Processes for producing optical effects layers

Abstract

The present invention relates to the field of protecting security documents, such as, for example, banknotes and identity documents, from counterfeiting and illegal copying. In particular, the present invention provides a method for producing an optical effect layer (OEL) comprising at least a first pattern and a second pattern, each of the patterns independently comprising sheet-like magnetic or magnetisable pigment particles oriented according to a specific magnetic pattern, wherein the first pattern and the second pattern have different magnetic orientation patterns and are at least partially adjacent and properly registered.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480079746.8 (22) Application Date 2024.12.19 (30) Priority Data 23218642.9 2023.12.20 EP (85) PCT International Application Entering National Phase Date 2026.06.16 (86) PCT International Application Application Data PCT / EP2024 / 087467 2024.12.19 (87) PCT International Application Publication Data WO2025 / 132834 EN 2025.06.26 (71) Applicant Sikbai Holding Ltd. Address Switzerland (72) Inventor N. Benninger (74) Patent Agency Beijing Linda Liu Intellectual Property Agency (General Partnership) 11277 Patent Attorneys Li Maojia and Duan Ran (51) Int.Cl. B05D 3 / 00 (2006.01) B05D 5 / 06 (2006.01) (54) Invention Title: Method for Generating an Optical Effect Layer (57) Abstract: This invention relates to the field of protecting secure documents such as banknotes and identity documents from counterfeiting and illegal copying. In particular, the invention provides a method for generating an optical effect layer (OEL) comprising at least a first pattern and a second pattern, each of the patterns independently comprising sheet-like magnetic or magnetizable pigment particles oriented according to a specific magnetic pattern, wherein the first pattern and the second pattern have different magnetic orientation patterns and are at least partially adjacent and properly registered. Claims 2 pages, Description 40 pages, Drawings 7 pages, CN 122396552 A 2026.07.14 CN 1 22 39 65 52 A 1. A method for forming an optical effect layer (OEL) on a substrate (x10), the optical effect layer (OEL) comprising a first pattern and a second pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, the second pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, the first magnetic pattern being different from the second magnetic pattern, the method comprising: a first set of steps, comprising: a') applying a first radiation-curable coating composition, preferably a first UV-Vis-curable coating composition, exhibiting color and comprising sheet-like magnetic or magnetizable pigment particles, to the substrate (x10) to form a first coating (x20') on the substrate (x10), the coating composition being in a first state, b') the steps a The radiation-curable coating composition of ') is exposed to the first magnetic field of the magnetic component (x30'),To magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles; c') to at least partially cure the radiation-curable coating composition of step b') to a second state to fix the sheet-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a first pattern; and a second set of steps, comprising: a'') applying a second radiation-curable coating composition, preferably a UV-Vis curable coating composition, having the same color as the first radiation-curable coating composition of step a') to form a second coating (x20'') on the substrate (x10), the coating composition being in the first state, and at least a portion of the second coating (x20'') being adjacent to at least a portion of the first coating (x20'); b'') to apply the second radiation-curable coating composition of step a') to a second state to form a second coating (x20'') on the substrate (x10), the coating composition being in the first state, and at least a portion of the second coating (x20') being adjacent to at least a portion of the first coating (x20'); b'') to apply the second radiation-curable coating composition of step a') to a second state to form a second coating (x20'') on the substrate (x10), the second ... radiation-curable coating composition being in the first state, and at least a portion of the second coating (x20' The radiation-curable coating composition of step b'') is exposed to a second magnetic field of the magnetic component (x30'') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles; and c'') the radiation-curable coating composition of step b'') is at least partially cured to a second state to fix the sheet-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a second pattern, wherein at least a portion of the second coating (x20'') is adjacent to at least a portion of the first coating (x20') meaning that the first pattern and the second pattern are continuous. 2. The method according to claim 1, wherein the radiation-curable coating composition of step a') and the radiation-curable coating composition of step a'') are the same. 3. The method according to claim 1 or 2, wherein at least one of step b') and step b'') is a one-step orientation step of uniaxially orienting the sheet-like magnetic or magnetizable pigment particles, or a one-step orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles, or a two-step orientation step comprising a first orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles. 4. The method according to claim 3, wherein step b') comprises a one-step orientation step of uniaxially or biaxially oriented, preferably biaxially oriented, of the sheet-like magnetic or magnetizable pigment particles, and step b'') is a two-step orientation step comprising a first orientation step and a subsequent second orientation step, wherein the first orientation step oriented the sheet-like magnetic or magnetizable pigment particles biaxially, and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles; or step b') is a two-step orientation step comprising a first orientation step and a subsequent second orientation step, wherein the first orientation step oriented the sheet-like magnetic or magnetizable pigment particles biaxially, and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles.And step b'') includes a one-step orientation step of uniaxially or biaxially oriented, preferably biaxially oriented, of the sheet-like magnetic or magnetizable pigment particles; or step b') is a two-step orientation step including a first orientation step and a subsequent second orientation step, wherein the first orientation step oriented the sheet-like magnetic or magnetizable pigment particles biaxially, and the second orientation step reorients the sheet-like magnetic or magnetizable pigment particles, and step b'') is a two-step orientation step including a first orientation step and a subsequent second orientation step, wherein the first orientation step oriented the sheet-like magnetic or magnetizable pigment particles biaxially, and the second orientation step reorients the sheet-like magnetic or magnetizable pigment particles. 5. The method according to claim 3 or 4, wherein at least one of step b') and step b'') comprises a one-step orientation step of biaxially oriented sheet-like magnetic or magnetizable pigment particles, or a two-step orientation step comprising a first orientation step and a subsequent second orientation step, the first orientation step biaxially orienteding the sheet-like magnetic or magnetizable pigment particles, the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles, wherein the first orientation step, which performs both the one-step and two-step orientation steps, biaxially oriented at least a portion of the sheet-like magnetic or magnetizable pigment particles such that i) both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) a first axis in the XY plane is substantially parallel to the surface of the substrate (x10), and a second axis is perpendicular to the first axis at a substantially non-zero elevation angle to the surface of the substrate (x10), or iii) their XY plane is parallel to the surface of an imaginary sphere. 6. The method according to any one of claims 1 to 5, wherein step c') is performed simultaneously with part of step b') and / or step c'') is performed simultaneously with part of step b''). 7. The method of claim 6, wherein step c') is performed by exposing the LED curing unit (x50') to UV-Vis light radiation, and / or step c'') is performed by exposing the LED curing unit (x50'') to UV-Vis light radiation. 8. The method of any one of claims 1 to 7, wherein at least a portion of the sheet-like magnetic or magnetizable pigment particles is composed of sheet-like optically variable magnetic or magnetizable pigment particles. 9. The method of any one of claims 1 to 8, wherein the substrate (x10) is selected from the group consisting of: paper or other fibrous materials, paper-containing materials, glass, metals, ceramics, polymers, metallized polymers, at least partially opaque polymer composites, and mixtures or combinations thereof. 10. The method of any one of claims 1 to 9,11. The method according to any one of claims 1 to 9, wherein the second radiation-curable coating composition is registered and applied to the same side of the substrate (x10) carrying the first coating (x20'), wherein preferably the substrate (x10) is a transparent substrate. 12. The method according to any one of claims 1 to 11, wherein the substrate (x10) comprises a printed pattern, preferably an offset printed pattern, and wherein at least one of the radiation-curable coating compositions of steps a') and a'') is at least partially applied to the printed pattern. 13. The method according to any one of claims 1 to 12, further comprising a third pattern having a third magnetic pattern and optionally a fourth pattern, the third magnetic pattern being different from the first magnetic pattern and different from the second magnetic pattern, and the fourth magnetic pattern being different from the first magnetic pattern, different from the second magnetic pattern and different from the third magnetic pattern. 14. The method according to any one of claims 1 to 13, wherein the first coating (x20') and the second coating (x20'') are registered within ±1 mm, preferably ±0.5 mm, more preferably ±0.2 mm. 15. The method according to any one of claims 1 to 14, wherein the method is a continuous method using a single machine, continuous meaning that the second set of steps is performed directly after the first set of steps, or, if the method includes a third set of steps, the third set of steps is performed directly after the second set of steps. Claims 2 / 2 Page 3 CN 122396552 A Method for Generating Optical Effect Layers Technical Field

[0001] The present invention relates to the field of methods for generating optical effect layers (OELs) comprising magnetically oriented sheet-like magnetic or magnetizable pigment particles. In particular, the present invention provides a method for magnetically oriented sheet-like magnetic or magnetizable pigment particles in more than one coating to generate an OEL, and the use of said OEL as an anti-counterfeiting means and for decorative purposes on secure documents or security articles. Background Art

[0002] It is known in the art to use inks, compositions, coatings, or layers containing oriented magnetic or magnetizable pigment particles, and in particular optically variable magnetic or magnetizable pigment particles, to generate security elements, for example, in the field of secure documents. Coatings or layers containing oriented magnetic or magnetizable pigment particles are disclosed, for example, in 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 are disclosed in WO 2002 / 090002 A2 and WO 2005 / 002866 A1.This results in particularly attractive optical effects that can be used to protect secure documents.

[0003] For example, security features for secure documents can generally be classified as “covert” security features on one hand and “overt” security features on the other. The protection provided by covert security features relies on the principle that the feature is difficult to detect, usually requiring specialized equipment and knowledge for detection, while “overt” security features rely on the concept that can be easily detected with unassisted human senses, for example, the feature can be visible and / or detectable via tactile senses, while still being difficult to produce and / or reproduce. However, the effectiveness of overt security features depends largely on their ease of identification as security features.

[0004] Magnetic or magnetizable pigment particles in printing inks or coatings allow the local orientation of magnetic or magnetizable pigment particles in an uncured (i.e., wet) coating to be induced by applying a correspondingly structured magnetic field, and then the coating is cured, to produce magnetically induced images, designs and / or patterns (also referred to in the art as “optical effect layers (OELs)”). The result is a fixed and stable magnetically induced image, design, or pattern. Materials and techniques for orienting magnetic or magnetizable pigment particles in a coating composition are known. The magnetically induced image in question can only be produced by simultaneously utilizing magnetic or magnetizable pigment particles or corresponding inks, along with specific techniques for printing the ink and orienting the pigments in the printing ink.

[0005] For the purpose of optimizing and improving the anti-counterfeiting properties of secure documents, particularly banknotes, conspicuous and sophisticated magnetically induced images and optical effect layers (OELs) have been developed. These OELs are obtained by using specific magnetic components and advantageously exhibit a dynamic appearance when tilted. Examples of such dynamic OELs include reflective area stripes that move with the tilt of the OEL, annular structures that move with the tilt of the OEL, annular structures with changing shapes as the OEL tilts, and bright and dark areas that move with the tilt of the OEL. WO 2012 / 104098 A1 discloses an OEL comprising more than one magnetically induced image, each image having a different magnetic orientation pattern. WO 2012 / 104098 A1 discloses an OEL comprising two regions, each region exhibiting a reflective area strip that moves as the OEL is tilted, one of the strips moving away from the observer as the OEL is tilted, and the other of the strips moving towards the observer as the OEL is tilted.

[0006] A method for producing an OEL comprising at least two regions made of a single cured layer includes: i) applying a UV-curable ink comprising magnetic or magnetizable particles to a substrate to form a coating; ii) exposing the coating to a magnetic field of a magnetic field generating device (page 1 / 40 of the specification 4 CN 122396552 A).This causes the pigment particles to orient; iii) curing one or more first regions of the coating to a second state to fix the magnetic or magnetizable particles in their adopted positions and orientations, said curing being carried out by selectively irradiating the coating with a radiation source; iv) exposing the coating to the magnetic field of a magnetic field generating device, thereby causing the magnetic or magnetizable particles contained in the coating, which are still in a wet liquid state and have not yet cured due to the selective curing of step iii), to reorient; and v) curing the coating to fix the magnetic or magnetizable particles in their newly adopted positions and orientations.

[0007] In the field of curing coating or ink compositions for producing OEL with the aid of a UV radiation source, it is known that the characteristics and construction of the UV radiation source and the precise exposure conditions of the coating or ink composition to the UV radiation source are crucial for obtaining high-resolution images and rapid curing of the composition. However, known methods for selective curing suffer from several disadvantages.

[0008] A method is disclosed that includes using a fixed photomask comprising one or more gaps corresponding to a pattern to be formed as part of an image on a coating carried by a fixed substrate. However, the disclosed method may result in potential shadowing effects on the coating due to the following constraints: a) the photomask may not contact the uncured ink layer but must be positioned at a distance from it, and b) the UV source must be an extended light source. All of these result in low-resolution images and require operation at low printing speeds due to the need to keep the substrate, photomask, and UV source in a fixed relative position during exposure time. Alternatively, a fixed photomask may be used with a coating carried by a moving substrate. The method may also result in shadowing effects and / or image blurring on the coating due to moving the substrate at industrial speeds during exposure to irradiation, without any possibility of implementing variable image information during printing. Alternatively, a moving photomask may be used with a moving substrate. However, the method may also result in shadowing effects on the coating, resulting in low-resolution imaging and is highly complex to implement.

[0009] Another method uses a laser beam. However, this method is known to require highly specialized equipment and is costly.

[0010] Another method uses an array of LED light-emitting diodes (LEDs). However, this method may suffer from unnecessarily low optical density, resulting in longer curing times and reduced printing performance.

[0011] There remains a need for improved and controlled methods for producing striking optical effect layers (OELs) on security printing presses at industrial speeds, wherein the OELs thus produced are easily verifiable by ordinary people, while the methods are very difficult for counterfeiters and the illicit market to implement in large-scale production. Summary of the Invention

[0012] Therefore, the objective of the present invention is to overcome the deficiencies of the prior art as described above. This is achieved by providing a method for producing an optical effect layer (OEL) on a substrate (x10).The optical effect layer (OEL) includes a first pattern and a second pattern, the first pattern including sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, and the second pattern including sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, wherein the first magnetic pattern is different from the second magnetic pattern, and the method includes:

[0013] a first set of steps, including:

[0014] a') applying a first radiation-curable coating composition, preferably a first UV-Vis curable coating composition, exhibiting color and including sheet-like magnetic or magnetizable pigment particles, to a substrate (x10) to form a first coating (x20') on the substrate (x10), the coating composition being in a first state;

[0015] b') exposing the radiation-curable coating composition of step a') to a first magnetic field of a magnetic component (x30') to magnetically oriented at least a portion of the sheet-like magnetic or magnetizable pigment particles;

[0016] c') Curing at least partially the radiation-curable coating composition of step b') to a second state to fix the flake-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a first pattern; and specification 2 / 40 pages 5 CN 122396552 A

[0017] A second set of steps, comprising:

[0018] a'') applying a second radiation-curable coating composition, preferably a UV-Vis curable coating composition, having the same color as the first radiation-curable coating composition of step a') to form a second coating (x20'') on the substrate (x10), the coating composition being in a first state, and at least a portion of the second coating (x20'') being adjacent to at least a portion of the first coating (x20');

[0019] b'') exposing the radiation-curable coating composition of step a'') to a second magnetic field of a magnetic component (x30'') to magnetically orient at least a portion of the flake-like magnetic or magnetizable pigment particles; and

[0020] c'') The radiation-curable coating composition of step b'') is at least partially cured to a second state to fix the flake-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a second pattern, the second pattern being suitably registered with the first pattern.

[0021] This document also describes a method for producing an OEL comprising a first pattern, a second pattern, and a third pattern, the first pattern comprising flake-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern as described herein, the second pattern comprising flake-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern as described herein, and the third pattern comprising flake-like magnetic or magnetizable pigment particles oriented according to a third magnetic pattern, wherein the first, second, and third magnetic patterns are different from each other.At least a portion of the third graphic is adjacent to at least a portion of the first graphic and / or at least a portion of the second graphic (i.e., the third graphic is at least partially adjacent to and properly registered with the first graphic and / or at least partially adjacent to and properly registered with the second graphic), and the method includes the first set of steps a'), b') and c') described herein, the second set of steps a''), b'') and c'') described herein, and the third set of steps a'''), b''') and c''') described herein, the third step a''') being performed after and continuously therewith step c'').

[0022] This document also describes a method in which a second radiation-curable coating composition is registered and applied to the same side of a substrate (x10) carrying a first coating (x20') and a method in which a second radiation-curable coating composition is registered and applied to the opposite side of a substrate (x10) carrying a first coating (x20').

[0023] This document also describes optical effect layers (OELs) and security documents produced by the methods described herein, as well as decorative elements and objects comprising one or more optical OELs described herein.

[0024] This document also describes a method of manufacturing a security document or decorative element or object, comprising a) providing a security document or decorative element or object, and b) providing an optical effect layer obtained by the method described herein, such that it is contained within the security document or decorative element or object.

[0025] The present invention provides a method that advantageously allows the manufacture of a striking optical effect layer (OEL) that is easily authenticated by the average person. In particular, the OEL produced by the method described herein contains first and second patterns described herein with the same color, thus allowing easy authentication due to the continuity of the colors, while combining a high level of anti-counterfeiting due to the complex adjacent registration patterns of different magnetic orientation patterns. Thanks to the controlled method described herein and the optical effect layer (OEL) thus obtained, authentication of the obvious security features allows an observer to easily distinguish between counterfeits (visually similar results obtained by different methods) and inferior copies (obtained by the same method but less well controlled). Brief Description of the Drawings

[0026] Figures 1-12 are provided in which the invention is schematically illustrated and not drawn to scale. The optical effect layer (OEL) and its generation described herein will now be described in more detail with reference to the accompanying drawings and specific embodiments, wherein

[0027] FIG1 schematically illustrates a combination of a first pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern and a second pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern.In its specification, page 3 / 40, 6 CN 122396552 A, the first and second patterns are placed on the same side of the substrate (110) (Fig. 1 Embodiment A) or on opposite sides of the substrate (110) (Fig. 1 Embodiment B).

[0028] FIG. 2 schematically shows flake-shaped pigment particles.

[0029] FIG. 3 schematically shows a method for producing an optical effect layer (OEL) on a substrate (310) including a first set of steps (1) and a second set of steps (2) according to the invention, wherein both orientation steps b') and b'') include an orientation step,

[0030] wherein a first coating (320') obtained by screen printing (340') (step a')) is exposed to a first magnetic field of a magnetic component (330') to magnetically orient at least a portion of the flake-shaped magnetic or magnetizable pigment particles (step b')), and is at least partially cured with a first curing unit (350') (step c')), and wherein

[0031] Following and continuing with step c'), the second coating (320'') obtained by screen printing (340'') (step a'') is exposed to the second magnetic field of the magnetic component (330'') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles (step b'')), and is at least partially cured with the second curing unit (350'') (step c'')).

[0032] FIG4A-1 schematically illustrates a one-step orientation step b) (b) is b') and / or b'')), wherein the coating (420) is exposed to the magnetic field of the magnetic component (430). Figures 4A-2 and 4A-3 illustrate an industrial one-step orientation step b), in which the coating (420) is exposed to the magnetic field of a magnetic component (430) mounted on a rotating magnetic cylinder, wherein the coating (420) faces the environment (Figure 4A-2), or is placed outside the rotating cylinder, wherein the coating (420) faces the magnetic component (430) (Figure 4A-3).

[0033] Figure 4B-1 schematically illustrates a one-step orientation step b) (b) is b') and / or b'')), in which the coating (420) is exposed to the combined magnetic field of the first magnetic component (430-a) and the second magnetic component (430-b). Figure 4B-2 illustrates an industrial one-step orientation step b), wherein the coating (420) is exposed to a combined magnetic field of a first magnetic component (430-a) and a second magnetic component (430-b), wherein the first magnetic component (430-a) is mounted on a rotating magnetic cylinder and the second magnetic component (430-a) is placed outside the rotating magnetic cylinder.

[0034] Figure 5-1 schematically illustrates a method for producing an optical effect layer (OEL) on a substrate (510) including a first set of steps (1) and a second set of steps (2) according to the invention, wherein both orientation steps b') and b'') comprise two orientation steps.

[0035] The first coating (520') obtained by screen printing (540') (step a') is first exposed to a first magnetic field of the magnetic component (530'-a) (step b'-1) and then subsequently exposed to a second magnetic field of the magnetic component (530'-b) (step b'-2) to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles (step b') and wherein the coating (520') is at least partially cured with a first curing unit (550') (step c') and wherein

[0036] Following and continuing with step c'), the second coating (520'') obtained by screen printing (540'') (step a'') is first exposed to the magnetic field of the first magnetic field of the magnetic component (530''-a) (step b''-1) and then subsequently exposed to the magnetic field of the second magnetic field of the magnetic component (530''-b) (step b''-2) to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles (step b'') and wherein the second coating (520'') is at least partially cured with the second curing unit (550'') (step c'')).

[0037] Figure 5-2 schematically illustrates the two steps b) (b) being b') and / or b'')), wherein the coating (520) is first exposed to the magnetic field of the first magnetic component (530-a) and subsequently exposed to the second magnetic component (530-b). Figure 5-3 schematically illustrates the industrial two-step orientation step b)(b) is b') and / or b'')), wherein the coating (520) is first exposed to the magnetic field of the first magnetic component (530-a) and subsequently exposed to the second magnetic component (530-b), which is placed on a rotating magnetic cylinder, and wherein the coating (520) is at least partially cured with the curing unit (550') (step c)). Figure 5-4 schematically illustrates an industrial two-step orientation step b)(b) is b') and / or b'')), wherein the coating (520) is first exposed to the magnetic field of a first magnetic component (530-a) and subsequently exposed to the combined magnetic field of a second magnetic component (530-b) and a third magnetic component (530-c), the second magnetic component (530-b) being mounted on a rotating magnetic cylinder and the third magnetic component (530-c) being outside the rotating magnetic cylinder as described on page 4 / 40 of the specification 7 CN 122396552 A, and wherein the coating (520) is at least partially cured with a curing unit (550') (step c)).

[0038] Figure 6-1 schematically illustrates a method with a one-step orientation step b)(b) is b') and / or b'')) used in the embodiment provided therein, wherein the coating (620) is exposed to the magnetic field of the magnetic component (630), and simultaneously with the orientation step b),The obtained magnetic orientation pattern is at least partially cured with curing unit (650) (step c)).

[0039] FIG6-2 schematically illustrates a method with two orientation steps b) (b) being b') and / or b'') used in the embodiments provided therein, wherein the coating (620) is first exposed to the magnetic field of the magnetic component (630-a) and subsequently exposed to the combined magnetic field of the second magnetic component (630-b) and the third magnetic component (630-c), and the obtained magnetic orientation pattern is at least partially cured with curing unit (650) (step c) simultaneously with orientation step b).

[0040] FIG7 schematically illustrates a magnetic component (730) for biaxially oriented pigment particles and used in the embodiments provided therein.

[0041] FIG8A-FIG.8B schematically illustrate a magnetic component (830) comprising a dipole magnet (830-1) used in the embodiments provided therein, and which is adapted to produce a pattern exhibiting dynamic movement when tilted, the dynamic movement being bright reflective strips that move when the pattern is tilted.

[0042] FIG9 schematically illustrates a magnetic assembly (930) comprising dipole magnets (930-1, 930-2, and 930-3) used in the embodiments provided therein, and is adapted to produce a graphic exhibiting dynamic movement when tilted, the dynamic movement being a pattern of bright and dark areas moving when the graphic is tilted.

[0043] FIG10 schematically illustrates a magnetic assembly (1030) used in the embodiments provided therein, and is adapted to produce a graphic exhibiting markings and exhibiting dynamic movement of reflective bars that move when the graphic is tilted, wherein the assembly (1030) comprises an engraved plate (1030-2) and a dipole magnet (1030-1).

[0044] FIG11 schematically illustrates a magnetic assembly (1130) used in the embodiments provided therein, and is adapted to produce a graphic exhibiting markings, wherein the assembly (1130) comprises a soft magnetic plate (1130-1) having indentations (I) in the form of markings.

[0045] Figure 12 shows photographic images of an OEL produced by the method of the present invention viewed from different angles.

[0046] The distances provided in the figures are illustrative only and not drawn to scale. Detailed Description

[0047] Definitions

[0048] The following definitions are used to clarify the meaning of terms defined in the discussion and claims of the specification.

[0049] As used herein, the indefinite article “a(a)” means one and greater than one, and does not necessarily limit its noun to the singular.

[0050] As used herein, the term “at least” is intended to define one or greater than one, for example, one, two, or three.

[0051] As used herein, the term “about” means that the quantity or value in discussion may be a specified particular value or some other value nearby. Generally,The term “about”, indicating a certain value, is intended to indicate a range within ±5% of that value. As an example, the phrase “about 100” indicates a range of 100 ± 5, i.e., a range of 95 to 105. Generally, when the term “about” is used, similar results or effects according to the invention can be expected to be obtained within ±5% of the indicated value.

[0052] As used herein, the term “and / or” means that all or only one of the elements of the group may be present. For example, “A and / or B” should mean “only A, or only B, or both A and B.” In the case of “only A,” the term also covers the possibility that B is not present, i.e., “only A, but not B.”

[0053] The term “comprising,” as used herein, is intended to be non-exclusive and open-ended. Thus, a coating composition, for example, comprising compound A (page 5 / 40 of specification 8 CN 122396552 A), may comprise other compounds besides A. However, as in particular embodiments thereof, the term “comprising” also encompasses the more restrictive meanings of “consistently composed of” and “composed of”, such that, for example, “a dampening solution comprising A, B and optional C” may also consist (substantially) of A and B, or (substantially) of A, B and C.

[0054] The term “optical effect layer (OEL)” as used herein refers to a coating or layer comprising oriented sheet-like magnetic or magnetizable pigment particles and a binder, wherein the sheet-like magnetic or magnetizable pigment particles are oriented by a magnetic field, and wherein the oriented sheet-like magnetic or magnetizable pigment particles are fixed / frozen in their orientation and position (i.e., after hardening / curing) to form a magnetically induced image.

[0055] The term “coating composition” refers to any composition capable of forming an optical effect layer (OEL) on a solid substrate, and which may preferably, but not exclusively, be applied by a printing method. The coating composition comprises the sheet-like magnetic or magnetizable pigment particles described herein and the binder described herein.

[0056] As used herein, the term “wet” refers to a coating that has not yet cured, such as a coating in which the flake-like magnetic or magnetizable pigment particles are still capable of changing their position and orientation under the influence of an external force acting upon them.

[0057] As used herein, the term “marking” refers to discontinuous layers, such as patterns, including but not limited to symbols, alphanumeric symbols, motifs, letters, words, numbers, signs, and drawings.

[0058] The term “hardening” is used to indicate a method in which the viscosity of a coating composition that has not yet hardened (i.e., wet) in a first physical state is increased in order to transform it into a second physical state, i.e., a hardened or solid state, in which the flake-like magnetic or magnetizable pigment particles are fixed / frozen in their current position and orientation.And it cannot be moved or rotated again.

[0059] The term "secure document" refers to a document that is typically protected against forgery or tampering by at least one security feature. Examples of secure documents include, but are not limited to, documents of value and goods of value.

[0060] The term "security feature" is used to refer to an image, pattern, or graphic element that can be used for authentication purposes.

[0061] Where this specification refers to "preferred" embodiments / features, combinations of these "preferred" embodiments / features should also be considered disclosed, provided that such combinations of "preferred" embodiments / features are technically meaningful.

[0062] The present invention provides a method for producing an optical effect layer (OEL) suitable as a security feature against forgery or fraud, and comprising magnetically oriented sheet-like magnetic or magnetizable pigment particles on a substrate. As shown in Figure 1, the OEL comprises a first pattern in the form of a cured first coating 120' and a second pattern in the form of a cured second coating 120''. The first pattern comprises sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, and the second pattern comprises sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, wherein the first magnetic pattern differs from the second magnetic pattern. The first and second patterns are at least partially adjacent to each other (i.e., the second pattern is adjacent to at least a portion of the first pattern) and properly registered. The first and second patterns are made of a cured coating composition having the same color as visible to the naked eye. The first and second patterns in the form of a cured first coating x 20'' and a second coating x 20'' may independently comprise a single sub-pattern, or may comprise more than one sub-pattern as shown in Figure 1, wherein the more than one sub-pattern independently forms the first and second patterns. For example, the OEL shown in Figure 1 comprises a balloon comprising a first pattern comprising three sub-patterns and a second pattern comprising three sub-patterns. If the first and / or second patterns described herein independently comprise the first and second sub-patterns (as shown, for example, in Figure 1), then a continuous optical effect is obtained by combining multiple sub-patterns.

[0063] As described herein, different magnetic patterns of the first and second patterns are obtained by independently exposing the radiation-curable coating composition of step a') and the radiation-curable coating composition of step a'') to different magnetic fields to form the first and second coatings (x20' and x20''), respectively. Different magnetic fields can be obtained by using different magnetic components (different x30' and x30'') or by using the same magnetic components (x30' and x30'' are the same) on different sides of the substrate (x10). For embodiments using "the same magnetic components" during industrial methods using a rotating cylinder, it means using the first magnetic component (x30') during step b').And during step b''), a second magnetic component (x30'') is used, wherein the component is two separate objects, rather than using "the" same object twice. The methods for preparing the OELs of the embodiments E1-E8 provided herein use different magnetic components.

[0064] The method described herein comprises at least two sets of steps, namely a first set comprising steps a'), b'), and c'), and a third set of steps comprising at least a second set (optionally comprising a'''), b'''), and c'''), and a fourth set of steps, optionally comprising a''''), b''''), and c'''), etc. Thus, the method described herein is a continuous method, which means that the second set of steps is performed directly after the first set, in other words, step a''' of the second set is performed after and directly after step c'') of the first set, without removing the substrate carrying the first coating (x20') from the printing press, i.e., it is a continuous feed to perform the second set of steps. In other words, the multi-step method described herein is a continuous method using a single machine that allows for the application, preferably printing, exposure of the composition to a magnetic field, and at least partial curing of the composition. This method allows for the preparation of an OEL comprising a first and second pattern (optionally a third, fourth, etc.) described herein with different magnetic patterns, wherein the first and second patterns are at least partially adjacent to each other (i.e., the second pattern is adjacent to at least a portion of the first pattern and properly registered). Examples of such a single machine allowing the multi-step process described herein are disclosed in US 2021 / 0316545, which comprises, in the following order: at least a first printing unit, a first alignment unit, a first curing unit, a second printing unit for downstream application of the composition, a second alignment unit, and a second curing unit.

[0065] According to one embodiment shown in Figure 1 (Embodiment A), the OEL described herein comprises first and second patterns (i.e., first cured coating 120' and second cured coating 120'') on the same side of a substrate (110), wherein the first and second patterns are adjacent to each other (i.e., the second pattern is adjacent to at least a portion of the first pattern) and fully registered, such that an observer perceives the OEL as a continuous security feature. By "adjacent," this means that the first and second patterns are continuous (i.e., they share at least one area together and have a common boundary). The first and second patterns of the OEL are at least partially adjacent to each other (i.e., the second pattern is adjacent to at least a portion of the first pattern) and properly registered, preferably at least partially juxtaposed and properly registered or at least partially staggered and properly registered. The first and second patterns may be continuous or discontinuous. For clarity, the term adjacent does not refer to superimposed patterns (i.e., the invention does not cover the second pattern being at least partially on top of the first pattern,Or the first graphic is at least partially on top of the second graphic.

[0066] According to another embodiment (Embodiment B) shown in FIG1, the OEL described herein includes first and second graphics (i.e., first cured coating 120' and second cured coating 120'') on opposite sides of a substrate (110), wherein the substrate (110) is preferably transparent, and wherein the first and second graphics are at least partially adjacent to each other (i.e., the second graphic is adjacent to at least a portion of the first graphic) and properly registered, such that an observer perceives the OEL as a continuous feature in either perspective or transparency viewing mode. By “adjacent”, this means that the projections of the first and second graphics on each side of the substrate (110) (see the dashed lines in FIG1, Embodiment B) are continuous (i.e., they share at least one area together and have a common boundary). The projections of the first and second graphics on each side of the substrate (110) are at least partially adjacent to each other (i.e., the second graphic is adjacent to at least a portion of the first graphic) and properly registered, preferably at least partially juxtaposed and properly registered or at least partially staggered and properly registered. The first and second graphics may be continuous or discontinuous. For clarity, the term adjacent does not refer to superimposed patterns on each side of the substrate (i.e., the invention does not cover a projection of the second pattern at least partially on top of the first pattern, or a projection of the first pattern at least partially on top of the second pattern).

[0067] The method described herein comprises at least two separate steps a') and a''), which include: applying a first radiation-curable coating composition to a substrate (x10) to form a first coating (x20') (step a'), and applying a second radiation-curable coating composition to form a second coating (x20'') (step a'')), wherein the first and second radiation-curable coating compositions are in a first physical state, which allows them to be applied as layers, and they are in a pre-cured (i.e., wet) state, wherein flake-like magnetic or magnetizable pigment particles can move and rotate within the binder material.

[0068] The method described herein comprises at least two independent steps b') and b''), which include: independently exposing the first and second radiation-curable coating compositions of steps a') and a'') to a magnetic field to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles, and forming first and second coatings (and forming first and second patterns), the first and second patterns thus obtained having a registered specific magnetic orientation pattern, i.e., the method described herein allows control of the position of the magnetic components (x30' and x30'') during steps b') and b'').

[0069] As mentioned herein,The first and second coatings (x20' and x20'') (and the respective first and second patterns) are at least partially adjacent to each other (i.e., the second pattern is adjacent to at least a portion of the first pattern) and properly registered. This means that not only is the radiation-curable coating composition applied with no or very limited (less than 1 mm, preferably less than 0.5 mm, more preferably less than or equal to 0.2 mm) misalignment and misalignment between the second coating (x20'') and the first coating (x20'), but the resulting OEL provides a first and second magnetic pattern that appears as a continuous image to the naked eye (i.e., an unbroken image). This registration is permitted using a single machine via a claimed continuous method. According to one embodiment, the first and second coatings (x20' and x20'') are applied within a registration of ±1 mm, preferably ±0.5 mm, more preferably ±0.2 mm. This registration is permitted using a single machine via a claimed continuous method.

[0070] Preferably, steps a') and a'') are performed independently by a printing method, preferably independently selected from the group consisting of screen printing, rotary gravure printing, flexographic printing, and gravure printing (also known in the art as engraving copperplate printing and engraving steel mold printing), more preferably selected from the group consisting of screen printing, rotary gravure printing, and flexographic printing, and even more preferably by screen printing.

[0071] Screen printing (also known in the art as silkscreen printing) is a stencil method in which ink is transferred to a surface through a stencil supported by a finely woven mesh of silk, such as monofilaments or multifilaments or metal wires made of synthetic fibers such as polyamide or polyester, stretched on a frame made of, for example, wood or metal (e.g., aluminum or stainless steel). Alternatively, the screen printing mesh can be a chemically etched, laser-etched, or electrically formed porous metal foil, such as stainless steel foil. The holes of the mesh are blocked in non-image areas and remain open in image areas; the image carrier is called the screen. Screen printing can be planar or rotary. Screen printing is further described, for example, in *The Printing Ink Manual*, RH Leach and RJ Pierce, Springer, 5th edition, pp. 58-62 and *Printing Technology*, J.M. Adams and PA Dolin, Delmar Thomson Learning, 5th edition, pp. 293-328.

[0072] Rotary gravure (also known in the art as gravure) is a printing method in which image elements are engraved in the surface of a cylinder. Non-image areas are at a constant original level. Before printing,The entire printing plate (both non-printing and printing elements) is inked and filled with ink. Before printing, the ink is removed from the non-image area by a wiper or doctor blade, leaving only ink in the cell. The image is transferred from the cell to the substrate by pressure typically in the range of 2-4 bar and by the adhesive force between the substrate and the ink. The term rotary gravure does not include, for example, intaglio printing methods that rely on different types of ink (also known in the art as engraving steel molds or copperplate printing methods). More details are available in "Handbook of print media", Helmut Kipphan, Springer, p. 48 and "The Printing ink manual", RH Leach and RJ Pierce, Springer, 5th edition, pp. 42-51. Specification 8 / 40 pages 11 CN 122396552 A

[0073] Flexographic printing preferably uses a cell with a doctor blade, preferably a cavity doctor blade, an anilox roller and a printing cylinder. Anilox rollers advantageously have small cells whose volume and / or density determine the ink application rate. A doctor blade is placed against the anilox roller and simultaneously scrapes away excess ink. The anilox roller transfers the ink to a plate cylinder, which ultimately transfers the ink to the substrate. Specific designs can be achieved using designed photopolymer plates. The plate cylinder can be made of polymer or elastomer materials. Polymers are primarily used as photopolymers in printing plates and sometimes as seamless coatings on sleeves. Photopolymer printing plates are made of photosensitive polymers that are cured by ultraviolet (UV) light. The photopolymer printing plate is cut to the desired size and placed in a UV light exposure unit. One side of the printing plate is fully exposed to UV light to harden or cure the base of the printing plate. The printing plate is then flipped over, the film for the job is mounted on the uncured side, and the printing plate is further exposed to UV light. This hardens the printing plate in the image areas. The printing plate is then processed to remove the uncured photopolymer from the non-image areas, which reduces the surface area of ​​the printing plate in these non-image areas. After treatment, the printing plate is dried and given a post-exposure dose of UV light to cure the entire plate. Preparation of the printing cylinder for flexographic printing is described in *Printing Technology*, J.M. Adams and P.A. Dolin, Delmar Thomson Learning, 5th ed., pp. 359-360, and *The Printing Ink Manual*, RH Leach and RJ Pierce, Springer Press, 5th ed.Described on pages 33-42.

[0074] The first and second radiation-curable coating compositions are applied independently during steps a') and a'') to form a first coating (x20') and a second coating (x20''), respectively. The first and second radiation-curable coating compositions independently contain a binder and the sheet-like magnetic or magnetizable pigment particles described herein.

[0075] The first radiation-curable coating composition exhibits a color, and the second radiation-curable coating composition exhibits the same color as seen by the naked eye. For optically variable sheet-like magnetic or magnetizable pigment particles, i.e., pigments that exhibit different colors when tilted (i.e., exhibiting face color and different angle color), "same color" means the same face color and the same angle color.

[0076] According to one embodiment, the first and second radiation-curable coating compositions have different binders but contain the same sheet-like magnetic or magnetizable pigment particles, such that they exhibit the same color as seen by the naked eye. According to another embodiment, the first and second radiation-curable coating compositions are identical, i.e., they contain the same binder and contain the same sheet-like magnetic or magnetizable pigment particles.

[0077] The first and second coating compositions described herein, as well as the first coating layer (x20') and the second coating layer (x20'') described herein, comprise the sheet-like magnetic or magnetizable pigment particles described herein. In contrast to needle-like pigment particles, which can be considered quasi-one-dimensional particles, sheet-like pigment particles are quasi-two-dimensional particles due to their large aspect ratio. As shown in Figure 2, sheet-like pigment particles can be considered as two-dimensional structures where dimensions X and Y are substantially larger than dimension Z. Sheet-like pigment particles are also referred to in the art as oblate particles or flakes. Such pigment particles can be described as having a principal axis X corresponding to their longest dimension passing through the pigment particle and a second axis Y perpendicular to X and corresponding to the second longest dimension passing through the pigment particle. In other words, the XY plane roughly defines the plane formed by the first and second longest dimensions of the pigment particle, with dimension Z being ignored.

[0078] The sheet-like magnetic or magnetizable pigment particles described herein have an isotropic reflectivity relative to incident electromagnetic radiation due to their non-spherical shape, for which the hardened / cured binder material is at least partially transparent. As used herein, the term "anisotropic reflectivity" means that the proportion of radiation incident from a first angle that is reflected by the particles to a certain (viewing) direction (second angle) is a function of particle orientation; that is, a change in particle orientation relative to the first angle can result in different magnitudes of reflection to the viewing direction.

[0079] In the first and second patterns of the OEL described herein, the sheet-like magnetic or magnetizable pigment particles described herein are dispersed in the first and second coatings (x20' and x20''), respectively.The layer comprises a hardened binder material that fixes the orientation of sheet-like magnetic or magnetizable pigment particles. The binder material, at least in its hardened or solid state (also referred to herein as a second state), is at least partially transparent to electromagnetic radiation in the wavelength range between 200 nm and 2500 nm, i.e., in the wavelength range commonly referred to as the “spectrum” and including the infrared, visible, and UV portions of the electromagnetic spectrum. Therefore, particles contained in the binder material in its hardened or solid state, and their orientation-dependent reflectivity, can be perceived at some wavelengths within this range. Preferably, the hardened binder material is at least partially transparent to electromagnetic radiation in the wavelength range between 200 nm and 800 nm, more preferably between 400 nm and 700 nm. In this document, the term "transparent" means that, at the relevant wavelength, electromagnetic radiation is transmitted through a 20 μm layer of hardened binder material present in the OEL (excluding sheet-like magnetic or magnetizable pigment particles, but all other optional components of the OEL in the presence of these components), with a transmittance of at least 50%, more preferably at least 60%, and even more preferably at least 70%. This can be determined, for example, by measuring the transmittance of a test piece of the hardened binder material (excluding sheet-like magnetic or magnetizable pigment particles) according to well-established test methods, such as DIN 5036-3 (1979-11).

[0080] Sheet-like magnetic or magnetizable pigment particles, as described herein, are defined as having an isotropic reflectivity relative to incident electromagnetic radiation due to their non-spherical shape, for which the cured binder material is at least partially transparent. As used herein, the term "anisotropic reflectivity" means that the proportion of radiation incident from a first angle that is reflected by the particles to a certain (viewing) direction (second angle) is a function of the particle orientation, i.e., a change in particle orientation relative to the first angle can result in different magnitudes of reflection to the viewing direction. Preferably, the sheet-like magnetic or magnetizable pigment particles described herein have anisotropic reflectivity relative to incident electromagnetic radiation in some portions or over the entire wavelength range of about 200 nm to about 2500 nm, more preferably about 400 nm to about 700 nm, such that a change in particle orientation results in a change in the direction of reflection from the particle. As is known to those skilled in the art, the magnetic or magnetizable pigment particles described herein differ from conventional pigments because conventional pigment particles exhibit the same color and reflectivity regardless of particle orientation, while the magnetic or magnetizable pigment particles described herein exhibit reflectivity or color, or both, depending on particle orientation.

[0081] The radiation-curable coating compositions and coatings (x20', x20') described herein contain the sheet-like magnetic or magnetizable pigment particles described herein, preferably in an amount of about 1 wt.% to about 40 wt.%.Preferably between about 3 wt.% and about 35 wt.%, more preferably between about 5 wt.% and about 30 wt.%, the weight percentages being based on the total weight of the radiation-curable coating composition or coating.

[0082] Suitable examples of the flake-like magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles comprising: magnetic metals selected from the group consisting of cobalt (Co), iron (Fe), and nickel (Ni); magnetic alloys of iron, manganese, cobalt, nickel, or mixtures thereof; magnetic oxides of chromium, manganese, cobalt, iron, nickel, or mixtures thereof; or mixtures thereof. The term “magnetic” with respect to metals, alloys, and oxides refers to ferromagnetic or ferrimagnetic metals, alloys, and oxides. Magnetic oxides of chromium, manganese, cobalt, iron, nickel, or mixtures thereof can be pure oxides or mixed oxides. Examples of magnetic oxides include, but are not limited to, iron oxides such as hematite (Fe2O3), magnetite (Fe3O4), chromium dioxide (CrO2), magnetic ferrite (MFe2O4), magnetic spinel (MR2O4), magnetic hexagonal ferrite (MFe12O19), magnetic positive ferrite (RFeO3), and magnetic garnet M3R2(AO4)3, where M represents a divalent metal, R represents a trivalent metal, and A represents a tetravalent metal.

[0083] Examples of the sheet-like magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles containing a magnetic layer M, said magnetic layer M being made of one or more magnetic metals such as cobalt (Co), iron (Fe), or nickel (Ni) and magnetic alloys of iron, cobalt, or nickel, wherein said magnetic or magnetizable pigment particles may be a multilayer structure containing one or more additional layers. Preferably,One or more additional layers are independently made of one or more of the following materials: metal fluorides such as magnesium fluoride (MgF2), silicon oxide (SiO), silicon dioxide (SiO2), titanium oxide (TiO2), and aluminum oxide (Al2O3), more preferably layer A made of silicon oxide (SiO2); or independently made of one or more of the following materials: metals and metal alloys, preferably the following materials: reflective metals and reflective metal alloys, more preferably the following materials: silver (Ag), aluminum (Al), chromium (Cr), and nickel (Ni), and even more preferably aluminum (Al); or a combination of one or more of the above-described layers A and one or more of the above-described layers B. Typical examples of the above-mentioned multilayered sheet-like magnetic or magnetizable pigment particles include, but are not limited to, A / M multilayer structure, A / M / A multilayer structure, A / M / B multilayer structure, A / B / M / A multilayer structure, A / B / M / B multilayer structure, A / B / M / B / A multilayer structure, B / M multilayer structure, B / M / B multilayer structure, M / A / M multilayer structure, B / A / M / A multilayer structure, B / A / M / B multilayer structure, B / A / M / B / A multilayer structure, B / A / M / A / B multilayer structure, B / A / M / A / B multilayer structure, B / A / B / A / M / A / B / A / B multilayer structure, and A / B / A / B / A / M / A / B / A / B / A multilayer structure, wherein layer A, magnetic layer M, and layer B are selected from those mentioned above.

[0084] The UV-Vis radiation-curable coating compositions described herein may comprise sheet-like optically variable magnetic or magnetizable pigment particles, and / or sheet-like magnetic or magnetizable pigment particles without optically variable properties. Preferably, at least a portion of the sheet-like magnetic or magnetizable pigment particles described herein constitutes sheet-like optically variable magnetic or magnetizable pigment particles. In addition to the explicit security provided by the color-changing properties of the optically variable magnetic or magnetizable pigment particles, which allows for easy detection, identification, and / or differentiation using unassisted human senses of articles or security documents carrying inks, coating compositions, or coatings containing the optically variable magnetic or magnetizable pigment particles described herein from their potential for counterfeiting, the optical properties of the optically variable magnetic or magnetizable pigment particles can also be used as a machine-readable tool for identifying OELs. Therefore, the optical properties of the optically variable magnetic or magnetizable pigment particles can simultaneously serve as implicit or semi-implicit security features in authentication processes that analyze the optical (e.g., spectral) properties of the pigment particles, thereby enhancing anti-counterfeiting capabilities.

[0085] The use of flake-shaped optically variable magnetic or magnetizable pigment particles in the coating used to produce OEL enhances the importance of OEL as a security feature in secure document applications, because this material is reserved for the secure document printing industry and is not commercially available to the public.

[0086] As described above,Preferably, at least a portion of the sheet-like magnetic or magnetizable pigment particles are composed of sheet-like optically variable magnetic or magnetizable pigment particles. These are more preferably selected from the group consisting of sheet-like magnetic thin-film interference pigment particles and sheet-like interference coated pigment particles.

[0087] 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 0 686 675 B1; WO 2003 / 000801 A2; US 6,838,166; WO 2007 / 131833 A1; EP 2 402 401 B1; WO 2019 / 103937 A1; EP 3 587 500 A1; EP 3 587 501 A1; EP 3 587 502 A1; EP 3 587503 A1; WO 2020 / 006286 A1; WO 2020 / 131700 A1; US ​​2021 / 0101402; US 2021 / 038812; US 2022 / 0282094 and the references therein. Preferably, the magnetic thin film interference pigment particles comprise pigment particles having a five-layer Fabry-Perot multilayer structure and / or pigment particles having a six-layer Fabry-Perot multilayer structure and / or pigment particles having a seven-layer Fabry-Perot multilayer structure and / or pigment particles having a nine-layer Fabry-Perot multilayer structure and / or pigment particles having an eleven-layer Fabry-Perot multilayer structure and / or pigment particles having a multilayer structure combining one or more multilayer Fabry-Perot structures.

[0088] The preferred five-layer Fabry-Perot multilayer structure is composed of an absorber / dielectric / reflector / dielectric / absorber multilayer structure, wherein the reflector and / or absorber are also magnetic layers, preferably the reflector and / or absorber are magnetic alloys containing nickel, iron and / or cobalt, and / or containing nickel, iron and / or cobalt.And / or a magnetic layer comprising a magnetic oxide of nickel (Ni), iron (Fe) and / or cobalt (Co).

[0089] A further preferred five-layer Fabry-Perot multilayer structure is composed of a dielectric / reflector / magnetic body / reflector / dielectric multilayer structure.

[0090] A preferred six-layer Fabry-Perot multilayer structure is composed of an absorber / dielectric / reflector / magnetic body / dielectric / absorber multilayer structure.

[0091] A preferred seven-layer Fabry-Perot multilayer structure is composed of an absorber / dielectric / reflector / magnetic body / reflector / dielectric / absorber multilayer structure as disclosed in US 4,838,648.

[0092] A preferred nine-layer Fabry-Perot multilayer structure is composed of a dielectric / absorber / dielectric / reflector / magnetic body / dielectric / absorber / dielectric multilayer structure.

[0093] The preferred eleven-layer Fabry-Perot multilayer structure is composed of an absorber / dielectric / absorber / dielectric / reflector / magnetic body / reflector / dielectric / absorber / dielectric / absorber multilayer structure.

[0094] Preferably, the reflector layer described herein is independently made of: 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 one or more of the group consisting of aluminum (Al), chromium (Cr), nickel (Ni) and their alloys, and even more preferably aluminum (Al). Preferably, the dielectric layer is independently made of: a metal fluoride selected from the group consisting of magnesium fluoride (MgF2), aluminum fluoride (AlF3), cerium fluoride (CeF3), lanthanum fluoride (LaF3), sodium aluminum fluoride (e.g., Na3AlF6), neodymium fluoride (NdF3), samarium fluoride (SmF3), barium fluoride (BaF2), calcium fluoride (CaF2), lithium fluoride (LiF), and metal oxides such as silicon oxide (SiO), silicon dioxide (SiO2), titanium oxide (TiO2), and aluminum oxide (Al2O3); more preferably, one or more selected from the group consisting of magnesium fluoride (MgF2) and silicon dioxide (SiO2); and even more preferably, magnesium fluoride (MgF2). Preferably,The absorber layer is independently made of one or more of the following: 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), their metal oxides, their metal sulfides, their metal carbides, and their metal alloys; more preferably, chromium (Cr), nickel (Ni), their metal oxides, and their metal alloys; and even more preferably, chromium (Cr), nickel (Ni), and their metal alloys. Preferably, the magnetic layer comprises nickel (Ni), iron (Fe), and / or cobalt (Co); and / or a magnetic alloy comprising nickel (Ni), iron (Fe), and / or cobalt (Co); and / or a magnetic oxide comprising nickel (Ni), iron (Fe), and / or cobalt (Co). When magnetic thin-film interference pigment particles containing a seven-layer Fabry-Perot structure are preferred, it is particularly preferred that the magnetic thin-film interference pigment particles contain a seven-layer Fabry-Perot absorber / dielectric / reflector / magnetic body / reflector / dielectric / absorber multilayer structure composed of Cr / MgF2 / Al / M / Al / MgF2 / Cr multilayer structure, wherein M is Ni, Fe or Co.

[0095] The magnetic thin-film interference pigment particles described herein can be multilayer pigment particles considered safe for human health and the environment, and are pigment particles based on, for example, five-layer Fabry-Perot multilayer structures, six-layer Fabry-Perot multilayer structures, seven-layer Fabry-Perot multilayer structures, nine-layer Fabry-Perot multilayer structures, eleven-layer Fabry-Perot multilayer structures, and multilayer structures having combinations of one or more multilayer Fabry-Perot structures, wherein the pigment particles comprise one or more magnetic layers containing a magnetic alloy having a substantially nickel-free composition comprising about 40 wt.% to about 90 wt.% iron, about 10 wt.% to about 50 wt.% chromium, and about 0 wt.% to about 30 wt.% aluminum. Typical examples of multilayer pigment particles considered safe for human health and the environment can be found in EP 2 402 401 B1, the contents of which are incorporated herein by reference in their entirety.

[0096] Suitable interference-coated pigment particles comprising one or more magnetic materials include, but are not limited to, structures consisting of a substrate selected from the group consisting of a core coated with one or more layers, wherein the core or at least one of the layers is magnetic. For example, suitable interference-coated pigment particles comprise a core made of magnetic materials as described above, the core being coated with one or more layers made of one or more metal oxides.Alternatively, they may have a structure consisting of a core made of synthetic or natural mica, layered silicates (e.g., talc, kaolin, and sericite), glass (e.g., borosilicate), silica (SiO2), alumina (Al2O3), titanium dioxide (TiO2), graphite, and mixtures thereof, the core being coated with one or more magnetic materials. Furthermore, one or more additional layers, such as a coloring layer, may be present.

[0097] The sheet-like magnetic or magnetizable pigment particles described herein preferably have a size d50 (measured by direct optical particle size analyzer) between about 2 μm and about 50 μm.

[0098] The sheet-like magnetic or magnetizable pigment particles described herein may be surface-treated to protect them from any degradation that may occur in the coating composition and coating and / or to promote their incorporation into the coating composition and coating; corrosion inhibitors and / or wetting agents may typically be used.

[0099] Furthermore, after independently applying the first and second radiation-curable coating compositions described herein to form the first coating (x20') and the second coating (x20'') (steps a' and a''), the first and second radiation-curable coating compositions of steps a') and a'') are independently exposed to the magnetic field of the magnetic components (x30' and x30'', respectively) to independently magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles (steps b' and b'', respectively).

[0100] The method described herein includes at least two independent steps b') and b''), which include exposing the radiation-curable coating compositions described herein to the magnetic field of the magnetic component (x30') or the magnetic component (x30''), respectively, to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles.

[0101] During the magnetic alignment steps b') and b'') described herein, the substrate (x10) may be independently disposed on a nonmagnetic support plate (x70) made of one or more nonmagnetic materials.

[0102] During the magnetic alignment steps b') and b'') described herein, the position of the magnetic components (x30', x30'') is not limited and depends on the selection and design of the magnetic alignment pattern to be generated. Depending on the selection and design of the magnetic alignment pattern to be generated, the magnetic components (x30', x30'') may be placed below the substrate (x10) or above the coating (x20).

[0103] As described below, "x30'" and "x30''" independently refer to a single magnet, or an assembly (x30) containing two or more magnets, or an assembly containing one or more magnets and an engraved magnetic plate, or an assembly containing one or more magnets and a soft magnetic plate.Alternatively, it refers to an assembly containing one or more magnets and pole pieces or containing two or more magnets and pole pieces, wherein the magnetic assemblies (x30' and x30'') are selected according to the design of the magnetic orientation pattern of the first and second patterns of the OEL to be produced. If the magnetic assemblies (x30' and x30'') contain more than one (i.e., two, three, etc.) component, the sheet-like magnetic or magnetizable pigment particles are exposed to the combined magnetic field of the more than one component.

[0104] According to one embodiment, the method herein includes a magnetic orientation step b') and a magnetic orientation step b'')) both comprising a one-step orientation step. According to one embodiment and as shown in FIG. 3, the magnetic orientation step b') and the magnetic orientation step b'')) are independently one-step orientation steps. The one-step orientation step described herein may be a uniaxial orientation or a biaxial orientation.

[0105] FIG. 4A-1 illustrates a method wherein the orientation step b) (b') and / or b'')) comprises a one-step orientation step, wherein the radiation-curable coating composition described herein is exposed to the magnetic field of a single magnetic component (430). The position of the magnetic component (430) in Figure 4A-1 is illustrative only, and the magnetic component may be placed on opposite sides of the substrate (410) depending on the selection and design of the magnetic orientation pattern to be produced; the distances provided in Figure 4A-1 are illustrative only and are not drawn to scale. Figure 4A-2 (not drawn to scale) illustrates a method in which orientation step b) (b') and / or b'')) includes an orientation step in which the radiation-curable coating composition described herein is exposed to the magnetic field of a single magnetic component (430), wherein the magnetic component (430) is mounted on a rotating magnetic cylinder. Figure 4A-3 (not drawn to scale) illustrates a method in which orientation step b) (b') and / or b'')) includes an orientation step in which the radiation-curable coating composition described herein is exposed to the magnetic field of a single magnetic component (430), wherein the magnetic component (430) is arranged in the vicinity of a rotating cylinder.

[0106] According to one embodiment, the method described herein allows the preparation of an OEL exhibiting more than one mark, wherein at least one of the first and second patterns (see page 13 / 40 of CN 122396552 A) comprises exposing a radiation-curable coating composition to an engraved magnetic plate (x30), wherein the engraved magnetic plate (x30) comprises more than one engraving (I) having a mark shape. The engraved magnetic plate (x30) described herein is preferably made of a permanent magnet powder material and a polymer. The engraved magnetic plate (x30) described herein can generally be produced by injection molding or by metal or laser engraving. Preferred permanent magnet powder materials include cobalt, iron and their alloys, chromium dioxide, general-purpose magnetic oxide spinel, and general-purpose magnetic garnet.This includes general-purpose magnetic ferrites such as hexagonal ferrites (CaFe12O19, SrFe12O19, BaFe12O19) respectively, general-purpose AlNiCo alloys, general-purpose Samarium-Cobalt (SmCo) alloys, and general-purpose rare-earth-iron-boron alloys (such as NdFeB), as well as their permanent magnet chemical derivatives (as indicated by general terms) and mixtures thereof. Plates made from composite materials containing polymers and permanent magnet powders can be obtained from many different sources, such as Bomatec, Höri, CH, ARNOLD® Magnetic Technologies (Plastiform®) or Materiali Magnetici, Albarate, Milano, IT (Plastoferrite).

[0107] According to an embodiment shown, for example, Figure 10 (Example E4, magnetic component 1030 used during step b''), the method described herein allows for the preparation of an OEL in which at least one of a first pattern and a second pattern exhibits dynamic movement and more than one mark when the OEL is tilted, wherein the at least one in steps b') and b'') comprises exposing a radiation-curable coating composition to a component (1030) comprising a rod-shaped dipole magnet (1030-1) and an engraved magnetic plate (1030-2), wherein the engraved magnetic plate (1030-2) comprises more than one engraving (I) having a mark shape in the form of "20", wherein the engraved magnetic plate (1030-2) is positioned above the rod-shaped dipole magnet (1030-1).

[0108] According to one embodiment, the method described herein includes at least one of steps b') and b''), said steps b') and b'') comprising exposing a radiation-curable coating composition to magnetic components disclosed in US 8,025,952 and EP 1,819,525 B1 and WO 2022 / 049024 A1, wherein the effect is the so-called "Venetian-blind" effect. Figures 5A-B of US 7,047,883 disclose a magnetic component comprising two spaced magnets 84 placed on a magnetic substrate 62, their north poles facing the substrate. Figure 9B of US 7,047,883 discloses a magnetic component comprising magnets 140, and the substrate comprising a coating positioned offset relative to the magnetic axis. Figure 9C of US 7,047,883 discloses a magnetic assembly comprising two magnets 142 and one magnet 142' having a rhomboid cross-section, wherein the north poles of the two magnets 142 face the substrate, and the south pole of the intermediate magnet 142' faces the substrate. Figure 9D of US 7,047,883 discloses a magnetic assembly.It comprises two magnets 144 and one magnet 144' having roof-shaped, hexagonal, circular, trapezoidal, or other cross-sections, wherein the north poles of the two magnets 144 face the substrate, and the south pole of the middle magnet 144' faces the substrate. Figure 9E of US 7,047,883 discloses a magnetic assembly comprising five magnets, wherein the first magnet 142 is a rhomboid magnet with its north pole facing the substrate, the second magnet 146 is a rectangular magnet with its south pole facing the substrate, the third magnet 148 is a magnet with a rounded top and its north pole facing the substrate, the fourth magnet 150 is roof-shaped with its south pole facing the substrate, and the fifth magnet 152 is also a roof-shaped magnet with its north pole facing the substrate. Figure 4A1 of WO 2022 / 049024 A1 discloses a magnetic assembly comprising rod-shaped dipole magnets, wherein particles are exposed to the magnetic field of the magnetic assembly in more than one region (shown as dashed rectangle A) (magnetic field lines are shown as lines with arrows pointing from the North Pole to the South Pole), wherein the magnetic field is substantially uniform, and wherein the magnetic field lines are substantially parallel to each other in said more than one region. Figure 4A2 of WO 2022 / 0490241 A discloses a magnetic assembly comprising two rod-shaped dipole magnets (M1, M2) having the same magnetic direction and an iron yoke (Y), wherein particles are exposed to the magnetic field of the magnetic assembly in more than one region (shown as dashed rectangle A) (magnetic field lines are shown as lines with arrows pointing from the North Pole to the South Pole), wherein the magnetic field is substantially uniform, and wherein the magnetic field lines are substantially parallel to each other in said more than one region. Figures 6A-B of WO 2022 / 049024 A1 disclose a magnetic assembly comprising a rectangular component containing two rod-shaped dipole magnets (M1, M2) and two pole pieces (P1, P2), and particles are exposed to the magnetic field of the magnetic assembly (magnetic field lines shown as lines with arrows pointing from the North Pole to the South Pole) in more than one region (shown as dashed lines, page 14 / 40, CN 122396552 A, rectangle A), wherein the magnetic field is substantially uniform and wherein the magnetic field lines are substantially parallel to each other in the region.

[0109] According to, for example, the magnetic assembly (830) used during step b'') of an embodiment shown in Figure 8A, the method described herein allows for the preparation of an OEL in which at least one of the first and second patterns exhibits dynamic movement when the OEL is tilted.The dynamic movement is a bright, reflective horizontal bar that moves vertically (up / down) as the OEL tilts about a horizontal axis; wherein at least one of steps b') and b'') involves exposing the radiation-curable coating composition to a rod-shaped dipole magnet (830-1) having a magnetic axis oriented substantially parallel to the substrate and substantially parallel to the machine feed direction (as indicated by the arrow in FIG8A). This effect is the so-called "rolling bar" effect, as disclosed in US 2005 / 0106367. The "rolling bar" effect is based on simulating the orientation of pigment particles across a curved surface of the coating. An observer sees specular reflective areas that move away from or towards the observer as the OEL tilts.

[0110] According to another embodiment shown in FIG8B (Examples E1-E3, magnetic component (830) used during step b'), the method herein allows for the preparation of an OEL in which at least one of the first and second patterns exhibits dynamic movement when the OEL is tilted, the dynamic movement of the OEL being a bright reflective vertical bar moving in a horizontal direction (left / right) when the OEL is tilted about a vertical axis; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to a rod-shaped dipole magnet (830-b1) having a magnetic axis oriented substantially parallel to the substrate (810) and substantially perpendicular to the machine feed direction (indicated by the arrow in FIG8B). This effect is the so-called “rolling bar” effect, as disclosed in US 2005 / 0106367.

[0111] According to another embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement of the OEL being a bright reflective vertical bar that moves in a horizontal (left / right) direction when the OEL is tilted about a horizontal axis; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to magnetic components such as those disclosed in WO 2020 / 160993 A1. Figures 2-5 of WO 2020 / 160993 A1 disclose a magnetic assembly comprising a) at least one dipole magnet (x40), which is a square or rectangular dipole magnet having a magnetic axis oriented substantially parallel to the substrate, and b) a combination of n groups of spaced-a1, x30-a2, where n is an integer equal to or greater than 1, wherein the north-south magnetic axis of each of the said rod-a1, x30-a2 is substantially parallel to the surface of the substrate, wherein, for each of the n groups,The north poles of the rod-shaped dipole magnets (x30-a1, x30-a2) point in the same direction and are substantially parallel to each other; wherein the vector sum H1 of the magnetic axes of the rod-shaped dipole magnets (x30-a1, x30-a2) and the vector sum H2 of at least one dipole magnet (x40) are formed at an angle α in the range of about 5° to about 175° or in the range of about 185° to about 355°, wherein a combination of n spaced-apart rod-shaped dipole magnets (x30-a1, x30-a2) is placed below or above at least one dipole magnet (x40), and wherein at least one dipole magnet (x40) and a combination of n spaced-apart rod-shaped dipole magnets (x30-b1, x30-b2) are substantially centered relative to each other (see, for example, Figure 2-5 of WO 2020 / 160993 A1).

[0112] According to another embodiment, the method described herein allows for the preparation of an OEL in which a combination of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement of the OEL being a bright reflective bar that moves in the vertical direction (up / down) when the OEL is tilted about a horizontal axis; wherein steps b') and b'') independently comprise exposing the radiation-curable coating composition to magnetic components such as those disclosed in WO 2014 / 198905 A2. Figures 2-5 of WO 2014 / 198905 A2 disclose a magnetic assembly comprising:

[0113] a) a rod-shaped dipole magnet (M1) and a pair of rod-shaped dipole magnets (M2) and (M3), the north-south axes of the rod-shaped dipole magnets (M1), (M2) and (M3) being substantially parallel to the substrate and having the same magnetic north-south direction, wherein a1) the rod-shaped dipole magnet (M1) is disposed below the substrate, and the pair of rod-shaped dipole magnets (M2) and (M3) are disposed separately from each other below the rod-shaped dipole magnet (M1); or a2) the pair of rod-shaped dipole magnets (M2) and (M3) are disposed below the substrate and separated from each other, and the rod-shaped dipole magnet (M1) is disposed below the pair of rod-shaped dipole magnets (M2) and (M3); Or

[0114] b) a pair of rod-shaped dipole magnets (M4) and (M5) and a pole piece (Y), wherein the north-south axes of the pair of rod-shaped dipole magnets (M4) and (M5) are substantially parallel to the substrate and have the same magnetic north-south direction, and the pole piece (Y) is disposed between the rod-shaped dipole magnets (M4) and (M5); or

[0115] c) a pair of rod-shaped dipole magnets (M4) and (M5), a pole piece (Y) and a magnetic plate (M6), wherein the north-south axes of the pair of rod-shaped dipole magnets (M4) and (M5) are substantially parallel to the substrate and have the same magnetic north-south direction, and the north-south axis of the magnetic plate (M6) is substantially perpendicular to the substrate.The pole piece (Y) is disposed between the rod-shaped dipole magnet (M4) and the rod-shaped dipole magnet (M5). Particularly suitable magnetic components are those shown in Figures 5c, 6c and 7d of WO 2014 / 198905 A2.

[0116] According to, for example, the magnetic component (930) used during step b') of one embodiment shown in Figure 9 (Example E4, E6-E8, E6-E8, E6-E8, E6-E8), the method described herein allows for the preparation of an OEL in which at least one of the first and second patterns exhibits dynamic movement when the OEL is tilted, the dynamic movement being a pattern of bright and dark areas moving when the OEL is tilted; wherein the at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to those magnetic components disclosed in WO 2013 / 167425 A1 and WO 2021 / 083809 A1. The magnetic assembly disclosed in WO 2021 / 083809 A1 comprises at least one dipole magnet (x41) having a magnetic axis oriented substantially parallel to a substrate, and a combination comprising at least four additional dipole magnets (x31) whose north poles point in the same direction and whose magnetic axes are oriented substantially parallel to the substrate. Each additional dipole magnet (x31) is arranged at the intersection of at least two substantially parallel straight lines αi (i=1, 2, ...) and at least two substantially parallel straight lines βj (j=1, 2, ...), forming a grid. At least two additional dipole magnets (x31) are arranged on one of the straight lines αi, and at least two other additional dipole magnets (x31) are arranged on the other of the straight lines αi, wherein the magnetic axes of the additional dipole magnets are oriented substantially parallel to the substantially parallel straight lines αi. At least one dipole magnet (x40) is disposed below a combination comprising at least four dipole magnets (x31). According to one embodiment, the vector H of the magnetic axes of each straight line αi and at least one dipole magnet (x41) is substantially parallel or substantially perpendicular to each other, and the OEL exhibits dynamic movement, which is a pattern of bright and dark areas moving when the substrate carrying the OEL is tilted, the pattern of bright and dark areas moving in the same direction as the tilt direction. According to another embodiment, the vector H of the magnetic axes of each straight line αi and at least one dipole magnet (x41) is substantially neither parallel nor substantially perpendicular to each other relative to the OEL. Preferably, the vector and H of the magnetic axes of each straight line αi and at least one dipole magnet (x41) form an angle γ, which is in the range of about 20° to about 70°, or in the range of about 110° to about 160°, or in the range of about 200° to about 250°.Or within the range of approximately 290° to approximately 340°; and the OEL exhibits dynamic movement, which is a pattern of bright and dark areas that moves not only diagonally when the substrate carrying the OEL is tilted about a vertical axis, but also diagonally when the substrate carrying the OEL is tilted about a horizontal axis (in other words, the optical effect layer OEL described herein provides an optical imprint of multiple dark spots and multiple bright spots that move when the substrate carrying the OEL is tilted about two vertical axes, namely the horizontal axis and the vertical / longitudinal axis). Suitable magnetic components are those shown in Figures 6-8 of WO 2021 / 083809 A1.

[0117] According to, for example, the magnetic component (930) used during step b') of one embodiment shown in Figure 9 (Example E4, magnetic component (930) used during step b''), the method described herein allows for the preparation of an OEL in which at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a pattern of bright and dark areas moving when the OEL is tilted; wherein at least one of steps b') and b'') comprises exposing the radiation-curable coating composition to those magnetic components disclosed in WO 2021 / 083808 A1. The magnetic assembly disclosed in WO 2021 / 083808 A1 comprises at least one dipole magnet (x41) having a magnetic axis oriented substantially parallel to a substrate and a combination comprising at least four additional dipole magnets (x31), the north poles of which point in the same direction and their magnetic axes are oriented substantially parallel to the substrate, wherein each additional dipole magnet (x31) is arranged at the intersection of at least two substantially parallel straight lines αi (i=1, 2, ...) and at least two substantially parallel straight lines βj (j=1, 2, ...), the lines αi and βj forming a grid, wherein at least two additional dipole magnets (x31) are arranged on one of the lines αi, and at least two other additional dipole magnets (x31) are arranged on the other of the lines αi. The magnetic axes of the additional dipole magnets (x31) are substantially parallel to the substrate and oriented along line αi. At least one dipole magnet (x41) is disposed below a combination comprising at least four first dipole magnets (x31). On each line αi and on each line βj, the north poles of adjacent additional dipole magnets (x31) point in opposite directions. The vector H of each line αi and the magnetic axis of at least one dipole magnet (x41) is substantially non-parallel and substantially non-perpendicular to each other. Preferably, the vector H of each line αi and the magnetic axis of at least one dipole magnet (x41) forms an angle γ.The angle γ is in the range of about 20° to about 70°, or about 110° to about 160°, or about 200° to about 250°, or about 290° to about 340°; and the OEL exhibits dynamic movement, which is a pattern of bright and dark areas that moves not only diagonally when the substrate carrying the OEL is tilted relative to the vertical / longitudinal axis, but also diagonally when the substrate carrying the OEL is tilted relative to the horizontal / transverse axis (in other words, the optical effect layer OEL described herein provides an optical imprint of multiple dark spots and multiple bright spots that move when the substrate carrying the OEL is tilted relative to the two vertical axes, namely the horizontal / transverse axis and the vertical / longitudinal axis). Suitable magnetic components are those shown in Figures 5-7 of WO 2021 / 083808 A1.

[0118] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a ring-shaped body that moves when the OEL is tilted; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to magnetic components such as those disclosed in WO 2014 / 108404 A2. The magnetic assembly disclosed in WO 2014 / 108404 A2 comprises a) at least one dipole magnet having a magnetic axis oriented substantially perpendicular to the substrate and one or more pole pieces, said one or more pole pieces being disposed below and in contact with and / or spaced apart from and laterally surrounding the at least one dipole magnet (see, for example, Figures 3-5 of WO 2014 / 108404 A2); b) at least one dipole magnet being a ring magnet with radial magnetization (i.e., its magnetic north-south axis extending radially from the center of the ring magnet to its outer periphery) (see, for example, Figure 6 of WO 2014 / 108404 A2); or c) at least one dipole magnet being three or more dipole magnets arranged in a ring arrangement with radial magnetization (i.e., the magnetic axis of each of said three or more dipole magnets is oriented substantially parallel to the substrate, and its magnetic axes are aligned such that they extend substantially radially from the center of symmetry of the ring arrangement). The north-south directions of the three or more dipole magnets are all pointed or all moved away from the center of symmetry (see, for example, Figure 7 of WO 2014 / 108404 A2). WO 2014 / 108404 A2 also discloses a rotatable magnetic assembly comprising a) at least two rod-shaped dipole magnets whose magnetic axes are substantially parallel to the substrate and have the same magnetic direction (Figure 9) or opposite magnetic directions (see Figure 11 of WO 2014 / 108404 A2), or comprising b) at least two rod-shaped dipole magnets.Their magnetic axes are substantially perpendicular to the substrate and have opposite magnetic directions (see Figure 10 of WO 2014 / 108404 A2).

[0119] According to one embodiment, the method described herein allows for the preparation of an OEL in which at least one of the first and second patterns exhibits dynamic movement when the OEL is tilted, the dynamic movement being a nested multi-ring body that moves when the OEL is tilted; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to those magnetic components disclosed in WO 2014 / 108303 A2. The magnetic assembly disclosed in WO 2014 / 108303 A2 comprises one of the following specifications, pages 17 / 40, 20 CN 122396552 A:

[0120] a) at least one dipole magnet and a pole piece (x60), said at least one dipole magnet being a ring magnet defining a ring and having a magnetic axis oriented substantially perpendicular to the substrate, said pole piece (x60) being disposed below the at least one dipole magnet and within the ring of said at least one dipole magnet and having one or more protrusions disposed within the ring of said at least one dipole magnet (see, for example, Figures 3-5 of WO 2014 / 108303 A2); or

[0121] b) Having at least one dipole magnet oriented substantially perpendicular to a magnetic axis of the substrate, another dipole magnet oriented substantially perpendicular to a magnetic axis of the substrate, and two or more pole pieces, wherein the at least one dipole magnet and the other magnet have the same magnetic direction and are disposed at different distances from the substrate, wherein the two or more pole pieces are arranged in the space between the magnets and in contact with them, and wherein at least one of the two or more pole pieces forms one or more annular protrusions around a central region in which at least one dipole magnet is disposed (see, for example, FIG. 6 of WO 2014 / 108303 A2); or

[0122] c) Having at least one dipole magnet oriented substantially perpendicular to a magnetic axis of the substrate, a plate-like pole piece disposed below and in contact with the at least one dipole magnet, and one or more annular pole pieces disposed on top of the at least one dipole magnet, wherein the central pole piece of the one or more annular pole pieces is in contact with the at least one dipole magnet, and wherein the plate-like pole piece may include one or more protrusions spaced laterally around the at least one dipole magnet (see, for example, WO 2014 / 108303 A2). (See Figure 7 of WO 2014 / 108303 A2). WO 2014 / 108303 A2 also discloses a rotatable magnetic assembly comprising a) at least two rod-shaped dipole magnets whose magnetic axes are substantially perpendicular to the substrate (see Figures 8-10 and 13-14 of WO 2014 / 108303 A2), or b) at least four rod-shaped dipole magnets.Their magnetic axes are substantially parallel to the substrate (see Figures 11, 12, and 15 of WO 2014 / 108303 A2).

[0123] According to one embodiment, the method described herein allows for the preparation of an OEL in which at least one of the first and second patterns exhibits dynamic movement when the OEL is tilted, the dynamic movement being a ring-shaped body whose size changes as the OEL is tilted; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to those magnetic components disclosed in WO 2017 / 064052 A1, WO 2017 / 080698 A1, and WO 2017 / 148789 A1. The magnetic components disclosed in WO 2017 / 064052 A1, WO 2017 / 080698 A1 and WO 2017 / 148789 A1 comprise one of:

[0124] - a) at least one dipole magnet (x40), which is a single rod-shaped dipole magnet having a north-south magnetic axis substantially parallel to the substrate or a combination of two or more rod-shaped dipole magnets having a obtained north-south magnetic axis substantially parallel to the substrate, and b) a ring-shaped magnetic field generating device (x30), which is a single ring-shaped dipole magnet having a north-south magnetic axis substantially perpendicular to the substrate or a combination of two or more dipole magnets arranged in a ring and having a obtained north-south magnetic axis substantially perpendicular to the substrate (see, for example, Figures 1-4 of WO 2017 / 064052 A1), or

[0125] - a) at least one dipole magnet (x40), which is a single dipole magnet having a magnetic axis substantially parallel to the substrate or a combination of two or more rod-shaped dipole magnets, each of the two or more rod-shaped dipole magnets having a magnetic axis substantially parallel to the substrate and having the same magnetic field direction; b) a ring-shaped magnetic field generating device (x31), which is a single ring-shaped dipole magnet having a magnetic axis substantially perpendicular to the substrate or a combination of two or more dipole magnets arranged in a ring, each of the two or more dipole magnets having a magnetic axis substantially perpendicular to the substrate and having the same magnetic field direction; and c) a single dipole magnet (x32) having a magnetic axis substantially perpendicular to the substrate or two or more dipole magnets, each of the two or more dipole magnets having a magnetic axis substantially perpendicular to the substrate and having the same magnetic field direction; and / or one or more pole pieces (see, for example, Figures 1-12 of WO 2017 / 080698 A1), or

[0126] - a) At least one dipole magnet (x40), which is a single rod-shaped dipole magnet having a magnetic axis substantially parallel to the substrate, or a combination of two or more rod-shaped dipole magnets.a) Each of two or more rod-shaped dipole magnets has a magnetic axis substantially parallel to the substrate and has the same magnetic field direction; b) a ring-shaped magnetic field generating device (x31), which is a single ring-shaped magnet or a combination of two or more dipole magnets (x31) arranged in a ring, the ring-shaped magnetic field generating device having radial magnetization; and c) a single dipole magnet (x32) having a magnetic axis substantially perpendicular to the substrate, or a single dipole magnet (x32) having a magnetic axis substantially parallel to the substrate, or two or more dipole magnets (x32), each of the two or more dipole magnets (x32) having a magnetic axis substantially perpendicular to the substrate, wherein when the... When the north pole of a single ring magnet (x31) or two or more dipole magnets (x31) forming a ring magnetic field generating device points to the outer periphery of the ring magnetic field generating device, the north pole of the single dipole magnet (x32) or the north pole of at least one of the two or more dipole magnets (x32) points to the substrate; or when the south pole of a single ring magnet (x31) or two or more dipole magnets (x31) forming a ring magnetic field generating device points to the outer periphery of the ring magnetic field generating device (x31), the south pole of the single dipole magnet (x32) or the south pole of at least one of the two or more dipole magnets (x32) points to the substrate (see, for example, Figures 1-14 of WO 2017 / 148789 A1).

[0127] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being one or more annular bodies whose shapes change as the OEL is tilted; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to magnetic components such as those disclosed in WO 2018 / 054819 A1. Specifically, the magnetic component disclosed in WO 2018 / 054819 A1 includes a ring-shaped magnetic field generating device (x31), which is a single ring-shaped magnet (x31) or a combination of two or more dipole magnets (x31) arranged in a ring, the ring-shaped magnetic field generating device (x31) having radial magnetization; and a single dipole magnet (x32) or two or more dipole magnets (x32) having a magnetic axis substantially perpendicular to the surface of the substrate, each of the two or more dipole magnets (x32) having a magnetic axis substantially perpendicular to the surface of the substrate, wherein the single dipole magnet (x32) or two or more dipole magnets (x32) is located inside, inside or above a portion of the ring defined by the single ring-shaped magnet (x31), or located inside, inside or above a portion of the ring defined by the two or more dipole magnets (x31) arranged in a ring.Furthermore, when the north pole of a single ring magnet (x31) or two or more dipole magnets (x31) forming the ring magnetic field generating device (x31) points to the outer periphery of the ring magnetic field generating device (x31), the south pole of the single dipole magnet (x32) or the south pole of each of the two or more dipole magnets (x32) points to the substrate surface; or when the south pole of a single ring magnet (x31) or two or more dipole magnets (x31) forming the ring magnetic field generating device (x31) points to the outer periphery of the ring magnetic field generating device (x31), the north pole of the single dipole magnet (x32) or the north pole of each of the two or more dipole magnets (x32) points to the substrate surface.

[0128] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a crescent shape that moves and rotates when the OEL is tilted; wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to magnetic components such as those disclosed in WO 2019 / 215148 A1. The magnetic assembly disclosed in WO 2019 / 215148 A1 includes a) a first magnetic field generating device (x30) having a north-south magnetic axis substantially perpendicular to the substrate surface and having a length L1; b) a second magnetic field generating device (x40) having a north-south magnetic axis substantially perpendicular to the substrate and having a length L3; and c) a flat pole piece (x50) having no protrusions or projections extending beyond the surface of the pole piece and having a length L5, wherein the first and second magnetic field generating devices have the same magnetic field direction, wherein the first magnetic field generating device faces the substrate and is disposed above the flat pole piece, wherein the second magnetic field generating device faces the environment and is disposed below the flat pole piece, wherein the length L1 of the first magnetic field generating device is less than the length L3 of the second magnetic field generating device, wherein the length L1 of the first magnetic field generating device is less than the length L5 of the flat pole piece, and wherein the length L3 of the second magnetic field generating device is less than the length L5 of the pole piece (see, for example, page 22 of specification 19 / 40, CN 122396552 A WO 2017 / 148789). A1 (Figures 1-12).

[0129] According to one embodiment, the method described herein allows for the fabrication of an OEL, wherein at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being an annulus surrounded by more than one annulus.The shape and / or brightness of the one or more annular bodies change when the OEL is tilted; wherein at least one of steps b') and b'') includes exposing the radiation-curable coating composition to those magnetic components disclosed in WO 2020 / 193009 A1. The magnetic assembly disclosed in WO 2020 / 193009 A1 comprises a) a combination of three or more first dipole magnets (x31-ai), each of which is centrally disposed on a ring in a plane parallel to the substrate, wherein the magnetic axis of the first dipole magnet (x31-ai) is oriented substantially parallel to the substrate, and b) at least one second dipole magnet (x41) having a magnetic axis oriented substantially perpendicular to the substrate and arranged such that the projection of its center onto the substrate is located at a projection point within the ring, wherein at least one second dipole magnet (x41) is disposed above the combination of three or more first dipole magnets (x31-ai), wherein the vectors (x1, x2, x3) of each vector (x31, x41, x31) and the magnetic axis of the corresponding first dipole magnet (x31-ai) are... An angle αi is formed between (x31-ai), wherein when measured in a counterclockwise direction, all angles αi are in the range of about 20° to about 160° or in the range of about 200° to about 340°, and wherein each of the first dipole magnets (x31-ai) is disposed at a first distance (Yi) on a substrate between the projection point and the center of the first dipole magnet (x31-ai) (see, for example, Figures 2-9 in WO 2020 / 193009 A1).

[0130] According to one embodiment, the method described herein allows the preparation of an OEL in which at least one of the first and second patterns exhibits dynamic movement when the OEL is tilted, the dynamic movement being a change from dark to light in two regions when the OEL is tilted (the effect is a so-called flip-flop); wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to those magnetic components disclosed in Figures 1, 3, and 6 of US 2005 / 0106367.

[0131] According to one embodiment, the method described herein allows for the fabrication of an OEL, wherein at least one of a first pattern and a second pattern exhibits dynamic movement when the OEL is tilted, said dynamic movement being at least one comet-shaped point rotating about the center of rotation when the OEL is tilted.At least one of steps b') and b'') comprises exposing the radiation-curable coating composition to magnetic components disclosed in WO 2019 / 038371 A1, WO 2019 / 038370 A1, and WO 2019 / 038369 A1. The magnetic components disclosed in WO 2019 / 038371 A1, WO 2019 / 038370 A1, and WO 2019 / 038369 A1 comprise at least one of the following:

[0132] -a) a first magnetic field generating device (x30) and b) a second magnetic field generating device (x40), wherein the first magnetic field generating device (x30) and the second magnetic field generating device (x40) have magnetic axes that are inclined to each other, wherein the magnetic axis of the first magnetic field generating device (x30) is substantially perpendicular to the rotation axis, and the magnetic axis of the second magnetic field generating device (x40) is substantially perpendicular to the rotation axis, and wherein the projection of the magnetic axis of the first magnetic field generating device (x30) and the projection of the magnetic axis of the second magnetic field generating device (x40) are perpendicular to the rotation axis along the rotation axis. An angle (Ω) is formed on the plane, the angle (Ω) being in the range of about 5° to about 175° or in the range of about -5° to about -175°, and wherein the first magnetic field generating device (x30) comprises a rod-shaped dipole magnet whose north-south magnetic axis is substantially perpendicular to the axis of rotation; or two or more rod-shaped dipole magnets, each of which has a north-south magnetic axis substantially perpendicular to the axis of rotation, and all of the two or more rod-shaped dipole magnets having the same magnetic field direction; or a ring-shaped dipole magnet whose north-south magnetic axis is substantially perpendicular to the axis of rotation; Or a disc-shaped dipole magnet nested inside a ring-shaped dipole magnet, wherein the north-south magnetic axis of each of the disc-shaped dipole magnet and the ring-shaped dipole magnet are substantially perpendicular to the axis of rotation and have the same magnetic field direction; or two or more nested ring-shaped dipole magnets, wherein the north-south magnetic axis of each of the two or more nested ring-shaped dipole magnets is substantially perpendicular to the axis of rotation, and all the two or more nested ring-shaped magnets have the same magnetic field direction; and wherein the second magnetic field generating device (x40) includes a disc-shaped dipole magnet whose north-south magnetic axis is substantially perpendicular to the axis of rotation; or a ring-shaped dipole magnet whose north-south magnetic axis is substantially perpendicular to the axis of rotation; or a rod-shaped dipole magnet whose north-south magnetic axis is substantially perpendicular to the axis of rotation; or

[0133] a) a first magnetic field generating device (x30) and b) a second magnetic field generating device (x40), wherein the first magnetic field generating device (x30) comprises at least a pair of two rod-shaped dipole magnets (x31) that are at least partially or completely embedded in a support base (x32), wherein the north-south magnetic axis of each of the rod-shaped dipole magnets (x31) is substantially parallel to the axis of rotation.At least one pair of the two rod-shaped dipole magnets (x31) have opposite magnetic field directions and are arranged symmetrically along line (α) about the rotation axis, and

[0134] the second magnetic field generating device (x40) includes b1) a disk-shaped dipole magnet (x41) whose north-south magnetic axis is substantially perpendicular to the rotation axis, b2) a ring-shaped dipole magnet (x41) whose north-south magnetic axis is substantially perpendicular to the rotation axis, b3) a rod-shaped dipole magnet (x41) whose north-south magnetic axis is substantially perpendicular to the rotation axis and is arranged on the rotation axis, and / or b4) at least one pair of two rod-shaped dipole magnets (x41), each of which has a north-south magnetic axis substantially parallel to the rotation axis, the at least one pair of the two rod-shaped dipole magnets (x41) having opposite magnetic field directions and arranged symmetrically along line (β) about the rotation axis. Arranged in a symmetrical configuration, wherein the projection of the line (α) of at least one pair of rod-shaped dipole magnets (x31) of the first magnetic field generating device (x30) and the projection of the magnetic axis of the second magnetic field generating device (x40) form an angle (Ω) along the rotation axis in a plane perpendicular to the rotation axis, said angle (Ω) being in the range of about 5° to about 175° or in the range of about -5° to about -175°; or

[0135] - a magnetic field generating device (x30) comprising a disk-shaped dipole magnet (x31) whose north-south magnetic axis is substantially perpendicular to the rotation axis; or an annular, preferably loop-shaped dipole magnet (x31) whose north-south magnetic axis is substantially perpendicular to the rotation axis; or a rod-shaped dipole magnet (x31) whose north-south magnetic axis is substantially perpendicular to the rotation axis and arranged on the rotation axis, wherein the disk-shaped dipole magnet (x31), annular, preferably loop-shaped dipole magnet (x31), or rod-shaped dipole magnet of the magnetic field generating device (x30) (x31) comprises at least one pair of indentations (I) and / or at least one pair of voids (V) and / or at least one pair of protrusions (P), wherein the at least one pair of indentations (I), at least one pair of voids (V) and / or at least one pair of protrusions (P) are positioned as follows: symmetrical about the axis of rotation, and mirror-asymmetric relative to the north-south magnetic axis of the disk-shaped dipole magnet (x31), annular, preferably loop-shaped dipole magnet (x31), or rod-shaped dipole magnet (x31) perpendicular to the magnetic field generating device (x30), and comprising the axis of rotation.

[0136] In contrast to a uniaxial orientation in which the sheet-like magnetic or magnetizable pigment particles are oriented in a manner in which only their principal axes are constrained by the magnetic field, a biaxial orientation means that the sheet-like magnetic or magnetizable pigment particles are oriented in a manner in which both of their principal axes are constrained. In contrast to needle-like pigment particles, which can be considered as one-dimensional particles, sheet-like pigment particles have an X-axis and a Y-axis that define the main extension plane of the particle. In other words, flake-shaped pigment particles can be considered two-dimensional particles due to their large aspect ratio, as can be seen in Figure 2. As shown in Figure 2, flake-shaped pigment particles can be considered a two-dimensional structure.Dimensions X and Y are substantially larger than dimension Z. Flaky pigment particles are also referred to in the art as flattened particles or flakes. Such pigment particles can be described as having a principal axis X corresponding to the longest dimension passing through the pigment particle and a second axis Y perpendicular to X, also located within the pigment particle. Biaxial orientation results in flaky magnetic or magnetizable pigment particles having two constrained principal axes; that is, adjacent flaky magnetic pigment particles with biaxial orientation are spatially close to each other and substantially parallel to each other. In other words, biaxial orientation aligns the planes of flaky magnetic or magnetizable pigment particles such that the planes of the pigment particles are oriented substantially parallel to the planes of adjacent (in all directions) flaky magnetic or magnetizable pigment particles.

[0137] According to one embodiment, the magnetic assembly described below allows for biaxial orientation of the flaky magnetic or magnetizable pigment particles described herein, such that the flaky magnetic or magnetizable pigment particles form a flaky structure whose X and Y axes are preferably substantially parallel to the substrate (x10) surface and are planarized in said two dimensions. Specification 21 / 40 pages 24 CN 122396552 A

[0138] According to another embodiment, the magnetic component described below allows for biaxial orientation of the sheet-like magnetic or magnetizable pigment particles described herein, such that the sheet-like magnetic or magnetizable pigment particles have a first axis that is substantially parallel to the surface of the substrate (x10) in the XY plane and a second axis that is substantially perpendicular to the first axis at a substantially non-zero elevation angle to the surface of the substrate.

[0139] According to another embodiment, the magnetic component described below allows for biaxial orientation of the sheet-like magnetic or magnetizable pigment particles described herein, such that the XY plane of the sheet-like magnetic or magnetizable pigment particles is substantially parallel to the surface of an imaginary sphere.

[0140] FIG. 6-1 discloses the method used in the embodiments provided therein, wherein at least one of the first and second patterns comprises biaxially oriented sheet-like magnetic or magnetizable pigment particles; wherein orientation step b) (is b') and / or b'')) comprises an orientation step and includes exposing the radiation-curable coating composition to the magnetic field of the magnetic component (630) to form a coating (620), and wherein curing step c) (is c') and / or c'')) comprises curing the coating (620) with a curing unit (650) at least partially simultaneously with step b). The position of the magnetic component (630) in FIG. 6-1 is illustrative only and may be placed on opposite sides of the substrate (610) depending on the selection and design of the magnetic orientation pattern to be produced.

[0141] According to an embodiment shown, for example, FIG. 7 (Examples E1-E8, magnetic component (730) used during steps b') and b''), the method described herein allows for the preparation of OEL,At least one of the first and second patterns comprises biaxially oriented sheet-like magnetic or magnetizable pigment particles; wherein the at least one in steps b') and b'') comprises exposing the radiation-curable coating composition to those magnetic components disclosed in WO 2021 / 239607 A1. The magnetic components disclosed in WO 2021 / 239607 A1 comprise:

[0142] a) at least a first group (S1) and a second group (S2), each of the first group (S1) and the second group (S2) comprising: i) a first rod-shaped dipole magnet (x31) having a first thickness (L1), a first length (L4) and a first width (L5), and having its magnetic axis oriented substantially parallel to the substrate, and ii) having a second thickness (L2), a second length (L6) and a second width (L7). Two second rod-shaped dipole magnets (x32a and x32b) have their uppermost surfaces flush with each other, and their magnetic axes are oriented substantially perpendicular to the substrate. The first rod-shaped dipole magnet (x31) of the first group (S1) has a magnetic direction opposite to that of the first rod-shaped dipole magnet (x31) of the second group (S2). The first rod-shaped dipole magnets (x31) of the first group (S1) and the second group (S2) are spaced apart. A first distance (d1) is created. The first rod-shaped dipole magnet (x31) of the first group (S1) and the first rod-shaped dipole magnet (x31) of the second group (S2) have substantially the same first thickness (L1), first length (L4), and first width (L5). Furthermore, the two second rod-shaped dipole magnets (x32a and x32b) of the first group (S1) and the two second rod-shaped dipole magnets (x32a and x32b) of the second group (S2) have substantially the same second thickness (L2). The first rod-shaped dipole magnet (x31) and the second rod-shaped dipole magnet (x32a and x32b) of each of the first group (S1) and the second group (S2) are aligned to form a column, wherein the first rod-shaped dipole magnet (x31) of the first group (S1) and the second group (S2) are respectively placed between and spaced apart from the second rod-shaped dipole magnets (x32a and x32b) by a second distance (d2), and the first width (L5) and The second length (L6) is essentially the same. The north pole of one of the second rod-shaped dipole magnets (x32a and x32b) in each of the first group (S1) and the second group (S2) points towards the first plane, while the north pole of the first rod-shaped dipole magnet (x31) points towards the second rod-shaped dipole magnet (x32a and x32b), and the south pole of the other second rod-shaped dipole magnet (x32a and x32b) in each of the first group (S1) and the second group (S2) points towards the first plane.And the south pole of the first rod-shaped dipole magnet (x31) points to the other second rod-shaped dipole magnet (x32a and x32b); and

[0143] b) the first pair (P1) of third rod-shaped dipole magnets (x33a and x33b) having a third thickness (L3), a third length (L8) and a third width (L9), and their magnetic axes are oriented substantially parallel to the substrate, the second width (L7) of the two second rod-shaped dipole magnets (x32a and x32b) of the first group (S1) and the second group (S2) having the same width as the third rod-shaped dipole magnet (x33a and x32b). The third width (L9) of x33b is substantially the same value. Each of the third rod-shaped dipole magnets (x33a and x33b) is aligned with a second rod-shaped dipole magnet (x32a and x32b) of the first group (S1) and a second rod-shaped dipole magnet (x32a and x32b) of the second group (S2) to form two lines. The third rod-shaped dipole magnets (x33a and x33b) are placed between the corresponding second rod-shaped dipole magnets (x32a and x32b) and spaced apart from them by a third distance (d). 3) When the north pole of one of the second rod-shaped dipole magnets (x32a and x32b) points toward the substrate, the north pole of the third rod-shaped dipole magnet (x33a and x33b) points toward said one of the second rod-shaped dipole magnets (x32a and x32b), or when the south pole of one of the second rod-shaped dipole magnets (x32a and x32b) points toward the substrate, the south pole of the third rod-shaped dipole magnet (x33a and x33b) points toward said one of the second rod-shaped dipole magnets (x32a and x32b).

[0144] According to one embodiment, the method described herein allows the preparation of an OEL, wherein at least one of the first and second patterns comprises biaxially oriented sheet-like magnetic or magnetizable pigment particles; wherein said at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to those magnetic components as described in EP 2 157 141 A1. The magnetic assembly disclosed in EP 2 157 141 A1 provides a magnetic field that changes the orientation of sheet-like magnetic or magnetizable pigment particles as they move through the assembly, forcing the particles to oscillate rapidly until the two principal axes become parallel to the substrate, i.e., the particles oscillate until they reach a stable sheet-like form, wherein their X and Y axes are parallel to the substrate and are planarized in said two dimensions. As shown in Figure 5 of EP 2 157 141, the magnetic assembly comprises a linear arrangement of at least three magnets positioned in an alternating or zigzag pattern on opposite sides of the feed path, wherein magnets on the same side of the feed path have the same polarity.The polarity of the magnets on opposite sides of the feed path, which are arranged in an alternating pattern, is opposite to that of the magnets. As the sheet-like magnetic or magnetizable pigment particles in the coating composition move past the magnets, the arrangement of at least three magnets provides a predetermined change in the field direction (direction of movement: arrow). According to one embodiment, the magnetic assembly includes a) a first magnet and a third magnet on a first side of the feed path, and b) a second magnet between the first and third magnets on a second opposite side of the feed path, wherein the first and third magnets have the same polarity, and wherein the second magnet has a polarity complementary to that of the first and third magnets. According to another embodiment, the magnetic assembly further includes a fourth magnet on the same side of the feed path as the second magnet, having the polarity of the second magnet and complementary to the polarity of the third magnet.

[0145] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of the first and second patterns comprises biaxially oriented sheet-like magnetic or magnetizable pigment particles; wherein the at least one in steps b') and b'') comprises exposing a radiation-curable coating composition to a magnetic assembly comprising a linear permanent magnet Halbach array, i.e., an assembly comprising a plurality of magnets and cylindrical devices with different magnetization directions. A detailed description of Halbach permanent magnets is given by Z.Q. Zhu and D. Howe (Halbach permanent magnet machines and applications: a review), IE. Proc. Electric Power Appl., 2001, 148, pp. 299-308. The magnetic field generated by such a Halbach array has the property that it is concentrated on one side and weakens to almost zero on the other side. Linear Helbeck arrays are disclosed, for example, in WO 2015 / 086257 A1 and WO 2018 / 019594 A1, and Helbeck cylindrical devices are disclosed in EP 3 224 055 B1.

[0146] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of a first pattern and a second pattern comprises biaxially oriented sheet-like magnetic or magnetizable pigment particles; wherein the at least one in steps b') and b'') comprises exposing a radiation-curable coating composition to a rotating magnetic component at an appropriate rate. Examples of rotating magnetic components are components comprising one or more disk-shaped rotating magnets or magnetic components magnetized substantially along their diameter. Magnetic components comprising rotating magnets or magnetic field generating devices are described in US 2007 / 0172261 A1, which generate a radially symmetrical time-varying magnetic field.This allows for biaxial orientation of pigment particles. These magnetic components are driven by a shaft (or spindle) connected to an external motor. CN 102529326 B discloses examples of magnetic components comprising a rotating magnet suitable for biaxial orientation of pigment particles. In a preferred embodiment, a suitable magnetic component is a shaftless disc-shaped rotating magnetic component confined within a housing made of a non-magnetic, preferably non-conductive, material and driven by one or more magnetic coils wound around the housing. Examples of such shaftless disc-shaped rotating magnetic components are disclosed in WO 2015 / 082344 A1, WO 2016 / 026896 A1, and WO2018 / 141547 A1.

[0147] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein at least one of steps b') and b'') comprises exposing a radiation-curable coating composition to a combined magnetic field of a combination of the magnetic component described above for biaxial orientation of pigment particles and a soft magnetic plate comprising one or more indentations (I) and / or one or more voids (V) and / or one or more protrusions (P). The soft magnetic plate described herein comprises one or more soft magnetic materials, i.e., materials having low coercivity and high permeability μ. Their coercivity, as measured according to IEC 60404-1:2000, is less than 1000 Am⁻¹, to allow for rapid magnetization and demagnetization. Suitable soft magnetic materials have a maximum relative permeability μRmax of at least 5, where the relative permeability μR is the permeability of the material μ relative to the permeability of free space μ0 (μR = μ / μ0) (Magnetic Materials, Fundamentals and Applications, 2nd ed., Nicola A. Spaldin, pp. 16-17, Cambridge University Press, 2011). Soft magnetic materials are described in, for example, the following handbooks: (1) Handbook of Condensed Matter and Materials Data, Chapter 4.3.2, Soft Magnetic Materials, pp. 758-793, and Chapter 4.3.4, Magnetic Oxides, pp. 811-813, Springer, 2005; (2) Ferromagnetic Materials, Volume 1, Iron, Cobalt and Nickel, pp. 1-70, Elsevier, 1999; (3) Ferromagnetic Materials, Volume 2, Chapter 2, Soft Magnetic Metallic Materials, pp. 55-188, and Chapter 3, Ferrites for Non-Microwave Applications.Pages 189-241, Elsevier, 1999; (4) Electric and Magnetic Properties of Metals, C. Moosbrugger, Chapter 8, Magnetic Soft Materials, pp. 196-209, ASM International, 2000; (5) Handbook of modern Ferromagnetic Materials, Chapter 9, High-Permeability High-Frequency Metal Strips, pp. 155-182, Kluwer Academic Publishers, 2002; and (6) Smithells Metals Reference Book, Chapter 20.3, Magnetic Soft Materials, pp. 20-9 to 20-16, Butterworth-Heinemann Ltd, 1992. The soft magnetic plate described herein can be a plate made of one or more metals, alloys, or compounds with high magnetic permeability (hereinafter referred to as a "soft magnetic metal plate"), or a plate made of a composite material containing soft magnetic particles dispersed in a non-magnetic material (hereinafter referred to as a "soft magnetic composite plate"). According to one embodiment, the soft magnetic metal plate described herein is made of one or more soft magnetic metals or alloys that can be readily used as sheets or wires. Preferably, the soft magnetic metal plate described herein is made of one or more materials selected from the group consisting of iron, cobalt, nickel, nickel-molybdenum alloys, nickel-iron alloys (permalloy or supermalloy-type materials), cobalt-iron alloys, cobalt-nickel alloys, iron-nickel-cobalt alloys (Fernico-type materials), Heusler-type alloys (such as Cu2MnSn or Ni2MnAl), low-silicon steel, low-carbon steel, ferrosilicon (electrical steels), iron-aluminum alloys, iron-aluminum-silicon alloys, amorphous metal alloys (e.g., Metglas®, iron-boron alloys, etc.), nanocrystalline soft magnetic materials (e.g., Vitroperm®), and combinations thereof, more preferably the group consisting of iron, cobalt, nickel, low-carbon steel, ferrosilicon, nickel-iron alloys, and cobalt-iron alloys, and combinations thereof. Figure 11 shows a suitable soft magnetic plate (1130-1) containing one or more indentations (I).

[0148] Figure 4B-1 (not drawn to scale) illustrates a method in which orientation step b) (is b') and / or b'')) includes an orientation step in which an assembly comprising a substrate (410) and a coating (420) as described herein is placed on a first magnetic assembly (430-a).The component also moves simultaneously in the vicinity of the static second magnetic component (430-b). The positions of the magnetic components (430-a and 430-b) in Figure 4B-1 are illustrative only, and depending on the selection and design of the magnetic orientation pattern to be generated, the magnetic components can be placed on opposite sides of the substrate (410). Figure 4B-2 illustrates a method in which orientation step b) (is b') and / or b'')) includes an orientation step in which an component comprising a substrate (410) containing the coating (420) described herein is placed on a first magnetic component (430-a), and the component moves simultaneously in the vicinity of a static second magnetic component (430-b), wherein the first magnetic component (430-a) is mounted on a transfer device as a rotating magnetic cylinder, and the second magnetic component (430-b) is arranged in the vicinity of the rotating magnetic cylinder. According to one embodiment, such as 4B-2, the method described herein allows for the preparation of OEL, wherein at least one of steps b') and b'') comprises the following steps: placing a substrate (410) carrying a radiation-curable coating composition in the form of a coating (420) on a first magnetic component (430-a) providing a first magnetic field vector component, the first magnetic component being mounted on a rotating magnetic cylinder such that sheet-like magnetic or magnetizable pigment particles are subjected to the first magnetic field vector component, and simultaneously moving the substrate (410) carrying the coating (420) and the first magnetic component (430-a) near a static second magnetic component (430-b), the second magnetic component (430-b) providing a second magnetic field vector component such that the sheet-like magnetic or magnetizable pigment particles are subjected to a time-dependent synthetic magnetic field formed by the first and second magnetic field vector components, such that at least a portion of the sheet-like magnetic or magnetizable pigment particles are biaxially oriented. According to one embodiment, the ratio of the magnetic flux density of the first magnetic component (430-a) to the magnetic flux density of the static second first magnetic component (430-b) is less than about 4.0, preferably less than about 1.9, and more preferably between about 1.5 and about 0.5. The first magnetic component (430-a) having a substrate (410) on which the coating (420) is carried is preferably selected from the magnetic components described above for uniaxial orientation of pigment particles and the soft magnetic plate described above. The second magnetic component (430-b) is preferably selected from the magnetic components described above for biaxial orientation of pigment particles. Such methods are disclosed in WO 2019 / 14142 A1 and WO 2019 / 141453 A1.

[0149] According to one embodiment, the method described herein includes a magnetic orientation step b') and / or a magnetic orientation step b'') as a two-step orientation step, the step comprising two steps: a first orientation step for biaxial orientation of the sheet-like magnetic or magnetizable pigment particles described herein,The subsequent second orientation step reorients the sheet-like magnetic or magnetizable pigment particles described herein. According to one embodiment and as shown in Figure 5-1, both magnetic orientation step b') and magnetic orientation step b'') comprise two orientation steps (b'-1 and b'2; b''-1 and b''-2). The positions of the magnetic components (530-a and 530-b) in Figure 5-1 (not drawn to scale) are illustrative only and can be placed on opposite sides of the substrate (510) depending on the selection and design of the magnetic orientation pattern to be produced. Figure 5-2 (not drawn to scale) illustrates a method in which orientation step b) (is b') and / or b'')) comprises two orientation steps, wherein the radiation-curable coating composition described herein is first exposed to the magnetic field of the first magnetic component (530-a) and subsequently exposed to the magnetic field of the second magnetic component (530-b). The positions of the magnetic components (530-a and 530-b) in Figure 5-2 are illustrative only and can be placed on opposite sides of the substrate (510) depending on the selection and design of the magnetic orientation pattern to be produced. Figure 5-3 (not drawn to scale) illustrates a method in which orientation step b) (is b') and / or b'')) comprises a two-step orientation step in which the radiation-curable coating composition described herein is first exposed to the magnetic field of the first magnetic component (530-a) and subsequently exposed to the magnetic field of the second magnetic component (530-b), wherein the second magnetic component (530-b) is mounted on a rotating magnetic cylinder. Figure 5-4 (not drawn to scale) illustrates a method in which orientation step b) (is b') and / or b'')) comprises a two-step orientation step, wherein the radiation-curable coating composition described herein is exposed to the magnetic field of a first magnetic component (530-a), and subsequently exposed to the combined magnetic field of a second magnetic component (530-b) and a third magnetic component (530-c), wherein the second magnetic component (530-b) is mounted on a rotating magnetic cylinder, and the third magnetic component (530-c) is disposed in proximity to the rotating magnetic cylinder. A suitable method in which orientation step b) (is b') and / or b'')) comprises a two-step orientation step is disclosed in WO 2015 / 086257 A1.

[0150] Figure 6-2 (not drawn to scale) discloses the method used in the embodiments provided therein, wherein at least one of the first and second patterns comprises biaxially oriented sheet-like magnetic or magnetizable pigment particles; wherein orientation step b) (is b') and / or b'')) comprises two orientation steps (b-1 and b-2) and includes the following: exposing the radiation-curable coating composition to the magnetic field of the first magnetic component (630-a),The radiation-curable coating composition is then exposed to the combined magnetic field of the second magnetic component (630-b) and the third magnetic component (630-c) to form a coating (620), wherein curing step c) (is c') and / or c'') includes curing the coating (620) with a curing unit (650) at least partially simultaneously with step b), particularly step b-2). The positions of the magnetic components (630-a, 630-b, and 630-c) in Figure 6-2 are illustrative only and may be placed on opposite sides of the substrate (610) depending on the selection and design of the magnetic orientation pattern to be produced.

[0151] This document also describes the following combinations of multiple sets of steps:

[0152] - A first set of steps and a second set of steps, the first set of steps comprising step b'), step b') comprising a one-step orientation step as a uniaxial orientation or biaxial orientation as described herein, preferably a biaxial orientation as described herein, the second set of steps comprising step b''), step b'') comprising a one-step orientation step as a uniaxial orientation or biaxial orientation as described herein, preferably a biaxial orientation as described herein, provided that the magnetic fields in steps b') and b'') are different;

[0153] - A first set of steps and a second set of steps, the first set of steps comprising step b'), step b') comprising a one-step orientation step as a uniaxial orientation or biaxial orientation as described herein, preferably a biaxial orientation as described herein, the second set of steps comprising step b''), step b'') comprising a two-step orientation step as described herein;

[0154] - A first set of steps and a second set of steps, the first set of steps including step b'), step b') including the two-step orientation steps described herein, the second set of steps including step b''), step b'') including a one-step orientation step as a uniaxial orientation or biaxial orientation, preferably the biaxial orientation described herein; and

[0155] - A first set of steps and a second set of steps, the first set of steps including step b'), step b') including the two-step orientation steps described herein, the second set of steps including step b''), step b'') including the two-step orientation steps described herein, provided that the magnetic fields in steps b') and b'') are different.

[0156] After or partially simultaneously, preferably partially simultaneously, the orientation of the sheet-like magnetic or magnetizable pigment particles is independently fixed or frozen by curing (step c' and step c'')). Therefore, it is noteworthy that the first and second coating compositions must have a first state, i.e., a liquid or paste state, in which the composition has not yet hardened and is sufficiently wet or soft, allowing the flake-like magnetic or magnetizable pigment particles dispersed in the composition to move, rotate, and orient freely when exposed to a magnetic field, and a second hardened state (e.g., a solid or solid state).The sheet-like magnetic or magnetizable pigment particles are fixed or frozen in their respective positions and orientations.

[0157] These first and second states are preferably provided by using some type of coating composition. For example, the components of the first and second radiation-curable coating compositions, other than the sheet-like magnetic or magnetizable pigment particles, can take the form of ink or coating compositions, such as those used in security applications such as banknote printing. The aforementioned first and second states can be provided by using materials that exhibit an increase in viscosity in response to stimuli such as, for example, temperature changes or exposure to electromagnetic radiation. That is, when the fluid binder material hardens or cures, the binder material transforms into a second state, i.e., a hardened or solid state, in which the sheet-like magnetic or magnetizable pigment particles are fixed in their current positions and orientations and cannot be moved or rotated within the binder material. As is known to those skilled in the art, the components contained in the ink or coating composition to be applied directly or indirectly to the substrate and the physical properties of the ink or coating composition must meet the requirements of the method for transferring the ink or coating composition. Therefore, the binder materials included in the coating compositions described herein are generally selected from those known in the art, and depend on the coating or printing method used to apply the ink or coating composition and the selected curing method.

[0158] The curing steps (step c') and c'') described herein independently involve chemical reactions, such as curing, which cannot be reversed by simple temperature increases (e.g., up to 80°C) that may occur during typical use of security documents. The terms “curing” or “curability” refer to a method of chemical reaction, crosslinking, or polymerization of at least one component of the applied coating composition, in which it is transformed into a polymer material having a molecular weight greater than that of the starting material. Preferably, curing results in the formation of a stable three-dimensional polymer network. Such curing is typically induced (steps c' and c'') by applying an external stimulus to the composition after (steps a') and a'')) and (ii) after or partially simultaneously with the orientation of at least a portion of the sheet-like magnetic or magnetizable pigment particles (steps b' and b''))). Advantageously, the curing steps (steps c' and c'')) of the first and second coatings (x20' and x20'') described herein are performed independently and partially simultaneously with the orientation of at least a portion of the sheet-like magnetic or magnetizable pigment particles (steps b' and b''))) (steps c' and c'')). Radiation curing, particularly UV-Vis curing, advantageously results in a transient increase in viscosity of the first and second radiation-curable coating compositions after exposure to radiation, thereby preventing any further movement of the pigment particles and thus preventing any loss of information after the magnetic orientation step. Preferably,The curing steps (steps c' and c'') are performed independently by UV-Vis irradiation (i.e., UV-Vis light curing) or by electron beam (i.e., electron beam curing), more preferably by UV-Vis irradiation, because UV-Vis curing advantageously allows for a very fast curing process and thus significantly reduces the preparation time of the OEL, documents and articles containing the OEL, and documents described herein.

[0159] Preferably, the first or second radiation-curable coating composition, preferably the first and second UV-Vis curable coating compositions, independently comprises one or more compounds selected from the group consisting of free radical curable compounds and cationic curable compounds. The compositions described herein may be mixed systems and comprise a mixture of one or more cationic curable compounds and one or more free radical curable compounds. The cationic curable compounds are cured by a cationic mechanism, which typically involves activation by irradiation of one or more photoinitiators that release cationic substances such as acids, which in turn initiate curing to cause the monomers and / or oligomers to react and / or crosslink, thereby hardening the coating composition. Radical-curable compounds are cured via a radical mechanism, which typically involves activation by radiation with one or more photoinitiators to generate radicals that, in turn, initiate polymerization to harden the coating composition. Different photoinitiators may be used depending on the monomer, oligomer, or prepolymer used to prepare the binder contained in the first and second radiation-curable coating compositions described herein. Suitable examples of radical photoinitiators are known to those skilled in the art and include, but are not limited to, acetophenones, benzophenones, benzyl dimethyl ketals, α-amino ketones, α-hydroxy ketones, phosphine oxides and phosphine oxide derivatives, and mixtures of two or more thereof. Suitable examples of cationic photoinitiators are known to those skilled in the art and include, but are not limited to, onium salts such as organic iodonium salts (e.g., diaryliodonium salts), oxonium salts (e.g., triaryloxonium salts), and sulfonium salts (e.g., triarylsulfonium salts), and mixtures of two or more thereof. Other examples of available photoinitiators can be found in standard textbooks. To achieve effective curing, a sensitizer combined with one or more photoinitiators may advantageously be included. Typical examples of suitable photosensitizers include, but are not limited to, isopropylthioxanthone (ITX), 1-chloro-2-propoxy-thioxanthone (CPTX), 2-chloro-thioxanthone (CTX), and 2,4-diethyl-thioxanthone (DETX), as well as mixtures of two or more thereof. The one or more photoinitiators included in the UV-Vis curable coating composition are preferably present in a total amount of about 0.1% to about 20% by weight, more preferably about 1% to about 15% by weight.The weight percentages are based on the total weight of the first and second radiation-curable coating compositions, respectively.

[0160] The first and second radiation-curable coating compositions described herein may further independently contain one or more additives, including but not limited to compounds and materials for adjusting the physical, rheological, and chemical parameters of the composition, such as viscosity (e.g., solvents and surfactants), consistency (e.g., anti-settling agents, fillers, and plasticizers), foaming properties (e.g., defoamers), lubricity (waxes), UV reactivity and stability (photosensitizers and light stabilizers), and adhesion. 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, wherein at least one particle size is in the range of 1 to 1000 nm. Specification 27 / 40 pages 30 CN 122396552 A

[0161] The first and second radiation-curable coating compositions described herein may be prepared independently by dispersing or mixing the sheet-like magnetic or magnetizable pigment particles described herein and one or more additives, when present, in the presence of the binder material described herein, thereby forming a liquid composition. When present, one or more photoinitiators may be added to the composition during the dispersion or mixing steps of all other components, or may be added at a later stage, i.e., after the formation of the liquid coating composition.

[0162] The method for generating an OEL described herein includes the steps of curing the radiation-curable coating composition in steps c) (steps c') and / or b'')) partially simultaneously with or after steps b) (steps b') and / or b'')) and preferably partially simultaneously. The step of curing the coating composition allows the sheet-like magnetic or magnetizable pigment particles to be fixed in their adopted positions and orientations in the desired pattern to form an OEL, thereby transforming the radiation-curable coating composition into a second state. However, the time from the end of step b) (steps b') and / or b'')) to the start of step c) (steps c') and / or c'')) is preferably relatively short to avoid any loss of orientation and information loss. Typically, the time between the end of step b)(step b') and / or b'') and the start of step c)(step c') and / or c'') is less than 1 minute, preferably less than 20 seconds, and more preferably less than 5 seconds. Particularly preferably, there is essentially no time interval between the end of the orientation step b)(step b') and / or b'') and the start of the curing step c)(step c') and / or c''); that is, step c) is performed immediately after step b) or step c) begins while step b) is still in progress (partially simultaneous). "Partially simultaneous" means that the two steps are performed partially simultaneously, i.e., the time for each step partially overlaps. In the context described herein, when curing is performed partially simultaneously with step c), it must be understood that...Curing becomes effective after orientation, allowing the flake-like magnetic or magnetizable pigment particles to be oriented before the OEL is fully or partially cured. As mentioned herein, the curing steps (step c) (steps c') and c'') can be carried out using different means or methods, depending on the binder material included in the coating composition, which also contains flake-like magnetic or magnetizable pigment particles.

[0163] The curing step can generally be any step that increases the viscosity of the radiation-curable coating composition to form a substantially solid material adhered to the substrate. The curing step can involve a physical process (i.e., physical drying) based on the evaporation of volatile components such as solvents and / or water evaporation. In this document, hot air, infrared radiation, or a combination of hot air and infrared radiation can be used. Alternatively, the curing step can include the curing, polymerization, or crosslinking of a chemical reaction, such as the curing, polymerization, or crosslinking of the binder and optional initiator compounds and / or optional crosslinking compounds included in the radiation-curable coating composition. This chemical reaction can be initiated by thermal or IR radiation for physical curing processes as described above, but may preferably include chemical reactions initiated by radiation mechanisms, including but not limited to ultraviolet-visible radiation curing (hereinafter referred to as UV-Vis curing) and electron beam radiation curing (electron beam curing); oxidative polymerization (oxidative networking, typically induced by the combined action of oxygen and preferably one or more catalysts 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.

[0164] Radiation curing is particularly preferred, and UV-Vis radiation curing is even more preferred, as these techniques advantageously result in a very fast curing process and thus significantly reduce the preparation time of any article containing the OEL described herein. Furthermore, radiation curing has the advantage of producing an almost instantaneous increase in viscosity of the coating composition upon exposure to curing radiation, thereby minimizing any further movement of the particles. Thus, any loss of orientation after the magnetic orientation step can be substantially avoided. Particularly preferred is radiation curing via photopolymerization under the influence of photochemical light with wavelength components in the UV or blue portion of the electromagnetic spectrum (typically 200 nm to 650 nm; more preferably 200 nm to 420 nm). Suitable curing units (x50) for curing steps (step c') and c'') may include high-power light-emitting diode (LED) lamps or arc discharge lamps, such as medium-pressure mercury arc lamps (MPMA) or metal vapor arc lamps, as photochemical radiation sources. In contrast to medium-pressure mercury lamps, which have emission bands in the UV-A, UV-B, and UV-C regions of the electromagnetic spectrum, UV-LED lamps emit radiation in the UV-A region and / or the visible (Vis) region, for example, in the range from about 350 nm to about 470 nm. Furthermore,Current UV-LED and Vis-LED lamps emit quasi-monochromatic radiation, i.e., they emit only at one wavelength, such as 365nm, 385nm, 395nm, 405nm, or 450nm. Preferably, at least one of steps c') and c'') described herein is performed by exposing the first coating (x20') and the second coating (x20'') to UV light, preferably to one or more wavelengths between about 355nm and about 415nm, more preferably by exposing to UV light of 365nm and / or 385nm and / or 395nm emitted from the LED curing unit (x50).

[0165] Prior to curing steps c) (c') and / or c''), the first coating (x20') and / or the second coating (x20'') may be independently subjected to customization to produce an OEL exhibiting more than one mark, wherein the customization steps are performed after orientation steps b') and b'') and prior to curing steps c' and c''). The customization steps are preferably performed by applying a liquid coating composition on top of the coating while it is still wet (wet-to-wet method), said application being performed by a non-contact fluid micro-dispensing method as disclosed in WO 2021 / 259527 A1.

[0166] The present invention provides a method for producing the OEL described herein on a substrate (x10) described herein. The substrates described herein are preferably selected from the group consisting of: paper or other fibrous materials such as cellulose (including woven and nonwoven fibrous materials), paper-containing materials, glass, metals, ceramics, plastics and polymers, metallized plastics or polymers, at least partially opaque plastics or polymers, composite materials, and mixtures or combinations thereof. Typical paper, paper-like, or other fibrous materials are made from a variety of fibers, including but not limited to, abaca, cotton, flax, wood pulp, and blends thereof. As is known to those skilled in the art, cotton and cotton / flax blends are preferred for banknotes, while wood pulp is commonly used for security documents other than banknotes. Typical examples of plastics and polymers include: polyolefins such as polyethylene (PE) and polypropylene (PP), including biaxially oriented polypropylene (BOPP), polyamides, etc.Polyesters such as polyethylene terephthalate (PET), polybutanediol terephthalate (PBT), and polyethylene 2,6-naphthelate (PEN), and polyvinyl chloride (PVC) can also be used as substrates. Spunbond olefin fibers, such as those sold under the trademark Tyvek®, can also be used. Typical examples of metallized plastics or polymers include the aforementioned plastic or polymer materials on which metals are deposited continuously or discontinuously on their surfaces. Typical examples of metals include, but are not limited to, aluminum (Al), chromium (Cr), copper (Cu), gold (Au), silver (Ag), their alloys, and combinations of two or more of the aforementioned metals. Metallization of the aforementioned plastic or polymer materials can be accomplished by electrodeposition, high-vacuum coating, or sputtering. Opaque polymers have been developed for the purpose of mimicking the appearance and some properties of conventional paper-based substrates used for secure documents and include transparent polymer substrates, which are typically surface-treated with an opaque layer on one or both sides to form an opaque polymer-based substrate. Typical examples of composite materials include, but are not limited to: paper and at least one plastic or polymeric material such as those described above, and multilayer structures or laminates incorporating paper-like or fibrous materials such as those described above, including plastic and / or polymeric fibers. Of course, the substrate may further contain additives known to those skilled in the art, such as fillers, sizing agents, brighteners, processing aids, reinforcing or humectant agents, etc. When the OEL produced according to the invention is used for decorative or cosmetic purposes, including, for example, nail polish, the OEL may be produced on other types of substrates including animal or human nails, artificial nails, or other parts.

[0167] The substrate (x10) described herein may be in the form of web, sheet, thread reel, film reel, labels of the roll, or label material, preferably in sheet form.

[0168] If the OEL generated according to the present invention is on a secure document, and for the purpose of further improving the security level of the secure document and its resistance to counterfeiting and illegal copying, the substrate may contain printed, coated or laser-marked or laser-perforated markings, watermarks, security threads, fibers, planchettes, luminescent compounds, windows, foils, labels, and combinations thereof. Also for the purpose of further improving the security level of the secure document and its resistance to counterfeiting and illegal copying (see page 29 / 40 of the specification, CN 122396552 A), the substrate may contain one or more marking substances or tracers and / or machine-readable substances. According to one embodiment, the substrate (x10) contains a printed pattern, preferably an offset-printed pattern.At least one of the radiation-curable coating compositions of steps a') and a'') is applied at least partially to the top of the printed pattern, and the method herein includes the step of printing ink on the substrate (x10) described herein, wherein, as appropriate, the step occurs prior to steps a') and a'') described herein.

[0169] If desired, a primer layer may be applied to the substrate (x10) prior to step a') and / or prior to step a''). This may improve the quality of the OEL described herein or promote adhesion. Examples of such primer layers can be found in WO 2010 / 058026 A2.

[0170] For the purpose of improving durability by increasing stain resistance or chemical resistance and cleanliness, thereby increasing the cycle life of articles, security documents, or decorative elements or objects containing OEL obtained by the method herein, or for the purpose of altering their aesthetic appearance (e.g., optical gloss), more than one protective layer may be applied on top of the OEL. When present, more than one protective layer is typically made of a protective varnish. These can be transparent, slightly tinted, or colored, and can be more or less glossy. The protective varnish can be a radiation-curing composition, a heat-drying composition, or any combination thereof. Preferably, one or more protective layers are radiation-curing compositions, more preferably UV-Vis curing compositions. The protective layer is typically applied after the OEL is formed.

[0171] The methods described herein may further include the step of embossing the OEL described herein using, for example, embossing dyes or gravure printing plates, as disclosed in WO 2012 / 025206 A2 and WO 2019 / 233624 A1.

[0172] The OEL described herein can be used in combination with holograms, microlenses, and / or micromirrors as described in WO 2020 / 244805 A1, EP 3 254 863 A1, US 2008 / 0160226, US 2005 / 0180020, and EP 2 284 017 A1, wherein the holograms, microlenses, and / or micromirrors are applied at locations spaced apart from or at least partially applied on top of or below the OEL.

[0173] The present invention further provides an optical effect layer (OEL) produced by the method according to the invention.

[0174] According to one embodiment, the OEL includes a first pattern, a second pattern, and a third pattern, wherein the first pattern includes sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern as described herein, the second pattern includes sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern as described herein, and the third pattern includes sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern as described herein, wherein the first, second, and third magnetic patterns are different from each other.Furthermore, at least a portion of the third graphic is at least partially adjacent to and properly registered with the first graphic and / or at least partially adjacent to and properly registered with the second graphic. This document also describes a method for generating an OEL having the three graphics described herein, wherein the method includes the first set of steps a'), b') and c') described herein, the second set of steps a''), b'') and c'') described herein, and the third set of steps a'''), b''') and c''') described herein, the third step being performed after and consecutively with step c''). This document also describes a method for generating an OEL having the three graphics described herein, wherein the method includes the first set of steps a'), b') and c') described herein, the second set of steps a''), b''') and c''') described herein, the third set of steps a'''), b''') and c''') described herein, and the fourth set of steps ai'''), bi''') and ci''') described herein, the third step being performed after and consecutively with step c''') and an optional fifth set of steps.

[0175] The OEL described herein can be directly applied to a substrate (x10), which will be permanently retained on the substrate (x10) (e.g., for banknote applications). Alternatively, the OEL comprising the first and second graphics described herein on the same side of the substrate (x10) can also be applied to a temporary substrate for production purposes, from which the OEL is subsequently removed. This can, for example, facilitate the formation of the OEL, particularly when the adhesive material is still in its fluid state. Subsequently, after curing the radiation-curable composition used to produce the OEL (see page 30 / 40 of the specification, CN 122396552 A), the temporary substrate can be removed from the OEL.

[0176] Alternatively, in another embodiment, an adhesive layer may be present. Thus, the adhesive layer can be applied after the curing steps of the last set of steps described herein have been completed. Such articles can be attached to all kinds of documents or other articles or articles without printing or other processes involving machinery and a considerable amount of work. Alternatively, the substrate described herein containing the OEL can be in the form of a transfer foil, which can be applied to the document or article in a separate transfer step. For this purpose, the substrate is provided with a release coating, on which an OEL is generated, as described herein.

[0177] This document also describes substrates (x10) comprising more than one, i.e., two, three, four, etc., OELs obtained by the methods described herein.Each of the OELs independently comprises the first and second patterns described herein in the form of first and second coatings (x20', x20''). The method described herein for producing more than one OEL on a substrate (x10) may include: a first set of steps a'), b'), and c') for producing the first pattern of the first OEL; a second set of steps a''), b''), and c'') for producing the second pattern of the first OEL; a third set of steps a'''), b'''), and c''') for producing the first pattern of the second OEL; and a fourth set of steps a''''), b''''), and c'''') for producing the second pattern of the second OEL. Alternatively, the method described herein for producing more than one OEL on a substrate (x10) may include: a first set of steps a'), b'), and c') for producing a first graphic of a first OEL; a second set of steps a''), b''), and c'') for producing a first graphic of a second OEL; a third set of steps a'''), b'''), and c''') for producing a second graphic of the first OEL; and a fourth set of steps a''''), b''''), and c'''') for producing a second graphic of the second OEL.

[0178] This document also describes articles comprising OELs produced according to the invention, particularly security documents, decorative elements, or objects. Such articles, particularly security documents, decorative elements, or objects, may comprise more than one (e.g., two, three, etc.) OELs produced according to the invention.

[0179] As described above, OELs produced according to the invention can be used for decorative purposes as well as for protecting and authenticating security documents.

[0180] Typical examples of decorative elements or objects include, but are not limited to, luxury goods, cosmetic packaging, vehicle parts, electronic / electrical appliances, furniture, and nail products.

[0181] Secure documents include, but are not limited to, documents of value and goods of value. Typical examples of documents of value include, but are not limited to, banknotes, contracts, bills, checks, vouchers, stamp duty stamps and tax labels, and agreements, as well as identity documents such as passports, ID cards, visas, driver's licenses, bank cards, credit cards, transaction cards, passes or cards, admission tickets, public transport tickets, or titles, preferably banknotes, identity documents, grant documents, driver's licenses, and credit cards. The term "goods of value" refers to packaging materials, particularly those used in cosmetics, nutritional products, pharmaceutical products, alcoholic beverages, tobacco products, beverages or food, electrical / electronic products, textiles, or jewelry—that is, articles that should be protected against counterfeiting and / or illegal reproduction to ensure the contents of the packaging, such as genuine medicines. Examples of such packaging materials include, but are not limited to, labels.Such as certified brand labels, tamper-evident labels, and seals. It should be noted that the disclosed substrates, valuable documents, and valuable goods are given for illustrative purposes only and do not limit the scope of the invention.

[0182] Alternatively, the OEL can be produced on an auxiliary substrate, such as, for example, a security thread, security strip, foil, decal, window, or label, and thus transferred to the security document in a separate step.

[0183] Several modifications to the specific embodiments described above can be conceived by those skilled in the art without departing from the spirit of the invention. These modifications are included in the invention.

[0184] Furthermore, all documents mentioned throughout this specification are incorporated herein by reference in their entirety, as described in full on pages 31 / 40 of this specification, CN 122396552 A.

[0185] Embodiments

[0186] The invention will now be described in more detail with reference to non-limiting embodiments. The following embodiments provide further details of the method according to the invention and suitable magnetic components for producing an optical effect layer (OEL).

[0187] The OEL obtained by the method of Examples E1-E8 and shown in Figure 12 was prepared on a laboratory apparatus according to a method including at least one step shown in Figures 6-1 and 6-2 to simulate an industrial method including at least one step shown in Figures 5-4. Precise registration of the first and second graphics (i.e., the first and second cured coatings (x20' and x20'')) was ensured by using a screen containing guide marks in addition to the graphics to be printed.

[0188] Examples E1-E8 were prepared independently using the UV-curable screen printing inks of Table 1, wherein the inks (steps a' and a'') were applied (steps a' and a'') to the same side of a substrate (x10) (trust paper from Louisenthal) to form the first and second coatings (x20' and x20'').

[0189] A first UV-curable screen printing ink (step a') is applied to the substrate by manual screen printing using a first T90 screen (x40') to form a first coating (x20') with a thickness of about 20 μm and having the shape shown in Table 2.

[0190] A second UV-curable screen printing ink (having the same composition as the first UV-curable screen printing ink) is applied to the substrate (x10) by manual screen printing using a second T90 screen (x40''). This second UV-curable screen printing ink is precisely registered with the first coating (x20') applied in step a') and is applied by manual screen printing using a second T90 screen (x40'').A second coating (x20'') with a thickness of about 20 μm and having a shape as shown in Table 2 is formed. A second UV-curable screen printing ink is applied to the same side as the first coating (x20').

[0191] Examples E8 during one-step orientation (step b') and Examples E1 and E5 during step b'', see Table 2 and Figure 6-1)

[0192] The substrate (610) carrying the coating (620) is moved over the static magnetic assembly (630) (step b)). Then, simultaneously with the orientation step b) portion (i.e., while the substrate (610) carrying the coating (620) is still in the magnetic field of the magnetic assembly), the magnetic orientation pattern of the sheet-like magnetic pigment particles thus obtained is fixed by exposing the coating containing the magnetically oriented pigment particles to a UV-LED lamp (650) from Phoseon (model FireFlex 50×75mm, 395nm, 8W / cm2) for about 0.3 seconds for UV curing (step c)).

[0193] Examples E1-E7 during the two-step orientation (step b') and Examples E2-E4, E6-E7 during step b'', see Table 2 and Figure 6-2)

[0194] The substrate (610) bearing the coating (620) is moved over the static magnetic assembly (630-a) (see the gray arrow in Figure 6-2) (step b-1) and then placed on the second magnetic assembly (630-b). Subsequently, the assembly containing the substrate (x10, 610) bearing the coating (620) and the magnetic assembly (630-b) is moved near and over the static magnetic assembly (630-c) (step b-2). Then, simultaneously with the orientation step b-2) (i.e., while the substrate (610) carrying the coating (620) is still in the magnetic field of the magnetic component (630-b), the magnetic orientation pattern of the thus obtained flake-shaped magnetic pigment particles is fixed by exposing the coating containing the pigment particles to a UV-LED lamp (650) from Phoseon (model FireFlex 50×75mm, 395nm, 8W / cm2) for about 0.3 seconds for UV curing (step c)).

[0195] Table 1 Specification 32 / 40 pages 35 CN 122396552 A

[0196]

[0197] ( ) Green to blue color-changing magnetic pigment particles (flake-shaped pigment particles) with a diameter d50 of about 11μm and a thickness of about 1μm obtained from Viavi Solutions, Santa Rosa, CA.

[0198] ( ) Green to blue color-changing magnetic pigment particles (flake-shaped pigment particles) with a diameter d50 of about 11μm and a thickness of about 1μm obtained from Viavi Solutions, Santa Rosa, CA.Five-layered, sheet-like magnetic pigment particles exhibiting a metallic silver color, with a diameter d50 of approximately 12 μm and a thickness of approximately 1 μm, obtained from CA.

[0199] ( ) Gold magnetic pigment particles with a diameter d90 of approximately 73.5 μm (determined by laser diffraction according to TDS) from Merck.

[0200] Magnetic assembly of FIG7

[0201] A magnetic assembly (730) for biaxially oriented pigment particles according to the method of the invention is disclosed in FIG3A of WO 2021 / 239607 A1. When used in FIG6-1, the magnetic assembly (730) comprises (630); when used in the first step b-1 of FIG6-2, the magnetic assembly (730) comprises (630-a); and when used in the second step b-2 of FIG6-2, the magnetic assembly (730) comprises (630-c).

[0202] The magnetic assembly (730) includes a) a first group (S1) comprising a first rod-shaped dipole magnet (731-a) and two second rod-shaped dipole magnets (732-a and 732-d); a second group (S2) comprising a first rod-shaped dipole magnet (731-b) and two second rod-shaped dipole magnets (732-b and 732-e); a third group (S3) comprising a first rod-shaped dipole magnet (731-c) and two second rod-shaped dipole magnets (732-c and 732-f); and b) a first pair (P1) of third rod-shaped dipole magnets (733-a and 733-b); and a second pair (P2) of third rod-shaped dipole magnets (733-c and 733-f).

[0203] The uppermost surfaces of the first rod-shaped dipole magnets (731-a, 731-b and 731-c) of the first group, the second group and the third group (S1, S2, S3), the second rod-shaped dipole magnets (732-a to 732-f) of the first group, the second group and the third group (S1, S2, S3), the first pair of specification pages 33 / 40 36 CN 122396552 A, and the third rod-shaped dipole magnets (733-a to 733-d) of the second pair (P1 and P2) are flush with each other.

[0204] The third rod-shaped dipole magnet (733-a) of the first pair (P1) is aligned with the second rod-shaped dipole magnet (732-a) of the first group (S1), the second rod-shaped dipole magnet (732-b) of the second group (S2), the third rod-shaped dipole magnet (733-c) of the second pair (P2), and the second rod-shaped dipole magnet (732-c) of the third group (S3), thereby forming a line. The third rod-shaped dipole magnet (733-b) of the first pair (P1) is aligned with the second rod-shaped dipole magnet (732-d) of the first group (S1), the second rod-shaped dipole magnet (732-e) of the second group (S2), the third rod-shaped dipole magnet (733-d) of the second pair (P2), and the second rod-shaped dipole magnet (732-f) of the third group (S3).Thus, lines are formed. For each line described herein, the third rod-shaped dipole magnet (733-a, 733-b, 733-c, and 733-d) and the second rod-shaped dipole magnet (732-a to 732-f) are spaced apart by a third distance (d2) of 2 mm. The first rod-shaped dipole magnet (731-a) of the first group (S1), the first rod-shaped dipole magnet (731-b) of the second group (S2), and the first rod-shaped dipole magnet (731-c) of the third group (S3) are spaced apart by a distance (d3) of 24 mm.

[0205] The first rod-shaped dipole magnets (731-a, 731-b, and 731-c) of the first, second, and third groups (S1, S2, S3) have the following dimensions: a first length (L1) of 60 mm, a first width (L2) of 40 mm, and a first thickness (L3) of 5 mm. Each of the second rod-shaped dipole magnets (732-a to 732-f) in the first, second, and third groups (S1, S2, S3) has the following dimensions: a second length of 40 mm (L4), a second width of 10 mm (L5), and a second thickness of 10 mm (L6). Each of the third rod-shaped dipole magnets (733-a to 733-d) in the first and second pairs (P1, P2) has the following dimensions: a third length of 20 mm (L7), a third width of 10 mm (L8), and a third thickness of 10 mm (L9).

[0206] The first rod-shaped dipole magnet (731-a) of the first group (S1) and the second rod-shaped dipole magnet (732-a and 732-d) of the first group (S1) are aligned to form a column; and the first rod-shaped dipole magnet (731-b) of the second group (S2) and the second rod-shaped dipole magnet (732-b and 732-e) of the second group (S2) are aligned to form a column; and the first rod-shaped dipole magnet (731-c) of the third group (S3) and the second rod-shaped dipole magnet (732-c and 732-f) of the third group (S3) are aligned to form a column. For each group (S1, S2, S3) and each column described herein, the first rod-shaped dipole magnets (731-a, 731-b, and 731-c) and the two second rod-shaped dipole magnets (732-a and 732-d; 732-b and 732-e; and 732-c and 732-f, respectively) are spaced apart by a second distance (d1) of 2 mm.

[0207] The magnetic axis orientation of the first rod-shaped dipole magnets (731-a, 731-b, and 731-c) in the first, second, and third groups (S1, S2, S3) is substantially parallel to the substrate (710) and substantially parallel to the substrate (710), wherein the magnetic direction of the first rod-shaped dipole magnet (731-a) in the first group (S1) is opposite to the magnetic direction of the first rod-shaped dipole magnet (731-b) in the second group (S2).Furthermore, the magnetic direction of the first rod-shaped dipole magnet (731-b) in the second group (S2) is opposite to that of the first rod-shaped dipole magnet (731-c) in the third group (S3). The first rod-shaped dipole magnet (731-a) in the first group (S1) and the first rod-shaped dipole magnet (731-b) in the second group (S2), as well as the first rod-shaped dipole magnet (731-b) in the second group (S2) and the first rod-shaped dipole magnet (731-c) in the third group (S3), are spaced apart by a first distance (d3) of 24 mm (corresponding to the sum of the third length (L7) and the two third distances (d2)).

[0208] The magnetic axis orientation of the two second rod-shaped dipole magnets (732-a to 732-f) in the first, second, and third groups (S1, S2, S3) is substantially perpendicular to the surface of the substrate (710). The south pole of the second rod-shaped dipole magnet (732-a) in the first group (S1), the south pole of the second rod-shaped dipole magnet (732-e) in the second group (S2), and the south pole of the second rod-shaped dipole magnet (732-c) in the third group (S3) point towards the substrate (710). The north pole of the second rod-shaped dipole magnet (732-d) in the first group (S1), the north pole of the second rod-shaped dipole magnet (732-b) in the second group (S2), and the north pole of the second rod-shaped dipole magnet (732-f) in the third group (S3) point towards the substrate (710). The north pole of the first rod-shaped dipole magnet (731-a) of the first group (S1) points to the second rod-shaped dipole magnet (732-d) of the first group (S1), the north pole of the second rod-shaped dipole magnet (731-b) of the second group (S2) points to the first rod-shaped dipole magnet (732-b) of the second group (S2), and the north pole of the first rod-shaped dipole magnet (731-c) of the third group (S3) points to the second rod-shaped dipole magnet (732-f) of the third group (S3), as per the specification page 34 / 40, CN 122396552 A. The south pole of the third rod-shaped dipole magnet (733-a) of the first pair (P1) points towards the second rod-shaped dipole magnet (732-a) of the first group (S1), and the south pole of the second rod-shaped dipole magnet (732-a) points towards the substrate (710); the south pole of the third rod-shaped dipole magnet (733-d) of the second pair (P2) points towards the second rod-shaped dipole magnet (732-e) of the second group (S2), and the south pole of the second rod-shaped dipole magnet (732-e) points towards the substrate (710). The south pole of the first pair (P1) points to the substrate (710); the north pole of the third rod-shaped dipole magnet (733-b) of the first pair (P1) points to the second rod-shaped dipole magnet (732-d) of the first group (S1), and the north pole of the second rod-shaped dipole magnet (732-d) points to the substrate (710); and the north pole of the third rod-shaped dipole magnet (733-c) of the second pair (P2) points to the second rod-shaped dipole magnet (732-b) of the second group (S2).The north pole of the second rod-shaped dipole magnet (732-b) points to the substrate (710).

[0209] The first rod-shaped dipole magnets (731-a, 731-b and 731-c) of the first, second and third groups (S1, S2, S3) and the second rod-shaped dipole magnets (732-a to 732-f) of the first, second and third groups (S1, S2, S3) are made of NdFeB N42; the third rod-shaped dipole magnets (733-a, 733-b, 733-c and 733-d) of the first pair and the second pair (P1, P2) are made of NdFeB N48. All magnets (731-a to 731-c, 732-a to 732-f, and 733-a to 733-d) are embedded in a non-magnetic support substrate (not shown) made of POM with the following dimensions: 200 mm × 120 mm × 12 mm.

[0210] Magnetic assembly of FIG8A

[0211] The magnetic assembly (830) comprises a rod-shaped dipole magnet (830-1) and a retaining box (870). The rod-shaped dipole magnet (830-1) has a length and width of approximately 30 mm and a thickness of approximately 8.5 mm. The north-south magnetic axis of the rod-shaped dipole magnet (830-1) is parallel to the surface of the substrate (810) and parallel to the machine feed direction (shown by the arrow in FIG8A). The rod-shaped dipole magnet (830-1) is made of NdFeB BMnPi 80 / 48.

[0212] The holding box (870) is made of a hollow top and bottom cover with curved surfaces. The hollow top has a length and width of about 40 mm, a thickness of about 15.1 mm, and is made of PPS. The bottom cover has a length of about 35 mm, a width of about 35 mm, a thickness of about 3 mm, and is made of POM. The curved surfaces are adapted to match the surface of the rotating magnetic cylinder of an industrial printing press. The hollow top is adapted to receive a rod-shaped dipole magnet (830-1).

[0213] The distance (h) between the surface of the rod-shaped dipole magnet (830-1) and the surface of the substrate (810) is about 3.35 mm.

[0214] Magnetic assembly of FIG8B

[0215] Except that the north-south magnetic axis is parallel to the surface of the substrate (810) and perpendicular to the machine feed direction (shown by the arrow in FIG8B),The magnetic assembly (830) is the same as the magnetic assembly (830) in FIG8A.

[0216] The distance (h) between the surface of the rod-shaped dipole magnet (830-1) and the surface of the substrate (810) is about 3.35 mm.

[0217] Magnetic assembly of FIG9

[0218] The magnetic assembly (930) includes a non-magnetic substrate (980) supporting 64 disk-shaped dipole magnets (930-2) and 64 disk-shaped dipole magnets (930-3), a square non-magnetic wedge (960), a rod-shaped dipole magnet (930-b1), and a holding box (970).

[0219] The holding box (970) is the same as the holding box (870).

[0220] The 64 disk-shaped dipole magnets (930-2) and 64 disk-shaped dipole magnets (930-3) have a diameter of about 2 mm and a thickness of about 2 mm. The north-south magnetic axes of the disk-shaped dipole magnets (930-2) and (930-3) are perpendicular to the surface of the substrate (910) and to their diameters. The north poles of the 64 disk-shaped dipole magnets (930-2) point towards the substrate, and the south poles of the 64 disk-shaped dipole magnets (930-3) point towards the substrate. The disk-shaped dipole magnets (930-2 and 930-3) are made of NdFeB N48.

[0221] The non-magnetic substrate (980) has a length and width of about 29.9 mm and a thickness of about 2 mm. The non-magnetic substrate (980) contains 128 voids for receiving the 64 disk-shaped dipole magnets (930-2) and the 64 disk-shaped dipole magnets (930-3). The non-magnetic substrate (980) is made of POM.

[0222] The center of each of the 64 disk dipole magnets (930-2), in particular the center of each of them, is arranged at the intersection of a grid containing eight parallel lines αi (i=1,…,8; α1 to α8) and eight parallel lines βi (i=1,…,8; β1 to β8) as per CN 122396552 A, page 35 / 40 of the specification; the center of each of the 64 disk dipole magnets (930-3), in particular the center of each of them, is arranged at the intersection of a grid containing eight parallel lines γi (i=1,…,8; γ1 to γ8) and eight parallel lines δi (i=1,…,8; δ1 to δ8); the center of the eight parallel lines αi (α1 to α8) and the eight parallel lines γi (γ1 to γ8) are also arranged at the intersection of a grid containing eight parallel lines γi (i=1,…,8; δ1 to δ8). 8) They are arranged parallel to each other and in an alternating manner; eight parallel straight lines βi (β1 to β8) and eight parallel straight lines δi (δ1 to δ8) are arranged parallel to each other and in an alternating manner, as shown in Figure 9.

[0223] The square non-magnetic wedge (960) has a length and width of about 29.5 mm and a thickness of 0.22 mm.And it is made of an adhesive film made of PVC / acrylic film.

[0224] The rod-shaped dipole magnet (930-1) has a length and width of about 29.9 mm and a thickness of about 6.9 mm. The north-south magnetic axis of the rod-shaped dipole magnet (930-1) is parallel to the surface of the substrate (910). The rod-shaped dipole magnet (930-1) is made of NdFeB BMnPi 80 / 48.

[0225] The distance (h) between the surface of the non-magnetic substrate (980) and the surface of the substrate (910) is about 1.1 mm.

[0226] Magnetic assembly of FIG10

[0227] The magnetic assembly (1030) includes a dipole magnet (1030-1) that is the same as the dipole magnet (830-1) of FIG8A and an engraved magnetic plate (1030-2) with engraving (I).

[0228] The engraved magnetic plate (1030-2) has a length and width of about 38 mm and a thickness of about 1 mm, and includes a 20-shaped engraving (indentation) with a depth of about 0.4 mm. The engraved magnetic plate (1030-2) is made of plastic hard ferrite (supplier = BOMATEC, CH-8181 Höri, CH) and is produced by injection molding.

[0229] The distance (h) between the surface of the engraved magnetic plate (1030-2) and the surface of the substrate (1010) is 0 mm (i.e., the substrate (1010) is in direct contact with the engraved magnetic plate (1030-2)).

[0230] Magnetic assembly of FIG11

[0231] The magnetic assembly (1130) includes a soft magnetic plate (1130-1) with indentation (I) and a retaining box (1170), which is the same as the retaining box (1170) of FIG8A.

[0232] The soft magnetic plate (1130-1) has a length and width of about 38 mm and a thickness of about 1 mm, and includes a 20-shaped indentation with a depth of about 0.7 mm. The soft magnetic plate (1130-1) (from Bomatec, Höri CH) is made of FeSi3 particles (from BASF's Catamold® FeSi3, a soft magnetic iron-silicon alloy with coercivity Hc=73 Am-1 and permeability μRmax=5215) injected into 25% polyoxymethylene (POM) at about 80% by weight.

[0233] The distance (h) between the surface of the soft magnetic plate (1130-1) and the surface of the substrate (1110) is 0 mm (i.e., the substrate (1110) is in direct contact with the soft magnetic plate (1130-1)).

[0234] Table 2 Specification 36 / 40 pages 39 CN 122396552 A

[0235] Specification 37 / 40 pages 40 CN 122396552 A

[0236]

[0237] OELs with flower shapes (see E1, E2, E3, E5),The combination of the first and second graphics shown in Table 2 has the following dimensions: a length of approximately 26 mm and a height of approximately 26 mm.

[0238] An OEL in the shape of a hot air balloon (see E4 and E6-E8), i.e., the combination of the first and second graphics shown in Table 2, has the following dimensions: a height of approximately 20 mm and a length of approximately 18 mm.

[0239] In contrast to methods known in the art and as shown in the provided embodiments E1-E8, the claimed method allows the production of an OEL comprising the first and second graphics described herein, which is perfectly registered not only in terms of the printed first and second graphics but also in terms of the effects derived from the first and second magnetic patterns, wherein the OEL benefits from its continuity in color (or in other words, from the common visible graphics as the OEL has no breaks) and from the striking effect obtained by a specific magnetic orientation pattern, and is easily identifiable by the common person, thereby making the OEL highly suitable as a security feature for demanding end-use applications.

[0240] The following items also form part of this disclosure:

[0241] Item 1. A method for forming an optical effect layer (OEL) on a substrate (x10), the optical effect layer (OEL) comprising a first pattern and a second pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, the second pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, the first magnetic pattern being different from the second magnetic pattern,

[0242] the method comprising:

[0243] a first set of steps comprising:

[0244] a') applying a first radiation-curable coating composition, preferably a first UV-Vis-curable coating composition, exhibiting color and comprising sheet-like magnetic or magnetizable pigment particles, to a substrate (x10) to form a first coating (x20') on the substrate (x10), the coating composition being in a first state,

[0245] b') Exposing the radiation-curable coating composition of step a') to a first magnetic field of the magnetic component (x30') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles;

[0246] c') Curing at least partially the radiation-curable coating composition of step b') to a second state to fix the sheet-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a first pattern; and

[0247] A second set of steps, comprising:

[0248] a'') Applying a second radiation-curable coating composition, preferably a UV-Vis curable coating composition, having the same color as the first radiation-curable coating composition of step a') to form a second coating (x20'') on the substrate (x10).The coating composition is in a first state, and at least a portion of the second coating (x20'') is adjacent to at least a portion of the first coating (x20').

[0249] b'') Exposing the radiation-curable coating composition of step a'') to a second magnetic field of the magnetic component (x30'') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles; and

[0250] c'') At least partially curing the radiation-curable coating composition of step b'') to a second state to fix the sheet-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a second pattern.

[0251] Item 2. The method according to Item 1, wherein the radiation-curable coating composition of step a') and the radiation-curable coating composition of step a'') are the same.

[0252] Item 3. The method according to Item 1 or 2, wherein at least one of step b') and step b'')

[0253] is a one-step orientation step of uniaxially orienting the sheet-like magnetic or magnetizable pigment particles, or

[0254] is a one-step orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles, or

[0255] is a two-step orientation step comprising a first orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles.

[0256] Item 4. The method according to Item 3, wherein

[0257] step b') comprises a one-step orientation step of uniaxially or biaxially orienting, preferably biaxially orienting, the sheet-like magnetic or magnetizable pigment particles, and step b'') is a two-step orientation step comprising a first orientation step and a subsequent second orientation step, the first orientation step uniaxially orienting the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles; or

[0258] step b') is a two-step orientation step comprising a first orientation step and a subsequent second orientation step, the first orientation step uniaxially orienting the sheet-like magnetic or magnetizable pigment particles, the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles, and step b'') comprises a one-step orientation step of uniaxially or biaxially orienting, preferably biaxially orienting, the sheet-like magnetic or magnetizable pigment particles; or

[0259] Step b') is a two-step orientation step including a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorients the sheet-like magnetic or magnetizable pigment particles, and step b'') is a two-step orientation step including a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorients the sheet-like magnetic or magnetizable pigment particles.

[0260] Item 5. The method according to item 3 or 4,At least one of steps b') and b'')

[0261] includes a one-step orientation step of biaxially oriented sheet-like magnetic or magnetizable pigment particles, or

[0262] includes a two-step orientation step of a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles, wherein the first orientation step of performing the one-step and two-step orientation steps biaxially oriented at least a portion of the sheet-like magnetic or magnetizable pigment particles such that i) both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) the first axis in the XY plane is substantially parallel to the surface of the substrate (x10), and the second axis is perpendicular to the first axis at a substantially non-zero elevation angle to the surface of the substrate (x10), or iii) their XY plane is parallel to the surface of an imaginary sphere.

[0263] Item 6. The method according to any one of items 1 to 5, wherein steps a') and a'') are performed independently by a printing method selected from the group consisting of screen printing, rotary gravure printing, flexographic printing and gravure printing, preferably by screen printing.

[0264] Item 7. The method according to any one of items 1 to 6, wherein steps c') and b') are performed simultaneously and / or steps c'') and b'') are performed simultaneously.

[0265] Item 8. The method according to item 7, wherein step c') is performed by exposing an LED curing unit (x50') to UV-Vis light radiation, and / or step c'') is performed by exposing an LED curing unit (x50'') to UV-Vis light radiation.

[0266] Item 9. The method according to any one of items 1 to 8, wherein at least a portion of the sheet-like magnetic or magnetizable pigment particles is composed of sheet-like optically variable magnetic or magnetizable pigment particles.

[0267] Item 10. The method according to any one of items 1 to 9, wherein the substrate (x10) is selected from the group consisting of: paper or other fibrous materials, paper-containing materials, glass, metals, ceramics, polymers, metallized polymers, at least partially opaque polymer composites, and mixtures or combinations thereof.

[0268] Item 11. The method according to any one of items 1 to 10, wherein a second radiation-curable coating composition is applied to the same side of the substrate (x10) carrying the first coating (x20').

[0269] Item 12. The method according to any one of items 1 to 10, wherein a second radiation-curable coating composition is applied to the opposite side of the substrate (x10) carrying the first coating (x20').The preferred substrate (x10) is a transparent substrate.

[0270] Item 13. The method according to any one of items 1 to 12, wherein the substrate (x10) comprises a printed pattern, preferably an offset printed pattern, and wherein at least one of the radiation-curable coating compositions of steps a') and a'') is applied at least partially to the printed pattern.

[0271] Item 14. The method according to any one of items 1 to 13, further comprising a third pattern having a third magnetic pattern and optionally a fourth pattern having a third magnetic pattern, the third magnetic pattern being different from the first magnetic pattern and different from the second magnetic pattern, and the fourth magnetic pattern being different from the first magnetic pattern, different from the second magnetic pattern and different from the third magnetic pattern.

[0272] Item 15. The method according to any one of items 1 to 14, wherein the first coating (x20') and the second coating (x20'') are registered within ±1 mm, preferably ±0.5 mm, more preferably ±0.2 mm. Instruction manual 40 / 40 pages 43 CN 122396552 A Figure 1 Figure 2 Figure 3 Figure 4A-1 Instruction manual drawing 1 / 7 pages 44 CN 122396552 A Figure 4A-2 Figure 4A-3 Figure 4B-1 Figure 4B-2 Instruction manual drawing 2 / 7 pages 45 CN 122396552 A Figure 5-1 Figure 5-2 Figure 5-3 Instruction manual drawing 3 / 7 pages 46 CN 122396552 A Figure 5-4 Figure 6-1 Figure 6-2 Instruction manual drawing 4 / 7 pages 47 CN 122396552 A Figure 7 Figure 8A Figure 8B Instruction manual drawing 5 / 7 pages 48 CN 122396552 A Figure 9 Figure 10 Figure 11 Instruction manual drawing 6 / 7 pages 49 CN 122396552 A Figure 12 Instruction manual drawing 7 / 7 pages 50 CN 122396552 A,

Claims

1. A method for forming an optical effect layer (OEL) on a substrate (x10), the OEL comprising a first pattern and a second pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, the second pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, wherein the first magnetic pattern is different from the second magnetic pattern. The method includes: The first set of steps includes: a') Applying a first radiation-curable coating composition, preferably a first UV-Vis-curable coating composition, that exhibits color and contains flake-like magnetic or magnetizable pigment particles to a substrate (x10) to form a first coating (x20') on the substrate (x10), wherein the coating composition is in a first state. b') Expose the radiation-curable coating composition of step a') to a first magnetic field of the magnetic component (x30') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles. c') Curing at least partially the radiation-curable coating composition of step b') to a second state to fix the flake-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a first pattern; and The second set of steps includes: a'') Apply a second radiation-curable coating composition, preferably a UV-Vis curable coating composition, having the same color as the first radiation-curable coating composition of step a') to form a second coating (x20'') on the substrate (x10), wherein the coating composition is in a first state and at least a portion of the second coating (x20'') is adjacent to at least a portion of the first coating (x20'). b'') Exposing the radiation-curable coating composition of step a'') to a second magnetic field of the magnetic component (x30'') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles; and c'') The radiation-curable coating composition of step b'') is at least partially cured to a second state to fix the flake-like magnetic or magnetizable pigment particles in their adopted positions and orientations, and to produce a second pattern. Where at least a portion of the second coating (x20'') is adjacent to at least a portion of the first coating (x20'), it means that the first and second patterns are continuous.

2. The method according to claim 1, wherein the radiation-curable coating composition of step a') and the radiation-curable coating composition of step a'') are the same.

3. The method according to claim 1 or 2, wherein at least one of step b') and step b'') It is an orientation step that uniaxially orients sheet-like magnetic or magnetizable pigment particles, or It is an orientation step that enables the biaxial orientation of sheet-like magnetic or magnetizable pigment particles, or It is a two-step orientation process, which includes a first orientation step that biaxially orients the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step that re-orients the sheet-like magnetic or magnetizable pigment particles.

4. The method according to claim 3, wherein Step b') includes a one-step orientation step of uniaxially or biaxially oriented, preferably biaxially oriented, of the sheet-like magnetic or magnetizable pigment particles, and step b'') is a two-step orientation step including a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles; or Step b') is a two-step orientation step comprising a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles, and step b'') includes a one-step orientation step of uniaxially or biaxially oriented, preferably biaxially oriented, of the sheet-like magnetic or magnetizable pigment particles; or Step b') is a two-step orientation step including a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorients the sheet-like magnetic or magnetizable pigment particles.

5. The method according to claim 3 or 4, wherein at least one of step b') and step b'') This includes a one-step orientation step that biaxially orients sheet-like magnetic or magnetizable pigment particles, or The two-step orientation step includes a first orientation step and a subsequent second orientation step, wherein the first orientation step biaxially oriented the sheet-like magnetic or magnetizable pigment particles, and the second orientation step reorienting the sheet-like magnetic or magnetizable pigment particles, wherein the first orientation step, which involves both the one-step and two-step orientation steps, biaxially oriented at least a portion of the sheet-like magnetic or magnetizable pigment particles such that i) both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) the first axis in the XY plane is substantially parallel to the surface of the substrate (x10), and the second axis is perpendicular to the first axis at a substantially non-zero elevation angle to the surface of the substrate (x10), or iii) their XY plane is parallel to the surface of an imaginary sphere.

6. The method according to any one of claims 1 to 5, wherein step c') and step b') are performed simultaneously and / or step c'') and step b'') are performed simultaneously.

7. The method of claim 6, wherein step c') is performed by exposing the LED curing unit (x50') to UV-Vis light radiation, and / or step c'') is performed by exposing the LED curing unit (x50'') to UV-Vis light radiation.

8. The method according to any one of claims 1 to 7, wherein at least a portion of the sheet-like magnetic or magnetizable pigment particles is composed of sheet-like optically variable magnetic or magnetizable pigment particles.

9. The method according to any one of claims 1 to 8, wherein the substrate (x10) is selected from the group consisting of: paper or other fibrous materials, paper-containing materials, glass, metals, ceramics, polymers, metallized polymers, at least partially opaque polymer composites, and mixtures or combinations thereof.

10. The method according to any one of claims 1 to 9, wherein the second radiation-curable coating composition is applied to the same side of the substrate (x10) carrying the first coating (x20').

11. The method according to any one of claims 1 to 9, wherein the second radiation-curable coating composition is applied to the opposite side of the substrate (x10) carrying the first coating (x20'), wherein preferably the substrate (x10) is a transparent substrate.

12. The method according to any one of claims 1 to 11, wherein the substrate (x10) comprises a printed pattern, preferably an offset printed pattern, and wherein at least one of the radiation-curable coating compositions of steps a') and a'') is applied at least partially to the printed pattern.

13. The method according to any one of claims 1 to 12, further comprising a third pattern having a third magnetic pattern and an optional fourth pattern having a third magnetic pattern, the third magnetic pattern being different from the first magnetic pattern and different from the second magnetic pattern, and the fourth magnetic pattern being different from the first magnetic pattern, different from the second magnetic pattern and different from the third magnetic pattern.

14. The method according to any one of claims 1 to 13, wherein the first coating (x20') and the second coating (x20'') are within a registration range of ±1 mm, preferably ±0.5 mm, more preferably ±0.2 mm.

15. The method according to any one of claims 1 to 14, wherein the method is a sequential method using a single machine, sequential meaning that the second set of steps is performed directly after the first set of steps, or, if the method includes a third set of steps, the third set of steps is performed directly after the second set of steps.

Images