AT500908A1 - Safety element with magnetic coding, method and device for the production thereof and its use - Google Patents

Description

Magnetic code security element, method and device for its manufacture and its use

The invention relates to a security element for data carriers, value documents, packaging and the like, which has a magnetic coding produced in situ.

EP 0 516 790 B1 discloses a security document with a security element in the form of a thread or band made of transparent plastic material, which has a metallic layer with recesses in the form of characters, patterns or the like, with a further magnetic layer above or below this metal layer is arranged such that at least the readable recesses remain free.

From EP 0 310 707 B1 a document with magnetically detectable security features is known, which have areas with variable magnetic field strength.

Magnetic features, in particular magnetic features on security elements produced by printing inks having magnetic properties, are generally easily recognizable by the dark coloration and, if visual recognition is not desired, must be covered by further layers, for example metallic or metallic appearance layers.

Furthermore, the magnetic layers described in the above-mentioned prior art to achieve the desired appearance and the desired properties (magnetic properties, covered, variable magnetic field strength) must be produced consuming in several steps. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

The object of the present invention was to provide a security element with magnetic coding, in which a defined magnetic coding can be produced in a simple manner and this magnetic coding is optionally visually not recognizable as magnetic coding.

The invention therefore relates to a security feature with magnetic coding, characterized in that generates on a flexible carrier substrate, the magnetic coding optionally simultaneously with optionally transparent recesses in the form of patterns, characters, letters, geometric figures, lines, guilloches and the like by printing in situ is readable both by the individual defined code elements and by the different intensity of the magnetic field strength.

Another object of the invention is a method for producing a security element with magnetic encoding, characterized in that a magnetpigmenthaltige or a metallic magnetic ink by means of a laser-coated cylinder or a printing plate is printed such that the magnetic code optionally simultaneously with optionally transparent recesses in the form of Patterns, characters, letters, geometric figures, lines, guilloches and the like is generated.

Another object of the invention is a printing plate or a printing cylinder used for the production of security elements with a defined magnetic coding, characterized in that the defined magnetic code is represented by different heights and depressions on the printing plate or the printing cylinder and thereby different amounts of color to be printed or . of the paint in the wells of the printing plate or the printing cylinder are guided. ♦ · ······················································································ 1

Another object of the invention is a method for producing a printing plate or a printing cylinder with surface and depth-variable structures.

The security feature according to the invention can be produced in a simple manner in the desired appearance and with the desired defined magnetic coding.

As support substrate for the security feature according to the invention, for example, carrier films are preferably flexible plastic films, for example of PI, PP, MOPP, PE, PPS, PEEK, PEK, PEI, PSU, PAEK, LCP, PEN, PBT, PET, PA, PC, COC, POM , ABS, PVC in question. The carrier films preferably have a thickness of 5 to 700 μm, preferably 5 to 200 μm, more preferably 5 to 50 μm.

Furthermore, metal foils, for example Al, Cu, Sn, Ni, Fe or stainless steel foils having a thickness of 5 to 200 μm, preferably 10 to 80 μm, particularly preferably 20 to 50 μm, may also serve as the carrier substrate. The films can also be surface-treated, coated or laminated, for example, with plastics or painted.

Furthermore, paper or composites with paper, for example composites with plastics having a weight per unit area of 20 to 500 g / m 2, preferably 40 to 200 g / m 2, can also be used as the carrier substrates. be used.

Further, as carrier substrates, woven or nonwoven fabrics, such as continuous fiber webs, staple fiber webs and the like, which may be needled or calendered, may be used. Preferably such fabrics or webs of plastics, such as PP, PET, PA, PPS and the like, but it can also be woven or nonwovens of natural, optionally treated fibers, such as viscose fiber webs are used. The fabrics or webs used have a basis weight of about 20 g / m 2 · · Up to 500 g / m2. Optionally, these fabrics or nonwovens may be surface treated.

The carrier substrate is printed with a paint or a paint having magnetic properties.

Magnetic colors capable of inducing high flux density magnetic fields or conducting high density magnetic fields are suitable for producing coded magnetic features in situ. The measurable gradient of the magnetic flux is generated by thickness modulation of the magnetic layers.

Particularly suitable are magnetic pigment pigments with pigments based on Fe oxides, such as Fe 2 O 3 or Fe 3 O 4, iron, nickel, cobalt and their alloys, cobalt / samarium, barium or cobalt ferrite, hard and soft magnetic iron and steel grades in aqueous or solvent-containing dispersions. Suitable solvents are, for example, i-propanol, ethyl acetate, methyl ethyl ketone, methoxypropanol, aliphatics or aromatics and mixtures thereof.

Preferably, the pigments are incorporated in acrylate polymer dispersions having a molecular weight of from 150,000 to 300,000, in acrylate-urethane dispersions, acrylate-styrene or PVC-containing dispersions or in solvent-containing dispersions of this type.

Particularly suitable are magnetic paints with pigments based on Cr / Ni steel, Al / Fe304 and the like. These magnetic colors, in contrast to the conventional magnetic colors, which appear black, brown or gray, have a silvery appearance and at the same time have the required magnetic properties described above. As a result, it is possible to obtain the metallic gloss appearance desired or required for many applications in one operation already by printing the same ft «- * • ftftft • ft • ftftft ·

Magnetic colors to produce. Overprinting or coating with metallic or metal layers to produce the desired appearance is therefore not necessary, but can be done easily, for example, to introduce additional identification features.

Such described magnetic colors make it possible to generate the necessary gradients of magnetic flux over small changes in layer thickness.

The printing is preferably carried out by means of a laser-coated cylinder or a printing plate, preferably in the gravure printing method, wherein the printing tool (cylinder or printing plate) is designed so that the coded magnetic layer optionally simultaneously with the characters to be imaged, patterns, letters, geometric figures, lines, guilloches and the like can be printed.

According to the currently known methods for the production of laser-printed printing tools (Scheppersverfahren, Thinkverfahren), the production of variable-area, but not depth-variable structures on the printing tool is possible.

The method according to the invention for the production of a printing tool which is both surface-variable and depth-variable is described below using the example of a printing cylinder.

A cylinder blank which is suitable for gravure printing is provided with a copper layer at least 80 μm thick, for example in a known galvanic method, wherein, depending on the material of the blank, for example aluminum, iron, etc., an adhesion promoter layer, for example nickel, may be previously applied can. The thickness of the copper layer is at least 80 .mu.m, usually 100-1500 μιη, preferably 250-500 μιτι. 6 6 • · · • ···· • t ··· ···············································································

The cylinder blank is turned to the exact girth and then ground to the appropriate roughness. The roughness value Ra is preferably 0.03-2.0, particularly preferably 0.05-1.5, in particular 0.06-1.2.

Subsequently, engraved on an engraving machine, such as an engraving machine manufacturer Hell or Ohio on the side of a passport in a defined size, for example 5x5mm, thickness 0.2 mm.

The cylinder prepared in this way is coated with a commercially available photoresist, for example LD 100 from OHKA Kogyo Ltd. The thickness of this coating is about 3 - 5 pm.

Subsequently, the cylinder is optionally provided with an overcoat with a layer thickness of 1-5 pm, for example with OC-40 of the abovementioned company or with an analogously similar commercial composition.

Subsequently, the cylinder is exposed, for example with an Ar / Ne laser. To control the zero point and the north impulse, the reference point is determined on the laser with the aid of optics and a camera (CCD camera).

The parts required as a protective layer are exposed. Usually, the laser beam has a tool width of 5 pm, which corresponds to a resolution of 40,000 dots / mm 2.

Subsequently, the exposed cylinder is developed, for example in a sodium carbonate solution (0.5% solution), this is usually followed by a cleaning process with water, after which the cylinder is dried

The exposed and developed cylinder is now etched to the first desired depth with a CuCfe solution, or the thickness of the copper layer on the surface is correspondingly reduced by means of a known galvanic process.

Subsequently, the first photoresist layer is removed, whereupon a new photoresist, as described above, is applied, a further exposure takes place and then the etching or the galvanic copper removal takes place to the desired second depth.

In this way, different depths can be made on the cylinder or the printing tool. The process described can be repeated until it is possible to encounter the primer layer.

As a first depth, for example, depending on the desired structures and the desired magnetic coding 10-150 μm, preferably 12-80 μm, more preferably 50-60 μm, for the second depth 10-150 μm, preferably 12-80 μm, particularly preferably 30 -40 μηι conceivable.

Depending on the geometry and arrangement of the depressions, either the generation of the greatest depth or the lowest etching depth takes place in the first step.

In an analogous manner, the production of a printing plate is possible.

If suitable laser energy is used, ceramic cylinders or other metal cylinders with the areal and depth-variable surface according to the invention can also be produced analogously.

Further, such structures can also be made using a stylus or a grid as a modification of conventional methods.

Such provided with a surface and depth variable surface pressure tool is used to produce the security feature of the invention. Due to the depth modulation, a signal modulation is achieved when printing a corresponding magnetic ink. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • M ·

In this case, the magnetic ink is applied in different thickness and shape corresponding to the surface of the printing tool in one step on the carrier substrate.

The carrier substrate may already have functional or decorative layers, or further layers may be applied after the magnetically encoded layer has been applied.

However, the carrier substrates can also additionally have a lacquer or color layer, which can be unstructured or structured, for example embossed. The lacquer layer can be, for example, a release-capable transfer lacquer layer, it can be crosslinked or crosslinked by radiation, for example UV radiation, and can be scratch-proof and / or antistatic. Both aqueous and solid coating systems, in particular lacquer systems based on polyester acrylate or epoxy acrylate rosin, acrylate, alkyd, melamine, PVA, PVC, isocyanate, urethane systems, conventional or reactive curing mixture or radiation-curing are suitable ) could be.

As color or lacquer layers, a wide variety of compositions can be used in each case. The composition of the individual layers may in particular vary according to their purpose, that is to say whether the individual layers serve exclusively for decorative purposes or should be a functional layer or whether the layer should be both a decorative corn and a functional layer.

These layers may be pigmented or unpigmented. As pigments, it is possible to use all known pigments, such as, for example, titanium dioxide, zinc sulfide, kaolin, ITO, ATO, FTO, aluminum, chromium oxides and silicon oxides, and also colored pigments. In this case, solvent-based coating systems and systems without solvents can be used. • · · ····· ··· 9 · · · «· ······················································

Suitable binders are various natural or synthetic binders.

These further functional layers already present on the carrier substrate or subsequently applied, for example, can have certain chemical, physical and also optical properties.

The optical properties of a further layer can be visualized by visible dyes or pigments, luminescent dyes or pigments which fluoresce or phosphoresce in the visible, in the UV region or in the IR region, effect pigments, such as liquid crystals, pearlescent, bronzes and / or Multilayer color change pigments and heat-sensitive colors or pigments influence. These are replaceable in all possible combinations. In addition, phosphorescent pigments can also be used alone or in combination with other dyes and / or pigments.

Furthermore, it is also possible for electrically conductive layers to be present on the substrate, or to be applied subsequently, for example electrically conductive polymeric layers or conductive dye or lacquer layers.

To adjust the electrical properties of the applied color or the applied paint, such as graphite, carbon black, conductive organic or inorganic polymers, metal pigments (for example, copper, aluminum, silver, gold, iron, chromium and the like), metal alloys such as copper-zinc or Copper-aluminum or amorphous or crystalline ceramic pigments such as ITO, ATO, FTO and the like can be added. Furthermore, it is also possible to use doped or non-doped semiconductors, such as, for example, silicon, germanium or doped or undoped polymeric semiconductors or ion conductors, such as amorphous or crystalline metal oxides or metal sulfides, as an additive. Further, to adjust the electrical properties of the layer polar or partially polar

Compounds such as surfactants, or nonpolar compounds such as silicone additives or hygroscopic or non-hygroscopic salts used or added to the paint.

As a layer having electrical properties, it is also possible to apply a full-surface or partial metal layer, wherein the partial application can be effected by means of an etching process (application of a full-surface metal layer and subsequent partial removal by etching) or by means of a demetallization process.

When using a demetallization process, preferably in a first step, a solvent-soluble ink (optionally in the form of an inverse coding) is applied, then, optionally after activation of the carrier substrate by a plasma or corona treatment, the metallic layer is applied, whereupon the soluble ink layer is removed by treatment with a suitable solvent including the existing metallization in these areas.

Furthermore, an electrically conductive polymer layer can also be applied as the electrically conductive layer. The electrically conductive polymers may be, for example, polyaniline or polyethylenedioxythiophene.

It is also possible to add the magnetic ink used, for example carbon black or graphite, whereby a simultaneously magnetic and also electrically conductive layer can be produced particularly advantageously in a defined coding by the method according to the invention.

Further additional security features also include other surface relief structures, for example diffraction gratings, holograms and the like, where these structures may also be metallized or partially metallized if appropriate. • · • «♦ · · • ··» + • · · • ··· #

For the production of such surface structures UV-curable deep-drawable lacquer is applied for the time being. Subsequently, for example, a surface structure by molding a die in this paint, which is pre-cured at the time of molding to the gel point, prepared, after which the radiation-curable coating is completely cured after application of the surface structure.

Due to the use of the UV-curable lacquer, layers which have been applied thereto after curing, and also an optionally introduced surface structure, are stable even under temperature load.

The radiation-curable lacquer can contain, for example, a radiation-curable lacquer system based on a polyester, an epoxy or polyurethane system containing 2 or more different photoinitiators familiar to the person skilled in the art, which can initiate curing of the lacquer system to varying degrees at different wavelengths. Thus, for example, one photoinitiator can be activated at a wavelength of 200 to 400 nm, the second photoinitiator then at a wavelength of 370 to 600 nm. Between the activation wavelengths of the two photoinitiators sufficient difference should be maintained, so that not too strong excitation of the second Photointiators takes place while the first is activated. The region in which the second photoinitiator is excited should be in the transmission wavelength range of the carrier substrate used. For the main curing (activation of the second photoinitiator) also electron radiation can be used.

As a radiation-curable varnish, a water-thinnable varnish can also be used. Preference is given to polyester-based paint systems.

Furthermore, the inventive security elements can be provided with a protective lacquer layer on one or both sides. The protective lacquer may be pigmented or unpigmented, using as pigments all known pigments or dyes, for example TiO 2, ZnS, kaolin, ATO, FTO,......

Aluminum, chromium and silicon oxides or, for example, organic pigments such as pthalocyanine blue, i-indolold yellow, dioxazine violet and the like can be used. Furthermore, luminescent dyes or pigments which fluoresce or phosphoresce in the visible, in the UV range or in the IR range, effect pigments such as liquid crystals, pearlescent, bronzes and / or multilayer color change pigments and heat-sensitive inks or pigments can be added. These are replaceable in all possible combinations. In addition, phosphorescent pigments can also be used alone or in combination with other dyes and / or pigments.

Furthermore, the security element according to the invention can be provided with a hot or cold seal adhesive or a self-adhesive coating for application to the security document or a package to be protected.

It is also possible to laminate the security element with a further carrier substrate, which optionally has further functional layers.

The security elements according to the invention, if appropriate after appropriate assembly (for example into threads, tapes, strips, patches or other formats), therefore, serve as security features in data carriers, in particular value documents such as identity cards, cards, banknotes or labels, seals and the like, but also in packaging materials for sensitive goods such as pharmaceuticals, foods, cosmetics, data carriers, electronic components and the like. Furthermore, the security elements can be applied to packaging materials for a wide variety of goods, such as films, paper, boxes, boxes and the like. 13 '···· • · • · • · • • ···· * · • · I «lt ·« ···

Examples:

Example 1:

A cylinder with a profile corresponding to FIG. 1 is produced.

An aluminum cylinder blank is coated with a 5 μm thick nickel adhesion promoter layer. Subsequently, a 300 pm thick copper layer is electrodeposited.

The cylinder blank is turned to the exact extent and then ground to a roughness Ra of 0.09.

Subsequently, engraved on an engraving machine, for example, a engraving machine of the type Hell or Ohio on the side of a passport (5x5 mm, thickness 0.2 mm).

The cylinder prepared in this way is coated with a 4 μm thick layer of the LD 100 photoresist from OHKA.

Subsequently, the cylinder is optionally provided with an overcoat with a layer thickness of 2 pm, (0040).

The exposure is carried out with an Ar / Ne laser with a tool width of 5 pm after fixing the reference point, after which the exposed cylinder is developed in a 0.5% sodium carbonate solution.

The exposed and developed cylinder is now etched to the first desired depth with a CuCh solution, in which case the greatest depth is begun. The depth of etching is 150 pm.

Subsequently, the first photoresist layer is removed, whereupon a new photoresist is applied as described above, a further exposure is carried out and then the etching is carried out to a depth of 80 μm. For the third etch, an etch depth of 40 pm is chosen after removal of the photoresist layer, application of a new photoresist layer, exposure and development.

By means of a gravure cylinder thus produced, a magnetic ink consisting of 40% Cr / Ni steel pigments (3μηι) is applied in an acrylate polymer dispersion on a polyester film of a thickness of 7 μίτι.

The coercive force was 90 Oerstedt, the flux density 200 - 600 nW / m, modulated

Example 2:

A cylinder with a profile corresponding to FIG. 2 is produced.

The cylinder is prepared analogously to Example 1 and again 3 different etching depths are provided. The etching process can be started either with the greatest depth or the lowest depth. The following etching depths were provided: 120 pm, 70 pm and 10 pm.

By means of this cylinder, a magnetic pigment color with 20% Fe203 pigments in nitrocellulose is applied to a polypropylene film having a thickness of 5 μπι.

The coercive force was 250 Oerstedt, the flux density 100 - 400 nW / m, modulated.

Claims (31)

1) Security feature with magnetic coding, characterized in that on a flexible carrier substrate, the magnetic coding optionally simultaneously with optionally transparent recesses is generated in the form of patterns, characters, letters, geometric figures, lines guilloches and the like by printing in situ, which is readable both by the individual defined code elements and by the different intensity of the magnetic field strength. 2) Security feature according to claim 1, characterized in that the carrier substrate additionally comprises further functional and / or decorative layers. 3) Security feature according to claim 2, characterized in that the carrier substrate additionally comprises electrically conductive and / or optically active and / or coloring layers. 4) Security feature according to one of claims 2 to 4, characterized in that the layers are present over the entire surface or partially on the carrier substrate. 5) Security feature according to one of claims 1 to 5, characterized in that the security element is provided on one or both sides with a protective lacquer layer. 6) Safety elements according to claim 5, characterized in that the protective lacquer layer is pigmented. 7) Security element according to one of claims 1 - 6, characterized in that the security element with one or more carrier substrate (s), which / optionally functional and / or decorative layers has / is laminated. 8) Security element according to claim 7, characterized in that the laminating adhesive is pigmented. 9) security elements according to one of claims 1 to 8, characterized in that the security element is provided on one or both sides with a hot or cold seal adhesive or a self-adhesive coating. 10) Security elements according to claim 9, characterized in that the hot or cold seal adhesive or the self-adhesive coating is applied over the entire surface or partially or structured. 11) Safety elements according to claim 10, characterized in that the hot or cold seal adhesive or the self-adhesive coating is pigmented. 12) film material with magnetic encoding, characterized in that on a flexible carrier substrate, the magnetic coding is optionally generated simultaneously with optionally transparent recesses in the form of patterns, characters, letters, geometric figures, lines guilloches and the like by printing in situ, both by the individual defined code elements as well as by the different intensity of the magnetic field strength can be read out. 13) film material according to claim 12, characterized in that the carrier substrate additionally comprises further functional and / or decorative layers. i • · • · · · · · · · · · · · · · · · · · · · · · · · · I · ··· «film material according to claim 13, characterized in that the carrier substrate additionally comprises electrically conductive and / or optically active and / or coloring layers. 15) Film material according to one of claims 13 to 14, characterized in that the layers are present over the entire surface or partially on the carrier substrate. 16) film material according to one of claims 11 to 15, characterized in that the security element is provided on one or both sides with a protective lacquer layer. 17) film material according to claim 16, characterized in that the protective lacquer layer is pigmented. 18) film material according to any one of claims 12-17, characterized in that the security element with one or more carrier substrate (s), which / optionally functional and / or decorative layers has / is laminated. 19) film material according to claim 18, characterized in that the laminating adhesive is pigmented. 20) film material according to one of claims 11 to 19, characterized in that the security element is provided on one or both sides with a hot or cold seal adhesive or a self-adhesive coating. 21) film material according to claim 20, characterized in that the hot or cold seal adhesive or the self-adhesive coating is applied over the entire surface or partially or structured. 22) film material according to claim 21, characterized in that the hot or cold seal adhesive or the self-adhesive coating is pigmented. 23) A method for producing a security element with magnetic encoding, characterized in that a magnet pigment-containing or a metallic magnetic ink by means of a laser-coated cylinder or a printing plate is printed such that the magnetic code simultaneously with recesses in the form of patterns, characters, letters, geometric figures , Guilloche lines and the like is generated. 24) A process for the production of a film material with magnetic coding, characterized in that a magnet pigment-containing or a metallic magnetic ink is printed by means of a laser-coated cylinder or a printing plate such that the magnetic code simultaneously with recesses in the form of patterns, characters, letters, geometric figures , Guilloche lines and the like is generated. 25) printing tool for producing security elements and / or film material with a defined magnetic coding, characterized in that the defined magnetic code is represented by different heights and depressions on the printing plate or the printing cylinder and thereby different amounts of color to be printed or the paint in the Wells of the printing plate or the printing cylinder are performed. 26) A method for producing a printing tool with surface and depth-variable structures, characterized in that a suitably prepared blank exposed in several stages and then etched at different depths or galvanic • • · · · • # • • · «« 1 * • ·······························································································, whereby the photoresist layer is removed between each step and a new photo layer is applied. 27) Use of the security elements according to one of claims 1 to 11 optionally after packaging as security features in data carriers, in particular documents of value such as identity cards, cards, banknotes or labels, seals on or as packaging material, for example in the pharmaceutical, electronics and / or food industry, for example in the form of blister foils, cartons, covers, foil packaging. 28) Use of the film material according to one of claims 12 to 22, optionally after packaging as security elements in data carriers, in particular documents of value such as identity cards, cards, banknotes or labels, seals on or as packaging material, for example in the pharmaceutical, electronics and / or food industry, for example in the form of blister foils, cartons, covers, foil packaging. 29) value documents having a security feature according to one of claims 1 to 11. 30) securities having at least one security feature according to one of claims 1 to 11, all over or partially embedded in the form of a thread, a window thread or a patch or at least partially applied to one or both surfaces. 31 packaging having a security feature according to one of claims 1 to 11.