signal image comparison is carried out. The evaluation signal obtained is fed to the central machine control ( FIG. 7a).

Example 3

A third embodiment represents a version of the production of partial Characteristic substance test zones.  

After the conventional paper web has been formed, a watermark ( 9 ) is generated by means of embossing rollers ( 5 ). During this watermark generation, the feature substance pigments or the feature substance as a dispersion are transferred to the paper web. This process is shown in FIG .

A feature substance transfer roller ( 7 ) is fed with feature substance through a storage container ( 16 ). This feature substance transfer roller in turn runs against the embossing roller ( 5 ), the feature substance being transferred to the embossing segment ( 25 ). Since the circumference of the embossing roller ( 5 ) corresponds to the distance between the watermarks ( 24 ) from one another, it is possible to produce these electrically conductive watermarks ( 24 ) on the endless web.

The formation of the signal image on the scanner sensor ( 11 ) is shown in FIG. 8a.

Example 4

In a fourth example it is described below how partial feature application of material to the paper web is realized by means of a drip device or by means of outlet pipes ( 17 ) which are positioned exactly above the paper web. The circulation of the suspension by pumps ( 20 ) in the entire pipe system including the reservoir for feature substance ( 26 ) is a prerequisite for a uniform supply of the dosing device with feature substance. Fig. 1 and 2 illustrate how by means of a targeted, multiple arranged electronically controlled metering device consisting of a nozzle (17) and an automatic valve, a partial feature substance order or a feature substance integration into the pulp web is carried out (19). Line-shaped continuous partial test zones ( 14 a) and / or discontinuous partial test zones ( 14 b) or selective test zones ( 14 c), as shown in FIG. 9, are applied. This gives you partial feature zones when cutting the paper web into sheet material. These can run over the entire sheet width or sheet length or can be present in sections in the sheet width or sheet length. The width of the lines or line sections is adapted to the scanner resolution. The width is preferably 2 mm. In Fig. 10, the signal images for the examination of continuous and discontinuous characteristic lines are shown in the sheet material. Optical sensors ( 13 ) activate the scanner sensor ( 11 ) when the sheet material is streaked. If the feature strip reaches the sensor, the signal image is 14 aa, 14 bb or 14 cc. The same signal images are also created by line or discontinuous line application by swiping on the paper web.

Reference list

1

Fourdrinier sieve

2nd

Circular sieve

3rd

Headbox

4th

Headbox

5

Watermark embossing roller

6

homogeneous feature substance in the paper

7

Feature transfer roller

8th

Machine chest

9

electrically conductive test zone watermark

10th

optical scanner sensor

11

capacitive scanner sensor

12th

optical measurement curve, measured on the measurement channels of the opt. Scanners

13

optical sensors to activate the capacitive scanner sensor

14

partial test zones

15

electrically conductive security thread

16

Feature storage container

17th

Outlet pipe

18th

Control section for outlet pipe

19th

automatic valve for discharge pipe dosing device in connection with

17th

20th

Feature cycle pump

21

Sensor channel straight numbering

22

Sensor channel odd numbering

23

Capacitive scanner sensor trace

24th

electrically conductive watermark in the homogeneous paper web

25th

Embossing segment

26

Storage container for feature substance for partial transfer

27

Pressure roller

Claims (17)

1. A method for integrating electrically conductive feature substances in paper webs for documents, securities and banknotes, characterized in that

• - That the feature substance in the form of pigments and or of transparent by means of D polymers by means of a metering device consisting of an outlet pipe ( 17 ) and an automatic valve ( 19 ) partially
• - Or introduced homogeneously into the paper stock by adding the feature substance in the machine chest ( 8 )
• - or is homogeneously or partially coated and / or rolled onto the paper web.

2. The method according to claim 1, characterized in that the feature substance is applied as a dispersion and or suspension by means of an outlet pipe ( 17 ) in the form of a drip tube on the paper web for partial feature substance distribution in line form continuously and / or discontinuously. 3. The method according to claim 1, characterized in that the feature substance as a dispersion or suspension by means of a controlled metering device, consisting of an outlet pipe ( 17 ) and an automatic valve ( 19 ), continuous partial test zones ( 14 a) and / or discontinuous partial test zones ( 14 b; 14 c) is applied to the paper web. 4. The method according to claim 1, characterized in that the feature substance is introduced as a dispersion in the machine chest ( 8 ) and mixed homogeneously with the paper stock, so that a special paper with homogeneous characteristic properties is formed on the wire section. 5. The method according to one or more of claims 1 to 3, characterized in that the feature substance in the form of pigments in a reservoir ( 26 ) and associated pipe system is kept in circulation by pumps ( 20 ) and by means of a metering device consisting of an outlet pipe ( 17 ) and an automatic valve ( 19 ) on the paper web. 6. The method according to one or more of the preceding claims characterized in that the feature pigments as additives in the Stock preparation are added. 7. The method according to one or more of the preceding claims, characterized in that the feature substance is transferred to watermark embossing rollers (5) and the watermark embossing rollers (5) transmitted during the embossing process the feature substance to the pulp web partially as an image of the die or parts of the image of the die. 8. Procedure for testing electrically conductive feature substances according to a or more of claims 1 to 7 have been integrated into paper webs, characterized in that the feature substance according to its data the electrical conductivity and / or other physical quantities and / or chemical properties to achieve a multiple test is detected. 9. The method according to claim 8, characterized in that the sensor means optical, magnetic and or mechanical sensors is activated and the Sensor for the detection of electrical conductivity from a variety of There are scanner channels that scan the electrical conductivity. 10. The method according to claim 8 or 91, characterized in that the electrical conductivity is scanned over the entire width of the sheet material by means of capacitive scanner sensors ( 11 ). 11. The method according to one or more of claims 8 to 10, characterized in that to reduce the stray coupling, the control of the sensor channels ( 21 ; 22 ) is carried out in such a way that in the first scanning process the channels with even numbering ( 21 ) in every second scanning process Channels with odd numbering ( 22 ) can be controlled, the scanning frequency preferably being 200 KHz. 12. The method according to one or more of claims 8 to 11, characterized in that the distance between the transmitting electrodes and the receiving electrode of the capacitive scanner sensor ( 11 ) is switched according to the test structures and the test plane. 13. The method according to one or more of claims 8 to 12, characterized characterized in that the optical properties that the electrically conductive Feature substance has, as a reference value for electrical conductivity as Double check of this feature is used. 14. The method according to one or more of claims 8 to 13, characterized in that a holding-down device opposite the scanner sensor ( 11 ) in the form of a roller or slide rail optimizes the transport of sheet material. 15. The method according to one or more of claims 8 to 14, characterized characterized in that the sheet material on both sides by means of sensor electrodes one functional electrode side above the sheet material and the other functional Page is arranged below the sheet material to be checked, is checked. 16. The method according to one or more of claims 8 to 15, characterized in that compliance with the production parameters is checked by a plurality of scanner sensors ( 11 ) arranged over the entire width of the paper web. 17. The method according to claim 16, characterized in that a control circuit which is connected downstream of the scanner sensors ( 11 ) regulates the feature substance addition.