EA040912B1 - METHODS FOR OBTAINING LAYERS WITH OPTICAL EFFECTS - Google Patents

Description

The field of technology to which the invention belongs

The present invention relates to the field of methods for producing optical effect layers (OEL) containing magnetically oriented lamellar magnetic or magnetizable pigment particles. In particular, the present invention provides methods for producing Optical Effect Layers (OELs) having two or more embedded indicia in coating layers containing oriented lamellar magnetic or magnetizable pigment particles, and using said OELs as anti-counterfeiting agents on security documents or security documents. products and for decorative purposes.

Prerequisites for the creation of the invention

It is known in the technical field to use paints, compositions, coatings or layers containing oriented magnetic or magnetizable pigment particles, in particular also optically variable magnetic or magnetizable pigment particles, to obtain security features, for example in the area of security documents. Coatings or layers containing oriented magnetic or magnetizable pigment particles are disclosed in, for example, US 2,570,856, US 3,676,273, US 3,791,864, US 5,630,877 and US 5,364,689. Coatings or layers containing oriented magnetic color changing pigment particles which result in eye-catching optical effects used to protect security documents are disclosed in WO 2002/090002 A2 and WO 2005/002866 A1.

Security features, for example, for security documents can be broadly divided into implicit security features on the one hand and overt security features on the other hand. The protection provided by covert security features is based on the principle that these features are difficult to detect; their detection usually requires special equipment and knowledge, while overt security features are based on the concept of easy detection by the naked human senses; for example, such features may be visible and/or tactilely detectable and still be difficult to manufacture and/or copy. However, the effectiveness of overt security features depends more on their easy recognition as a security feature.

Magnetic or magnetizable pigment particles in printing inks or coatings allow the creation of magnetically induced images, patterns and/or designs by applying an appropriate structured magnetic field causing local orientation of the magnetic or magnetizable pigment particles in the uncured (i.e. wet) coating with subsequent curing of the coating. As a result, a fixed and stable magnetically induced image, pattern or drawing is obtained. Materials and techniques for orienting magnetic or magnetizable pigment particles in coating compositions are disclosed in US Pat. 2004/0009308, EP 0710508 A1, WO 2002/09002 A2, WO 2003/000801 A2, WO 2005/002866 A1, WO 2006/061301 A1. Thus, magnetically induced patterns can be obtained which are highly resistant to counterfeiting. The security element in question can only be made with access to both the magnetic or magnetizable pigment particles or the corresponding ink and the specific technology used to print said ink and to orient said pigment in the printed ink.

EP 1641624 B1, EP 1937415 B1 and EP 2155498 B1 disclose apparatus and method for magnetically transferring indicia into a not yet hardened (i.e. wet) coating composition containing magnetic or magnetizable pigment particles to form Optical Effect Layers (OELs). ). The disclosed methods advantageously provide for the creation of secure documents and articles having an individual magnetic pattern.

EP 1641624 B1 discloses a device for magnetically transferring indicia corresponding to a pattern to be transferred into a wet coating composition containing magnetic or magnetizable particles on a substrate. The disclosed device comprises a body of permanent magnet material permanently magnetized in a direction substantially perpendicular to said body's surface, said body's surface bearing etching indicia causing interference with its magnetic field. The disclosed devices are well suited for transferring high resolution patterns in high speed printing processes such as those used in the field of security printing. However, as described in EP 1937415 B1, the devices disclosed in EP 1641624 B1 can result in poorly reflective optical effect layers having a rather dark appearance.

EP 1937415 B1 discloses an improved device for magnetically transferring indicia into a wet coating composition containing magnetic or magnetizable pigment flakes on a substrate. The disclosed device contains at least one magnetized magnetic plate having a first magnetic field and having a surface relief, engravings or cutouts on its surface, representing the indicated signs, and at least one additional magnet having a second magnetic field, while the additional magnet is stationary located

- 1 040912 adjacent to the magnetic plate to ensure a significant overlap of their magnetic fields.

The moving ring effects are designed to be effective security features. Moving ring effects consist of optically illusory images of objects such as bells, cones, balls, circles, ellipses, and hemispheres that appear to move in any xy direction, depending on the angle of inclination of said optical effect layer. Methods for obtaining moving ring effects are disclosed, for example, in EP 1710756 A1, US 8343615, EP 2306222 A1, EP 2325677 A2 and US 2013/084411.

WO 2011/092502 A2 discloses a moving ring imaging apparatus displaying a single ring that appears to move as the viewing angle changes. The disclosed moving ring images can be obtained or created using a device that allows the orientation of magnetic or magnetizable particles using a magnetic field generated by a combination of a soft magnetizable sheet and a spherical magnet, the magnetic axis of which is perpendicular to the plane of the coating layer, and located under the said soft magnetizable sheet.

WO 2014/108404 A2 discloses optical effect layers (OELs) containing a plurality of magnetically oriented non-spherical magnetic or magnetizable particles that are dispersed in a coating. The specific magnetic orientation pattern of the disclosed OELs provides the viewer with an optical effect or impression of a single loop-like body that moves as the OELs are tilted. In addition, WO 2014/108404 A2 discloses OELs further showing an optical effect or impression of a protrusion in a loop body caused by a reflection zone in a central region surrounded by a loop body. The exposed protrusion provides the impression of a three-dimensional object, such as a hemisphere, present in a central region surrounded by a loop body.

WO 2014/108303 A1 discloses optical effect layers (OELs) containing a plurality of magnetically oriented non-spherical magnetic or magnetizable particles that are dispersed in a coating. The specific magnetic orientation pattern of the disclosed OELs provides the viewer with an optical effect or the impression of a plurality of nested loop-like bodies surrounding one common central region, said bodies exhibiting apparent movement depending on the viewing angle.

Therefore, there remains a need for methods for producing optimized optical effect layers (OELs) having multiple, i. two or more nested dynamic effects on a good quality substrate, which methods must be reliable, easy to implement and able to operate at high operating speed, allowing the creation of dynamic OELs that not only have an eye-catching effect but also a striking appearance with good resolution.

Brief description of the invention

Accordingly, the aim of the present invention is to overcome the disadvantages of the prior art discussed above. It is achieved by providing a method for producing an optical effect layer (OEL) comprising the steps

a) applying to the surface of the substrate (x20) a coating composition containing

i) lamellar magnetic or magnetizable pigment particles, and ii) a binder to form a coating layer (x10) on said substrate (x20), wherein said coating composition is in a first liquid state;

b) exposing the coating layer (x10) to the magnetic field of a magnetic assembly (x30) containing

i) a soft magnetic plate (x31) containing one or more soft magnetic metals, alloys or compounds with high magnetic permeability or made of a composite material containing from about 25 wt.% to about 95 wt.% soft magnetic particles dispersed in a non-magnetic material, while the weight percentage is calculated based on the total weight of the magnetic plate (x31), while the soft magnetic plate (x31) contains one or more cavities (V) for receiving one or more dipole magnets (x32), while the soft magnetic plate (x31) contains one or more notches (I) and/or one or more protrusions (P), while each of the specified one or more notches (I) and/or one or more protrusions (P) forms one or more continuous looped indicia and/or one or more discontinuous looped indicia, wherein one or more cavities (V) are surrounded by one or more continuous looped indicia and/or one or more cavities (V) are surrounded by one or more discontinuous loop-like signs, ii) one or more dipole magnets (x32), wherein the magnetic axis of each of said one or more dipole magnets (x32) is essentially perpendicular to the surface of the substrate (x20) and all of said one or more dipole magnets (x32) have the same magnetic direction, wherein said one or more dipole magnets (x32) are located within one or more cavities (V); And

c) causing the coating composition to solidify into a second state while fixing the lamellar magnetic or magnetizable pigment particles in their positions and orientations.

Also described herein are optical effect layers (OELs) obtainable by the method described herein, and security documents, as well as decorative elements and objects containing one or more of the optical OELs described herein.

Also described herein are methods for manufacturing a security document or decorative element or object, including

a) providing a security document or decorative element or object, and

b) providing an optical effect layer such as those described herein, in particular such as those obtained by the method described herein, so that it is included in a security document or decorative element or object.

Also described herein is the use of the soft magnetic plate (x31) described herein together with one or more dipole magnets (x32) described herein, wherein the magnetic axis of each of said one or more dipole magnets (x32) is substantially perpendicular to the surface of the substrate (x20) (and substantially perpendicular to the surface of the soft magnetic plate (x31)) and all of said one or more dipole magnets (x32) have the same magnetic direction, with said one or more dipole magnets (x32) located in within the cavities (V) for magnetically orienting lamellar magnetic or magnetizable pigment particles in the coating layer on the substrate.

The present invention provides a reliable and easy-to-implement method for obtaining optical effect layers (OELs) having highly dynamic multiple, i.e. two or more loop-like effects, said method comprising orienting lamellar magnetic or magnetizable pigment particles in the coating layer formed from the coating composition in the first state, i.e. not yet hardened (i.e. wet) state, while the lamellar magnetic or magnetizable pigment particles can move and rotate freely to form the specified optical effect layer (OEL) after the coating layer has solidified to the second state, while the orientation and position of the lamellar magnetic or magnetizable pigment particles are fixed/immobilized. When creating the desired effect in the not yet hardened (ie, wet) coating layer, the coating composition is partially or completely cured while permanently fixing/immobilizing the relative position and orientation of the lamellar magnetic or magnetizable pigment particles in the OEL.

As a result, the present invention, in particular the soft magnetic plate and dipole magnets, can produce optimized optical effect layers having multiple nested dynamic effects on a good quality substrate, and the method for producing the optical effect layer is reliable, easy to implement, and can be used. at high speeds, enabling dynamic optical effect layers with not only an eye-catching effect, but also a bright appearance with good resolution. In particular, with the above-described soft magnetic plate shape, a plurality of dipole magnets is not necessary to obtain desired effects such as the ability to obtain an OEL having two or more nested signs on a substrate.

Moreover, the method of the present invention is mechanically reliable, easy to implement with industrial high-speed printing equipment, without resorting to problematic, tedious and costly modifications to said equipment.

In a preferred embodiment, the soft magnetic plate (x31) has one or more notches (I) and the top surface of the one or more dipole magnets (x32) is flush with the top surface of the soft magnetic plate (x31). This makes it possible to obtain a particularly compact configuration of the soft magnetic plate containing the magnets.

In another preferred embodiment, the soft magnetic plate (x31) has one or more protrusions (P) and the top surface of the one or more dipole magnets (x32) is flush with the top surface of the soft magnetic plate (x31). This makes it possible to easily obtain a particularly compact configuration of the soft magnetic plate containing the magnets.

Preferably, the method further comprises the step of exposing the coating layer (x10) to the dynamic magnetic field of the biaxial device at least a portion of the lamellar magnetic or magnetizable pigment particles, said step being carried out before or simultaneously with step b) and before step c). This step makes it possible to further increase the complexity of the structure and/or the quality of the indicia on the substrate.

- 3 040912

According to a preferred embodiment, the soft magnetic plate (x31) is made of a composite material containing from about 25 wt.% to about 95 wt.% soft magnetic particles dispersed in a non-magnetic material, which is a polymer matrix containing or consisting of either thermoplastic materials, selected from the group consisting of polyamides, copolyamides, polyphthalimides, polyolefins, polyesters, polytetrafluoroethylenes, polyacrylates, polymethacrylates, polyimides, polyetherimides, polyether ether ketones, polyaryl ether ketones, polyphenylene sulfides, liquid crystal polymers, polycarbonates and mixtures thereof, or a thermosetting material selected from the group consisting from epoxy resins, phenolic resins, polyimide resins, silicone resins and mixtures thereof. These materials have been proven to be particularly suitable for the OEL production process.

Preferably the soft magnetic particles are selected from the group consisting of carbonyl iron, carbonyl nickel, cobalt, and combinations thereof. Again, these materials have proven to be particularly suitable for the OEL production process.

In a preferred embodiment, the depth of one or more cavities (V) is from about 5% to about 100% of the thickness of the soft magnetic plate (x31), and/or the depth of one or more notches (I) is from about 5% to about 100%, preferably from about 5 to 90% compared to the thickness of the soft magnetic plate (x31), and/or the height (H) of one or more projections (P) is from about 5% to about 100% compared to the thickness of the soft magnetic plates (x31). These relative dimensions make it possible to obtain a very compact yet very effective soft magnetic plate in the present context.

More preferably, the diameter of one or more dipole magnets (x32) is smaller than the size of one or more cavities (V). This not only allows dipole magnets to be placed in the cavities, but also allows for a more complex and thus more difficult to counterfeit appearance of the signs.

Preferably the lamellar magnetic or magnetizable pigment particles are lamellar optically variable magnetic or magnetizable pigment particles selected from the group consisting of lamellar magnetic thin film interference pigment particles, lamellar magnetic cholesteric liquid crystal pigment particles, lamellar interference coated pigment particles containing magnetic material, and mixtures of two or more of them. These particles have been proven to be particularly suitable for OEL and are thus preferred.

Brief description of the drawings

In the following, optical effect layers (OELs) described herein, as well as their manufacture, will be described in more detail with reference to the drawings and specific embodiments, in which the following is indicated.

In FIG. 1A is a schematic top view of a soft magnetic plate (131) containing a cavity (V), in particular a loop-shaped cavity (V), and a notch (I) forming a continuous loop-like character, in particular a star. The cavity (V) is surrounded by a continuous loop-shaped mark formed by a notch (I).

In FIG. 1B schematically illustrates a top view of a soft magnetic plate (131) containing a cavity (V), in particular a loop-shaped cavity (V), and a number of notches (I) forming a broken loop-shaped sign, in particular a star. The cavity (V) is surrounded by a discontinuous loop-shaped mark formed by a notch (I).

In FIG. 2A, 2B schematically illustrate cross sections of a soft magnetic plate (231) containing a cavity (V) 100% deep (D) (FIG. 2B) or less than 100% deep (FIG. 2A).

In FIG. 3A-3D are schematic plan views of various embodiments of x notches or ridges, where x=1 (FIG. 3A), x=2 (FIG. 3B), x=3 (FIG. 3C), and x=4 (FIG. 3D). ).

In FIG. 4A is a schematic cross-sectional view of a soft magnetic plate (331) of thickness (T) containing a cavity (V) and a notch (I).

In FIG. 4B schematically illustrates a cross section of a soft magnetic plate (431) of thickness (T) containing a cavity (V) and a projection (P) of thickness (H).

In FIG. 5A, 5B are schematic cross sections of a soft magnetic plate (531) containing a cavity (V) less than 100% deep and a notch (I) with a dipole magnet (532) located within the cavity (V).

In FIG. 5C-5F are schematic cross sections of a soft magnetic plate (531) containing a cavity (V) 100% deep and a notch (I) with a dipole magnet (532) located within the cavity (V).

In FIG. 6A is a schematic cross-sectional view of a soft magnetic plate (631) containing a cavity (V) less than 100% deep and a protrusion (P), with a dipole magnet (632) located within the cavity (V).

In FIG. 6B, 6C schematically illustrate a cross-section of a soft magnetic plate (631) containing a cavity (V) 100% deep and a protrusion (P), wherein the dipole magnet (632)

- 4 040912 is located within the cavity (V).

In FIG. 7A schematically illustrates a method for producing an Optical Effect Layer (OEL) having five independent effects, wherein two or more nested loop-shaped, in particular circular and star-shaped, indicia can be observed on the substrate (720); said method includes using i) a magnetic assembly (730) with orientation of at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (710) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (730 ) contains i) a soft magnetic plate (731) containing loop-shaped, in particular round, cavities (V) and loop-shaped, in particular star-shaped, notches (I); and ii) dipole magnets (732) disposed symmetrically within a first loop defined by each of the loop-shaped cavities (V), the upper surface of which is flush with the upper surface of the soft magnetic plate (731) and the lower surface of which is flush with the lower surface of the soft magnetic plate (731). plates (731).

In FIG. 7B, 7C schematically illustrate top view (FIG. 7B) and cross section (FIG. 7C) of the soft magnetic plate (731) shown in FIG. 7A.

In FIG. 7D shows photographic images of the OEL, said OEL obtained using the method shown in FIG. 7A.

In FIG. 8A schematically illustrates a process for producing an optical effect layer (OEL) having two or more nested loop-like, in particular two nested circular, indicia on a substrate (820), said method comprising the use of i) a magnetic assembly (830) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (810) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (830) contains i) a soft magnetic plate (831) containing a loop-like, in particular a round cavity (V) and a loop-shaped, in particular round notch (I); and ii) a dipole magnet (832) disposed symmetrically within the first loop defined by a loop-shaped cavity (V) whose upper surface is flush with the upper surface of the soft magnetic plate (831).

In FIG. 8B, 8C schematically illustrate top view (FIG. 8B) and cross section (FIG. 8C) of the soft magnetic plate (831) shown in FIG. 8A.

In FIG. 8D shows photographic images of the OEL, said OEL obtained using the method shown in FIG. 8A.

In FIG. 9A schematically illustrates a process for producing an Optical Effect Layer (OEL) having two or more nested loop-like, in particular two nested circular, indicia on a substrate (920), said method comprising using i) a magnetic assembly (930) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (910) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (930) contains i) a soft magnetic plate (931) containing a loop-like, in particular a round cavity (V) and a loop-shaped, in particular round notch (I); and ii) four dipole magnets (932a-d) arranged symmetrically within the first loop defined by the loop-shaped cavity (V), with the top surface of one of said four dipole magnets (932a) flush with the top surface of the soft magnetic plate (931) , and three other dipole magnets (932b-d) are located under the dipole magnet (932a).

In FIG. 9B, 9C schematically illustrate top view (FIG. 9B) and cross section (FIG. 9C) of the soft magnetic plate (931) shown in FIG. 9A.

In FIG. 9D are photographic images of the OEL, said OEL obtained using the method shown in FIG. 9A.

In FIG. 10A schematically illustrates a process for producing an Optical Effect Layer (OEL) having two or more nested loop-like, in particular two nested circular, indicia on a substrate (1020), said method comprising using i) a magnetic assembly (1030) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (1010) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (1030) comprises i) a soft magnetic plate (1031) containing a loop-like, in particular round cavity (V) and loop-shaped, in particular round ledge (P); and ii) five dipole magnets (1032a-d) arranged symmetrically within the first loop defined by the loop-shaped cavity (V), with the top surface of one of said five dipole magnets (1032a) flush with the top surface of the soft magnetic plate (1031) , and four other dipole magnets (1032b-e) are located under the dipole magnet (1032a).

In FIG. 10B, 10C schematically illustrate top view (FIG. 10B) and cross section (FIG. 10C) of the soft magnetic plate (1031) shown in FIG. 10A.

In FIG. 10D shows photographic images of the OEL, with the specified OEL obtained using

- 5 040912 using the method shown in FIG. 10A.

In FIG. 11A is a schematic illustration of a method for producing an Optical Effect Layer (OEL) having two or more nested loop-shaped, in particular round and square, indicia on a substrate (1120), said method comprising the use of i) a magnetic assembly (1130) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (1110) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (1130) contains i) a soft magnetic plate (1131) containing a loop-like, in particular a round cavity (V) and a loop-shaped, in particular square, notch (I); and ii) four dipole magnets (1132a-d) arranged symmetrically within the first loop defined by the loop-shaped cavity (V), with the top surface of one of said four magnets (1132a) below the top surface of the soft magnetic plate (1131), and three other dipole magnets (1132b-d) are located below the dipole magnet (1132a).

In FIG. 11B, 11C schematically illustrate top view (FIG. 11B) and cross section (FIG. 11C) of the soft magnetic plate (1131) shown in FIG. 11A.

In FIG. 11D shows photographic images of the OEL, said OEL obtained using the method shown in FIG. 11A.

In FIG. 12A schematically illustrates a process for producing an Optical Effect Layer (OEL) having two or more nested loop-like, in particular two nested circular, indicia on a substrate (1220), said method comprising using i) a magnetic assembly (1230) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (1210) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (1230) comprises i) a soft magnetic plate (1231) containing a loop-like, in particular a round cavity (V) and a loop-shaped, in particular round notch (I); and ii) four dipole magnets (1232a-d) arranged asymmetrically within the first loop defined by the loop-shaped cavity (V), wherein the top surface of one of said four magnets (1232a) is flush with the top surface of the soft magnetic plate (1231), and three other dipole magnets (1232b-d) are located under the dipole magnet (1232a).

In FIG. 12B, 12C schematically illustrate top view (FIG. 12B) and cross section (FIG. 12C) of the soft magnetic plate (1231) shown in FIG. 12A.

In FIG. 12D shows photographic images of the OEL, said OEL obtained using the method shown in FIG. 12A.

In FIG. 13A schematically illustrates a process for producing an Optical Effect Layer (OEL) having two or more nested loop-like, in particular two nested star-shaped, indicia on a substrate (1320), said method comprising using i) a magnetic assembly (1330) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (1310) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (1330) comprises i) a soft magnetic plate (1331) containing a loop-like, in particular a star-shaped cavity (V) and a loop-shaped, in particular star-shaped notch (I); and ii) three dipole magnets (1332a-c) arranged symmetrically within the first loop defined by the loop-shaped cavity (V), with the upper surface of one of said magnets (1332a) being flush with the upper surface of the soft magnetic plate (1331), and two other dipole magnets (1332b-c) are located under the dipole magnet (1332a).

In FIG. 13B, 13C schematically illustrate top view (FIG. 13B) and cross section (FIG. 13C) of the soft magnetic plate (1331) shown in FIG. 13A.

In FIG. 13D are photographic images of the OEL, said OEL obtained using the method shown in FIG. 13A.

In FIG. 14A schematically illustrates a process for producing an Optical Effect Layer (OEL) having two or more nested loop-like, in particular two nested star-shaped, indicia on a substrate (1420), said method comprising using i) a magnetic assembly (1430) oriented along at least a portion of lamellar magnetic or magnetizable pigment particles of a coating layer (1410) made from a coating composition containing said lamellar magnetic or magnetizable pigment particles, wherein the magnetic assembly (1430) comprises i) a soft magnetic plate (1431) containing a loop-like, in particular a star-shaped cavity (V) and a loop-shaped, in particular star-shaped notch (I); and ii) three dipole magnets (1432a-c) arranged symmetrically within the first loop defined by the loop-shaped cavity (V), with the upper surface of one of said magnets (1432a) being flush with the upper surface of the soft magnetic plate (1331), and three other dipole magnets (1432b-d) are located below the dipole magnet (1432a).

In FIG. 14B, 14C schematically illustrate top view (FIG. 14B) and cross section

- 6 040912 (FIG. 14C) of the soft magnetic plate (1431) shown in FIG. 14A.

In FIG. 14D are photographic images of the OEL, with said OEL obtained using the method shown in FIG. 14A.

Detailed description

Definitions.

To interpret the meaning of the terms discussed in the description and set forth in the claims, the following definitions should be used.

In the context of this document, the singular form of an object indicates one or more objects, and does not necessarily limit the object to a single number.

In the context of this document, the term at least means one or more than one, such as one, or two, or three.

In the context of this document, the term approximately means that the specified quantity or value may have a specific defined value or some other value adjacent to it. In general, the term approximately, denoting a specific value, is intended to mean a range within ±5% of the value. As one example, the phrase approximately 100 means the range 100±5, i. e. a range of 95 to 105. In general, when using the term approximately, similar results or effects according to the present invention can be expected to be obtained in a range within ±5% of the indicated value.

In the context of this document, the term and/or means that either all or only one of the elements of the specified group may be present. For example, A and/or B would mean only A, or only B, or both A and B. In the case of only A, the term also covers the possibility of the absence of B, i.e. only A, not B.

The term containing in the context of this document is non-exclusive and subject to change. Thus, for example, a coating composition containing compound A may contain compounds other than A. However, the term comprising also encompasses, as does its specific embodiment, the more restrictive meanings of consisting essentially of and consisting of, so that, for example, a moisturizing solution containing A, B, and optionally C can also (mostly) consist of A and B or (mostly) consist of A, B and C.

The term optical effect layer (OEL) in the context of this document means a coating or layer that contains oriented lamellar magnetic or magnetizable pigment particles and a binder, while said lamellar magnetic or magnetizable pigment particles are oriented by a magnetic field, while oriented lamellar magnetic or magnetizable particles the pigments are fixed/immobilized in their orientation and position (ie after hardening/curing) to form a magnetically induced image.

The term magnetic axis refers to the theoretical line connecting the respective north and south poles of a magnet and passing through said poles. This term does not include any particular magnetic direction.

The term magnetic direction refers to the direction of the magnetic field vector along the magnetic field line extending from the north pole on the outside of the magnet to the south pole (see Handbook of Physics, Springer, 2002, pp. 463-464).

The term coating composition refers to any composition that is capable of forming an optical effect layer (OEL) on a solid substrate and that can be applied preferably, but not exclusively, by printing. The coating composition contains the lamellar magnetic or magnetizable pigment particles described herein and the binder described herein.

In the context of this document, the term wet refers to a coating layer that is not yet cured, such as a coating in which lamellar magnetic or magnetizable pigment particles can still change their positions and orientations under the influence of external forces acting on them.

In the context of this document, the term indicia will refer to intermittent layers such as patterns, including, without limitation, symbols, alphanumeric characters, ornaments, letters, words, numbers, logos, and graphics.

The term curing is used to refer to a process in which there is an increase in the viscosity of the coating composition in a first physical state that is not yet cured (i.e., wet) into a second physical state, i.e. a hardened or solid state in which lamellar magnetic or magnetizable pigment particles are fixed/immobilized in their current positions and orientations and can no longer move or rotate.

The term security document refers to a document that is usually protected from forgery or falsification by at least one security feature. Examples of secure documents include, without limitation, valuable documents and valuable commercial items.

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The term security feature is used to refer to an image, drawing or graphic element that can be used for authentication purposes.

When the present description relates to preferred embodiments/features, combinations of these preferred embodiments/features should also be considered as disclosed as long as the given combination of preferred embodiments/features is technically relevant.

The present invention provides a method for producing an optical effect layer (OEL) having two or more nested indicia. The term nested characters is used to refer to an arrangement of characters each providing an optical effect or optical impression of the character, nested meaning that one or more characters are surrounded by another one or more characters. Preferably, the two or more nested indicia thus obtained are two or more looped indicia, and more preferably, said nested looped indicia are concentric, where the outer one or more looped indicia completely surround the inner one or more looped indicia without crossing each other. An optical effect layer (OEL) having two or more nested loop-shaped indicia, preferably two or more loop-shaped indicia, refers to a layer in which the orientation of the lamellar magnetic or magnetizable pigment particles described herein within the OEL allows said indicia to be observed.

The two or more nested characters may take any form, including, but not limited to, symbols, alphanumeric characters, ornaments, letters, words, numbers, logos, and graphics. The two or more nested loop-shaped characters may take any form, including, but not limited to, symbols, alphanumeric characters, ornaments, letters, words, numbers, logos, and loop-shaped graphics. Two or more nested characters and two or more nested loop-shaped characters may have the same shape (for example, in the case of two characters, for example, two circles, two rectangles, two triangles, two hexagons, etc.) or may have a different shape .

As mentioned herein, the two or more nested characters may take any form, including, without limitation, symbols, alphanumeric characters, ornaments, letters, words, numbers, logos, and graphics. The one or more loop-shaped indicia may be round, oval, ellipsoidal, triangular, square, rectangular, or any polygonal shape. Examples of loop shapes include ring or circle, rectangle or square (with or without rounded corners), triangle (with or without rounded corners), (regular or irregular) pentagon (with or without rounded corners), (regular or irregular) hexagon (with or without rounded corners), (regular or irregular) heptagon (with or without rounded corners), (regular or irregular) octagon (with or without rounded corners), any polygonal shape (with or without rounded corners), heart, star, moon etc.

The present invention provides a process for producing an optical effect layer (OEL) having two or more nested indicia, in particular two or more nested loop-like indicia, in a not yet hardened (i.e. wet or liquid) coating layer made from a composition for coating containing lamellar magnetic or magnetizable pigment particles and a binder material on a substrate by magnetically orienting said pigment particles by exposing the coating layer (x10) to the magnetic field of a magnetic assembly (x30) containing

i) soft magnetic plate (x31) described in this document and containing

a) one or more cavities (V), wherein each of said one or more cavities defines a sign, preferably a loop-shaped sign, and

b) one or more notches (I) and/or one or more protrusions (P), wherein each of said one or more notches (I) and/or one or more protrusions (P) forms one or more continuous looped indicia and/or one or more intermittent looped indicia, and ii) one or more dipole magnets (x32) described herein.

The soft magnetic plate (x31) described herein has one or more notches (I) and/or one or more protrusions (P), i. e. The soft magnetic plate (x31) described herein has one or more serrations, or has one or more ridges, or has a combination of one or more serrations (I) and one or more ridges (P).

Each of said one or more notches (I) and/or one or more protrusions (P) forms one or more continuous loop-shaped indicia and/or one or more discontinuous loop-shaped indicia. By continuous looped indicia is meant that said indicia are composed of a single piece having the shape of said indicia, and by discontinuous looped indicia is meant that said indicia are composed of a plurality of pieces forming together looped indicia. In FIG. 1A is a view of a soft magnetic plate (131) containing a cavity (V) and one notch (I) forming a continuous loop-shaped mark (ie star). In FIG. 1B shows a soft magnetic plate (131) containing a cavity (V) and several notches (I) forming an intermittent loop-like sign (ie a star).

Depending on the number of notches (I) and protrusions (P), combinations of one or more continuous and/or one or more discontinuous loop-shaped indicia can be obtained, including without limitation the following embodiments (see Fig. 3A-3D):

the soft magnetic plate (x31) described herein has one notch (I), said one notch (I) forming a continuous loop-like indicia; in other words, the specified soft magnetic plate (x31), described in this document, contains one loop-shaped notch (I) (see Fig. 3A);

the soft magnetic plate (x31) described herein comprises one protrusion (P), said one protrusion (P) forming a continuous loop-like indicia; in other words, the specified soft magnetic plate (x31), described in this document, contains one loop-shaped protrusion (P) (see Fig. 3A);

the soft magnetic plate (x31) described herein comprises two serrations (I), wherein said two serrations (I) either form two continuous looped indicia or form one intermittent looped indicium (see FIG. 3B);

the soft magnetic plate (x31) described herein comprises two protrusions (P), wherein said two protrusions (P) either form two continuous looped indicia or form one discontinuous looped indicium (see FIG. 3B);

the soft magnetic plate (x31) described herein contains 3n serrations (I), where n=1, 2, 3, etc., wherein said 3n serrations (I) either form 3n continuous loop-shaped indicia, or form n intermittent looped characters. For example, the soft magnetic plate (x31) described herein contains three serrations (I) (n=1), wherein said three serrations (I) either form three continuous loop-like indicia or form one discontinuous loop-like indicium (see Fig. Fig. 3C);

the soft magnetic plate (x31) described herein contains 3n protrusions (P), where n=1, 2, 3, etc., while these 3n protrusions (P) either form 3n continuous loop-shaped characters, or form n intermittent looped characters. For example, the soft magnetic plate (x31) described herein has three protrusions (P) (n=1), wherein said three protrusions (P) either form three continuous loop-like indicia or form one discontinuous loop-like indicium (see fig. Fig. 3C);

the soft magnetic plate (x31) described herein contains 4m notches (I), where m=1, 2, 3, etc., wherein said 4m notches (I) either form 4m continuous loop-shaped indicia, form m intermittent loop marks, form m continuous loop marks and m intermittent loop marks, or form 2m continuous loop marks and m intermittent loop marks. For example, the soft magnetic plate (x31) described herein has four serrations (I) (m=1), wherein said four serrations (I) either form four continuous looped indicia, form one intermittent looped indicium, form one continuous a looped mark and one intermittent looped mark, or form two continuous looped marks and two broken looped marks (see Fig. 3D);

the soft magnetic plate (x31) described herein contains 4m protrusions (P), where m=1, 2, 3, etc., wherein said 4m protrusions (P) either form 4m continuous loop-shaped indicia, form m intermittent loop marks, form m continuous loop marks and m intermittent loop marks, or form 2m continuous loop marks and m intermittent loop marks. For example, the soft magnetic plate (x31) described herein has four protrusions (P) (m=1), wherein said protrusions (P) either form four continuous looped indicia, form one intermittent looped indicium, or form one continuous looped indicium. indicia and one intermittent looped indicia, or form two continuous looped indicia and two intermittent looped indicia (see Fig. 3D), as well as any combinations thereof.

The magnetic orientation and position of lamellar magnetic or magnetizable pigment particles is fixed/immobilized by allowing the coating composition to solidify to produce high resolution, bright, dynamic Optical Effect Layers (OELs). Two or more nested indicia, preferably two or more nested loop-shaped indicia, are transferred from the magnetic assembly (x30) to the uncured coating layer (x10) containing lamellar magnetic or magnetizable pigment particles. The present invention provides these methods for producing high resolution individual bright optical effect layers (OELs) having a dynamic appearance on a printed document or article in a simple to implement and highly reliable manner.

The method according to the present invention includes the steps

a) applying to the surface of a substrate (x20) a coating composition containing lamellar magnetic or magnetizable pigment particles and a binder material as described herein to form a coating layer (x10) on said substrate (x20), wherein said composition

- 9 040912 the coating solution is in the first liquid state;

b) exposing the layer (x10) of the coating to the magnetic field of the magnetic assembly (x30) described in this document and containing

i) a soft magnetic plate (x31) described herein and containing one or more cavities (V), as well as one or more notches (I) and / or one or more protrusions (P) described herein, while each of said one or more notches (I) and/or one or more protrusions (P) forms one or more continuous loop marks and/or one or more discontinuous loop marks, and ii) one or more dipole magnets (x32 ) described in this document; And

c) causing the coating composition to solidify into a second state while fixing the lamellar magnetic or magnetizable pigment particles in their adopted positions and orientations.

The method described in this document includes the step

a) applying to the surface of the substrate (x20) described herein, a coating composition containing the lamellar magnetic or magnetizable pigment particles described herein to form a coating layer, said coating composition being in a first physical state, which allows it to be applied as a layer and which is still in an uncured (ie wet) state, while lamellar magnetic or magnetizable pigment particles can move and rotate within the binder material. Since the coating composition described herein is to be provided on the surface of the substrate, it is necessary that the coating composition containing at least the binder material described herein and lamellar magnetic or magnetizable pigment particles be in a form that provides the possibility of processing it on the desired equipment for printing or coating.

Preferably, this step a) is carried out by a printing process, preferably selected from the group consisting of screen printing, rotogravure printing, flexographic printing, inkjet printing and gravure printing (also referred to in the art as copper plate printing and embossed steel die printing). ), more preferably selected from the group consisting of screen printing, rotogravure printing and flexographic printing.

Screen printing (also referred to in the art as silk screen printing) is a stencil process in which ink is transferred to a surface through a stencil supported by a fine fabric mesh of silk, one or more filaments made from synthetic fibers such as, for example, polyamides or polyesters, or with metal threads tautly stretched over a frame made, for example, of wood or metal (eg aluminum or stainless steel). Alternatively, the screen printed mesh may be chemically etched, laser etched, or electroformed with a porous metal foil such as stainless steel foil. The mesh pores are blocked in non-image areas and left open in image areas, the image carrier being called screen mesh. Screen printing can be flat or rotary. Screen printing is further described, for example, in The Printing ink manual, R.H. Leach and R.J. Pierce, Springer Edition, 5th edition, p. 58-62; and in Printing Technology, J.M. Adams and P.A. Dolin, Delmar Thomson Learning, 5th edition, p. 293-328.

Rotary gravure printing (also referred to in the art as gravure printing) is a printing process in which image elements are engraved on the surface of a cylinder. Areas without an image are at a constant baseline. Before printing, the entire printing form (non-printable and printable elements) is covered with ink and filled with ink. The ink is removed from the non-image area with a sponge or knife before printing so that the ink remains only in the cells. The image is transferred from the cells to the substrate under pressure, typically in the range of 2-4 bar, and adhesive forces between the substrate and the paint. The term rotogravure does not cover other gravure printing processes (also referred to in the art as engraved steel die embossing processes or engraved copper plate printing processes) which are based, for example, on different types of inks. More details are provided in the Handbook of print media, Helmut Kipphan, Springer Edition, p. 48; and in The Printing ink manual, R.H. Leach and R.J. Pierce, Springer Edition, 5th edition, p. 42-51.

In flexographic printing, a doctor blade unit is preferably used, preferably a doctor blade, an anilox roller and a plate cylinder. The anilox roll advantageously has small cells, the volume and/or density of which determines the degree of ink application.

The doctor blade is located opposite the anilox roller and simultaneously removes excess ink. The anilox roller transfers the ink to the plate cylinder, which ultimately transfers the ink to the substrate. A specific design can be achieved using a specially designed photopolymer printing plate. Form cylinders can be made of polymeric or elastomeric materials. Resins are primarily used as photopolymer in printing plates and sometimes as a seamless coating on a roll. Photopolymer printing plates are made from photosensitive polymers that cure when exposed to ultraviolet (UV) light. Photopolymer printing plates are cut to the required size and placed in a UV light exposure unit. One side of the printing plate is completely exposed to UV light to cause solidification or curing of the base of the printing plate. Then the printing plate is turned over, the reverse side of the blank is placed on top of the uncured side, and the printing plate is further exposed to UV light. This ensures that the printing plate hardens in the areas of the image. The printing plate is then processed to remove the uncured photopolymer from the non-image areas, which reduces the surface of the printing plate in these non-image areas. After processing, the printing plate is dried and exposed to an additional dose of UV light to cure the entire printing plate. Preparation of printing cylinders for flexography is described in Printing Technology, J. M. Adams and P.A. Dolin, Delmar Thomson Learning, 5th edition, p. 359-360; and in The Printing ink manual, R.H. Leach and R.J. Pierce, Springer Edition, 5th edition, p. 33-42.

The coating composition described herein, as well as the coating layer described herein, contain lamellar magnetic or magnetizable pigment particles. Preferably, the lamellar magnetic or magnetizable pigment particles described herein are present in an amount of from about 5 wt.% to about 40 wt.%, more preferably from about 10 wt.% to about 30 wt.%, with the weight percentage calculated based on the total weight of the coating composition.

Unlike needle-like pigment particles, which can be considered as quasi-one-dimensional particles, lamellar pigment particles are quasi-two-dimensional particles due to the large aspect ratio of their sizes. A lamellar pigment particle can be considered a two-dimensional structure, where the X and Y dimensions are substantially larger than the Z dimension. Lamellar pigment particles are also referred to in the art as flattened particles or flakes. Such pigment particles can be described by a major X-axis corresponding to the longest dimension intersecting the pigment particle, as well as a second Y-axis perpendicular to X and corresponding to the second longest dimension intersecting the pigment particle. In other words, the XY plane generally defines the plane defined by the first and second longest pigment particle sizes, with the Z dimension not taken into account.

The lamellar magnetic or magnetizable pigment particles described herein, due to their non-spherical shape, exhibit anisotropic reflectance to incident electromagnetic radiation, to which the cured/cured binder material is at least partially transparent. In the context of this document, the term anisotropic reflectivity means that the proportion of incident radiation at a first angle reflected by a particle in a certain (view) direction (second angle) depends on the orientation of the particles, i.e. changing the orientation of the particle with respect to the first corner can result in a different amount of reflection in the viewing direction.

In the OELs described herein, the lamellar magnetic or magnetizable pigment particles described herein are dispersed in a coating composition containing a cured binder that fixes the orientation of the lamellar magnetic or magnetizable pigment particles. The binder material is at least in its hardened or solid state (also referred to herein as the second state) at least partially transparent to electromagnetic radiation in the wavelength range of 200 to 2500 nm, i. within the wavelength range commonly referred to as the optical spectrum, which contains the infrared, visible, and UV portions of the electromagnetic spectrum. Accordingly, the particles contained in the binder in its hardened or solid state, as well as their orientation-dependent reflectivity, can be perceived through the binder at some wavelengths within this range. Preferably the cured binder is at least partially transparent to electromagnetic radiation in the wavelength range of 200 to 800 nm, more preferably 400 to 700 nm. As used herein, the term transparent means that the transmission of electromagnetic radiation through the 20 µm layer of cured binder material present in the OEL (not including lamellar magnetic or magnetizable pigment particles, but including all other optional components of the OEL if such components are present) is at least 50%, more preferably at least 60%, even more preferably at least 70% at the considered wavelength(s). This can be determined, for example, by measuring the transmittance of a test piece of the cured binder (not including lamellar magnetic or magnetizable pigment particles) in accordance with well-known test methods, for example according to DIN 5036-3 (1979-11). If the OEL serves as a latent security feature, then technical means will generally be required to detect the (full) optical effect produced by the OEL under appropriate lighting conditions, including

- 11 040912 the selected wavelength in the invisible region; this detection requires that the wavelength of the incident radiation be chosen outside the visible range, for example in the near UV range. In this case, it is preferred that the OEL contains luminescent pigment particles exhibiting luminescence in response to a selected wavelength outside the visible spectrum contained in the incident radiation. The infrared, visible and UV parts of the electromagnetic spectrum correspond approximately to the wavelength ranges 700-2500, 400-700 and 200-400 nm, respectively.

Suitable examples of the lamellar magnetic or magnetizable pigment particles described herein include, without limitation, pigment particles containing a magnetic metal selected from the group consisting of cobalt (Co), iron (Fe), and nickel (Ni); a magnetic alloy of iron, manganese, cobalt, nickel, or a mixture of two or more of them; magnetic oxide of chromium, manganese, cobalt, iron, nickel, or a mixture of two or more of them; or a mixture of two or more of them. The term magnetic in relation to metals, alloys and oxides refers to ferromagnetic or ferrimagnetic metals, alloys and oxides. The magnetic oxides of chromium, manganese, cobalt, iron, nickel, or mixtures of two or more of these, may be pure or mixed oxides. Examples of magnetic oxides include, without limitation, iron oxides such as hematite (Fe ₂ O ₃ ), magnetite (Fe ₃ O4 ) chromium dioxide (CrO ₂ ), magnetic ferrites (MFe ₂ O ₄ ), magnetic spinels (MR2O4 ), magnetic hexaferrites ( MFe ₁₂ O ₁₉ ), magnetic orthoferrites (RFeO ₃ ), magnetic garnets M ₃ R ₂ (AO ₄ ) ₃ , where M is a divalent metal, R is a trivalent metal, and A is a tetravalent metal.

Examples of the lamellar magnetic or magnetizable pigment particles described herein include, without limitation, pigment particles comprising a magnetic layer M made of one or more magnetic metals such as cobalt (Co), iron (Fe), or nickel (Ni); as well as a magnetic alloy of iron, cobalt or nickel, while said magnetic or magnetizable pigment particles can be multilayer structures containing one or more additional layers.

Preferably, the one or more additional layers are A layers independently made of one or more materials selected from the group consisting of metal fluorides such as magnesium fluoride (MgF2), silicon oxide (SiO), silicon dioxide (SiO ₂ ), oxide titanium (TiO ₂ ) and alumina (Al ₂ O ₃ ), more preferably silicon dioxide (SiO ₂ ); or layers B independently made of one or more materials selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective metal alloys, and more preferably selected from the group consisting of aluminum (Al) , chromium (Cr) and nickel (Ni), and even more preferably aluminum (Al); or a combination of one or more layers A, such as the layers described herein above, and one or more layers B, such as the layers described herein above.

Typical examples of lamellar magnetic or magnetizable pigment particles that are multilayer structures described herein above include, without limitation, A/M multilayer structures, A/M/A multilayer structures, A/M/B multilayer structures, A/B multilayer structures. /M/A, A/B/M/B multilayer structures, A/B/M/B/A multilayer structures, W/M multilayer structures, W/O/B multilayer structures, B/A/M/A multilayer structures , B/A/M/B multilayer structures, B/A/M/B/A/ multilayer structures, wherein A layers, M magnetic layers, and B layers are selected from those described herein above.

The coating composition described herein may contain lamellar optically variable magnetic or magnetizable pigment particles and/or lamellar magnetic or magnetizable pigment particles having no optically variable properties. Preferably, at least a portion of the lamellar magnetic or magnetizable pigment particles described herein is formed by lamellar optically variable magnetic or magnetizable pigment particles. In addition to the clear protection afforded by the color-changing property of optically variable magnetic or magnetizable pigment particles, which makes it easy to detect, recognize and/or distinguish an article or document to be protected on which an ink has been applied, a coating composition or coating layer containing optically variable magnetic or The magnetizable pigment particles described herein can also be used as a machine-readable tool for OEL recognition by using the optical properties of optically variable magnetic or magnetizable pigment particles from their possible counterfeits using the naked human senses. Thus, the optical properties of the optically variable magnetic or magnetizable pigment particles can simultaneously be used as a latent or semi-hidden security feature in an authentication process in which the optical (eg, spectral) properties of the pigment particles are analyzed.

The use of plate-like optically variable magnetic or magnetizable pigment particles in coating layers to create OELs increases the value of OELs as a security feature in security document applications, since such materials are intended for printing security documents and are not commercially available indefinitely.

- 12 040912 persons.

As noted above, preferably at least a portion of the lamellar magnetic or magnetizable pigment particles is formed by lamellar optically variable magnetic or magnetizable pigment particles. They are more preferably selected from the group consisting of magnetic thin film interference pigment particles, magnetic cholesteric liquid crystal pigment particles, interference coated pigment particles containing magnetic material, and mixtures of two or more of them.

Magnetic thin film interference pigment particles are known to those skilled in the art and are disclosed, for example, in US 4,838,648; WO 2002/073250 A2; EP 0686675 B1; WO 2003/000801 A2; US 6838166; WO 2007/131833 Al; EP 2402401 A1 and in the documents referred to therein. Preferably, the magnetic thin film interference pigment particles are pigment particles having a five-layer Fabry-Perot structure and/or pigment particles having a six-layer Fabry-Perot structure and/or pigment particles having a seven-layer Fabry-Perot structure.

Preferred five-layer Fabry-Perot structures consist of absorber/dielectric/reflector/dielectric/absorber multilayer structures, wherein the reflector and/or absorber is also a magnetic layer, preferably the reflector and/or absorber is a magnetic layer containing nickel, iron and/ or cobalt and/or a magnetic alloy containing nickel, iron and/or cobalt, and/or a magnetic oxide containing nickel (Ni), iron (Fe) and/or cobalt (Co).

Preferred six-layer Fabry-Perot structures consist of absorber/dielectric/reflector/magnetic material/dielectric/absorber multilayer structures.

Preferred seven-layer Fabry-Perot structures consist of absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber multilayer structures such as those described in US 4,838,648.

Preferably, the reflector layers described herein are independently made from one or more materials selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective metal alloys, more preferably selected from the group consisting of aluminum (Al), silver (Ag), copper (Cu), gold (Au), platinum (Pt), tin (Sn), titanium (Ti), palladium (Pd), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni) and their alloys, even more preferably selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni) and their alloys, and even more preferably aluminum (Al). Preferably the dielectric layers are independently made from one or more materials selected from the group consisting of metal fluorides such as magnesium fluoride (MgF2), aluminum fluoride (AlF ₃ ), cerium fluoride (CeF ₃ ), lanthanum fluoride (LaF ₃ ), aluminum fluorides sodium (for example, Na ₃ AlF ₆ ), neodymium fluoride (NdF ₃ ), samarium fluoride (SmF ₃ ), barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ), lithium fluoride (LiF), as well as metal oxides, such as silicon oxide (SiO), silicon dioxide (SiO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), more preferably selected from the group consisting of magnesium fluoride (MgF ₂ ) and silicon dioxide (SiO ₂ ), and even more preferably magnesium fluoride (MgF ₂ ). Preferably, the absorber layers are independently made from one or more materials selected from the group consisting of aluminum (Al), silver (Ag), copper (Cu), palladium (Pd), platinum (Pt), titanium (Ti), vanadium (V ), iron (Fe), tin (Sn), tungsten (W), molybdenum (Mo), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni), oxides of these metals, sulfides of these metals, carbides of these metals, as well as alloys of these metals, more preferably selected from the group consisting of chromium (Cr), nickel (Ni), oxides of these metals and alloys of these metals, and even more preferably selected from the group consisting of chromium (Cr) , nickel (Ni) and alloys of these metals. Preferably the magnetic layer contains nickel (Ni), iron (Fe) and/or cobalt (Co); and/or a magnetic alloy containing nickel (Ni), iron (Fe) and/or cobalt (Co); and/or a magnetic oxide containing nickel (Ni), iron (Fe) and/or cobalt (Co). If the magnetic thin film interference pigment particles comprising a seven-layer Fabry-Perot structure are preferred, it is particularly preferred that the magnetic thin-film interference particles of a pigment comprise a seven-layer Fabry-Perot absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber structure consisting of multilayer structure Cr/MgF ₂ /Al/Ni/Al/MgF ₂ /Cr.

The magnetic thin film interference pigment particles described herein may be multilayer pigment particles that are considered safe for human health and the environment and are based on, for example, five-layer Fabry-Perot structures, six-layer Fabry-Perot structures, and seven-layer Fabry-Perot structures. Feather, wherein said pigment particles contain one or more magnetic layers containing a magnetic alloy having a substantially nickel-free composition comprising from about 40 wt.% to about 90 wt.% iron, from about 10 wt.% to about 50 wt. % chromium and from about 0 wt.% to about 30 wt.% aluminum. Typical examples of multilayer pigment particles that are considered safe for human health and the environment can be found in the document

- 13 040912

EP 2402401 A1, the contents of which are incorporated herein by reference in their entirety.

The magnetic thin film interference pigment particles described herein are typically produced by the conventional technique of depositing various desired layers onto a web. After the required number of layers have been deposited, for example by physical vapor deposition (PVD), chemical vapor deposition (CVD), or electroplating, the stack of layers is removed from the web either by dissolving the release layer in a suitable solvent or by stripping material from the web. The material thus obtained is then broken into flakes, which must be further processed by crushing, grinding (such as, for example, jet milling processes) or any suitable method designed to obtain pigment particles of the desired size. The resulting product consists of flat flakes with torn edges, irregular shapes and various size ratios. Further information on the preparation of suitable magnetic thin film interference pigment particles can be found, for example, in EP 1710756 A1 and EP 1666546 A1, the contents of which are incorporated herein by reference.

Suitable magnetic cholesteric liquid crystal pigment particles exhibiting optically variable characteristics include, without limitation, magnetic single layer cholesteric liquid crystal pigment particles and magnetic multilayer cholesteric liquid crystal pigment particles. Such pigment particles are disclosed, for example, in WO 2006/063926 A1, US 6582781 and US 6531221. WO 2006/063926 A1 discloses monolayers and pigment particles obtained from them with increased gloss and color change properties, as well as additional special properties. , such as magnetization. The disclosed monolayers and pigment particles, which are obtained from them by grinding said monolayers, include a three-dimensionally cross-linked cholesteric liquid crystal mixture and magnetic nanoparticles. US 6,582,781 and US 6,410,130 disclose lamellar cholesteric multilayer pigment particles that contain the sequence A1/B/A ² , where A ¹ and A ² may be identical or different and each contains at least one cholesteric layer and B is an intermediate layer that absorbs all or some of the light transmitted by layers A ¹ and A ² and provides magnetic properties to the specified intermediate layer. US 6,531,221 discloses lamellar cholesteric multilayer pigment particles containing the sequence A/B and optionally C, where A and C are absorbent layers containing pigment particles imparting magnetic properties to them, and B is a cholesteric layer.

Suitable interference coated pigments containing one or more magnetic materials include, without limitation, structures consisting of a substrate selected from the group consisting of a core coated with one or more layers, wherein at least one of the core or one or more layers has magnetic properties. For example, suitable interference coated pigments comprise a core made of a magnetic material such as described herein above, said core being coated with one or more layers made of one or more metal oxides, or having a structure consisting of a core, made of synthetic or natural mica, layered silicates (eg talc, kaolin and sericite), glasses (eg borosilicates), silicon dioxide (SiO ₂ ), aluminum oxides (Al ₂ O ₃ ), titanium oxides (TiO ₂ ), graphites and mixtures of two or more of them. Moreover, one or more additional layers, such as coloring layers, may be present.

The surface of the magnetic or magnetizable pigment particles described herein may be treated to protect them from any damage that may occur in the coating composition and coating layer and/or to facilitate their incorporation into said coating composition and coating layer; typically, anti-corrosion materials and/or wetting agents can be used.

In addition, after applying the coating composition described herein to the surface of the substrate (x20) described herein to form the coating layer (x10) (step a)), the coating layer (x10) is subjected to (step b)) exposed to the magnetic field of a magnetic assembly (x30) containing a soft magnetic plate (x31) containing one or more cavities (V), preferably one or more loop-shaped cavities (V), described herein, for receiving one or more dipole magnets (x32 ) described herein and one or more notches (I) and/or one or more protrusions (P) forming one or more continuous loop-shaped indicia and/or one or more discontinuous loop-shaped indicia; and one or more dipole magnets (x32) described herein.

After or partly simultaneously, preferably partly simultaneously, with the steps for orienting the lamellar magnetic or magnetizable pigment particles described herein (step b)), the orientation of the lamellar magnetic or magnetizable pigment particles is fixed or immobilized (step c)). Thus, it should be noted that the coating composition must have a first liquid state in which the coating composition is not yet hardened and moist or soft enough that the lamellar magnetic or magnetizable pigment particles dispersed in the coating composition can freely move, rotate and/or orient when subjected to a magnetic field, as well as a second solidified (e.g., solid or solid-like) state in which the lamellar magnetic or magnetizable pigment particles are fixed or immobilized in their respective positions and orientations.

Such first and second states are preferably created using a specific type of coating composition. For example, the components of the coating composition, other than lamellar magnetic or magnetizable pigment particles, may take the form of an ink or coating composition, such as those used for security purposes, such as for printing banknotes. The aforementioned first and second states can be achieved by using a material that exhibits an increase in viscosity in response to an impact such as a change in temperature or exposure to electromagnetic radiation. Thus, if the liquid binder is solidified or solidified, said binder is converted to the second state, i.e. a hardened or solid state in which lamellar magnetic or magnetizable pigment particles are fixed in their current positions and orientations and can no longer move or rotate within the binder. As known to those skilled in the art, the ingredients contained in an ink or coating composition to be applied to a surface, such as a substrate, and the physical properties of said ink or coating composition must meet the requirements of the process used to transfer the ink or coating composition to the substrate. substrate surface. Therefore, the binder contained in the coating composition described herein is generally selected from binders known in the art, and the choice depends on the coating or printing process used to apply the ink or coating composition, as well as selected curing process.

The OEL described herein contains lamellar magnetic or magnetizable pigment particles which, due to their shape, are characterized by non-isotropic reflectivity. The lamellar magnetic or magnetizable pigment particles are dispersed in a binder material that is at least partially transparent to electromagnetic radiation of one or more wavelengths in the range of 200 to 2500 nm.

The curing step described herein (step c)) may be of a purely physical nature, for example in cases where the coating composition contains a polymeric binder and solvent and is applied at high temperatures. The lamellar magnetic or magnetizable pigment particles are then oriented at high temperature by applying a magnetic field and the solvent is evaporated, followed by cooling of the coating composition. In this way, the coating composition is cured and the orientation of the pigment particles is fixed.

Alternatively, and preferably, curing of the coating composition involves a chemical reaction, for example by curing, which is not reversible by a simple increase in temperature (for example, up to 80°C) that may occur during normal use of the document to be protected. The terms cure or curable refer to processes involving the chemical reaction, crosslinking or polymerization of at least one component in the applied coating composition such that it is converted into a polymeric material having a higher molecular weight than the starting materials. Preferably, curing causes the formation of a stable three-dimensional polymer network. Such curing is typically caused by applying an external force to the coating composition (i) after it has been applied to the substrate (step a)) and (ii) after or partly simultaneously with the orientation of at least a portion of the lamellar magnetic or magnetizable pigment particles (step b)) . Preferably, the curing (step c)) of the coating composition described herein is carried out partly simultaneously with the orientation of at least a portion of the lamellar magnetic or magnetizable pigment particles (step c)). Thus, preferably the coating composition is selected from the group consisting of radiation-curable compositions, heat-curable compositions, oxidation-curable compositions, and combinations thereof. Particularly preferred are coating compositions selected from the group consisting of radiation curable compositions. Radiation curing, in particular UV-visible radiation curing, advantageously leads to an immediate increase in the viscosity of the coating composition after exposure to radiation, thus preventing any further movement of the pigment particles and consequently any loss of information after the step magnetic orientation. Preferably, the curing step (step d)) is carried out under the influence of UV-visible radiation (i.e. UV-visible curing) or under the influence of electron beam radiation (i.e. electron-beam curing). -beam radiation), more preferably under the influence of radiation in the UV and visible regions.

- 15 040912

Thus, suitable coating compositions according to the present invention include radiation-curable compositions that can be cured by exposure to UV-visible radiation (hereinafter referred to herein as UV-visible radiation-curable) or with electron beam radiation (hereinafter referred to as EL). According to one particularly preferred embodiment of the present invention, the coating composition described herein is a UV-visible curable coating composition. Curing under the influence of radiation in the UV and visible regions advantageously allows very fast curing processes and, therefore, significantly reduces the time to obtain the OEL described in this document, documents and products, as well as documents containing the specified OEL.

Preferably, the UV-visible curable coating composition comprises one or more compounds selected from the group consisting of radical curable compounds and cationic curable compounds. The UV-visible radiation-curable coating composition described herein may be a hybrid system and contain a mixture of one or more cationically curable compounds and one or more radically curable compounds. Cationically curable compounds are cured by cationic mechanisms, typically involving radiation activation of one or more photoinitiators that release cationic species such as acids, which in turn initiate curing so as to react and/or crosslink the monomers and/ or oligomers to allow the coating composition to harden in this way. Radical curable compounds are cured by free radical mechanisms, typically involving radiation activation of one or more photoinitiators, thereby generating radicals which in turn initiate polymerization to cause the coating composition to cure in this way. Depending on the monomers, oligomers, or prepolymers used to form the binder contained in the UV-Vis curable coating compositions described herein, various photoinitiators may be used. Suitable examples of free radical photoinitiators are known to those skilled in the art and include, without limitation, acetophenones, benzophenones, benzyl dimethyl ketals, alpha-aminoketones, alpha-hydroxy ketones, phosphine oxides, and phosphine oxide derivatives, as well as mixtures of two or more of these. Suitable examples of cationic photoinitiators are known to those skilled in the art and include, without limitation, onium salts such as organic iodonium salts (eg, diaryloiodonium salts), oxonium (eg, triaryloxonium salts), and sulfonium salts (eg, triarylsulfonium salts), as well as mixtures of the two or more of them. Other examples of photoinitiators used can be found in standard scientific textbooks. In order to achieve effective curing, it may also be advantageous to include the sensitizer together with one or more photoinitiators. Representative examples of suitable photosensitizers include, but are not limited to, isopropylthioxanthone (ITX), 1-chloro-2-propoxythioxanthone (CPTX), 2-chlorothioxanthone (CTX), and 2,4-diethylthioxanthone (DETX), as well as mixtures of two or more of these. The one or more photoinitiators contained in the UV-visible curable coating compositions are preferably present in a total amount of from about 0.1 wt.% to about 20 wt.%, more preferably from about 1 wt.% to approximately 15 wt.%, while the weight percentage is calculated based on cured under the influence of radiation in the UV and visible regions of the coating compositions.

Alternatively, a polymeric thermoplastic bonding material or a thermosetting material can be used. Unlike thermosets, thermoplastic resins can re-melt and solidify when heated and cooled without undergoing any significant change in properties. Typical examples of a thermoplastic resin or polymer include, but are not limited to, polyamides, polyesters, polyacetals, polyolefins, styrenic polymers, polycarbonates, polyarylates, polyimides, polyether ether ketones (PEEK), polyether ketone ketones (PEKK), polyphenylene-based resins (e.g., polyphenylene ethers, polyphenylene oxides, sulfides polyphenylene), polysulfones and mixtures of two or more of them.

The coating composition described herein may further comprise one or more coloring components selected from the group consisting of organic pigment particles, inorganic pigment particles, as well as organic colorants and/or one or more additives. The latter include, without limitation, compounds and materials that are used to adjust the physical, rheological, and chemical parameters of the coating composition, such as viscosity (e.g., solvents, thickeners, and surfactants), consistency (e.g., anti-settling agents, fillers, and plasticizers), foaming properties (for example, antifoam agents), lubricating properties (waxes, oils), UV resistance (photostabilizers), adhesive properties, antistatic properties, storage stability (polymerization inhibitors), etc. The additives described herein may be present in the coating composition in amounts and forms known in the art, including so-called nanomaterials, in which at least one of the additive sizes is in the range

1-1000 nm.

The coating composition described herein may additionally contain one or more additives, including, without limitation, compounds and materials that are used to adjust the physical, rheological and chemical parameters of the composition, such as viscosity (for example, solvents and surfactants), consistency (eg anti-settling agents, fillers and plasticizers), foaming properties (eg antifoam agents), lubricity properties (waxes), reactivity and UV resistance (photosensitizers and photostabilizers) and adhesion properties, etc. The additives described herein may be present in the coating compositions described herein in amounts and forms known in the art, including in the form of so-called nanomaterials, in which at least one of the particle sizes is in range 1-1000 nm.

The coating composition described herein may further comprise one or more marker substances or markers and/or one or more machine-readable materials selected from the group consisting of magnetic materials (other than the magnetic or magnetizable pigment particles described herein), luminescent materials, electrically conductive materials and infrared absorbing materials. As used herein, the term machine-readable material refers to material that exhibits at least one distinctive property that is detectable by a device or machine and that may be contained in a coating to provide a method for authenticating said coating, or an article containing said coating, through the use of specific equipment to its detection and/or authentication.

The coating compositions described herein can be prepared by dispersing or mixing the magnetic or magnetizable pigment particles described herein and in the presence of one or more additives in the presence of the binder material described herein, thereby forming liquid compositions. . If present, one or more photoinitiators may be added to the composition either during the dispersion or mixing step of all other ingredients, or may be added at a later stage, ie. after formation of the liquid coating composition.

As described herein, the coating layer (x10) is exposed to the magnetic field of the magnetic assembly (x30) described herein.

The magnetic assembly (x30) described herein comprises the soft magnetic plate (x31) described herein, wherein said soft magnetic plate (x31) is made from one or more soft magnetic metals, alloys, or compounds with high magnetic permeability, or made of a composite material containing from about 25 wt.% to about 95 wt.% soft magnetic particles dispersed in a non-magnetic material, while the weight percentage is calculated based on the total weight of the magnetic plate (x31), contains one or more cavities (V ), preferably one or more loop-shaped cavities (V) described herein, for receiving one or more dipole magnets (x32) described herein, and contains one or more notches (I) and/or one or more protrusions ( P) described herein, wherein each of said one or more barbs (I) and/or one or more protrusions (P) forms one or more more continuous loop marks and/or one or more intermittent loop marks.

The soft magnetic plate (x31) described herein contains one or more cavities (V) described herein. If the soft magnetic plate (x31) described herein contains multiple cavities (V), said cavities (V) may have the same shape or may have different shapes. If the soft magnetic plate (x31) described herein contains multiple cavities (V), each of said multiple cavities (V) may be surrounded by one or more continuous loop-shaped indicia and/or each of said multiple cavities (V) surrounded one or more intermittent loop-like characters. Alternatively, two or more of said multiple cavities (V) may be surrounded by one or more continuous loop-like indicia and/or each of said multiple cavities (V) may be surrounded by one or more discontinuous loop-shaped indicia.

According to one embodiment, the soft magnetic plate (x31) described herein comprises one or more cavities (V) whose shape is not loop-shaped and one or more loop-shaped cavities (V) described herein.

According to another embodiment, the soft magnetic plate (x31) described herein comprises one or more loop-shaped cavities (V). If the soft magnetic plate (x31) described herein contains several loop-shaped cavities (V), these loop-shaped cavities (V) may have the same shape or may have a different shape.

- 17 040912

In FIG. 1A, 1B are schematic views of a soft magnetic plate (131) of thickness (T) containing a cavity (V), in particular a loop-shaped cavity (V) (the round cavity in FIGS. 1A, 1B). The term cavity means in the context of the present invention a recess in the soft magnetic plate (see Fig. 2A), or an opening or channel that passes through the soft magnetic plate (see Fig. 2B) and connects both sides of it.

In FIG. 2A, 2B are schematic cross sections of a soft magnetic plate (231) containing a cavity (V), said cavity (V) having a depth (D). According to one embodiment, and as shown, for example, in FIG. 2A, the soft magnetic plate (231) described herein contains one or more cavities (V) less than 100% deep, i. one or more cavities (V) are presented as depressions. According to another embodiment, and as shown, for example, in FIG. 2B, the soft magnetic plate (331) described herein contains one or more cavities (V) 100% deep, i. e. one or more cavities (V) are in the form of holes or channels that pass through the soft magnetic plate (331) and connect both sides of it.

One or more cavities (V), preferably one or more loop-shaped cavities (V), of the soft magnetic plate (x31) described herein are configured to receive one or more dipole magnets (x32) described herein, i.e. e. they allow one or more of the dipole magnets (x32) described herein to be incorporated into said soft magnetic plate (x31).

According to one embodiment, the soft magnetic plate (x31) described herein comprises one or more cavities (V), preferably one or more loop-shaped cavities (V) described herein, said one or more cavities, in particular cavities 100% deep may be filled with a non-magnetic material including a polymeric binder such as described hereinafter and optional fillers. The soft magnetic plate (x31) described herein, containing one or more cavities (V), preferably one or more loop-shaped cavities (V) described herein, may be located on a non-magnetic holder or spacer (x33), such as described later in this document.

In addition to one or more cavities (V), preferably one or more loop-shaped cavities (V) described herein and as shown, for example, in FIG. 1A, 1B and 3A-6C, the soft magnetic plate (x31) described herein further comprises one or more notches (I) and/or one or more protrusions (P), each of said one or more notches (I) and/or one or more protrusions (P) form one or more continuous loop-like characters and/or one or more intermittent loop-like characters described herein. As shown, for example, in FIG. 1A, 1B and 3A-6C and as described above, one or more cavities (V) described herein are surrounded by one or more continuous loop-shaped indicia and/or one or more cavities (V) are surrounded by one or more discontinuous loop-shaped indicia, formed by one or more notches (I) and/or one or more protrusions (P) described in this document.

In one embodiment, one or more of the cavities (V) described herein are loop-shaped cavities (V), and said one or more loop-shaped cavities (V) are surrounded and nested by one or more continuous loop-shaped indicia and/or one or more discontinuous loop-shaped characters formed by one or more notches (I) and/or one or more protrusions (P) described in this document. In other words, the loop(s) defined by one or more loop-like cavities (V) and the loop(s) defined by one or more barbs (I) and/or one or more projections (P) are nested , wherein the outer loop, defined by one or more continuous loop-like indicia and/or one or more discontinuous loop-like indicia formed by one or more notches (I) and/or one or more protrusions (P), surrounds the inner loop, defined by one or more loop-shaped cavities (V).

According to one embodiment, and as shown, for example, in FIG. 4A, the soft magnetic plate (x31) described herein has one or more barbs (I). As shown, for example, in FIG. 4A, the soft magnetic plate (x31) described herein has one or more barbs (I) (eg, one loop bar (I) or two bars (I)). As shown in FIG. 4A, the thickness (T) of the soft magnetic plate (441) containing one or more loop-shaped cavities (V) and one or more serrations (I) refers to the thickness of the regions of the soft magnetic wafer (431) in which one or more serrations are missing ( I) and one or more cavities (V) are missing (i.e., the thickness of the non-notched areas of the soft magnetic plate (431)).

According to another embodiment, and as shown, for example, in FIG. 4B, the soft magnetic plate (x31) described herein includes one or more protrusions (P).

The term ridge refers to the positive relief that emerges from the surface. In FIG. 4B is a schematic cross-sectional view of a soft magnetic plate (431) containing one or more protrusions (P) (eg, one looped protrusion (P) or two protrusions (P)). As shown in FIG. 4B, the soft magnetic plate (431) has a thickness (T) and said protrusion (P) has a height (H). The thickness (T) of the soft magnetic plate (x31) containing one or more protrusions (P) refers to the total thickness of the soft magnetic plate (x31), i.e. a combination of the height (H) of the highest protrusion of the one or more protrusions (P) and the thickness of the areas of the soft magnetic plate (x31) that lack said one or more protrusions (P).

According to another embodiment, the soft magnetic plate (x31) described herein comprises one or more notches (I) and one or more protrusions (P).

One or more areas missing one or more of the protrusions (P) of the soft magnetic plate (x31) described herein may be filled with a non-magnetic material including a polymeric binder such as those described herein above and optionally fillers. The soft magnetic plate (x31) described herein, containing one or more protrusions (P), may be located on a non-magnetic holder or spacer (x33), such as described hereinafter.

In addition to the soft magnetic plate (x31) described herein, the magnetic assembly (x30) described herein comprises one or more dipole magnets (x32) described herein, wherein the magnetic axis of all of said one or more dipole magnets magnets (x32) is substantially perpendicular to the surface of the substrate (x20) (also substantially perpendicular to the surface of the soft magnetic plate (x31)) and all of said one or more dipole magnets (x32) have the same magnetic direction.

One or more located dipole magnets (x32) are preferably independently made of high coercive force materials (also referred to as strong magnetic materials). Suitable high coercivity materials are materials having a coercive force field value of at least 50 kA/m, preferably at least 200 kA/m, more preferably at least 1000 kA/m, even more preferably at least 1700 kA / m. They are preferably made from one or more sintered or polymer bonded magnetic materials selected from the group consisting of alnico, such as, for example, alnico 5 (R1-1-1), alnico 5 DG (R1-1-2), alnico 5- 7 (R1-1-3), alnico 6 (R1-1-4), alnico 8 (R1-1-5), alnico 8 HC (R1-1-7) and alnico 9 (R1-1-6); hexaferrites according to the formula MFe ₁₂ O ₁₉ , (for example, strontium hexaferrite (SrOx6Fe ₂ O ₃ ) or barium hexaferrites (ВаОχ6Fe ₂ O ₃ )), magnetically hard ferrites according to the formula MFe ₂ O ₄ (for example, as cobalt ferrite (CoFe ₂ O ₄ ) or magnetite (Fe ₃ O ₄ )), where M is a divalent metal ion), ceramic 8 (SI-1-5); rare earth magnetic materials selected from the group consisting of RECo ₅ (where RE=Sm or Pr), RE2TM17 (where RE=Sm, TM=Fe, Cu, Co, Zr, Hf), RE2TM14B (where RE=Nd, Pr, Dy , TM=Fe, Co); anisotropic alloys Fe, Cr, Co; materials selected from PtCo, MnAlC, RE cobalt 5/16, RE cobalt 14 consisting of Nd ₂ Fe ₁₄ B and SmCo ₅ . Particularly preferred are easily processed permanent magnet composites containing a permanent magnet filler such as strontium hexaferrite (SrFe ₁₂ O ₁₉ ) or neodymium-iron-boron (Nd ₂ Fe ₁₄ B) powder in a plastic or rubber matrix.

The soft magnetic plate (x31) described herein contains one or more cavities (V), preferably one or more loop-shaped cavities (V) described herein, each of said one or more cavities (V) allowing one or more dipole magnets (x32) described herein into said soft magnetic plate (x31).

One or more dipole magnets (x32) described herein may be located symmetrically or asymmetrically within one or more cavities (V) described herein.

As shown, for example, in FIG. 9A-9D, multiple dipole magnets (x32), in particular four dipole magnets (x32), can be used instead of one dipole magnet. (x32). When multiple dipole magnets (x32) are used, said plurality of dipole magnets (x32) are preferably stacked on top of each other. These multiple dipole magnets (x32) may have the same diameter or may have different diameters. These multiple dipole magnets (x32) may have the same thickness or may have different thicknesses.

In FIG. 4A, 5A, 5B and 6A are schematic cross sections of a soft magnetic plate (x31) containing a cavity (V) less than 100% deep, i. one or more cavities (V), preferably one or more loop-shaped cavities (s) described herein, are presented in the form of recesses, while the specified soft magnetic plate (x31) contains one or more notches (I) (for example, one loop-shaped barb (I) or two barbs (I); Fig. 4A and 5A, 5B) or one or more protrusions (P) (for example, one loop-shaped protrusion (P) or two protrusions (P); Fig. 4B and 6A).

In FIG. 5C-5F and 6B, 6C are schematic cross sections of a soft magnetic plate (x31) containing a cavity (V) 100% deep, i. one or more cavities (V), preferably one or more loop-shaped cavities (s), described in this document, are presented in the form of holes or channels, while the specified soft magnetic plate (x31) contains one or more serrations (I ) (for example, one looped barb (I) or two barbs (I); Fig. 5C-5F) or one or more protrusions (P) (for example, one looped protrusion (P) or two protrusions (P); Fig. 6B , 6C).

The soft magnetic plate (x31) described herein is characterized by a top surface, said top surface consisting of a surface on which a substrate (x20) bearing a coating layer (x10) will be placed, in direct contact or in indirect contact. As shown, for example, in FIG. 4A and 5A-5D, the top surface (TS, dotted line) of the soft magnetic wafer (x31) containing one or more notches (I) described herein consists of the top surface of the wafer itself. As shown, for example, in FIG. 4B and 6A, 6B, the top surface (TS, dotted line) of the soft magnetic plate (x31) containing one or more protrusions (P) described herein consists of the top surface of one or more protrusions (P). The upper surface of the soft magnetic plate (x31) containing one or more notches (I) and one or more protrusions (P) consists of the upper surface of one or more protrusions (P).

According to one embodiment, the magnetic assembly (x30) described herein comprises

i) a soft magnetic plate (x31) as described herein, comprising one or more cavities (V), preferably one or more loop-shaped cavities (V) as described herein, and one or more barbs (I) as described herein. document, and ii) one or more dipole magnets (x32) described herein, wherein the top surface of one or more dipole magnets (x32) is either flush with the top surface of the soft magnetic plate (x31) (see, for example, FIG. 5A and 5C, 5D), or located below the upper surface of the soft magnetic plate (x31) (see, for example, Fig. 5B and 5E, 5F), preferably with the upper surface of one or more dipole magnets (x32) located flush with the top surface of the soft magnetic plate (x31).

According to one embodiment, the magnetic assembly (x30) described herein comprises

i) a soft magnetic plate (x31) described herein, containing one or more cavities (V), preferably one or more loop-shaped cavities (s) described in this document, and one or more protrusions (P) described in this document. document, and ii) one or more dipole magnets (x32), wherein the top surface of the one or more dipole magnets (x32) is preferably flush with the top surface of the soft magnetic plate (x31) (see, for example, Figs. 6A-6C) .

According to one embodiment, the magnetic assembly (x30) described herein comprises

i) a soft magnetic plate (x31) described herein, comprising one or more cavities (V), preferably one or more loop-shaped cavities (s) described herein, one or more barbs (I) described herein , and one or more protrusions (P) described herein, and ii) one or more dipole magnets (x32), while the top surface of one or more dipole magnets (x32) is preferably flush with the top surface of the soft magnetic plate (x31 ).

According to one embodiment and as shown in FIG. 4A and 5A, 5B, the magnetic assembly (x30) described in this document contains

i) a soft magnetic plate (x31) comprising one or more cavities (V), preferably one or more loop-shaped cavities as described herein less than 100% deep as described herein, and one or more barbs (I) as described herein, and ii) one or more dipole magnets (x32) described herein, wherein said one or more dipole magnets (x32) are located symmetrically or asymmetrically within one or more cavities (V), preferably within a loop , defined by one or more loop-shaped cavities (V) described in this document, while the upper surface of said one or more dipole magnets (x32)

a) is flush with the upper surface (dashed line) of the soft magnetic plate (x31), preferably the lower surface of said one or more dipole magnets (x32) is flush with the upper surface of one or more cavities (V) of the soft magnetic plate (x31) (see Fig. 5A), or

b) located under the upper surface (dashed line) of the soft magnetic plate (x31), and preferably the lower surface of said one or more dipole magnets (x32) is flush with the upper surface of one or more cavities (V) of the soft magnetic plate (x31) (see Fig. 5B).

According to one embodiment and as shown in FIG. 4B and 6A, the magnetic assembly (x30) described in this document contains

i) a soft magnetic plate (x31) containing one or more cavities (V), preferably one or more loop-shaped cavities described herein, less than 100% deep, described-

- 20 040912 described in this document, and one or more protrusions (P) described in this document, and ii) one or more dipole magnets (x32) described in this document, while said one or more dipole magnets (x32) located symmetrically or asymmetrically within one or more cavities (V), preferably within a loop defined by one or more loop-shaped cavities (V), and while the upper surface of these one or more magnets (x32) is flush with the upper surface (dashed line ) soft magnetic plate (x31), and preferably the lower surface of said one or more dipole magnets (x32) is flush with the upper surface of one or more cavities (V) of the soft magnetic plate (x31).

According to one embodiment and as shown in FIG. 5C-5F, the magnetic assembly (x30) described in this document contains

i) a soft magnetic plate (x31) comprising one or more loop-shaped cavities (V) 100% deep described herein and one or more loop-shaped notches (I) described herein, and ii) one or more dipole magnets (x32) described herein, wherein said one or more dipole magnets (x32) are located symmetrically or asymmetrically within one or more cavities (V), preferably within a loop defined by one or more loop-shaped cavities (V) described in this document, while the upper surface of the specified one or more dipole magnets (x32)

a) is flush with the top surface (dashed line) of the soft magnetic plate (x31), and the bottom surface of said one or more dipole magnets (x32) is either flush with the bottom surface of the soft magnetic plate (x31) (see Fig. 5C), either located under the soft magnetic plate (x31) (see Fig. 5D), or

b) located below the top surface (dashed line) of the soft magnetic plate (x31), wherein the bottom surface of said one or more dipole magnets (x32) is either flush with the bottom surface of the soft magnetic plate (x31) (see FIG. 5E), or located under the soft magnetic plate (x31) (see Fig. 5F).

According to one embodiment and as shown in FIG. 6B-6C, the magnetic assembly (x30) described herein contains

i) a soft magnetic plate (x31) comprising one or more loop-shaped cavities (V) 100% deep described herein and one or more loop-shaped protrusions (P) described herein, and ii) one or more dipole magnets (x32) described herein, wherein said one or more dipole magnets (x32) are located symmetrically or asymmetrically within one or more cavities (V), preferably within a loop defined by one or more loop-shaped cavities (V) described herein, wherein the top surface of said one or more dipole magnets (x32) is flush with the top surface (dashed line) of the soft magnetic plate (x31), wherein the bottom surface of said one or more dipole magnets (x32) is either flush with the bottom surface of the soft magnetic plate (x31) (see Fig. 6B), or located under the soft magnetic plate (x31) (see Fig. 6C).

The surface of the soft magnetic plate (x31) described herein can be further treated to facilitate contact with the substrate (x20) carrying the coating layer (x10) described herein, reducing friction and/or wear and/or electrostatic charge in high speed printing applications.

According to one embodiment, the soft magnetic plate (x31) described herein is flat or planar. According to another embodiment, the soft magnetic plate (x31) described herein is curved to fit into or onto a rotating cylinder of print units. It is understood that the rotating cylinder is used in part or in combination with part of or is part of the equipment for printing or coating, and also includes one or more of the soft magnetic plates described in this document. In an embodiment, the rotary cylinder is part of a rotary, sheet or web fed industrial printing press that operates continuously at high print speeds.

The soft magnetic plate (x31) described herein may be either a plate containing one or more soft magnetic metals, alloys or compounds with high magnetic permeability (or a plate made of a composite material containing soft magnetic particles dispersed in a non-magnetic material (hereinafter referred to as soft magnetic composite plate).

According to one embodiment, the soft magnetic plate (x31) described herein comprises one or more soft magnetic metals, alloys or compounds with high magnetic permeability (hereinafter referred to as soft magnetic metal plate). Soft magnetic materials are characterized by low coercive force and high saturation magnetization. Suitable materials with a low coercive value and a high saturation value have a coercive force value that is less than 1000 Am ^-1 as measured according to IEC 60404-1:2000, which enables fast magnetization and demagnetization, and their saturation magnetization is preferably at least 1 T, more preferably at least 1.5 T, and even more preferably at least 2 T. Soft magnetic materials are described, for example, in the following manuals:

1) Handbook of Condensed Matter and Materials Data, sec. 4.3.2, Soft Magnetic Materials, p. 758-793, and sec. 4.3.4, Magnetic Oxides, p. 811-813, Springer, 2005;

2) Ferromagnetic Materials, vol. 1, Iron, Cobalt and Nickel, p. 1-70, Elsevier, 1999;

3) Ferromagnetic Materials, vol. 2, sec. 2, Soft Magnetic Metallic Materials, p. 55-188, and sec. 3, Ferrites for non-microwave Applications, p. 189-241, Elsevier, 1999;

4) Electric and Magnetic Properties of Metals, C. Moosbrugger, sec. 8, Magnetically Soft Materials, p. 196-209, ASM International, 2000;

5) Handbook of modern Ferromagnetic Materials, sec. 9, High-permeability High-frequency Metal Strip, p. 155-182, Kluwer Academic Publishers, 2002; And

6) Smithells Metals Reference Book, sec. 20.3, Magnetically Soft Materials, p. from 20-9 - 20-16, Butterworth-Heinemann Ltd, 1992.

Highly permeable materials are preferably those with a magnetic permeability greater than 1.0 x 10' ² H/m.

In one embodiment, the soft magnetic metal plate (x31) described herein is made from one or more soft magnetic metals or alloys that are easily machined as sheets or filaments. Preferably, the soft magnetic metal plate (x31) described herein is made from one or more materials selected from the group consisting of iron, cobalt, nickel, nickel- and molybdenum-based alloys, nickel-based and iron-based alloys (permalloy type materials). or supermalloy), cobalt and iron based alloys, cobalt and nickel based alloys, iron, nickel and cobalt based alloys (Fernico type materials), Heusler type alloys (such as Cu ₂ MnSn or Ni ₂ MnAl), steels with low silicon content, low carbon steels, silicious cast iron (electrical steels), iron-aluminum alloys, iron-aluminum-silicon alloys, amorphous metal alloys (e.g. Metglas® type alloys, iron-boron alloys) , nanocrystalline soft magnetic alloys (e.g. Vitroperm®) and combinations thereof, more preferably selected from the group consisting of iron, cobalt, nickel, low carbon, silicon iron, nickel-iron alloys and cobalt-iron alloys, and combinations thereof.

The thickness of the soft magnetic metal plate described herein is preferably from about 10 µm to about 3000 µm, more preferably from about 50 µm to about 2000 µm, even more preferably from about 500 µm to about 2000 µm, and even more preferably from about 1000 µm to approximately 2000 µm. As described herein above, the thickness of the soft magnetic metal plate containing one or more cavities (V) and one or more serrations (I) refers to the thickness of areas of the soft magnetic metal plate in which one or more cavities (V) and one or more notches (I) are missing (see FIG. 4A), and the thickness of the soft magnetic metal plate containing one or more protrusions (P) refers to the total thickness of the soft magnetic metal plate, i.e. a combination of the height of the tallest protrusions of the one or more protrusions and the thickness of the areas of the soft magnetic metal plate that lack said one or more protrusions (see FIG. 4B). The low magnetic permeability of the soft magnetic metal plate makes it possible to work with the thicknesses described in this document, thereby maintaining the mechanical strength of the plate.

According to one embodiment, the soft magnetic metal plate described herein comprises one or more cavities (V), preferably one or more loop-shaped cavity(s) described herein, 100% deep. According to another embodiment, the soft magnetic metal plate described herein comprises one or more cavities (V), preferably one or more loop-shaped cavity(s) described herein, less than 100% deep; those. depressions or notches, preferably from about 20% to about 90% of the thickness of the soft magnetic metal plate, more preferably from about 30% to about 90% of the thickness of the soft magnetic metal plate, and even more preferably from about 50% to about 90% of the thickness of the soft magnetic metal plate. compared to the thickness of a soft magnetic metal plate.

The soft magnetic metal plate described herein has one or more notches (I) described herein and/or one or more protrusions (P) described herein, wherein, in one embodiment, the depth of one or more barbs (I) is preferably from about 20% to about 100% compared to the thickness

- 22 040912 soft magnetic metal plate, more preferably from about 30% to about 100% compared to the thickness of the soft magnetic metal plate, and even more preferably from about 50% to about 100% compared to the thickness of the soft magnetic metal plate; in another embodiment, the depth of one or more loop-shaped barbs (I) is preferably from about 20% to about 90% of the thickness of the soft magnetic metal plate, more preferably from about 30% to about 90% of the thickness of the soft magnetic metal plate and even more preferably from about 50% to about 90% compared to the thickness of the soft magnetic metal plate and/or the height of one or more protrusions (P) is preferably from about 20% to about 100% compared to the thickness of the soft magnetic metal plate, more preferably from about 30% to about 100% of the thickness of the soft magnetic metal plate, and even more preferably from about 50% to about 100% of the thickness of the soft magnetic metal plate.

The soft magnetic metal plate described herein may be placed on a non-magnetic holder or spacer (x33). Typically, said non-magnetic holder or spacer (x33), such as a non-magnetic metal plate, may be made from one of the polymeric matrix materials described herein. For example, a soft magnetic metal plate containing one or more of the cavities (V) described herein, 100% deep, may be located on said non-magnetic holder or spacer (x33). For example, a soft magnetic metal plate containing one or more protrusions (P) described herein, 100% high, can be located on the specified non-magnetic holder or separator (x33).

One or more cavities (V), preferably one or more loop-shaped cavities(s) described herein, as well as one or more barbs (I) and/or one or more protrusions (P) of the soft magnetic metal plate described herein. document can be produced by any cutting or engraving technique known in the art, including, without limitation, casting, shaping, hand engraving, or ablation instruments selected from the group consisting of mechanical ablation instruments, gaseous or liquid jet ablation instruments, for chemical etching, electrochemical etching and laser ablation (eg CO ^2- , Nd-YAG or excimer lasers).

According to another embodiment, the soft magnetic plate (x31) described herein is made of a composite material containing from about 25 wt.% to about 95 wt.% soft magnetic particles dispersed in a non-magnetic material, with the weight percentage calculated based on from the total weight of the soft magnetic plate (x31). Preferably, the soft magnetic composite plate composite contains from about 50 wt.% to about 90 wt.% soft magnetic particles, with the weight percentage calculated based on the total weight of the soft magnetic composite plate. The soft magnetic particles described herein are made from one or more soft magnetic materials, preferably selected from the group consisting of iron (primarily iron pentacarbonyl, also referred to as carbonyl iron), nickel (primarily nickel tetracarbonyl, also referred to as carbonyl nickel) , cobalt, soft magnetic ferrites (for example, manganese and zinc ferrites and nickel and zinc ferrites), soft magnetic oxides (for example, oxides of manganese, iron, cobalt and nickel) and combinations thereof, more preferably selected from the group consisting of carbonyl iron, carbonyl nickel, cobalt and combinations thereof.

The soft magnetic particles may be needle-shaped, plate-shaped, or spherical. Preferably, the soft magnetic particles are spherical to maximize saturation of one or more soft magnetic composite plates, and are in the highest concentration possible without losing the cohesion of the soft magnetic composite plate. Preferably, the soft magnetic particles are spherical and have an average particle size (d ₅₀ ) of from about 0.1 µm to about 1000 µm, more preferably from about 0.5 µm to about 100 µm, even more preferably from about 1 µm to about 20 µm, and even more preferably from about 2 µm to about 10 µm, with d ₅₀ measured by laser diffraction using, for example, a Microtrac X100 particle size analyzer.

The soft magnetic composite plate described herein is made of a composite material, wherein said composite material contains the soft magnetic particles described herein dispersed in a non-magnetic material. Suitable non-magnetic materials include, without limitation, polymeric materials that form a matrix for the dispersed soft magnetic particles. The polymeric materials forming the matrix may be one or more thermoplastic materials or one or more thermoset materials, or contain one or more thermoplastic materials or one or more thermoset materials.

- 23 040912 materials. Suitable thermoplastic materials include, without limitation, polyamides, copolyamides, polyphthalimides, polyolefins, polyesters, polytetrafluoroethylenes, polyacrylates, polymethacrylates (e.g., PMMA), polyimides, polyetherimides, polyether ether ketones, polyaryl ether ketones, polyphenylene sulfides, liquid crystal polymers, polycarbonates, and mixtures thereof. Suitable thermosetting materials include, without limitation, epoxy resins, phenolic resins, polyimide resins, polyester resins, silicone resins, and mixtures thereof. One or more of the soft magnetic plates described herein are made from a composite material containing from about 5 wt.% to about 75 wt.% of the non-magnetic material described herein, with the weight percentage calculated based on the total weight of the soft magnetic composite plate.

The composite material described herein may additionally contain one or more additives such as, for example, hardeners, dispersants, plasticizers, fillers/thinners and defoamers.

The thickness of the soft magnetic composite plate described herein is preferably at least about 0.5 mm, more preferably at least about 1 mm, and even more preferably from about 1 mm to about 5 mm. As described herein above, the thickness of the soft magnetic composite plate containing one or more loop-shaped cavities (V) described herein refers to the thickness of the regions of the soft magnetic composite plate in which one or more loop-shaped cavities (V) are missing, and the thickness of the soft magnetic composite plate containing one or more protrusions (P) described herein refers to the total thickness of the soft magnetic composite plate, i.e. a combination of the height of the highest protrusions of the one or more protrusions and the thickness of the areas of the soft magnetic composite plate that lack said one or more protrusions.

In one embodiment, the soft magnetic composite plate described herein comprises one or more cavities (V), preferably one or more loop-shaped cavities(s) described herein, preferably from about 5% to about 100% deep compared to with a soft magnetic composite wafer thickness, more preferably from about 10% to about 100% of the soft magnetic composite wafer thickness, and even more preferably from about 50% to about 100% of the soft magnetic composite wafer thickness.

According to one embodiment, the soft magnetic composite plate described herein comprises one or more cavities (V), preferably one or more loop-shaped cavity(s) described herein, 100% deep. According to another embodiment, the soft magnetic composite plate described herein comprises one or more cavities (V), preferably one or more loop-shaped cavity(s) described herein, less than 100% deep; those. depressions or notches, preferably from about 5% to about 90% of the thickness of the soft magnetic composite wafer, more preferably from about 10% to about 90% of the thickness of the soft magnetic composite wafer, and even more preferably from about 50% to about 90% of the thickness of the soft magnetic composite wafer. compared with the thickness of a soft magnetic composite plate.

The soft magnetic composite plate described herein comprises one or more notches (I) described herein and/or one or more protrusions (P) described herein, wherein, in one embodiment, the depth of one or more than barbs (I) is preferably from about 5% to about 100% compared to the thickness of the soft magnetic composite plate, more preferably from about 10% to about 100% compared to the thickness of the soft magnetic composite plate, and even more preferably from about 50% up to about 100% compared to the thickness of the soft magnetic composite plate; according to another embodiment, the depth of one or more notches (I) is preferably from about 5% to about 90% compared to the thickness of the soft magnetic composite plate, more preferably from about 10% to about 90% compared to the thickness of the soft magnetic composite plate, and even more preferably from about 50% to about 90% compared to the thickness of the soft magnetic composite plate and/or the height of one or more projections (P) is preferably from about 5% to about 100% compared to the thickness of the soft magnetic metal plate, more preferably from about 10% to about 100% of the thickness of the soft magnetic composite plate, and even more preferably from about 50% to about 100% of the thickness of the soft magnetic metal plate.

The soft magnetic composite plate described herein may be placed on a non-magnetic holder or spacer (x33). Typically, said non-magnetic holder or spacer (x33), such as a non-magnetic metal plate, may be made from one of the polymer matrix materials described herein. For example, a soft magnetic composite plate containing one or more cavities 100% deep may be placed on said non-magnetic holder or spacer (x33). For example, a soft magnetic composite plate containing one or more protrusions (P) described herein, with a height

100%, can be located on the specified non-magnetic holder or spacer (x33).

The present invention advantageously utilizes the soft magnetic composite plates described herein because these plates can be easily produced and processed like any other polymeric material. Well-known techniques may be used, including 3D printing, layer molding, compression molding, resin transfer molding, or injection molding. After molding, standard curing procedures can be applied, such as cooling (when using thermoplastic polymers) or curing at high or low temperature (when using thermosetting polymers). Another way to obtain one or more of the soft magnetic composite plates described in this document is to remove parts from them to obtain the required one (th) or more of the cavities (V), and/or notches (I), and/or protrusions (P ) using standard plastic processing tools. In particular, mechanical ablation instruments can advantageously be used.

The distance (h) from the top surface of the soft magnetic plate (x31) of the magnetic assembly (x30) described herein to the substrate (x20) carrying the coating layer (x10) is adjusted and selected to obtain the desired bright layers with high optical effect. resolution with a dynamic effect. It is particularly preferable to use a distance from the top surface of the soft magnetic plate (x31) to the substrate (x20) that is close to or equal to zero.

The substrate (x20) carrying the coating layer (x10) is subjected to the magnetic field of the magnetic assembly (x30) described herein so that the lamellar magnetic or magnetizable pigment particles are oriented while the coating layer/composition is still wet (i.e., wet). e. not yet hardened) state.

The method for producing the OEL described herein may further comprise before or simultaneously with step b) step (step b2)) of exposing the coating layer (x10) to the dynamic magnetic field of a biaxially oriented device of at least a portion of the lamellar magnetic or magnetizable pigment particles, wherein said step is carried out before or simultaneously with step b) and before step c). Methods comprising such a step of exposing the coating composition to the dynamic magnetic field of a biaxial device of at least a portion of lamellar magnetic or magnetizable pigment particles are disclosed in WO 2015/086257 A1. After exposing the coating layer (x10) to the magnetic field of the magnetic assembly (x30) described herein, and while the coating layer (x10) is still wet or soft enough so that lamellar magnetic or magnetizable pigment particles in it can further move and rotate, lamellar magnetic or magnetizable pigment particles are further reoriented using the apparatus described herein. Biaxial orientation means that the lamellar magnetic or magnetizable pigment particles are oriented in such a way that their two principal axes are fixed. Therefore, each lamellar magnetic or magnetizable pigment particle can be considered to have a major axis in the plane of the pigment particle and an orthogonal minor axis in the plane of the pigment particle. Under the influence of a dynamic magnetic field, the orientation of each major and minor axis of lamellar magnetic or magnetizable pigment particles occurs. As such, this results in adjacent lamellar magnetic pigment particles that are spaced close to each other to be substantially parallel to each other. In order to perform biaxial orientation, lamellar magnetic pigment particles must be subjected to a sharply time-varying external magnetic field.

Particularly preferred devices for biaxially orienting lamellar magnetic or magnetizable pigment particles are disclosed in EP 2157141 A1. The device disclosed in EP 2157141 A1 provides a dynamic magnetic field that changes its direction causing lamellar magnetic or magnetizable pigment particles to rapidly oscillate until both principal axes, the X-axis and the Y-axis, are substantially parallel to the surface of the substrate, i.e. e. lamellar magnetic or magnetizable pigment particles rotate until they form a stable sheet-like structure, while their X and Y axes are essentially parallel to the surface of the substrate and planarized in two specified dimensions. Other particularly preferred devices for biaxially orienting lamellar magnetic or magnetizable pigment particles are Halbach assemblies with linear permanent magnets, i.e. assemblies containing a plurality of magnets with different directions of magnetization. A detailed description of Halbach permanent magnets has been given by Z.Q. Zhu and D. Howe (Halbach permanent magnet machines and applications: a review, IEE. Proc. Electric Power Appl., 2001, 148, pp. 299-308). The magnetic field generated by such a Halbach assembly has the properties that it is concentrated on one side while attenuating to almost zero on the other side. WO 2016/083259 A1 discloses

- 25 040912 suitable devices for biaxially orienting lamellar magnetic or magnetizable pigment particles, said devices comprising a Halbach cylinder assembly. Other particularly preferred devices for biaxially orienting lamellar magnetic or magnetizable pigment particles are rotating magnets, said magnets comprising disk-shaped rotating magnets or magnetic assemblies which are substantially magnetized along their diameter. Suitable rotating magnets or magnetic assemblies are described in US 2007/0172261 A1, wherein said rotating magnets or magnetic assemblies generate radially symmetrical, time-varying magnetic fields allowing for biaxial orientation of lamellar magnetic or magnetizable pigment particles of an as-yet uncured or hardened composition. for coverage. These magnets or magnetic assemblies are driven by a shaft (or spindle) attached to an external motor. CN 102529326 B discloses examples of devices containing rotating magnets that may be suitable for biaxially orienting lamellar magnetic or magnetizable pigment particles. In a preferred embodiment, suitable devices for biaxially orienting lamellar magnetic or magnetizable pigment particles are non-shaft mounted, disk-shaped rotating magnets or magnetic assemblies mounted in a housing made of non-magnetic, preferably non-conductive materials, and are driven by one or more electromagnetic coils, wrapped around the body. Examples of such non-shaft mounted disc-shaped rotating magnets or magnet assemblies are disclosed in WO 2015/082344 A1, WO 2016/026896 A1 and pending EP 17153905.9.

The method for producing the OEL described herein includes the step of providing curing (step c)) of the coating composition, wherein said step c) is carried out preferably partly simultaneously with step b) or partly simultaneously with step b2) when carrying out said second step b2) orientation. The step of causing the coating composition to solidify causes the lamellar magnetic or magnetizable pigment particles to be fixed in their adopted positions and orientations in the desired pattern to form an OEL, thereby converting the coating composition to the second state. However, the time from the completion of step b) to the start of step c) is preferably relatively short in order to avoid any confusion and loss of information. Typically, the time between the end of step b) and the start of step c) is less than 1 minute, preferably less than 20 seconds, more preferably less than 5 seconds. It is particularly advantageous if there is basically no time interval at all between the completion of the orienting step b) (or the second orienting step b2) and the start of the hardening step c) i.e. if step c) immediately follows step b) or already starts when step b) is still ongoing (partially simultaneously). By partly simultaneously it is to be understood that both steps are partly carried out simultaneously, i. e. the execution times of each of the stages partially overlap. In the context of this document, when the curing is carried out partly simultaneously with step b) (or step b2)) in carrying out the second orienting step, it should be understood that the curing takes effect after the orienting, so that the lamellar magnetic or magnetizable pigment particles are oriented before the final or partial hardening OEL. As noted herein, the hardening step (step c)) can be carried out using various means or processes depending on the binder contained in the coating composition, which also contains lamellar magnetic or magnetizable pigment particles.

The hardening step can generally be any step that increases the viscosity of the coating composition so that a substantially solid material adheres to the substrate. The curing step may include a physical process based on evaporation of a volatile component such as a solvent and/or evaporation of water (ie physical drying). In this case, hot air, infrared radiation, or a combination of hot air and infrared radiation can be used. Alternatively, the curing process may include a chemical reaction such as curing, polymerizing, or crosslinking the binder and optional initiator compounds and/or optional crosslinkers contained in the coating composition. Such a chemical reaction may be initiated by heat or IR radiation as described above for physical curing processes, but may preferably include initiation of a chemical reaction by a radiation mechanism, including, but not limited to, ultraviolet and visible radiation curing (hereinafter referred to herein as curing in the UV and visible areas) and curing under the influence of electron beam radiation (curing under the influence of electron beam radiation), oxypolymerization (oxidative reticulation, as a rule, caused by the combined action of oxygen and one or more catalysts, preferably selected from the group, consisting of cobalt-containing catalysts, vanadium-containing catalysts, zirconium-containing catalysts, bismuth-containing catalysts and manganese-containing catalysts); crosslinking reactions or any combination thereof.

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Radiation curing is particularly preferred, and UV-visible radiation curing is even more preferred, as these technologies advantageously lead to very fast curing processes and therefore significantly reduce the time to produce any product containing the OEL described in this document. In addition, the advantage of radiation curing is to provide an almost instantaneous increase in the viscosity of the coating composition after exposure to radiation to cause curing, thus minimizing any further movement of the particles. As a consequence, basically any loss of orientation after the magnetic alignment step can be avoided. Particularly preferred is radiation curing by photopolymerization with actinic light having a wavelength component in the UV or blue portion of the electromagnetic spectrum (generally 200 to 650 nm, more preferably 200 to 420 nm). UV-visible curing equipment may include a high power light emitting diode (LED) lamp or an arc lamp such as a medium pressure mercury arc lamp (MPMA) or a metal vapor discharge lamp as source of actinic radiation.

According to one embodiment, the method for producing an OEL described herein comprises a curing step c) which is a radiation curing step, preferably a UV-visible radiation curing step, and with a photomask comprising one or more windows. An example of methods using photomasks is disclosed in WO 02/090002 A2. A photomask containing one or more windows is placed between the coating layer (x10) and the radiation source, thereby making it possible to fix/immobilize the orientation of the lamellar magnetic or magnetizable pigment particles described herein in only one or more areas located under one or more windows. Lamellar magnetic or magnetizable pigment particles dispersed in non-exposed parts of the coating layer (x10) can be reoriented in a subsequent step using a second magnetic field.

The method comprising step c) of providing curing, which is a step of curing under the influence of radiation, preferably a step of curing under the influence of radiation in the UV and visible regions and using a photomask, described herein, further includes the step of d) exposing the layer (x10) of the coating exposure to the magnetic field of the device generating the magnetic field, thereby orienting lamellar magnetic or magnetizable pigment particles in one or more areas of the coating layer (x10) that are in the first state due to the presence of one or more areas of the photomask in which one or more windows are missing, wherein said magnetic field generating device enables the pigment particles to be magnetically oriented to follow any orientation pattern except random orientation. The devices described herein for biaxially orienting lamellar magnetic or magnetizable pigment particles can be used for the second orienting step (step d)). A method comprising step c) of providing curing, which is a radiation-curing step, preferably a UV-visible radiation-curing step using a photomask, described herein, additionally with step d) described herein , further includes step e) simultaneous, partially simultaneous or sequential, preferably simultaneous or partially simultaneous, causing the coating layer (x10) to harden, fixing or immobilizing the magnetic or magnetizable pigment particles in their adopted positions or orientations, such as those described herein above .

The present invention provides a method for producing an optical effect layer (OEL) on a substrate. The substrate (x20) described herein is preferably selected from the group consisting of paper or other fibrous materials (including woven and nonwoven fibrous materials) such as cellulose, paper containing materials, glasses, metals, ceramics, plastics and polymers, metallized plastics or polymers, composite materials and mixtures or combinations of two or more of them. Typical paper, paper-like, or other fibrous materials are made from a wide variety of fibers including, without limitation, manila hemp, cotton, flax, wood pulp, and mixtures thereof. As is well known to those skilled in the art, cotton fiber and cotton/linen fiber blends are preferred for banknotes, while wood pulp is generally used for non-banknote security documents. Typical examples of plastics and polymers include polyolefins such as polyethylene (PE) and polypropylene (PP), including biaxially oriented polypropylene (BOPP), polyamides, polyesters such as poly(ethylene terephthalate) (PET), poly(1,4-butylene terephthalate) (PBT), poly(ethylene-2,6-naphthoate) (PEN) and polyvinyl chlorides (PVC). The substrate can also be olefin fibers spun with high velocity air flow, such as those sold under the trademark Tyvek®. Typical examples of metallized plastics or polymers include the plastics or polymeric materials described herein above that have metal continuously or discontinuously on their surface.

Typical examples of metals include, without limitation, aluminum (Al), chromium (Cr), copper (Cu), gold (Au), silver (Ag), their alloys, and combinations of two or more of the above metals. The plating of the plastic or polymeric materials described herein above can be carried out using an electrodeposition process, a high vacuum coating process, or a sputtering process. Typical examples of composite materials include, but are not limited to, multilayer structures or laminates of paper and at least one plastic or polymer material such as those described herein above, as well as plastic and/or polymer fibers incorporated into a paper-like or fibrous material such as described above in this document. Of course, the substrate may contain additional additives known to those skilled in the art, such as fillers, sizing agents, brighteners, processing aids, reinforcing or wet strength agents, etc. When the OELs obtained according to the present invention are used for decorative or cosmetic purposes, including, for example, nail polishes, said OEL can be obtained on other types of substrates, including nails, artificial nails, or other animal or human parts.

If the OEL obtained according to the present invention will be on a security document, and in order to further increase the level of security and protection against forgery and illegal reproduction of this security document, the substrate may contain printed coated or laser marked or laser-marked or laser-perforated marks, watermarks, security threads, fibers, confetti, luminescent compounds, windows, foils, decals, and combinations of two or more of these. For the same purpose of further increasing the level of security and protection against counterfeiting and illegal reproduction of protected documents, the substrate may contain one or more marker substances or markers and / or machine-readable substances (for example, luminescent substances, substances that absorb in the UV / visible / IR ranges , magnetic substances and their combinations).

If necessary, a layer of primer can be applied to the substrate prior to step a). This may improve the quality of the optical effect layer (OEL) described herein or promote adhesion. Examples of these primer layers can be found in WO 2010/058026 A2.

For the purpose of improving durability by increasing soil resistance or chemical resistance and cleanliness and thus the service life of a product, a document to be protected or a decorative element or object containing an optical effect layer (OEL) obtained by the method described herein, or with in order to change their aesthetic appearance (eg optical gloss), one or more protective layers can be applied over the optical effect layer (OEL). If present, one or more protective layers are usually made of protective varnishes. Protective varnishes may be clear or lightly colored and may be more or less glossy. Protective varnishes can be radiation-curable compositions, heat-curable compositions, or any combination thereof. Preferably, the one or more protective layers are radiation-curable compositions, more preferably UV-visible radiation-curable compositions. Protective layers are generally applied after the optical effect layer (OEL) has been formed.

The present invention further provides optical effect layers (OEL) obtainable by the method of the present invention.

The optical effect layer (OEL) described herein can be applied directly to a substrate on which it is to remain permanently (eg for bank note applications). Alternatively, for industrial purposes, an optical effect layer (OEL) can also be applied to a temporary substrate from which the OEL is subsequently removed. This can, for example, facilitate the production of an optical effect layer (OEL), in particular while the binder is still in its liquid state. Then, after the coating composition has cured to form an Optical Effect Layer (OEL), the temporary OEL substrate can be removed.

Alternatively, in another embodiment, an adhesive layer may be present on an Optical Effect Layer (OEL) or may be present on a substrate containing the OEL, said adhesive layer being located on the side of the substrate opposite to the side on which the OEL is applied, or on the the same side as the OEL and on top of the OEL. Thus, an adhesive layer can be applied to an optical effect layer (OEL) or to a substrate, said adhesive layer being preferably applied after the curing step has been completed. Such a product can be attached to all types of documents or other products or objects without printing or other processes involving machines and mechanisms and rather high labor costs. Alternatively, the substrate described herein containing the Optical Effect Layer (OEL) described herein may be in the form of a transfer foil that can be applied to a document or article in a separate transfer step. To this end, the substrate is provided with a release coating on which an optical effect layer (OEL) is produced as described herein. On top of the optical effect layer (OEL) thus obtained, one or more adhesive layers can be applied.

Also described herein are substrates containing more than one, i. two, three, four, etc., optical effect layers (OEL), obtained by the method described in this document.

This document also describes articles, in particular security documents, decorative elements or objects, containing an optical effect layer (OEL) obtained according to the present invention. Products, in particular security documents, decorative elements or objects, may contain more than one (eg, two, three, etc.) OEL obtained according to the present invention.

As mentioned above in this document, the optical effect layer (OEL) obtained according to the present invention can be used for decorative purposes, as well as for the protection and authentication of a security document.

Typical examples of decorative elements or objects include, without limitation, luxury goods, cosmetic packaging, automotive parts, electronic/electrical appliances, furniture, and nail art.

Security documents include, without limitation, valuable documents and valuable commercial items. Typical examples of documents of value include, without limitation, banknotes, legal documents, tickets, cheques, vouchers, revenue and duty stamps, agreements, etc., identification documents such as passports, identity cards, visas, driver's licenses, bank cards , credit cards, transaction cards, access documents or cards, entrance tickets, public transport tickets or public transport entitlement documents, etc., preferably banknotes, identity documents, eligibility documents on possession, driver's licenses and credit cards. The term high value commercial product refers to packaging materials, in particular for cosmetics, nutraceuticals, pharmaceuticals, liquor, tobacco, beverages or food, electrical/electronic products, fabrics or jewelry, i.e. products that must be protected from counterfeiting and/or illegal reproduction, in order to guarantee the authenticity of the contents of the package, such as genuine medicines. Examples of these packaging materials include, but are not limited to, labels such as product authentication labels, tamper-evident labels and seals. It should be noted that the disclosed substrates, valuable documents, and valuable commercial items are provided by way of example only, without limiting the scope of the present invention.

Alternatively, an optical effect layer (OEL) can be applied to a secondary substrate such as, for example, a security thread, security strip, foil, decal, window or label, and then transferred to the security document in a separate step.

The specialist can make a number of changes within the essence of the present invention in the specific embodiments described above. These changes are within the scope of the present invention.

In addition, all documents referenced throughout this specification are hereby incorporated in this specification in their entirety as if they were set forth therein in their entirety.

Examples

Black commercial paper (Gascogne Laminates M-cote 120) was used as the backing (x20) for the examples described below.

UV curable ink for screen printing, described in table. 1 was used as a coating composition containing plate-like optically variable magnetic pigment particles to form a coating layer (x20). The coating composition was applied to a substrate (x20) (40x30 mm), this application was carried out manually by screen printing using a T90 grid to form a layer (x10) of the coating, the thickness of which was approximately 20 μm.

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Table 1

Epoxy acrylate oligomer 36% Trimethylolpropane triacrylate monomer 13.5% Tripropylene glycol diacrylate monomer 20% Genorad ^1M 16 (Rahn) 1% Aerosil® 200 (Evonik) 1% Speedcure TPO-L (Lambson) 2% IRGACURE® 500 (BASF) 6% Genocure EPD (Rahn) 2% Tego® Foamex N (Evonik) 2% Lamellar optically variable magnetic pigment particles (7 layers)(*) 16.5%

(*) Gold to green optically variable magnetic pigment particles shaped like flakes with a diameter of d50 of approximately 9 µm and a thickness of approximately 1 µm obtained from Viavi Solutions, Santa Rosa, California.

Magnetic assemblies (x30) shown in FIG. 7A-14C were independently used to orient lamellar optically variable magnetic pigment particles in a coating layer (x10) made from the UV curable screen printing ink described in Table 1. 1 to obtain the optical effect layers (OEL) shown in FIG. 7D-14D.

The magnetic assemblies (x30) comprised a soft magnetic plate (x31) and one or more dipole magnets (x32), wherein the magnetic axis of each of said one or more dipole magnets (x32) was substantially perpendicular to the surface of the substrate (x20) and also along substantially perpendicular to the surface of the soft magnetic plate (x31), all of said one or more dipole magnets (x32) had the same magnetic direction and were held in place relative to the soft magnetic plate (x31) by a piece (x33) of clean Scotch® Removable Poster Tape for modeling holder.

Soft magnetic plates (x31) were made from a composite composition (see Table 2) containing carbonyl iron as soft magnetic particles (see Table 2). Soft magnetic plates (x31) used in examples 1-8, independently obtained by thoroughly mixing the ingredients of table. 2 for 3 minutes in a speed mixer (Flack Tek Inc DAC 150 SP) at 2500 rpm. Then the mixture was poured into a silicon mold and left for three days until complete solidification.

The soft magnetic plates (x31) independently comprised a loop-shaped cavity (V) defining a loop, and independently comprised a notch(s) (I) or a protrusion(s) (P), wherein said notch(s) (I) or the protrusion(s) (P) formed a continuous looped mark (see Figs. 7A-13A) or an intermittent looped mark (see Fig. 14A), while the specified continuous looped mark or intermittent looped mark surrounded the cavity (V). The magnetic assemblies (x30) independently contained one or more dipole magnets (x32) located within the loop formed by the loop-shaped cavity (V).

The cavities (V), notches (I), and protrusions (P) of the soft magnetic plates (x31) were mechanically engraved in the thus obtained soft magnetic plates (x31) with a grid of 1 and 2 mm in diameter (computer-controlled mechanical engraving machine, IS500 from Gravograph ).

table 2

Ingredients E2 Epoxy (1170 from PHD-24) 13.6 wt. % Hardener (130 from PHD-24) 4.4 wt. % BASF carbonyl iron powder, spherical shape, d ₅₀ \u003d 4-6 μm, density 7.7 kg / dm ³ 82 wt. %

After application of the UV-curable screen printing ink as described above, and after magnetically orienting the lamellar optically variable magnetic pigment particles by placing a substrate (x20) bearing a coating layer (x10) on the magnetic assemblies (x30) (see Fig. 7A-14A), the magnetically oriented lamellar optically variable pigment particles were fixed/immobilized partly simultaneously with the magnetic alignment step by UV curing of the coating layer (x20) with

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Phoseon UV LED lamp (Type FireFlex 50x75mm, 395nm, 8W/ ^cm2 ).

Images of the thus obtained OELs were sampled using the following settings.

Light source: 150 W quartz halogen fiber optic source (Fiber-lite DC-950 from Dolan-Jenner). The illumination angle is 10° relative to the perpendicular to the substrate.

1.3 MP Camera: PixeLINK color camera (PL-B7420) with USB interface.

Lens: 0.19X telecentric lens.

Color images were converted to black and white images using free software (Fiji).

Example 1 (FIGS. 7A-7D).

As shown in FIG. 7A-7D, an OEL having five independent effects, with each effect exhibiting two nested marks, in particular two nested loop marks (a round mark and a regular tetrahedral star mark), was obtained by using a magnetic assembly (730) with orientation of at least a portion lamellar optically variable magnetic particles of the pigment layer (710) of the coating on the substrate (720). Each of the five notches (I) of the soft magnetic plate (731) independently formed a continuous loop-shaped mark (star), and each of said loop-shaped marks surrounded a cavity (V) having a circular loop-shaped shape.

Four of the five regular tetrahedral star-signs formed the corners of the square (width (A3) = 13 mm), and the fifth sign was located in the center of the square (meaning at a distance of sqrt(2) / 2-A3 or 9.2 mm from each of four stars located at the corner of the square). In FIG. 7B shows only one tetrahedral star for the sake of clarity, while FIG. 7C is a cross section of the magnetic assembly (730) passing through the virtual center of the two stars that form the side of the indicated square.

The magnetic assembly (730) comprised i) a soft magnetic plate (731) (width (A1)=40 mm, thickness (A2)=2 mm), said soft magnetic plate (731) containing five circular cavities (V) (diameter (A4)=3.5 mm, depth (A7)=2 mm) and five regular tetrahedral star-shaped notches (I) (inner diameter (A8)=5 mm, outer diameter (A9)=12 mm, thickness (A5)= 1 mm, depth (A10)=1.6 mm). As shown in FIG. 7A-7C, each circular cavity (V) defined a loop, and each circular cavity (V) was symmetrically surrounded by one of the tetrahedral star serrations (I).

The magnetic assembly (730) contained ii) five dipole magnets (732) (diameter (A6)=2 mm, thickness (A7)=2 mm) made of NdFeB N45, each of said five dipole magnets (732) being independently located symmetrically within the loop defined by each of the round cavities (V). The magnetic axis of each of the five dipole magnets (732) was substantially perpendicular to the surface of the substrate (720) (also substantially perpendicular to the surface of the soft magnetic plate (731)), with its north pole pointing towards said surface of the substrate (720). As shown in FIG. 7C, the top surface of each of the five dipole magnets (732) was flush with the top surface of the soft magnetic plate (731), and the bottom surface of each of the five dipole magnets (732) was flush with the bottom surface of the soft magnetic plate (731). The five dipole magnets (732) were held in place with a piece (733) of Scotch® double sided tape (13x5mm).

The distance (h) from the upper surface of the soft magnetic plate (731) to the surface of the substrate (720) was 0 mm, i.e. the substrate (720) carrying the coating composition (710) was placed in direct contact with the magnetic assembly (730), i. e. with soft magnetic plate (731).

The OEL resulting from the magnetic assembly (730) illustrated in FIG. 7A-7C is shown in FIG. 7D at different viewing angles by tilting the substrate (720) from 30° to -30°.

Example 2 (FIGS. 8A-8D).

As shown in FIG. 8A-8C, an OEL having two nested indicia, in particular two nested loop-shaped indicia (circular indicia), was obtained by using a magnetic assembly (830) orienting at least a portion of the lamellar optically variable magnetic particles of the coating layer (810) pigment on a substrate ( 820). The notch (I) of the soft magnetic plate (831) formed a continuous loop-shaped mark (circle), while said loop-shaped mark surrounded a cavity (V) having a circular loop-like shape.

The magnetic assembly (830) comprised i) a soft magnetic plate (831) (width (A1)=40 mm, thickness (A2)=2 mm), said soft magnetic plate (831) containing a circular cavity (V) (diameter ( A4)=7 mm, depth (A7)=2 mm) and a round notch (I) (diameter (A8)=13 mm, thickness (A5)=1 mm, depth (A10)=1.6 mm). As shown in FIG. 8A-8C, a circular cavity (V) defined a loop and was symmetrically surrounded by a circular barb (I).

The magnetic assembly (830) comprised ii) a cylindrical dipole magnet (832) (diameter (A6)=3mm, thickness=8mm) made of NdFeB N45, said dipole magnet (832) being positioned symmetrically within the loop defined by round cavity (V). The magnetic axis of the dipole

- 31 040912 magnet (832) was essentially perpendicular to the surface of the substrate (820) (also essentially perpendicular to the surface of the soft magnetic plate (831)), while its north pole pointed towards the specified surface of the substrate (820). As shown in FIG. 8C, the top surface of the dipole magnet (832) was positioned flush with the top surface of the soft magnetic plate (831), and the bottom surface of the dipole magnet (832) was positioned below the bottom surface of the soft magnetic plate (831). The dipole magnet (832) was held in place with a piece (833) of double sided Scotch® tape (13x13mm).

The distance (h) from the top surface of the soft magnetic plate (831) to the surface of the substrate (820) was 0.1 mm.

The OEL resulting from the magnetic assembly (830) illustrated in FIG. 8A-8C is shown in FIG. 8D at different viewing angles by tilting the substrate (820) from 30° to -30°.

Example 3 (FIGS. 9A-9D).

As shown in FIG. 9A-9C, an OEL having two nested indicia, in particular two nested loop-shaped indicia (circular indicia), was obtained by using a magnetic assembly (930) orienting at least a portion of the lamellar optically variable magnetic particles of the coating layer (910) pigment on a substrate ( 920). The notch (I) of the soft magnetic plate (931) formed a continuous loop-shaped mark (circle), while said loop-shaped mark surrounded a cavity (V) having a circular loop-like shape.

The magnetic assembly (930) comprised i) a soft magnetic plate (931) (width (A1)=40 mm, thickness (A2)=2 mm), said soft magnetic plate (931) containing a circular cavity (V) (diameter ( A4)=7 mm, depth (A7)=2 mm) and a round notch (I) (diameter (A8)=12 mm, thickness (A5)=1 mm, depth (A10)=1.6 mm). As shown in FIG. 9A-9C, a circular cavity (V) defined a loop and was symmetrically surrounded by a circular barb (I).

The magnetic assembly (930) contained ii) four cylindrical dipole magnets (932a-d) (diameter (A6)=3 mm, thickness (A7)=2 mm) made of NdFeB N45 and arranged symmetrically within a loop defined by a circular cavity ( V). The magnetic axis of each of said four dipole magnets (932a-d) was substantially perpendicular to the surface of the substrate (920) (also substantially perpendicular to the surface of the soft magnetic plate (931)), with its north pole pointing towards said surface of the substrate (920). ). The first dipole magnet (932a) was placed symmetrically within the loop defined by the circular cavity (V) and held in place with a piece (933) of Scotch® double sided tape (13x13mm). Three other dipole magnets (932b-d) were placed one below the other under the piece (933), said three dipole magnets (932b-d) were aligned with the first dipole magnet (932a), and the magnetic axis of all of said magnets pointed in the same direction . The dipole magnets (932b-d) were held in place by the magnetic force provided by the alignment of their magnetic axis. As shown in FIG. 9C, the top surface of the first dipole magnet (932a) was positioned flush with the top surface of the soft magnetic plate (931), and the bottom surface of the fourth dipole magnet (932d) was positioned below the bottom surface of the soft magnetic plate (931).

The distance (h) from the upper surface of the soft magnetic plate (931) to the surface of the substrate (920) was 0 mm, i.e. the substrate (920) carrying the coating composition (910) was placed in direct contact with the magnetic assembly (930), i. e. with soft magnetic plate (931).

The OEL resulting from the magnetic assembly (930) illustrated in FIG. 9A-9C is shown in FIG. 9D at different viewing angles by tilting the substrate (920) from 30° to -30°.

The OEL thus obtained exhibits an effect similar to that shown for Example 2 in FIG. 8D, it demonstrates that the set, i.e. more than one, dipole magnets aligned along their magnetic axis can be replaced by one dipole magnet.

Example 4 (FIGS. 10A-10D).

As shown in FIG. 10A-10C, an OEL having two nested indicia, in particular two nested loop-shaped indicia (circular indicia), was obtained by using a magnetic assembly (1030) orienting at least a portion of the lamellar optically variable magnetic particles of the coating layer (1010) pigment on a substrate ( 1020). The protrusion (P) of the soft magnetic plate (1031) formed a continuous loop-shaped mark (circle), while said loop-shaped mark surrounded a cavity (V) having a circular loop-like shape.

The magnetic assembly (1030) comprised i) a soft magnetic plate (1031) (width (A1)=40 mm, thickness (A2+A10)=(0.4+1.6) 2 mm), said soft magnetic plate ( 1031) contained a round cavity (V) (diameter (A4)=4 mm, depth (A7)=2 mm) and a round ledge (P) (diameter (A8)=10 mm, thickness (A5)=2 mm, height ( A10)=1.6 mm). As shown in FIG. 10A-10C, a circular cavity (V) defined the loop and was symmetrically surrounded by a circular projection (P).

The magnetic assembly (1030) contained ii) five cylindrical dipole magnets (1032a-e) (diameter (A6)=2 mm, thickness (A7)=2 mm) made of NdFeB N45 and arranged symmetrically within a loop defined by a circular cavity ( V). The magnetic axis of each of the indicated five dipoles

- 32 040912 magnets (1032a-e) was substantially perpendicular to the surface of the substrate (1020) (also substantially perpendicular to the surface of the soft magnetic plate (1031)), with its north pole pointing towards said surface of the substrate (1020). The first dipole magnet (1032a) was placed symmetrically within the loop defined by the circular cavity (V) and held in place with a piece (1033) of Scotch® double sided tape (13x10mm). Four other dipole magnets (1032b-e) were placed one below the other under the piece (1033), said four dipole magnets (1032b-e) were aligned with the first dipole magnet (1032a) and the magnetic axis of all of said magnets pointed in the same direction. The dipole magnets (1032b-e) were held in place by the magnetic force provided by the alignment of their magnetic axis. As shown in FIG. 10C, the top surface of the first dipole magnet (1032a) was flush with the top surface of the soft magnetic plate (1031), i. with the top surface of the protrusion (P), and the bottom surface of the fifth dipole magnet (1032e) was located under the bottom surface of the soft magnetic plate (1031).

The distance (h) from the upper surface of the soft magnetic plate (1031) to the surface of the substrate (1020) was 0 mm, i.e. the substrate (1020) carrying the coating composition (1010) was placed in direct contact with the magnetic assembly (1030), i. e. with the protrusion (P) of the soft magnetic plate (1031).

The OEL resulting from the magnetic assembly (1030) illustrated in FIG. 10A-C is shown in FIG. 10D at different viewing angles by tilting the substrate (1020) from 30° to -30°.

Example 5 (FIGS. 11A-11D).

As shown in FIG. 11A-11C, an OEL having two nested characters, in particular two nested loop-shaped characters (a round character and a square character), was obtained by using a magnetic assembly (1130) with the orientation of at least a portion of the plate-like optically variable magnetic particles of the coating layer (1110) on a substrate (1120). The notch (I) of the soft magnetic plate (1131) formed a continuous loop-shaped mark (square), while said loop-shaped mark surrounded a cavity (V) having a circular loop-like shape. The magnetic assembly (1130) comprised i) a soft magnetic plate (1131) (width (A1)=40 mm, thickness (A2)=1.5 mm), said soft magnetic plate (1131) containing a circular cavity (V) ( diameter (A4)=5mm, depth (A7)=1.5mm) and square notch (I) ((A8)=(A9)=12mm, thickness (A5)=2mm, depth (A10)=1 .1 mm). As shown in FIG. 11A-11C, a circular cavity (V) defined a loop and was symmetrically surrounded by a square notch (I).

The magnetic assembly (1130) contained ii) four cylindrical dipole magnets (1132a-d) made of NdFeB N45 and arranged symmetrically within a loop defined by a circular cavity (V). The magnetic axis of each of said four dipole magnets (1132a-d) was substantially perpendicular to the surface of the substrate (1120) (also substantially perpendicular to the surface of the soft magnetic plate (1131)), with its north pole pointing towards said surface of the substrate (1120). ). The first dipole magnet (1132a) (diameter (A6)=3mm, thickness (A11)=1mm) was positioned symmetrically within the loop defined by the circular cavity (V) and held in place with a piece (1133) of Scotch® double-sided adhesive tape (13x12 mm). Three other dipole magnets (1132b-d) (diameter (A6)=3 mm, thickness (A12)=2 mm) were placed one below the other under the piece (1133), said three dipole magnets (1132b-d) were aligned with the first dipole magnet (1132a) and the magnetic axis of all of these magnets pointed in the same direction. The dipole magnets (1132b-d) were held in place by the magnetic force provided by the alignment of their magnetic axis. As shown in FIG. 11C, the top surface of the first dipole magnet (1132a) was located 0.5 mm below the top surface of the soft magnetic plate (1131), and the bottom surface of the fourth dipole magnet (1132d) was located under the bottom surface of the soft magnetic plate (1131).

The distance (h) from the upper surface of the soft magnetic plate (1131) to the surface of the substrate (1120) was 0 mm, i.e. the substrate (1120) carrying the coating composition (1310) was placed in direct contact with the magnetic assembly (1130), i. e. with soft magnetic plate (1131).

The OEL resulting from the magnetic assembly (1130) illustrated in FIG. 11A-11C is shown in FIG. 11D at different viewing angles by tilting the substrate (1120) from 30° to -30°.

Example 6 (FIGS. 12A-12D).

As shown in FIG. 12A-12C, an OEL having two nested indicia, in particular two nested loop-shaped indicia (circular indicia), was obtained by using a magnetic assembly (1230) orienting at least a portion of the lamellar optically variable magnetic particles of the coating layer (1210) pigment on a substrate ( 1220). The notch (I) of the soft magnetic plate (1231) formed a continuous loop-shaped mark (circle), while said loop-shaped mark surrounded a cavity (V) having a circular loop-like shape.

The magnetic assembly (1230) comprised i) a soft magnetic plate (1231) (width (A1)=40 mm,

- 33 040912 thickness (A2)=2 mm), while the specified soft magnetic plate (1231) contained a round cavity (V) (diameter (A4)=5 mm, depth (A7)=2 mm) and a round notch (I) (diameter (A8)=15 mm, thickness (A5)=1 mm, depth (A10)=1.6 mm). As shown in FIG. 12A-12C, a circular cavity (V) defined a loop and was asymmetrically surrounded by a circular barb (I).

The magnetic assembly (1230) contained ii) four cylindrical dipole magnets (1232a-d) (diameter (A6)=3mm, thickness (A7)=2mm) made of NdFeB N45 and arranged symmetrically within a loop defined by a circular cavity ( V). The magnetic axis of each of said four dipole magnets (1232a-d) was substantially perpendicular to the surface of the substrate (1220) (also substantially perpendicular to the surface of the soft magnetic plate (1231)), with its north pole pointing towards said surface of the substrate (1220). ). The first dipole magnet (1232a) was positioned symmetrically within the loop defined by the circular cavity (V) and held in place with a piece (1233) of Scotch® double sided tape (13x12mm). Three other dipole magnets (1232b-d) were positioned one below the other under the piece (1233), said three dipole magnets (1232b-d) were aligned with the first dipole magnet (1232a) and the magnetic axis of all of said magnets pointed in the same direction. The dipole magnets (1232b-d) were held in place by the magnetic force provided by the alignment of their magnetic axis. As shown in FIG. 12C, the top surface of the first dipole magnet (1232a) was positioned flush with the top surface of the soft magnetic plate (1231), and the bottom surface of the fourth dipole magnet (1232d) was positioned below the bottom surface of the soft magnetic plate (1231).

The distance (h) from the upper surface of the soft magnetic plate (1231) to the surface of the substrate (720) was 0 mm, i.e. the substrate (1220) carrying the coating composition (1210) was placed in direct contact with the magnetic assembly (1230), i. e. with soft magnetic plate (1231).

The OEL resulting from the magnetic assembly (1230) illustrated in FIG. 12A-12C is shown in FIG. 12D at different viewing angles by tilting the substrate (1220) from 30° to -30°.

Example 7 (FIGS. 13A-13D).

As shown in FIG. 13A-13C, an OEL having two nested indicia, in particular two nested loop-shaped indicia (two regular hexagonal star indicia), was obtained by using a magnetic assembly (1330) orienting at least a portion of the lamellar optically variable magnetic particles of the pigment layer (1310) of the coating on a substrate (1320). A notch (I) of the soft magnetic plate (1331) formed a continuous loop-shaped mark (star), while said loop-shaped mark surrounded a cavity (V) having a loop-shaped star shape.

The magnetic assembly (1330) comprised i) a soft magnetic plate (1331) (width (A1)=40 mm, thickness (A2)=2 mm), said soft magnetic plate (1331) containing a regular hexagonal star-shaped cavity (V) ( outer diameter (A4)=6 mm, inner diameter (A4')=4 mm, depth (A7)=2 mm) and a regular hexagonal star notch (I) (outer diameter (A9)=15 mm, inner diameter (A8) =8 mm, thickness (A5)=1 mm and depth (A10)=1.6 mm). As shown in FIG. 13A-13C, a star-shaped cavity (V) defined a loop and was symmetrically surrounded by a star-shaped notch (I).

The magnetic assembly (1330) contained ii) three cylindrical dipole magnets (1332a-c) (diameter (A6)=3 mm, thickness (A7)=2 mm) made of NdFeB N45 and arranged symmetrically within a loop defined by a star-shaped cavity ( V). The magnetic axis of each of said three dipole magnets (1332a-c) was substantially perpendicular to the surface of the substrate (1320) (also substantially perpendicular to the surface of the soft magnetic plate (1331)), with its north pole pointing towards said surface of the substrate (1320). ). The first dipole magnet (1332a) was positioned symmetrically within the loop defined by the star cavity (V) and held in place with a piece (1333) of Scotch® double-sided tape (13x13mm). Two other dipole magnets (1332b-c) were positioned one below the other under the piece (1333), said two dipole magnets (1332b-c) were aligned with the first dipole magnet (1332a) and the magnetic axis of all of said magnets pointed in the same direction. The dipole magnets (1332b-c) were held in place by the magnetic force provided by the alignment of their magnetic axis. As shown in FIG. 13C, the top surface of the first dipole magnet (1332a) was positioned flush with the top surface of the soft magnetic plate (1331), and the bottom surface of the third dipole magnet (1332c) was positioned below the bottom surface of the soft magnetic plate (1331).

The distance (h) from the upper surface of the soft magnetic plate (1331) to the surface of the substrate (1320) was 0 mm, i.e. the substrate (1320) carrying the coating composition (1310) was placed in direct contact with the magnetic assembly (1330), i. e. with soft magnetic plate (1331).

The OEL resulting from the magnetic assembly (1330) illustrated in FIG. 13A-13C is shown in FIG. 13D at different viewing angles by tilting the substrate (1320) from 30° to -30°.

-

Claims (1)

Example 8 (FIGS. 14A-14D). As shown in FIG. 14A-14C, an OEL having two nested indicia, in particular two nested loop-shaped indicia (two hexagonal star indicia), was obtained by using a magnetic assembly (1430) orienting at least a portion of the plate-like optically variable magnetic particles of the coating layer (1410) onto substrate (1420). Six notches (I) of the soft magnetic plate (1431) formed an intermittent loop-shaped mark (star), while said loop-shaped mark surrounded a cavity (V) having a loop-shaped star shape. The magnetic assembly (1430) comprised i) a soft magnetic plate (1431) (width (A1)=40 mm, thickness (A2)=1.5 mm), said soft magnetic plate (1431) containing a regular hexagonal star-shaped cavity (V ) (outer diameter (A4)=6mm, inner diameter (A4')=4mm, depth=1.5mm) and six serrations (I) forming a discontinuous regular hexagonal star mark (I) (diameter (A8)= 8.5 mm, thickness (A5)=1 mm, depth (A10)=1.6 mm and length (A13)=3 mm). As shown in FIG. 14A-14C, a star-shaped cavity (V) defined the loop and was symmetrically surrounded by a discontinuous regular hexagonal star-shaped sign made of six notches (I). The magnetic assembly (1430) contained ii) four cylindrical dipole magnets (1432a-d) (diameter (A6)=3 mm, thickness (A7)=2 mm) made of NdFeB N45 and arranged symmetrically within a loop defined by a star-shaped cavity ( V). The magnetic axis of each of said four dipole magnets (1432a-c) was substantially perpendicular to the surface of the substrate (1420) (also substantially perpendicular to the surface of the soft magnetic plate (1431)), with its north pole pointing towards said surface of the substrate (1420). ). The first dipole magnet (1432a) was positioned symmetrically within the loop defined by the star cavity (V) and held in place with a piece (1433) of Scotch® double sided tape (13x13mm). Three other dipole magnets (1432b-c) were positioned one below the other under the piece (1433), said two dipole magnets (1432b-c) were aligned with the first dipole magnet (1432a) and the magnetic axis of all of said magnets pointed in the same direction. The dipole magnets (1432b-c) were held in place by the magnetic force provided by the alignment of their magnetic axis. As shown in FIG. 14C, the top surface of the first dipole magnet (1432a) was positioned flush with the top surface of the soft magnetic plate (1431), and the bottom surface of the fourth dipole magnet (1432c) was positioned below the bottom surface of the soft magnetic plate (1431). The distance (h) from the upper surface of the soft magnetic plate (1431) to the surface of the substrate (1420) was 0 mm, i.e. the substrate (1420) carrying the coating composition (1410) was placed in direct contact with the magnetic assembly (1430), i. e. with soft magnetic plate (1431). The OEL resulting from the magnetic assembly (1430) illustrated in FIG. 14A-14C is shown in FIG. 14D at different viewing angles by tilting the substrate (1420) from 30° to -30°. CLAIM 1. A method for producing an optical effect layer (OEL) having two or more nested characters on a substrate (x20), characterized in that said method includes the steps a) applying to the surface of the substrate (x20) a coating composition containing i) lamellar magnetic or magnetizable pigment particles, and ii) a binder to form a coating layer (x10) on said substrate (x20), wherein said coating composition is in a first liquid state; b) exposing the coating layer (x10) to the magnetic field of a magnetic assembly (x30) containing i) a soft magnetic plate (x31) containing one or more soft magnetic metals, alloys or compounds with high magnetic permeability or made of a composite material containing from about 25 wt.% to about 95 wt.% soft magnetic particles dispersed in a non-magnetic material, while the weight percentage is calculated based on the total weight of the magnetic plate (x31), while the soft magnetic plate (x31) contains one or more cavities (V) for receiving one or more dipole magnets (x32), while the soft magnetic plate (x31) contains one or more notches (I) and/or one or more protrusions (P), while each of the specified one or more notches (I) and/or one or more protrusions (P) form one or more continuous looped indicia and/or one or more discontinuous looped indicia, wherein one or more cavities (V) are surrounded by one or more continuous looped indicia and/or one or more cavities (V) are surrounded by one or more intermittent loop-shaped signs, ii) one or more dipole magnets (x32), while the magnetic axis of each of these one or more dipole magnets (x32) is su-