EP3501839B1 - Particles for counterfeit prevention - Google Patents

Description

The invention relates to particles for use in a printing ink or a lacquer for protection against forgery. The invention also relates to a production method for such particles, as well as a printing ink or a lacquer with such particles.

The particles can also be introduced into a plastic body or processed as the core of a capsule.

Data carriers such as banknotes, shares, bonds, certificates, vouchers, checks, high-quality admission tickets, but also other forgery-prone papers, such as passports or other identification documents, as well as product packaging and article security elements for product brand protection, are often provided with security prints for security purposes, which allow a check of the Allow authenticity of the document of value and at the same time serve as protection against unauthorized reproduction.

In security printing, for example, a printing ink is applied in which particles or pigments with preselected special properties, for example certain magnetic or luminescent properties, are dispersed. The preselected properties of the particles or pigments are then queried during the authenticity check and serve to confirm the authenticity of the data carrier provided with the security print.

FR 3 012 367 A1 discloses the preamble of claim 1.

Proceeding from this, the invention is based on the object of specifying particles of the type mentioned at the outset which, on the one hand, ensure a high level of protection against counterfeiting and, on the other hand, can be produced simply and inexpensively, ideally on the industrial scale required in the security sector.

This object is achieved by the features of the independent claims. Developments of the invention are the subject of the dependent claims.

The invention provides an anisotropic printing / coating particle for use in a printing ink or a varnish for counterfeit protection, which has at least two separate surface areas with different physical properties, at least one of the surface areas mentioned being formed by a coating material and at least one component of the particle is formed by a printing substance, in particular a printing ink.

Particulate solid bodies with multifunctional properties have been the subject of current research for some time under the name "Janus particles". At present, such Janus particles are mostly produced by phase separation, self-orientation or masking.

During the production of Janus particles by phase separation, two incompatible liquid components are mixed, for example by means of microfluidics. The mixed liquid components then separate again into their original components and form a common Janus particle with two different surface areas.

In the production of Janus particles through self-orientation, processes for the production of block copolymers are used. As a result of the self-organization of the polymers, for example at a phase boundary of the coating media, alternating layers of different materials and thus Janus particles can form.

After all, masking is a relatively old and safe method of making Janus particles. In this case, a particle with only one first property is first applied to a carrier medium, which represents the mask for the first property. The second property of the particle is then produced from the opposite upper side by spraying on a liquid, condensing a gas or by vapor deposition or sputtering, for example with a metal.

However, all of the methods mentioned have certain disadvantages. For example, in the case of production by phase separation, it is difficult to ensure that the phase separation works reliably on an industrial scale and that, even if this works, two separate particles with the two different properties are not produced instead of one Janus particle. The problem with production through self-orientation is that the particle size is based on the selected substances. A particular difficulty with the masking method lies in the fact that the application on a carrier medium works at a defined penetration depth and the coating agent does not connect several particles with one another, so that if the coated particles are detached from the carrier medium, the separation of the particles fails or the coating is detached again .

A further difficulty of all three methods mentioned is the reliable selection of good material. If, for example, one of the properties allows magnetic separation, a particle is accepted as a good material even if it only has the magnetic property. On the other hand, a selection based on the specific weight is only possible if the two material properties differ significantly in terms of specific weight. The separation is also very complex, since two passes are required for the selection.

Janus particles are currently mainly produced in research, where the limitations of the described processes are often acceptable. The processes are time-consuming and costly and, in particular, are prone to errors in their reproducibility, which means that the particles are often only produced on a milligram or gram scale. In some cases, when using the methods described, there is the problem that a defined alignment of the Janus interface with respect to a permanent magnetic magnetization of the particle is hardly or only with difficulty. The first applications for Janus particles are in the medical field, where usually only small amounts are required.

In contrast to this, the combined use of printing and coating processes according to the invention now allows a reproducible and scalable production of anisotropic particles with at least two separate surface areas with different physical properties. The anisotropic particles produced in a combination of at least one printing process and at least one coating process are referred to in this application as “printing / coating particles”.

The inventors have surprisingly found that, with the aid of a suitable combination of printing and coating processes, at least two different substances, namely at least one printing substance and at least one coating substance, are connected to one another directly or indirectly can to produce the at least two separate surface areas with different physical properties.

According to the invention, the at least one printing material is applied by continuous ink jet printing, ink jet printing, screen printing or 3D printing to an existing component of the particle, for example a carrier component of the particle or to an auxiliary carrier (from which the particles are detached after they have been built up) upset. The at least one printing material can in particular, and this is not claimed, by means of dispenser printing systems (e.g. DMD100 from Kelenn technology) or aerosol printing systems (e.g. systems from Optomec, Neotech AMT, Fraunhofer IWS Dresden) on an already existing component of the particle , for example a carrier component of the particle or on an auxiliary carrier (from which the particles are detached after their build-up).

In order to produce large layer thicknesses by means of ink-jet printing, thermoplastic printing inks, in particular thermoplastic, UV-crosslinking printing inks, are used with particular advantage. The ink-jet printing ink is heated in the area of the print head, thereby reducing its viscosity. When the ink is applied to the target object (the partial build-up of particles or the auxiliary carrier), a sudden drop in temperature leads to an increase in viscosity, so that the ink does not run any further.

In the case of high print layers (for example ink-jet layers), support layers are preferably printed which avoid the applied Janus print layers run uncontrollably or spread on the auxiliary carrier. These support points represent a wall for the Janus particles and can be removed again afterwards. The support points themselves can consist of a water-soluble binder such as PVOH or a UV-drying binder that is not fully hardenable (e.g. due to an underconcentration of photoinitiator), so that they can be detached for example with acetone or ethanol is possible.

The interpolation points are advantageously generated inline for each applied Janus layer in order to improve the register situation of the interpolation point with the Janus layer and to avoid imperfections in the print of the Janus layers.

According to the invention, the at least one coating material is applied by a contactless coating process, PVD (Physical Vapor Deposition) processes, CVD (Chemical Vapor Deposition) processes or spray coating processes being used according to the invention.

The PVD methods that can be used include, in particular, thermal evaporation, electron beam evaporation, laser beam evaporation, electric arc evaporation, molecular beam epitaxy, sputtering, ion beam-assisted deposition and ion plating. For example, in the case of particularly suitable laser or electron beam evaporation, the material to be evaporated is heated in a pan by means of a laser, so that it changes into the gaseous phase and condenses on the substrate to be coated, among other things. The vaporized material can be directed to the substrate to be coated either ballistically or by electrical fields, depending on the process. The coating takes place in a vacuum at typical working pressures of 10 ^-4 Pa to about 10 Pa. Oxides can also be deposited through the use of reactive process gases. The layer thickness of the deposit depends, among other things, on the amount of evaporated material, the chamber design, the substrate width and the path speed of the substrate. Common materials for vapor deposition are metals such as copper, aluminum, chromium and the like.

In the CVD processes that can be used within the scope of the invention, there are individual methods that work in the low temperature range with reduced pressure (<200 mbar), so that coating on temperature-sensitive Materials are possible. For CVD processes, temperatures of around 150 ° C are currently necessary. In particular, plasma-assisted chemical vapor deposition (PECVD) is also suitable for coating more temperature-sensitive materials. For example, aluminum can be deposited on materials by reducing aluminum trichloride and hydrogen. CVD processes can also be used, for example, to form _{Fe 2} O _{3 layers from gaseous iron chloride (FeCl 3} ) and water vapor, or blacken one side of a particle by means of carbon deposition. At higher temperatures, SiO ₂ coatings, for example, are also possible.

Spray coating is a high-pressure spraying process in which the coating material is atomized, so that the finest droplets are created, which are deposited as a thin film of material on the product to be coated. The spray film is dried, for example, by oxidizing drying, thermally or photochemically induced.

In the case of the invention, the different printing and coating materials are advantageously arranged so that they fit one another, overlap one another, or are arranged butt to butt.

In an advantageous manufacturing variant, it is provided that the different printing and coating materials are first applied to an auxiliary carrier and each connected there to form an anisotropic printing / coating particle and that the anisotropic printing / coating particles formed are then detached from the auxiliary carrier , preferably to be removed mechanically. The mechanical detachment can take place with the aid of a mechanical stripping device, for example by means of a doctor blade, brush, air jet or water jet. Also a stripping A sharp-edged deflection of the auxiliary carrier in the form of an endless belt with a cylinder with a small diameter or a fixed, rounded plate comes into consideration. The fixed plate can for example consist of plastic, polished steel, chrome-plated polished steel, Teflon, PTFE or ceramic-coated steel. A combination of the variants mentioned is also well suited to detaching generated particles from the auxiliary carrier. Furthermore, the tools mentioned can also be supported by an application of ultrasound.

In a further advantageous variant, the auxiliary carrier is provided with a release layer in the form of a wax emulsion. After thermal drying, there is a full-surface first or more PVD coating (s) for the first Janus property, one or more print layers matched by printing technology, and finally one or more further PVD layers for the second Janus property. Since the PVD layers are very thin (a few nanometers) and brittle compared to the printing layer, the middle layer of the Janus particle created by printing technology defines the shape and size of the particles.

The variant described above can, by means of the middle layer produced by printing, bring with it a further Janus property which is not visually apparent. This can, for example, be a magnetic polarity (N / S pole perpendicular to the generated particle top.

In another advantageous variant, after the printing / coating particles have been produced, the endless belt is deflected in a bath in which there is a separating liquid that detaches the particles from the belt. The bath can also be coupled with an ultrasound transmitter or an ultrasound probe to support the process of separating the particles from the endless belt.

In a further advantageous variant, the auxiliary carrier is provided with a solvent-soluble layer. This layer can be water-soluble, for example. PVOH, for example, is suitable. After the application of the particles, the pigment is separated, for example, in the manner described above in a separating liquid bath.

Said endless belt can also be provided with a shaping die, for example in the form of half-shell troughs, in order to define the shape of the printing / coating particles.

The particles are preferably applied to a web-shaped auxiliary carrier.

An endless belt can be used as an auxiliary carrier, which is fitted or printed again after the generated Janus particles have been detached and an optional additional cleaning process.

Roll material can also be used as an auxiliary carrier, which is wound up again after the generated Janus particles have been detached and fed to a new assembly. The roll material can be cleaned (e.g. offline) and then reused or disposed of.

In a further preferred embodiment, an auxiliary carrier sheet, preferably flexible, or a board, preferably rigid, is used as the carrier material.

The use of sheets or boards has the advantage that fast and slow process steps can be better combined.

In a first possible variant, the process steps are separated as described below:
For example, in a first process step, the panels are coated with a release layer, for example by printing, and then stacked again after thermal drying. In the second process step, the Janus particles are then generated. The detachment of the generated Janus particles then takes place in a third offline process step, as this requires more time, for example. The panels are then optimally cleaned in a fourth process step.

In a second possible variant, process steps of different speeds are combined with the help of switches in an online process or automated process in such a way that a faster process step is not slowed down by a slow process step.

1. 1. Anlage Tafeln (Hilfsträger) mit Transporteinrichtung über Saug- und Bändertisch (analog Bogen-Offsetdruckmaschine)
2. 2. Applikation Ablöseschicht (z.B. PVOH) mit Hilfe von Ink-Jet-Druck und thermische Trocknung mit Heißluft oder/ und IR-Strahler
3. 3. Applikation der Janus-Partikel incl. UV-Trocknung
4. 4. Weiche zu zwei Partikel-Ablöse-Stationen welche wechselseitig geschaltet werden (da der Ablöseprozess in diesem Beispiel mehr Zeit benötigt)
5. 5. Zuführung der Tafeln an eine Reinigungsstation Nach dem Ablösen kann eine Trennung der Partikel durch ein zentrifugales Verfahren in unterschiedliche Dichten erfolgen, wobei z.B. zu leichte Partikel - beispielsweise wegen fehlender zweiter magnetischer Beschichtung - als fehlerhafte Partikel aussortiert werden.

This should be illustrated by the following example with the listed process steps:

1. 1. System panels (auxiliary carrier) with transport device via suction and belt table (analogous to sheet-fed offset printing machine)
2. 2. Application of release layer (eg PVOH) with the help of ink-jet printing and thermal drying with hot air and / or IR radiator
3. 3. Application of the Janus particles including UV drying
4. 4. Switch to two particle detachment stations which are switched alternately (since the detachment process requires more time in this example)
5. 5. Feeding the panels to a cleaning station After detachment, the particles can be separated into different densities by a centrifugal process, whereby, for example, excessively light particles - for example due to the lack of a second magnetic coating - are sorted out as defective particles.

At least one printing material is advantageously magnetic and the at least one magnetic printing material is magnetically pre-oriented after application and before or during its drying or curing.

If the printing speed of a single printer is not sufficient when applying a printing material to produce the desired amount of printing / coating particles, the output can be scaled up as required by parallel production. The typical risks associated with the scalability of processes are eliminated.

In the case of the anisotropic printing / coating particles mentioned, at least one of the surface areas mentioned is advantageously formed by a printing substance, in particular a printing ink.

• der Oberflächenspannung der Oberflächenbereiche,
• dem spezifischen Gewicht der die Oberflächenbereiche ausbildenden Materialien,
• der Farbigkeit der Oberflächenbereiche, insbesondere dem Farbspektrum der Oberflächenbereiche im UV, VIS und/oder IR, wobei der Begriff Farbigkeit sowohl nicht-farbvariable als auch farbvariable, beispielsweise farbkippende oder in anderer Weise optisch variable Gestaltungen einschließt,
• den magnetischen Eigenschaften der Oberflächenbereiche bzw. der die Oberflächenbereiche ausbildenden Materialien,
• den Lumineszenzeigenschaften der Oberflächenbereiche bzw. der die Oberflächenbereiche ausbildenden Materialien,
• der elektrischen Leitfähigkeit der Oberflächenbereiche bzw. der die Oberflächenbereiche ausbildenden Materialien,
• den Polarisationseigenschaften der Oberflächenbereiche bzw. der die Oberflächenbereiche ausbildenden Materialien, und
• dem Glanz und der Reflektivität der Oberflächenbereiche.

The separate surface areas advantageously differ with regard to one or more of the physical properties of the group, which is formed from:

• the surface tension of the surface areas,
• the specific weight of the materials forming the surface areas,
• the color of the surface areas, in particular the color spectrum of the surface areas in UV, VIS and / or IR, the term color being both non-color-variable and color-variable, for example includes color-changing or otherwise optically variable designs,
• the magnetic properties of the surface areas or the materials forming the surface areas,
• the luminescence properties of the surface areas or the materials forming the surface areas,
• the electrical conductivity of the surface areas or the materials forming the surface areas,
• the polarization properties of the surface areas or of the materials forming the surface areas, and
• the gloss and the reflectivity of the surface areas.

In an advantageous embodiment, the separate surface areas of the particle have the same shape and / or size. In other variants, it can be advantageous to design the separate surface areas of the particle with a different shape and / or size, for example in order to allow one of the properties of the particle to predominate or even to dominate.

While the anisotropic printing / coating particle can in principle have any geometric shape, it is currently particularly preferred if the anisotropic printing / coating particle is lamellar or hemispherical. In addition, spherical, dumbbell-shaped, rod-shaped or cylindrical designs are also possible.

In an advantageous variant of the invention, the component of the particle formed by said printing substance represents a carrier component which defines the spatial shape of the particle. This carrier component does not necessarily have to form one of the surface areas mentioned, but can do this in advantageous configurations. The carrier component can be filled with a high density filler that enables gravimetric orientation of the particle. For example, barium sulfate with a density of about 4.5 g / cm ³ and titanium dioxide (4.2 g / cm ³ ) can be used as fillers.

In preferred embodiments, the carrier component is transparent and allows the perception of a material area arranged below or above the carrier component with desired physical, in particular visually perceptible or optically detectable properties. The carrier component advantageously comprises a solvent or water-based binder, in particular a UV-crosslinking binder and particularly preferably a UV-drying binder. In an advantageous embodiment, the component of the particle formed by the named printing substance forms one of the named surface areas.

The volume fraction of the coating materials is advantageously less than 50%, preferably less than 30%, in particular less than 10% or even less than 5% of the volume fraction of the printing materials.

Furthermore, at least one coating material advantageously represents a two-dimensional coating of a component of the particle formed by at least one printing material, in particular of the carrier component.

The anisotropic printing / coating particle advantageously has a maximum dimension of 3-70 µm, preferably 3-50 µm and particularly preferably 3-30 µm. Alternatively or additionally, the printing / coating particle has a volume below 3.5 × 10 ^-13 m ³ , preferably below 1.25 x 10 ^-13 m ³ and particularly preferably below 0.3 x 10 ^-13 m ³ .

The exact relationship between maximum expansion and volume depends on the shape of the particles. For example, hemispherical anisotropic printing / coating particles advantageously have a maximum dimension of 1.5-35 μm, preferably 1.5-25 μm and particularly preferably 1.5-15 μm, and accordingly advantageously have a volume between 7 μm ³ and 90,000 μm ³ , preferably between 7 μm ³ and 32,500 μm ³ and particularly preferably between 7 μm ³ and 7,000 μm ³ .

Platelet-shaped anisotropic printing / coating particles advantageously have a pigment thickness of 1-10 μm, preferably 1-7 μm. For illustration purposes, the particles are assumed to have a circular surface area; the results for other surface shapes can then easily be derived. For example, a platelet-shaped particle with a circular disk diameter of 30 μm and a thickness of 1 μm has a volume of 707 μm ³ , and a thickness of 3 μm has a volume of 2,120 μm ³ . A platelet-shaped particle with a circular disk diameter of 50 μm has a volume of 5,890 μm ³ with a thickness of 3 μm and a volume of 9,820 μm ³ with a thickness of 5 μm. A platelet-shaped particle with a circular disk diameter of 70 μm has a volume of 11,545 μm ³ with a thickness of 3 μm and a volume of 19,240 μm ³ with a thickness of 5 μm.

In a particularly preferred variant, the density of the particulate material (printing and coating materials) is in the range from 0.8 g / cm ³ to 4 g / cm ³ .

According to an advantageous development, the anisotropic printing / coating particle is easily movable and its spatial alignment can be controlled, so that in particular the alignment of the separate surface areas can be set as desired. This setting can be made permanently, for example by fixing the spatially oriented particles in an ambient medium. However, the setting can also be reversible, for example in that a printing / coating particle core is movably accommodated in a capsule shell. For this purpose, the anisotropic printing / coating particle preferably has a magnetic core which can be aligned by an external magnet. Alternatively, an alignment of the particle cores by means of electric fields is also possible, for which purpose the cores have, for example, an electric charge or an electric dipole moment or are sufficiently polarizable. The alignability can be destroyed by fixing the printing / coating particles in a printing ink, or, as in the case of the encapsulated printing / coating particles described below, can also be permanently retained.

In an expedient development of the invention, the printing / coating particle has a capsule shell and a carrier fluid enclosed in the capsule shell, in which at least one printing / coating particle core is dispersed, which has at least two separate surface areas with different physical properties and in which at least one of the surface areas mentioned is formed by a coating material and at least one component of the particle core is formed by a printing material, in particular a printing ink. A plurality of identical or dissimilar printing / coating particle cores can also be contained in the carrier fluid. In this further development, the printing / coating particle initially generated is therefore used together with dispersed and encapsulated in a carrier fluid so that it forms at least one printing / coating particle core which is enclosed within a capsule shell. In the case of a magnetic particle, this can be reversibly aligned by an external stimulus using a magnetic field.

In order to avoid that a changed position of the particle cores is permanently maintained, it can be provided that after a reorientation of the particle cores a reorientation takes place by utilizing gravimetric forces and / or by elastic restoring forces of the carrier fluid of the capsule.

The invention also contains a printing ink or a varnish for counterfeit protection in which or in which anisotropic printing / coating particles of the type described are dispersed.

The invention further includes a counterfeit-proof article with an applied, in particular printed, layer with anisotropic printing / coating particles of the type described. The layer can in particular be produced by using the above-mentioned printing ink or varnish. The forgery-proof object can in particular be a value document such as a bank note, a passport, a certificate, an identity card or the like, or also a product packaging secured by the particle layer. The object advantageously contains a substrate made of paper, plastic or a paper-plastic hybrid, onto which the printing / coating particle layer is applied, in particular printed.

The printing / coating particle layer can be combined on the object with further layers with security features, their properties interact advantageously with the physical properties of the printing / coating particles. For example, the printing / coating particles can have luminescent properties and be overprinted with a luminescent layer or a layer containing a UV absorber in some areas, so that a luminescence that is combined in some areas or modified in some areas results.

Finally, the invention also includes a method for producing anisotropic printing / coating particles of the type described, in which at least one printing material with a printing process and at least one coating material with a coating process are connected to one another directly or indirectly in order to provide the at least two separate surface areas to produce different physical properties. According to the invention, the coating material is applied in a contactless coating process, namely by a PVD (Physical Vapor Deposition) process, a CVD (Chemical Vapor Deposition) process or a spray coating process, and the printing material is applied according to the invention using continuous ink jet printing, ink - Jet printing, screen printing or 3D printing applied.

Any drying or crosslinking of the constituents of the particle formed by printing processes can take place before or after the coating of the constituent.

Printing and coating processes that can advantageously be used have already been mentioned and described in more detail elsewhere. In any case, the coating process is not a printing process. The different printing and coating materials are advantageously arranged so that they fit one another, overlap one another, or butt to butt.

In an advantageous embodiment, the different printing and coating materials are applied to an auxiliary carrier and each connected there to form an anisotropic printing / coating particle. The anisotropic printing / coating particles formed are then detached from the auxiliary carrier, preferably detached mechanically. A possible The components of the particle formed by printing processes are advantageously dried or crosslinked after the particles have been detached from the auxiliary carrier.

At least one printing material is advantageously magnetic and the at least one magnetic printing material is magnetically pre-oriented after application and before or during its drying or curing. The pre-orientation can also take place when a coating is applied. If the particle has a magnetic core or is itself magnetic, the magnetic core or the magnetic alignment advantageously has a fixed alignment with respect to the alignment of the different physical properties of all Janus particles produced. In order to prevent the particles from being reoriented by a strong external magnetic field, the magnetic structures of the particles, as known in principle from the GMR (Giant Magneto Resistance) effect, can be formed in multiple layers with a sequence of magnetic and non-magnetic thin layers. Such layer sequences have proven to be very resistant to magnetic reversals.

Further exemplary embodiments as well as advantages of the invention are explained below with reference to the figures, in the representation of which a reproduction true to scale and proportion was dispensed with in order to increase the clarity.

Fig. 1

schematisch eine Druckfarbe mit einem UV-trocknenden Bindemittel, in welches anisotrope Druck-/ Beschichtungs-Partikel zweier verschiedener Arten eingebracht sind,

Fig. 2

eine genauere Darstellung eines der Druck-/ Beschichtungs-Partikel der Fig. 1, wobei (a) einen Querschnitt, (b) eine Aufsicht aus Richtung B und (c) eine Aufsicht aus Richtung C zeigt,

Fig. 3

ein Sicherheitssubstrat mit einem durch die Druckfarbe der Fig. 1 gebildeten Aufdruck mit bereichsweise unterschiedlichem Erscheinungsbild,

Fig. 4

in (a) bis (c) drei verschiedene anisotrope Druck-/Beschichtungs-Partikel im Querschnitt,

Fig. 5

in (a) bis (d) weitere vorteilhafte Ausgestaltungen anisotroper Druck-/Beschichtungs-Partikel mit einem drucktechnisch erzeugten Trägerbestandteil im Querschnitt,

Fig. 6

in (a) bis (d) Beispiele für das Erscheinungsbild erfindungsgemäßer Druck-/Beschichtungs-Partikel in Aufsicht,

Fig. 7

eine anisotrope Druck-/Beschichtungs-Partikel-Kapsel mit einem halbkugelförmigen Partikelkern,

Fig. 8

eine schematische Illustration der Herstellung erfindungsgemäßer Druck-/Beschichtungs-Partikel auf einem Trägersubstrat,

Fig. 9

in (a) ein von dem Trägersubstrat der Fig. 8 abgelöstes Rohpartikel mit einem noch vorhandenen Überstand und in (b) das fertige Janus-Partikel,

Fig. 10

eine schematische Illustration der Herstellung erfindungsgemäßer Druck-/ Beschichtungs-Partikel auf einem Trägersubstrat nach einem weiteren Ausführungsbeispiel,

Fig. 11

ein von dem Trägersubstrat der Fig. 10 abgelöstes Partikel, und

Fig. 12

schematisch die Herstellung anisotroper Druck-/ Beschichtungs-Partikel durch Druck und nachfolgende Beschichtung auf einem umlaufenden Endlosband.

Show it:

Fig. 1

schematically a printing ink with a UV-drying binder, in which anisotropic printing / coating particles of two different types are introduced,

Fig. 2

a more accurate representation of one of the print / coating particles of the Fig. 1 , where (a) shows a cross section, (b) shows a plan view from direction B and (c) shows a plan view from direction C,

Fig. 3

a security substrate with a through the printing ink of the Fig. 1 formed imprint with a different appearance in some areas,

Fig. 4

in (a) to (c) three different anisotropic printing / coating particles in cross section,

Fig. 5

in (a) to (d) further advantageous configurations of anisotropic printing / coating particles with a carrier component produced by printing technology in cross section,

Fig. 6

in (a) to (d) examples of the appearance of printing / coating particles according to the invention in plan view,

Fig. 7

an anisotropic pressure / coating particle capsule with a hemispherical particle core,

Fig. 8

a schematic illustration of the production of printing / coating particles according to the invention on a carrier substrate,

Fig. 9

in (a) one of the carrier substrate Fig. 8 detached raw particle with a supernatant still present and in (b) the finished Janus particle,

Fig. 10

a schematic illustration of the production of printing / coating particles according to the invention on a carrier substrate according to a further exemplary embodiment,

Fig. 11

one of the carrier substrate Fig. 10 detached particle, and

Fig. 12

schematically the production of anisotropic printing / coating particles by printing and subsequent coating on a circulating endless belt.

The invention will now be explained in more detail using the example of a printing ink for security printing. Figure 1 shows schematically a printing ink 10 with a UV-drying binder 12 into which anisotropic printing / coating particles 14, 16 of two different types are introduced. Each of the printing / coating particles of the first type 14 and of the second type 16 has two separate surface areas 14A, 14B and 16A, 16B, respectively, with different physical properties.

The different properties of the surface areas 14A, 14B and 16A, 16B are illustrated in the figures by different or missing hatching of the substances forming the surface areas. The printing / coating particle of the first type 14 is in Fig. 2 shown in more detail, where Fig. 2 (a) a cross section, Fig. 2 (b) a top view from direction B and Fig. 2 (c) a top view from direction C of Fig. 2 (a) indicates.

In practice, the different properties include in particular one or more physical properties from the group which is formed from the surface tension of the surface areas, the specific gravity of the materials forming the surface areas, the Color of the surface areas, in particular the color spectrum of the surface areas in UV, VIS and / or IR, the magnetic properties of the surface areas or the materials forming the surface areas, the luminescence properties of the surface areas or the materials forming the surface areas, the electrical conductivity of the surface areas or the materials forming the surface areas and the gloss and reflectivity of the surface areas.

Specifically, the surface areas 14A, 14B of the print-coating particles 14 in the exemplary embodiment differ in their color in the visible spectral range. For example, the surface areas 14A appear red and the surface areas 14B appear blue. The printing / coating particles of the second type 16 are basically structured like the printing / coating particles of the first type 14 ( Fig. 2 ), but the surface areas 16A, 16B of the print / coating particles 16 differ in their luminescence properties, for example the surface areas 16A luminesce green after UV excitation and the surface areas 16B red.

Regarding Fig. 2 the printing / coating particles of the first type 14 consist of two layers 18-1, 18-2 produced by printing technology, which are each formed by a red reflective printing ink. In order to make the first layer 18-1 flat and the second layer 18-2 hemispherical, the red reflective printing inks used during manufacture have different rheological and / or physical interface properties. The layers 18-1, 18-2 produced by printing technology are provided with a coating 18-3 made of a blue reflective coating material, which is carried out with a coating process, in the exemplary embodiment by physical Gas phase deposition (PVD) is applied to the layers 18-1,18-2 produced by printing technology.

The particles 14 have a diameter (largest dimension) D of approximately 25 μm, and their height H is approximately 20 μm. The layer thickness of the coating 18-3 is only about 1 μm, so that the volume fraction of the coating material is very small compared to the volume fraction of the printing ink that forms the layers 18-1 and 18-2.

The printing / coating particles 14, 16 not only have the visual properties mentioned, but are also magnetic, so that they can be aligned as desired by an external magnetic field during or after the printing of the printing ink 10 and before the binding agent is dried . In the exemplary embodiment, the magnetic alignability is determined by the magnetic properties of the materials forming the surface areas 14A, 14B, 16A, 16B, namely the above-mentioned printing ink of the layers 18-1, 18-2, the coating material of the coating 18-3 and the corresponding materials of the Particles 16 provided themselves, in such a way that the surface areas 14A and 16A each form a magnetic north pole and the surface areas 14B and 16B each form a magnetic south pole. In other configurations, the magnetic alignability can also be provided by a further magnetic material arranged in the interior of the particle. This magnetic material is preferably provided by a printing material.

Figure 3 FIG. 11 schematically shows a security substrate 20, such as a bank note, with one through the printing ink 10 of FIG Fig. 1 formed imprint with a different appearance in some areas. For this purpose, the printing ink 10 was printed onto the substrate 20 and the anisotropic printing / coating particles 14, 16 aligned by an external magnetic field in such a way that they are oriented opposite one another in first and second regions 22, 24. The binder 12 of the printing ink 10 was dried by UV radiation while the magnetic field was still applied, and the set alignment of the printing / coating particles 14, 16 was thereby permanently fixed.

In the first area 22, the surface areas 14A, 16A of the printing / coating particles 14, 16 point towards the viewer, so that the first area 22 shows a red color impression in the visible spectral range and a green luminescence after UV excitation. In the second area 24, on the other hand, the opposite surface areas 14B, 16B of the printing / coating particles 14, 16 point towards the viewer, so that this area shows a blue color impression in the visible spectral range and a red luminescence after UV excitation.

Advantageous designs of anisotropic printing / coating particles according to the invention will now be described with reference to FIG Figures 4 to 6 described in more detail. The printing / coating particles can, for example, be produced in the manner described in more detail below.

First shows Fig. 4 (a) in cross section a platelet-shaped anisotropic printing / coating particle 30, which consists of a carrier component 32 produced by printing technology with a first physical property and a coating 34 with a second, different physical property. The carrier component 32 defines the basic shape of the particle 30, which is practically not changed by the comparatively thin coating 34. The carrier component 32 and the coating 34 form two surface areas of the particle 30 of different physical properties Properties. The diameter D (largest dimension) of the particle 30 is between 3 μm and 70 μm, and the height H of the particle is typically in the range of a few micrometers.

This in Fig. 4 (b) Essentially hemispherical printing / coating particles 40 shown in cross-section are designed in a manner similar to the particles 14, 16 of FIGS a coating 44 is provided from a coating material. In order to make the first layer 42-1 flat and the second layer 42-2 hemispherical, the printing inks used during manufacture have different rheological and / or physical interface properties. The first printed layer 42-1 forms a first surface area of the particle 40 with a first physical property, and the coating 44 of the second printed layer 42-2 forms the second surface area with a second, different physical property. The second layer 42-2 produced by printing technology is transparent in this embodiment and / or has a different physical property than the first layer 42-1.

Also in Fig. 4 (c) The substantially hemispherical printing / coating particles 50 shown in cross section are similar to the particles 14, 16 of FIG Figures 1 to 3 and consists of two layers 52-1, 52-2 produced by printing technology, the layer 52-2 being provided with a coating 54 made of a coating material. In order to make the first layer 52-1 flat and the second layer 52-2 hemispherical, the printing inks used during manufacture have different rheological and / or physical interface properties. The first layer 52-1 produced by printing technology is transparent, while the second Layer 52-2 produced by printing technology forms a first surface area of the particle 50 with a first physical property. The coating 54 forms a second surface area with a second, different physical property.

In the designs of the Fig. 4 (b) and 4 (c), the transparent layer 42-2 or 52-1 can have additional material properties which lie outside the visible spectral range, such as luminescence that can be excited in the UV or IR absorption. The transparent layer can also have a polarizing property, which can be verified with an aid such as a polarization filter.

Further advantageous configurations of anisotropic printing / coating particles with a carrier component produced by printing technology are shown in the cross-sections of FIG Figs. 5 (a) to 5 (c) shown.

Figure 5 (a) shows first a platelet-shaped printing / coating particle 60 with a transparent, printing technology-generated carrier component 62, which defines the size and basic shape of the particle 60, and which is provided with two coatings 64-1, 64-2 with different optical properties. The transparent carrier component 62 does not cover the optical properties of the first coating 64-1, while these are covered by the second coating 64-2. From the viewing direction 66, therefore, it is predominantly the optical properties of the first coating 64-1 that can be seen, while from the opposite viewing direction 68, it is predominantly the optical properties of the second coating 64-2 that appear.

The platelet-shaped printing / coating particle 70 of Fig. 5 (b) has a similar structure to particle 60 of FIG Fig. 5 (a) on, although an intermediate layer 72 is provided between the coatings 64-1, 64-2, which serves to improve the adhesion of the second coating 64-2 or the orientation of the second coating 64-2 on the first coating 64-1.

Finally, the platelet-shaped printing / coating particle 80 of FIG Fig. 5 (c) is similar in structure to particle 70 of FIG Fig. 5 (b) on. In this case, the intermediate layer 82 represents a layer with a visually less attractive appearance which is covered by the second coating 64-2. The intermediate layer 82 can be, for example, a magnetic or magnetizable layer, a layer with good thermal conductivity or an electrically conductive layer. The intermediate layer 82 can also consist of several individual or alternating layers.

Furthermore, a structure is also possible in which the coatings 64-1, 64-2 are applied to opposite sides of a carrier component 62, as in FIG Fig. 5 (d) shown. In this case, the carrier component 62 can also be semitransparent or even opaque in order to avoid a mutual visual influence of the coatings 64-1, 64-2.

The coatings 64-1, 64-2 can in particular be optically variable coatings such as thin-film elements, interference layers or liquid crystal layers. For example, the coating 64-1 can be a color-shifting liquid crystal layer and the coating 64-2 can be a non-color-changeable coating. In addition to their color-changing effect, liquid crystal layers can also have light-polarizing properties which, in addition to the different colors, can represent a second, different physical property of the coatings.

Figure 6 shows in (a) to (d) examples of the appearance of printing / coating particles 90 according to the invention in plan view. The shape of the particles 90 is in particular a platelet shape, hemispherical shape, spherical shape, rod shape, the shape of a dumbbell, a mushroom, a tetrahedron.

The relative proportions of the at least two different printing / coating materials of the particles according to the invention can be the same, approximately the same (proportions by volume or mass within 10%) or different based on the volume or the mass of the particles.

In order to improve the adhesion of a coating, a layer produced by printing technology can be pretreated, for example, by means of flame pretreatment, corona pretreatment or plasma pretreatment, also with a supply of process gas. A layer produced by printing technology can also be provided with a primer layer or adhesive layer by means of spray coating. Another possibility is to apply an adhesive layer, for example an oxidic coating, using a PVD process.

Figure 7 shows as a further embodiment an anisotropic pressure / coating particle capsule 100 in which a hemispherical particle core 102, for example in connection with Fig. 2 described manner, is encapsulated in a liquid-filled microcapsule shell 104. For example, an oil can be provided as the separating agent 106, which increases the mobility of the particle core 102 within the microcapsule shell 104 even after a die has been printed on and dried Printing / coating particle capsules 100 containing printing ink guaranteed. Such printing / coating particle capsules 100 are used in particular when the visible or measurable physical properties of the particles are to be able to be changed permanently by external stimuli even after the particles have been applied. For example, a magnetic particle core 102 can be aligned differently during the authenticity check by an external magnet and thereby show the viewer one of the two different surface areas 102A, 102B depending on the orientation.

In the case of encapsulation, it is advantageous if the particles to be encapsulated do not have a platelet structure but a pronounced 3D structure (symmetrical or asymmetrical) in order to avoid “glass plate effects” in a capsule. In the case of platelet structures, there is a risk that several platelets will stick to one another and these will be encapsulated together. However, what is usually desired is the encapsulation of individual particles in a capsule each. The more pronounced the 3D structure, the more likely there is only one particle per capsule.

In a further very advantageous variant, the printing / coating particles produced are provided with an additional coating in a subsequent process. In the case of the additional coating, a distinction is made between an additional coating that does not change the shape of the particles and an additional coating that changes the shape. In the case of an additional coating that does not change the shape, for example, the chemical resistance or the surface tension of the printing / coating particles is influenced. The additional coating can take place, for example, in a gas phase or a spray coating. With an additional coating that changes its shape For example, it is about optimizing the mechanical and / or chemical resistance of the particles. Furthermore, an additional coating that changes the shape can contribute to optimizing the rotatability of the particle cores in a capsule or reducing the accumulation of particle cores during encapsulation. Suitable methods for such an additional coating are, for example, the method from Brace GmbH or an eddy current coating method.

The particles can be made mechanically more stable or chemically more stable by the additional coating and / or the outer shape of the particles can be changed with a preferably transparent layer, for example in order to make a spherical particle out of a rod-shaped particle.

For the sake of simplicity, those described above are included Figures 4 to 7 for illustration, printing / coating particles or particle cores are shown with only two different surface areas, but it goes without saying that the invention also includes designs with three or more different surface areas.

The anisotropic printing / coating particles of the invention can be produced by various combinations of printing and coating processes, exemplary production processes now with reference to FIG Figures 8 to 12 are explained in more detail.

In the embodiment of Fig. 8 a printing layer 112 is generated on a carrier substrate 110 using a printing process, first in partial areas, the shape and size of which defines the flat and the three-dimensional basic shape of the printing / coating particle. As a printing process For example, ink-jet processes (DOD) (according to the invention), laser printing (not claimed), transfer printing processes (not claimed), in particular thermal transfer printing processes based on fusible raw materials, flexographic printing (not claimed), screen printing (according to the invention) or gravure printing (not claimed) can be used claimed)
come into use. The layer 112 produced by printing technology does not necessarily have to have one of the desired different physical properties of the finished particle, but can, for example, simply represent a transparent layer and / or form a carrier component of the finished particle.

The layer 112 produced by printing technology can be dried or hardened before the subsequent process (for example in the case of a UV-hardening binder) or it can be processed further without drying / hardening.

In a further work step, at least one further layer 114 is applied without registering and spanning a large number of the layer areas 112 produced by printing technology by means of a coating process such as spray coating, sputtering or another PVD process (all according to the invention). In doing so, at least one further desired physical property of the finished particle is generated. At the latest with the last coating, the entire particle is dried or hardened.

Since the layers 114 produced by means of the coating process break mechanically due to the brittleness of the material and the layer thickness, among other things are preferably the outer edges of the layers 112 produced by printing technology.

Figure 9 (a) shows a raw particle 120 detached from the carrier substrate 110, which comprises the layer 112 produced by printing technology, the regions 118 of the coating 114 located on the layer 112, and a coating overhang 122 still present on the left side of the raw particle 120. This protrusion is removed in a further processing step so that the in Fig. 9 (b) The finished Janus particles 124 shown are produced. It goes without saying that particles with more than one layer produced by printing technology and with more than one layer produced by a coating process can also be built up on the carrier substrate 110 in this way.

The raw particles 120 can be separated from the carrier substrate 110 in different ways, as already explained in more detail above.

The printing and coating processes can also be combined with one another in the reverse order to that shown in FIG Figures 10 and 11 explained. In the embodiment of Fig. 10 a coating 114 is applied over a large area to a carrier substrate 110 initially using a coating process such as spray coating, sputtering or another PVD process (all according to the invention). A printing layer 112 is then produced on the coating in each case in partial areas using a printing process. Ink-jet processes (DOD) (according to the invention), laser printing (not claimed), transfer printing processes (not claimed), in particular thermal transfer printing processes based on fusible raw materials, flexographic printing (not claimed), screen printing (according to the invention) or Gravure printing (not claimed) can be used. When the layer sequence 114, 112 is detached from the carrier substrate, the outer edges of the layers produced by printing technology form 112 predetermined breaking points which lead to a precisely registered breaking off of the coating 114 at the edges of the printing layers 112.

Figure 11 shows schematically a particle 126 detached from the carrier substrate 110, which comprises a layer 112 produced by printing technology, as well as regions 118 of the coating 114 located on or under the layer 112. Due to the precisely registered breaking off of the coating 114, the shape and size of the printing layer 112 also defines the flat and three-dimensional basic shape of the printing / coating particle 126 in this manufacturing variant Layer and can be built up with more than one layer produced by a coating method on the carrier substrate 110.

The in Fig. 12 In order to produce the anisotropic printing / coating particles 124, layer regions 112 are first printed onto a continuous endless belt 110 in each case. The layer areas 112 are printed on the endless belt 110 with a continuous ink jet, an ink jet or a 3D printer. Then a multiplicity of layer regions 112 together with the regions of the endless belt 110 lying therebetween are provided with a coating 114 without registering.

The endless belt 110 runs at a stripping station through a mechanical stripping device 130. The stripping takes place in the exemplary embodiment by a sharp-edged deflection of the endless belt 110 on a fixed, rounded plate 132. The loosened raw particles 120 are caught in a collecting device 134 and, if necessary, after sorting in good and bad particles, further processed to the finished printing / coating particles 124.

If the coating protrusion 122 of the particles 120 has not yet been sufficiently removed from the carrier substrate 110 during the detachment process, the protrusions 122 can be subsequently broken, for example in a pigment mixer, for example a drum mixer. Alternatively, an air jet mill can also be used, for example.

The free coating material, ie not connected to a layer produced by printing technology, can be removed, for example, by means of a water bath in which the flakes of the coating material float up and can be skimmed off. If necessary, you can use a soda maker to help. In this case, the air bubbles generated help to accelerate the buoyancy of the tinsel. As an alternative, the coating layer that is not connected to a layer produced by printing technology can also be separated, for example with a sifter, in order to produce the required product quality.

The proportion of the printing / coating particles 14, 16 in the printing ink 10 is expediently at least 0.1%, advantageously more than 3%. The maximum particle size (D90) is based on the printing and coating processes used. In offset printing, the maximum particle size is advantageously less than 5 µm, while in screen printing a maximum particle size below 50 µm is advantageous. The printing / coating particles used in the printing ink 10 can be of the same type or, as in the exemplary embodiment of FIG Fig. 1 , also be dissimilar and contain two or more different types of printing / coating particles.

In a further application example, the printing / coating particles (Janus particles) can also be added to a printing ink as a visually visible security feature. In this case, physically orientable printing / coating particles are used and the ink is only cured after the orientation or after the orientation of some of the particles. The alignment of the particles can take place by means of a magnetic field, an electric field, a location-dependent repulsion effect, caused for example by a location-dependent surface tension, by gravimetric forces, by capillary forces in the printed substrate or by a combination of the forces mentioned.

Furthermore, the particles can also be aligned only in a partial area of the applied color, for example by masked drying or magnetic alignment only in certain areas.

The detection of the printing / coating particles can be carried out with aids, such as a UV lamp, or in the case of visible colors, even without aids. The information given above on the advantageous proportion of particles in the printing ink (> 0.1%, in particular> 3%) and on the particle size (<5 µm in offset printing, <50 µm in screen printing) also apply to this application example.

In a further application example, the Janus particles or printing / coating particles can also be designed in the form of a capsule 100, as in FIG Fig. 7 shown. The shape of the capsule 100 is arbitrary. The capsule 100 contains a carrier medium 106 for the particle cores 102 which can be liquid or gaseous. The carrier medium 106 can be solid, liquid or gaseous depending on the temperature or a light or pH-induced orientation state.

While Fig. 7 shows only a single particle core 102 in the interior of a capsule 100, a plurality of similar or dissimilar particle cores can generally also be contained in a capsule 100. The capsules 100 can be part of a printing ink, a coating, a lacquer or a plastic. As a result of the encapsulation, the printing / coating particles can also be subsequently oriented in the applied and cured printing ink, coating agent, lacquer or plastic if the carrier medium is in a liquid or gaseous state. The alignment can be done by magnetic forces, electrical forces, gravimetric forces or also by strong shaking movements. Detection with aids such as a magnet is also possible inside a transparent capsule.

A coating with Janus particles or anisotropic printing / coating particles, coatings based on encapsulated Janus particles or anisotropic printing / coating particles or encapsulated Janus particles or anisotropic printing / coating particles incorporated into plastics can be used to secure documents of value such as Banknotes, vouchers, certificates, certificates, documents, ID documents, spare parts, license plates, brand protection, packaging and the like can be used. For example, they can also be used for switchable displays.

List of reference symbols

10

Printing ink

12th

binder

14th

anisotropic printing / coating particle

14A, 14B

Surface areas

16

anisotropic printing / coating particle

16A, 16B

Surface areas

18-1, 18-2

layers produced by printing technology

18-3

Coating

20th

Security substrate

22.24

Areas

30th

platelet-shaped printing / coating particles

32

Carrier component

34

Coating

40

hemispherical printing / coating particle

42-1, 42-2

layers produced by printing technology

44

Coating

50

hemispherical printing / coating particle

52-1.52-2

layers produced by printing technology

54

Coating

60

platelet-shaped printing / coating particles

62

Carrier component

64-1, 64-2

Coatings

66.68

Viewing directions

70

platelet-shaped printing / coating particles

72

Intermediate layer

80

platelet-shaped printing / coating particles

82

Intermediate layer

90

Printing / coating particles in plan

100

anisotropic printing / coating particle capsule

102

Particle core

102A, 102B

Surface areas

104

Microcapsule shell

106

Release agent

110

Carrier substrate

112

Print layer

114

Coating

116

Areas lying outside the layers 112

118

areas located on layer 112

120

Raw particles

122

Coating overhang

124

finished Janus particle

126

detached particle

130

Stripping device

132

rounded plate

134

Fall arrest facility

Claims (18)

1. An anisotropic printing/coating particle (14, 16, 30, 40, 50, 60, 70, 80, 90, 100), for use in a printing ink or a lacquer for counterfeit protection, which comprises at least two separate surface regions (14A, 14B, 16A, 16B) having different physical properties, characterized in that

   - at least one of said surface regions is formed by a coating substance (18-3, 34, 44, 54, 64-1, 64-2, 114) applied in a non-contact coating method, namely is formed by a coating substance applied in the PVD (physical vapor deposition) method, CVD (chemical vapor deposition) method or spray coating method, and

   - at least one component of the particle is formed by a printing substance (18-1, 18-2, 32, 42-1, 42-2, 52-1, 52-2, 112), namely by a printing substance applied in continuous inkjet printing, inkjet printing, screen printing or 3D printing.
2. The particle according to claim 1, characterized in that at least one of said surface regions is formed by a printing substance, especially a printing ink.
3. The particle according to claim 1 or 2, characterized in that the different printing and coating substances are arranged one on top of another in register with one another, overlapping with one another or edge to edge.
4. The particle according to at least one of claims 1 to 3, characterized in that the separate surface regions differ with a view to one or more of the physical properties of the group that is formed by:

   - the surface tension of the surface regions,

   - the specific weight of the materials that form the surface regions,

   - the coloring of the surface regions, especially the color spectrum of the surface regions in the UV, VIS and/or IR, the term coloring including both non-color-variable and color-variable, for example color-shifting or otherwise optically variable, designs,

   - the magnetic properties of the surface regions or of the materials that form the surface regions,

   - the luminescent properties of the surface regions or of the materials that form the surface regions,

   - the electrical conductivity of the surface regions or of the materials that form the surface regions,

   - the polarization properties of the surface regions or of the materials that form the surface regions and

   - the gloss and the reflectivity of the surface regions.
5. The particle according to at least one of claims 1 to 4, characterized in that the separate surface regions of the particle have the same shape and/or size.
6. The particle according to at least one of claims 1 to 5, characterized in that the particle is formed to be lamellar, spherical, hemispherical, dumbbell shaped, rod shaped or cylindrical.
7. The particle according to at least one of claims 1 to 6, characterized in that the particle component formed by said printing substance constitutes a carrier component that defines the spatial shape of the particle.
8. The particle according to claim 7, characterized in that the carrier component is filled with a high-density filler that facilitates a gravimetric orientation of the particle.
9. The particle according to claim 7 or 8, characterized in that the carrier component is transparent.
10. The particle according to at least one of claims 1 to 8, characterized in that the particle component formed by said printing substance forms one of said surface regions.
11. The particle according to at least one of claims 1 to 10, characterized in that the volume fraction of the coating substances is less than 50%, preferably less than 30%, especially less than 10% of the volume fraction of the printing substances.
12. The particle according to at least one of claims 1 to 11, characterized in that at least one coating substance constitutes an areal coating of a particle component formed by at least one printing substance, especially of the carrier component.
13. The particle according to at least one of claims 1 to 12, characterized in that the particle has a maximum dimension of 3 - 70 µm, preferably 3 - 50 µm and particularly preferably 3 - 30 µm, and/or in that the printing/ coating particle has a volume below 3.5 x 10^-13 m³, preferably below 1.25 x 10^-13 m³ and particularly preferably below 0.3 x 10^-13 m³.
14. The particle according to at least one of claims 1 to 13, characterized in that the particle has a magnetic core.
15. The particle according to at least one of claims 1 to 14, characterized in that the particle (100) comprises a capsule shell (104) and, enclosed in the capsule shell, a carrier fluid (106) in which is dispersed at least one anisotropic printing/coating particle core that comprises at least two separate surface regions having different physical properties and in which at least one of said surface regions is formed by a coating substance and at least one component of the particle core is formed by a printing substance, especially a printing ink.
16. A printing ink or lacquer for counterfeit protection in which anisotropic printing/ coating particles according to one of claims 1 to 15 are dispersed.
17. A counterfeit-protected object having an applied, especially imprinted, layer having anisotropic printing/coating particles according to one of claims 1 to 15.
18. A method for producing anisotropic printing/coating particles according to one of claims 1 to 15, in which, with a printing method, at least one printing substance, and with a coating method, at least one coating substance are amalgamated directly or indirectly to produce the at least two separate surface regions having different physical properties,
    the coating substance being applied in a non-contact coating method, namely by a PVD (physical vapor deposition) method, a CVD (chemical vapor deposition) method or a spray coating method, and the printing substance being applied in continuous inkjet printing, inkjet printing, screen printing or 3D printing.

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