EP1402483B1 - Security strips - Google Patents

Abstract

Security strips for identifying the genuineness of sheet material such as documents, securities and banknotes. The security strips are constructed of several different components, encoding means and electrically conductive layers connected in different arrangements on a support substrate. Layers of known per se electrically conductive polymers are being used. The security strips are applied on the sheet material or they are integrated in the sheet material. These security strips constitute insurmountable technological obstacles for a forger.

Description

The invention relates to security tapes for identifying the originality of Sheet material such as documents, securities and banknotes.

In conjunction with an ever-increasing quality of existing copy and computer engineering continues with an increasing number of imitations of documents, Securities and banknotes. For example, with the help of modern copying techniques no longer fake bank notes from human visual distinguish genuine banknotes. Therefore, special measures are to be taken which do not coincide overcome the technology available to counterfeiters today and in the foreseeable future can. In addition to special papers for such securities are, for example, banknotes with diffractive optical security elements and embedded in the paper Security tape equipped.

The examination of the diffractive optical safety elements is not readily possible within a document processing machine, as these with high Speeds works. The test is done visually in both banknote production as well as in the possibly required sorting of flowing back from circulation Paper money. This procedure is time consuming and costly.

Embedded in the paper security tapes, which usually by a Film structure can be embodied, consisting of at least one carrier film and one on the carrier film applied metallization and in the paper web completely or with so-called windows (window thread) is usually due to the electrical conductivity tested, with the methods of inductive and capacitive coupling established to have. The examination of the electrical conductivity of the metallization is made difficult, that on the one hand the banknotes in their use of a high mechanical stress subject, for example, by kinking and folding by the user, but also by bending in ATMs and counting machines. On the other hand, the film structure is subject even during the technological process of papermaking Tensioning and bending in a round screen of considerable stress. As a result of this occur In the metallization randomly distributed fine hairline cracks, which makes the measurement results uncertain and not reproducible. To counterfeit this security feature, is not just the presence of metallization in ATM test equipment but the authenticity is due to a specific measurement of the conductivity to determine.

DE 22 15 628 describes a metal safety thread or strip with Machine-readable, individualizing codes in the form of a perforated security strip or a strip of magnetic information.

A security document, in particular a banknote with a security element, which provided with at least in transmitted light visually readable characters and electrically is conductive and has additional substances for machine testing, is in the DE 40 41 025 Al describes. The security element is preferably made of a transparent Foil strip, which has a visually good verifiable negative writing and in addition is provided with electrically conductive and magnetic materials.

The known test characteristics for the authenticity test of objects, securities, Banknotes, in particular, have the main disadvantage of being known lies. Namely in a reputation that allows the counterfeiter, from the knowledge of Test methods and devices and their functioning on the characteristics to be tested shut down.

In DE 197 18 859 a method for applying a conductive Layer described on a plastic film. It is on the printable film first a primer and then a conductive organic polymer printed.

Furthermore, in DE 198 36 503 a method for the integration of electrical conductive feature substances in the pulp web of documents with an electrically conductive Security thread described, wherein an electrically conductive polymer is homogeneous or partially in or on the pulp web is brought.

US 5 639 126 discloses security tapes for identifying originality of sheet material, consisting of substrates, of areal metallized applications with a defined sheet resistance and electrically conductive polymers with a defined sheet resistance, as well as release agents or adhesive layers, wherein the Safety straps are integrated in sheet material.

DE 198 56 457 describes a film for a film capacitor in which for reducing the total resistance of the electrode on the electrically conductive layer Current paths are formed, which have a lower sheet resistance than the electrically conductive Have layer. The electrically conductive layer may include both a metal layer and be a conductive plastic layer. The current paths consist of the same or one of them other electrically conductive material.

In addition, DE 199 15 155 describes an electrically conductive feature substance for security features to be introduced in paper webs for the examination of documents described, wherein the feature substance is an electrically conductive polymer. As a security feature serves a film structure of at least one carrier film, an applied metallization with demarcation in sections and a layer of the electrically conductive Polymer. Cracks in the metallization are made by the layer in parallel bridged electrically conductive polymer.

Finally, in DE 199 28 060 an optically variable security feature with at least one carrier film, a reflection layer, diffractive structures and a protective layer for the examination of documents, wherein in the layer structure of Security feature introduced at different locations an electrically conductive polymer is as a liquid coating material in the form of a solution, a dispersion or suspension or in the form of a monomer together with a polymerizing agent with a carrier material is associated and that the reflective layer of at least one film-like metal pigments containing paint job consists.

In DE 199 35 434 a method for electroless deposition of metallic Layers with high metallic conductivity are described, being on a substrate Slip is applied, the at least one organic binder, at least one reducing agent and at least one solvent. Subsequently, the solvent removed from the layer and the layer brought into contact with a solution containing the deposited Contains metal in the form of ions.

Finally, in WO 94/19813 a metallized film capacitor is described, in which the metallization of the films is made as thin as possible to the improve dielectric strength. In the process, conductivities of 5 - 300 ohms / □ are achieved. The invention is based inter alia on the use of metal layers of different thicknesses, which are carried out separately.

The object of the invention, in addition to overcoming the disadvantages of the Prior art, security tapes for identifying the originality of sheet material such as To propose documents, securities and banknotes. From the optional only the manufacturer or the authorized control body known combination of metallized surfaces, Surface brilliance, electrically conductive surfaces and surface resistance changes are for to suggest the technician unconquerable technological hurdles.

At the beginning of the description of the invention, terms are defined below be as they are understood throughout the claims. Under areal Metallization becomes a homogeneously metallized surface with a homogeneous surface brilliance Understood. Under streufafter metallization is a non-homogeneously metallized Area or a homogeneously metallized area with demetallizations or a homogeneous metallized surface with inhomogeneous surface brilliance or a homogeneously metallized Surface with inhomogeneous surface brilliance and demetallization. When Substrate or carrier substrate is referred to any material, on or in which coding are on or bring, wherein under material, for example, plastic or Metal foil, paper, cardboard and textile fabrics are to be understood. Under coding are in the Below in this description and in the claims means for securing and coding understood, with electrical, optical or magnetic effects. As a security tape In the following, the most varied security tapes, strips, threads and security films and the like collectively referred to wholly and / or partially are visible in plan view and / or in review on or in the sheet material. Under sheet material are all security papers or documents for documents, securities and banknotes to understand.

The security bands according to the invention are made of several different ones Components, encoders and electrically conductive layers constructed, these in different arrangement are connected to a carrier substrate. Layers themselves known electrically conductive polymers are used. These safety bands are in Sheet material applied or integrated. Prerequisite for the use of electrically conductive Polymer layers in combination with a metallization layer is a significant difference between the surface resistances (≈ 100 kΩ / □), in particular is a very high electrical Sheet resistance of the metallization required (≈ 200 kΩ / □). The usual market and applied metallization technologies achieve low surface resistivity.

In particular, the coating by means of electrically conductive polymer, for. B. Polyethylendioxythiophenpolystyrolsulfonat (PEDT / PSS) in combination with a metallization layer is to be used as a technological hurdle for counterfeiters, whereby the PEDT / PSS characterized by a sheet resistance in the range of 15-100 kΩ / □. On PE films a surface resistance of 50 kΩ / □ is achieved using a primer. The polymer layer is applied areally or partially, preferably surface modulated or applied as a scattering pressure. Due to the partially changing surface resistances creates a readable encoding. This in turn can be easily adapted to different Detehrtieren kind, in particular by means of capacitive coupling. Advantageous is a possible mechanical dual physical testing of the electrically conductive polymer PEDT / PSS, which on the one hand, the electrical conductivity, on the other hand, the optical property, for example detected in the IR range. The IR properties are increasing in wavelength (> 900 nm) as well as the application weight or the layer thickness effectively usable. By absorption and wavelength change are given measurable characteristics. Through this double examination is the probability of identification of counterfeits or the error rate the unrecognized forgeries or even the error rate of the genuine as counterfeit detected products significantly reduced.

A metallized surface to be used according to the invention - in particular with high brilliance, which would be expected to have good electrical conductivity has, which could include an electrically conductive security feature or even itself represents a safety feature via coded surface resistance changes - provides a Another hurdle for a counterfeiter, since the task, function and operation of the metallized Surface neither to suspect nor are obvious.

In particular, the invention relates to security bands for identifying the Originality of sheet material such as documents, securities and banknotes. The Safety bands consist of substrates of areally or scattered metallized applications with a defined surface resistance and of electrically conductive polymers, likewise with a defined surface resistance. According to the invention, the sheet resistance of areal or scattered metallized applications greater than 200 kΩ / □, and the sheet resistance of electroconductive polymers is on an order of magnitude from 15 to 100 kΩ / □. The difference between the surface resistances of the applications and the electrically conductive polymer is greater than 100 kΩ / □. This type according to the invention Security tapes are used with sheet material - for example, value documents and banknotes - in associated with known manner.

The structure of the security tapes - so the arrangement of substrates electrically conducting polymers, planar or scattered metallized applications, protective coatings, Release agents and / or adhesive layers - is selected depending on the destination, wherein the individual layers are interchangeable. As a release agent find preferably siliconized layers or transfer tapes or layers application. Depending on Purpose and applied manufacturing technology are primers used, wherein the primers serve both as a primer and for smoothing according to the invention of coated substrates are suitable. The electrically conductive polymers, the areal or streuhaft metallized applications, the substrates, possibly also the Protective layers and the primers are arranged according to the invention as coding means, that their electrical or optical or magnetic effects as a coding agent application find, with the electrical effects detectable means of capacitive coupling are.

According to the invention is also provided, the electrically conductive polymers applied partially or surface modulated or partially surface modulated. Also for this Case is a resulting coding capacitive detectable. Likewise are partial or surface-modulated or partially surface-modulated applied areally or scattered metallized Applications detectable as coding by means of capacitive coupling.

According to the invention, the coding means of the security tapes are physical influenced. In particular, by energy supply in the form of visible light UV, IR or Heat radiation, the coding means react, perceived by the examiner or originality feature, either in the security tapes or in conjunction with a Value document or a banknote. The electric according to the invention to be used conductive polymer is preferably a Polyethylendioxythiophenpolystyrolsulfonat (PEDT / PSS).

A particular embodiment of the invention provides for subbands to put together a safety tape. The individual subbands can - as already described - made of substrates, of areal or scattered metallized applications and consist of electrically conductive polymers, wherein the individual subbands also made Protective layers, release coatings, adhesive layers and a primer can exist. The selection and arrangement of the individual layers depends on the desired Use and after the processing technology. Different surface resistances individual layers in the subbands are also within the scope of the invention. The same or produced with different structure sub-bands result on their own or in addition after their connection to a security band encodings. All coding on the subbands and on the security band may vary on the surface to be applied be aligned.

• Figur 1a: Schematisierte Teildarstellung eines Sicherheitsbandes
• Figur 1b: Schematisierte Teildarstellung eines Sicherheitsbandes mit Kodierung
• Figur 2a bis 2c: Schematischer Schichtaufbau verschiedener Varianten von Sicherheitsbändem
• Figur 3a bis 3c: Weitere Varianten eines schematischen Schichtaufbaus von Sicherheitsbändern
• Figur 4: Schematische Darstellung eines Zweikomponenten-Sicherheitsbandes

The invention will be explained and described in more detail below with reference to the exemplary embodiments illustrated in the drawings. The drawings show:

• FIG. 1a: Schematized partial representation of a security band
• FIG. 1b: Schematized partial representation of a security band with coding
• Figure 2a to 2c: Schematic layer structure of different variants of Sicherheitsbändem
• Figure 3a to 3c: Other variants of a schematic layer structure of safety bands
• Figure 4: Schematic representation of a two-component security band

Example 1:

FIG. 1 a shows schematically a safety belt 1 according to the invention for identifying the originality of sheet material 2 as a section. It essentially contains a substrate 10, an areal or scattered metallized application or application layer 13 and an electrically conductive polymer 12 having a sheet resistance of the order of 15-100 kΩ / □, wherein the difference between the sheet resistance of the surface or scattered metallized layer 13 and the sheet resistance of the electrically conductive polymer 12 is greater than 100 kΩ / □. The layers are optionally interchangeable. Modified from the described embodiment, FIG. 1b shows a section of a security strip 1 , comprising a substrate 10 and a laminar metallized layer 13 having a sheet resistance greater than 200 kΩ / □. The electrically non-visible polymer (shown graphically in FIG. 1b) 12 - here a polyethylenedioxythiophene polystyrenesulfonate (PEDT / PSS) - indicates here the value of the banknote and a serial number. The PEDT / PSS is applied to the metallized layer 13 in a manner known per se using a primer 11 .

Example 2:

FIG. 2 a shows another variant of the security tape 1 according to the invention. A substrate 10 is smoothed with a primer 11 . On this is the electrically conductive polymer 12, which in turn is provided with a primer 11 if necessary. This is followed by the metallized layer 13 and, if required by application, a final protective layer 14, wherein a primer 11 may also be required between the metallized layer 13 and the protective layer 14 . On the protective layer 14 may also be a color paint - not shown in the figure 2a - be applied for optical finishing. It is also conceivable that the protective layer 14 consists of such a lacquer layer. The position of the electrically conductive polymer 12 can be interchanged with the metallized layer 13 . The primers 11 used can each also act as adhesion promoters. In addition, the security tape 1 contains an adhesive layer 15 for connection or integration with the sheet material 2. If the security tape 1 is pressed or sealed with the sheet material 2 , the adhesive layer 15 can be dispensed with. Since the security tape 1 is usually wound on rolls, it makes sense to provide one side of it with a release agent 9, in particular a silicone film. As a release agent 9 , the security tape 1 can also be provided with a transfer belt 16 (Figure 2c), wherein the transfer belt 16 adjustment means 8 , for example, perforations, magnetic tracks or optical marks for positionally accurate application of the security tape 1 on the sheet material 2 contains. Of the exemplary embodiments, in this embodiment - shown in Figure 2b - the substrate 10 coated on both sides, wherein on one side of the substrate 10 , an electrically conductive polymer 12 and on the other side, the metallized layer 13 is located.

Example 3:

Another variant is shown in FIG. 2c. Two subbands 30; 31 are manufactured and connected independently of each other. The subbands 30; 31 are glued or pressed or sealed, for example, and together form the security tape 1 . The one sub-band 30 consists, among other layers, of a substrate 10 and the electrically conductive polymer 12 and the other sub-band 31 substantially of a substrate 10 and the metallized layer 13 . Depending on the intended future use and depending on technological possibilities, the essential layers of the sub-bands 30; 31 interchangeable, and the subbands 30; 31 are in different places zusammenfügbar.

Example 4:

In a further embodiment of the security tape 1 or the subbands 30; 31 , the electrically conductive polymer 12 is applied surface modulated. FIG. 3 a illustrates the schematic structure of a section of a security strip 1 . Due to the different application thickness and the resulting changing surface resistances, a coding results. In this exemplary embodiment, the modulated sheet resistances represent a specific coding of the sheet material 2.

Example 5:

This example describes a security band 1 or subbands 30; 31 similar to that described in Example 4, wherein the electrically conductive polymer 12 is partially applied. As shown in FIG. 3b, the partial applications of polymer 12 result in partially changing surface resistances, which in turn serve as codes and can represent batch or serial numbers.

Example 6:

Varying from examples 4 and 5, with reference to FIG. 3c, a further embodiment of the security band 1 or the subbands 30; 31 presented. The electrically conductive polymer 12 is partially applied, and the respective sections of the partial jobs are applied surface modulated. Due to the thus partially changing surface resistances creates a coding, which is the manufacturer and the date of manufacture and by the surface modulated sections is a coding, which represent a specific coding of the sheet material 2.

Example 7:

According to this embodiment, one or more codes are combined according to the examples 4, 5 and / or 6 proposed, wherein these are realized in different surface directions. Thus, for example, the electrically conductive polymer 12 in a surface direction partially-surface modulated - see Example 6 - applied and partially in another area direction - see Example 5 - applied, with different codings in both directions.

Example 8:

In a further embodiment of the security tape 1 or the subbands 30; 31 , a primer 11 such as the electrically conductive polymer 12 in Examples 4 to 7 is applied partially or surface modulated or partially surface modulated. The resulting structure of the primer application 11 is transferred as a master structure to the applied layer of electrically conductive polymer 12 and / or a metallized layer 13. Encoding results as described in Examples 4 to 7.

Example 9:

Two manufacturers of thread components make parts of a security tape 1 . These subbands 30; 31 are connected to one another by means of customary transfer methods-shown in FIG. 4-and represent codings or combinations with one another. Advantageously, the subbands 30; 31 or the combination of subbands 30; 31 compatible with the usual systems. As already explained above, each sub-band 30; 31 alone or the combination of subbands 30; 31 represent a coding. From the combination of two sub-bands 30; 31 creates a coded security tape 1 . Only through the accurate matching of the two sub-bands 30; 31 , the desired coding, which represents the authenticity of the sheet material 2, is produced. The individual coding means can have different, preferably electrical, magnetic, optical modes of action. Individual subbands 30; 31 may according to the invention also have coding, which are physically influenced, for example by energy supply, in particular in the form of visible light, UV, IR or thermal radiation.

Example 10:

Using the variants described in the preceding examples, coding is activated only by connecting or integrating a security strip 1 with the sheet material 2 . The result is a decipherable or detectable coding by combining the security tape 1 with markings of the sheet material . 2

The features of the invention are beyond the embodiments set forth herein Also apparent from the claims and the drawings, the features alone or in the form of subcombinations of the individual elements represent advantageous, protectable versions for which protection is claimed here.

Claims (19)

1. Security strips (1) for the identification of the genuineness of sheet material (2), comprising substrates (10), surface or randomly metallized applications (13) having a defined surface resistance and electrically conductive polymers (12) applied partially or with surface modulation and having a defined surface resistance, the difference between the surface resistances being greater than 100 kΩ/□, and also, optionally, protective layers (14), release agents (9), which contain primers (11) smoothing the substrates or adhesive layers (15), and the security strips (1) being integrated in sheet material (2), for example documents, securities, banknotes.
2. Security strips according to Claim 1, characterized in that the surface resistance of the surface or randomly metallized applications (13) is greater than 200 kΩ/□.
3. Security strips according to Claim 1, characterized in that the surface resistance of electrically conductive polymers (12) is of the order of magnitude of 15 - 100 kΩ/□.
4. Security strips according to Claim 1, characterized in that the release agent (9) is preferably a siliconized layer or a transfer tape (16) and is equipped with adjustment means (8), for example perforations, magnetic tracks, optical marks or else with their combination.
5. Security strips according to one or more of the preceding claims, characterized in that the electrically conductive polymers (12) applied partially or with surface modulation, the surface or randomly metallized applications (13), substrates (10), protective layers (14) and primers (11) are optionally arranged as coding means.
6. Security strips according to one or more of the preceding claims, characterized in that the coding means are equipped with electrical and/or optical and/or magnetic modes of action.
7. Security strips according to one or more of the preceding claims, characterized in that the surface resistance of the electrically conductive polymers (12) applied partially or with surface modulation is a legible code, in particular a code detectable by means of capacitive coupling.
8. Security strips according to one or more of the preceding claims, characterized in that the surface or randomly metallized applications (13) are applied partially or with surface modulation or with partial surface modulation.
9. Security strips according to one or more of the preceding claims, characterized in that the surface resistance of the surface or randomly metallized applications (13) is a legible code, in particular a code detectable by means of capacitive coupling.
10. Security strips according to one or more of the preceding claims, characterized in that the coding means can be influenced physically or chemically.
11. Security strips according to one or more of the preceding claims, characterized in that the coding means react as a result of the supply of energy, in particular in the form of visible light, UV, IR or thermal radiation, as a security feature in the security strips (1) and/or in conjunction with the sheet material (2).
12. Security strips according to one or more of the preceding claims, characterized in that the coding means comprise components of a reactive ink and react with one another only when contact is made between the components.
13. Security strips according to one or more of the preceding claims, characterized in that the primers (11) are applied partially or with surface modulation.
14. Security strips according to one or more of the preceding claims, characterized in that the electrically conductive polymer (12) is a polyethylene dioxythiophene polystyrene sulphonate (PEDT/PSS).
15. Security strips (1) for the identification of the genuineness of sheet material (2) as described in Claims 1 to 14, comprising a plurality of part strips (30; 31), each of these part strips (30; 31) comprising substrates (10), surface or randomly metallized applications (13) having a defined surface resistance, or electrically conductive polymers (12) applied partially or with surface modulation and having a defined surface resistance, or combinations thereof, and the difference between the surface resistances being greater than 100 kΩ/□, and the security strips (1) joined together from part strips (30; 31) being integrated in the sheet material (2), for example documents, securities, banknotes.
16. Security strips according to Claim 15, characterized in that the part strips (30; 31) are arranged in the layer structure in such a way that they contain independent coding means and, when they are joined to one another, the part strips (30; 31) contain other, assembled coding means.
17. Security strips according to Claims 15 and 16, characterized in that, by means of the number, arrangement and/or geometry of the substrate (10), electrically conductive polymers (12) applied partially or with surface modulation, surface or randomly metallized applications (13) and their accurate-register combination to form security strips (1), coding means are provided, for example as a production location (20) or as production data (21).
18. Security strips according to one or more of Claims 15 to 17, characterized in that components of a reactive ink are contained in the part strips (30; 31) and the components react with one another to form a coding means only after contact is made between the part strips (30; 31).
19. Security strips according to one or more of the preceding Claims 1 to 18, characterized in that the security strips (1) and/or the part strips (30; 31) contain coding means and these are arranged partially or with surface modulation or with partial surface modulation in different surface directions.

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