Processes for producing optical effects layers

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 producing an optical effect layer (OEL) comprising at least a first and a second pattern, each pattern independently comprising sheet-like magnetic or magnetizable pigment particles.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480079857.9 (22) Application Date 2024.11.28 (30) Priority Data 23218609.8 2023.12.20 EP (85) PCT International Application Entering National Phase Date 2026.06.16 (86) PCT International Application Application Data PCT / EP2024 / 083920 2024.11.28 (87) PCT International Application Publication Data WO2025 / 131613 EN 2025.06.26 (71) Applicant Sikbai Holding Ltd. Address Switzerland (72) Inventor N. Benninger G. Bodin (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) B05D 7 / 00 (2006.01) (54) Invention Title: Method for Generating Optical Effect Layers (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 pattern independently comprising sheet-like magnetic or magnetizable pigment particles. Claims 3 pages, Description 46 pages, Drawings 7 pages, CN 122422063 A 2026.07.17 CN 1 22 42 20 63 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 method comprising: a first set of steps, comprising: a') applying a first radiation-curable coating composition comprising sheet-like magnetic or magnetizable pigment particles, preferably a first UV-Vis curable coating composition, onto the substrate (x10) to form a first coating (x20') on the substrate (x10), the coating composition being in a first state, b') step a c') The first radiation-curable coating composition of step b') is exposed to the magnetic field of the magnetic component (x30') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles; c') The first 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.The process involves: producing a first pattern; and a second set of steps, comprising: a'') applying a second radiation-curable coating composition, preferably a second UV-Vis curable coating composition, containing flake-like magnetic or magnetizable pigment particles, to form a second coating (x20''), 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''); b'') exposing the second radiation-curable coating composition of step a''') to the magnetic field of a magnetic component (x30'') to biaxially oriented at least a portion of the flake-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) their XY plane is parallel to the surface of an imaginary sphere; c'') at least partially curing the second 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 the 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 and second patterns are superimposed. 2. The method of claim 1, wherein step b') is a one-step orientation step or a two-step orientation step comprising a first orientation step of biaxially oriented sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles. 3. The method of claim 2, wherein step b') is a two-step orientation step comprising a first orientation step of biaxially oriented 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 any one of claims 1 to 3, wherein the first orientation step of the two-step orientation step b') is performed to 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. 5. The method according to any one of claims 1 to 4, wherein the first radiation-curable coating composition and the second radiation-curable coating composition exhibit the same color. 6. The method according to any one of claims 1 to 4, wherein the first radiation-curable coating composition and the second radiation-curable coating composition exhibit different colors. Claims 1 / 3 page 2 CN 122422063 A 7. The method according to any one of claims 1 to 6,Step c') and step b') are performed simultaneously and / or steps c'') and b'') are performed simultaneously. 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 claim 9, wherein the substrate (x10) is a transparent substrate. 11. The method according to any one of claims 1 to 10, wherein the optical effect layer (OEL) comprises a first pattern, a second pattern, and a third 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 third pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a third magnetic pattern, the method further comprising a third set of steps including: a''') applying a third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising sheet-like magnetic or magnetizable pigment particles to a side of a substrate (x10) free of the first coating (x20') and free of the second coating (x20''), to form a third coating (x20'''), the coating composition being in a first state, and at least a portion of the third coating (x20''') being adjacent to the first coating (x20''). At least a portion of the first coating (x20'') is adjacent to and / or adjacent to at least a portion of the second coating (x20''), or a third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to the side of the substrate (x10) containing the first coating (x20'') in a cured state and excluding the second coating (x20''), to form the third coating (x20'''), wherein the coating composition is in the first state, and at least a portion of the third coating (x20' ... is applied to the side of the substrate (x10) containing the first coating (x20'') in a cured state, and at least a portion of the second The Vis curable coating composition is applied to the side of a substrate (x10) containing a second coating (x20'') in a cured state and excluding the first coating (x20') to form a third coating (x20'''), wherein the coating composition is in a first state.And at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or a''') a third radiation-curable coating composition, preferably a third UV-Vis-curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to one side of the substrate (x10) comprising the first coating (x20') and the second coating (x20'') in a cured state to form the third coating (x20'''), the coating composition being in a first state, and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''); b''') Exposing the third radiation-curable coating composition of step a''') to the magnetic field of the magnetic component (x30''') to cause at least a portion of the sheet-like magnetic or magnetizable pigment particles to biaxial orientation; and c''') At least partially curing the second 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 third pattern, wherein at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20'') means that the third pattern is superimposed on the first pattern and / or the second pattern. Claims 2 / 3 Page 3 CN 122422063 A 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, wherein the first coating (x20') and the second coating (x20'') are registered within ±1 mm, preferably ±0.5 mm, more preferably ±0.2 mm. 14. The method according to any one of claims 1 to 13, 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. 15. The method according to any one of claims 1 to 14, wherein step b') of the first set of steps includes orienting at least a portion of the sheet-like magnetic or magnetizable pigment particles.This causes the first graphic to display a dynamic effect. Claims 3 / 3 Page 4 CN 122422063 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 sheet-like magnetic or magnetizable pigment particles with magnetic orientation. In particular, the present invention provides a method for magnetically orienting 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 secure 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, resulting 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 hand. The protection provided by implicit security features relies on the principle that the feature is difficult to detect, typically requiring specialized equipment and knowledge for detection, while “explicit” security features rely on the concept that can be easily detected with unassisted human senses; for example, the feature may be visible and / or detectable via tactile senses, while still being difficult to produce and / or reproduce. However, the effectiveness of explicit security features depends heavily on their ease of identification as security features.

[0004] Explicit features in the form of foils or patches, including holograms, lens structures, and arrays of microlenses and micromirrors, have been widely used in security documents, particularly banknotes. These security features are produced individually and integrated into the security document during its production. Foils and patches are produced on a roll of substrate using several techniques selected from the group consisting of printing, coating, vapor deposition, etching, painting, and / or combinations thereof, the roll of substrate being ultimately cut into foils and patches for insertion into the security document substrate during its production, and applied to the security document substrate by gluing or by thermal printing. These structures can be integrated into windowed security threads, security foils, security patches, or applied to secure document substrates, for example, via thermal printing.For example, applied to the transparent window of a security document.

[0005] The security feature is known as a highly conspicuous feature due to its high brightness, typically in metallic terms. The security feature is particularly suitable for application to the foil and window of valuable documents, especially banknotes. Due to the demanding applications of protecting valuable documents, especially banknotes, the security feature exhibits poor chemical and physical resistance during its exposure to the environments and conditions met during the cycle of the valuable document carrying those security features, thus leading to its premature degradation.

[0006] For the purpose of optimizing and improving the anti-counterfeiting properties of security documents, especially banknotes, conspicuous and sophisticated magnetically induced images and optical effect layers (OELs) have been developed. Magnetic or magnetizable pigment particles in the printing ink or coating allow the local orientation of magnetic or magnetizable pigment particles in the 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 discussed 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 printed ink, as described on page 1 / 46 of the specification (CN 122422063 A). The OEL is obtained by using specific magnetic components and advantageously exhibits a dynamic appearance when tilted. Examples of such dynamic OELs include reflective area strips that move with the tilt of the OEL, annular bodies that move with the tilt of the OEL, annular bodies that change shape with the tilt of the OEL, and bright and dark areas that move with the tilt of the OEL. WO 2012 / 104098 A1 discloses an OEL containing more than one magnetically induced image. 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 when the OEL is tilted, and the other of the strips moving towards the observer when the OEL is tilted.

[0007] There remains a need for improved methods for producing conspicuous and highly bright visible security features for security printers at industrial speeds, wherein the security features thus produced are easily authenticated by the average person, can withstand chemical and physical stress conditions borne by security documents or articles containing said features, and are very difficult for counterfeiters and the black market to implement in large-scale production. Summary of the Invention

[0008] Therefore, the object 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 magnetically oriented according to a first magnetic pattern orientation, and the second pattern including sheet-like magnetic or magnetizable pigment particles magnetically oriented according to a second magnetic pattern orientation. The method includes:

[0009] a first set of steps, including:

[0010] a') applying a first radiation-curable coating composition, preferably a first UV-Vis curable coating composition, containing sheet-like magnetic or magnetizable pigment particles onto a substrate (x10) to form a first coating (x20') on the substrate (x10), the coating composition being in a first state;

[0011] b') exposing the first radiation-curable coating composition of step a') to a magnetic field of a magnetic component (x30') to magnetically oriented at least a portion of the sheet-like magnetic or magnetizable pigment particles;

[0012] c') Curing at least partially the first 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

[0013] a second set of steps, comprising:

[0014] a'') applying a second radiation-curable coating composition, preferably a second UV-Vis curable coating composition, containing flake-like magnetic or magnetizable pigment particles, to form a second coating (x20''), 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');

[0015] b'') exposing the second radiation-curable coating composition of step a'') to the magnetic field of the magnetic component (x30''). To make at least a portion of the sheet-like magnetic or magnetizable pigment particles biaxially oriented, i) so that both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) so that their XY plane is parallel to the surface of an imaginary sphere;

[0016] c'') to at least partially cure the second 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.

[0017] 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 sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern as described herein, the second pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern as described herein, and the third pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a third magnetic pattern, wherein the first and second patterns are different from each other and the third and second patterns may be the same as or different from each other.The third graphic is adjacent to and properly registered with at least a portion of the first graphic and / or adjacent to and properly registered with 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 (S1) a'), b') and c') described herein, the second set of steps (S2) a''), b'') and c'') described herein, and the third set of steps (S3) a'''), b''') and c'''), wherein the third step a''') is performed after and consecutively with step c'').

[0018] The OEL described herein comprises at least the first and second patterns described herein, i.e., the OEL described herein may comprise a third pattern, a fourth pattern, etc., provided that at least one pattern of the outermost facing environment comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a magnetic pattern orientation, wherein the particles have i) such that both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) such that their XY plane is parallel to the surface of an imaginary sphere.

[0019] The present invention 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.

[0020] The present invention 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 (OEL) obtained by the methods described herein, such that it is contained within the security document or decorative element or object.

[0021] The present invention provides a method advantageously allowing the manufacture of eye-catching, highly bright optical effect layers (OELs) that are easily identifiable by the average person. Optical effect layers (OELs) thus produced by security inks containing pigment particles oriented according to a specific magnetic pattern are highly bright, reflective, metallic, and dynamic when viewed from the side of the substrate bearing at least a second coating, and are therefore particularly attractive for protecting security documents, especially banknotes, due to the combined striking optical effects, their resistance to physical and chemical attacks from the environment, and the high design flexibility in their production. Brief Description of the Drawings

[0022] Figures 1-13 are provided, in which the invention is schematically illustrated and not drawn to scale. The optical effect layers (OELs) described herein and their production are now described in more detail with reference to the accompanying drawings and specific embodiments, wherein

[0023] Figures 1A and 1B schematically show a combination of a first pattern containing sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern and a second pattern containing sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, wherein the first and second patterns are located on the same side (Figure 1A) or opposite side (Figure 1B) of the substrate.When viewed from the side carrying the second graphic (120''), the OEL is highly bright, particularly highly bright and dynamic (see the eye in AB of FIG. 1).

[0024] FIG. 1C schematically shows a combination of a first graphic containing sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, a second graphic containing sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, and a third graphic containing sheet-like magnetic or magnetizable pigment particles oriented according to a third magnetic pattern, wherein the first and second graphics are on the same side of the substrate (110), and the third graphic is on the opposite side of the substrate (110), wherein when viewed from the side carrying the second graphic (120'') and / or from the side carrying the third graphic (120'''), the OEL is highly bright, particularly highly bright and dynamic (see the eye in 1C).

[0025] FIG. 2 schematically shows sheet-like pigment particles.

[0026] FIG3A schematically illustrates the first set of steps (S1) described herein, wherein the orientation step b') is an orientation step, and wherein the substrate (310) carrying the first coating (320') obtained by screen printing (340') (step a') is exposed to the magnetic field of the magnetic component (330'), and wherein the first coating (320') is at least partially cured simultaneously with the first curing unit (350') and step b') (step c') with the first curing unit (350').

[0027] Figures 3B and 3C show the industrial one-step orientation step b') shown in Figure 3, wherein the first coating (320') is exposed to the magnetic field of the magnetic component (330') mounted on a rotating magnetic cylinder, wherein the first coating (320') faces the environment (Figure 3B), or the magnetic component (330') is placed outside the rotating cylinder, wherein the first coating (320') faces the magnetic component (330') (Figure 3C), and wherein the first coating (320') is at least partially cured simultaneously with step b') by the curing unit (350') (step c')).

[0028] FIG4A illustrates the first set of steps (S1) described herein, wherein the orientation step b') is a one-step orientation step, wherein the first coating (420') is exposed to the combined magnetic field of the first magnetic component (430'-a) and the second magnetic component (430'-b), and wherein the first coating (420') is at least partially cured simultaneously with the first curing unit (450') and step b') (step c').

[0029] FIG4B illustrates the industrial one-step orientation step b') shown in FIG4A, wherein the first coating (420') is exposed to the combined magnetic field of the first magnetic component (430'-a) and the second magnetic component (430'-b).The first magnetic component (430'-a) is mounted on a rotating magnetic cylinder, and the second magnetic component (430'-b) is placed outside the rotating magnetic cylinder, and the first coating (420') is at least partially cured simultaneously with the curing unit (450') in step b') (step c')).

[0030] FIG5A schematically illustrates the first set of steps (S1) described herein, wherein the orientation step b') is a two-step orientation step, and wherein the substrate (510) carrying the first coating (520') obtained by screen printing (540') (step a') is first exposed to the first magnetic field of the magnetic component (530'-a) (step b'-1)) and then subsequently exposed to the second magnetic field of the magnetic component (530'-b) (step b'-2)) to reorient the pigment particles (step b')), and wherein the first coating (520') is at least partially cured simultaneously with the first curing unit (550') in step b') (step c')).

[0031] FIG5B shows the industrial two-step orientation step b') shown in FIG5A, wherein the first coating (520') 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 first magnetic component (530'-a) is placed outside the rotating magnetic cylinder and placed before the rotating magnetic cylinder, and the second magnetic component (530'-b) is mounted on the rotating magnetic cylinder, and wherein the first coating (520') is at least partially cured simultaneously with the curing unit (550') and step b') (step c')).

[0032] FIG6A schematically illustrates the first set of steps (S1) described herein, wherein the orientation step b') is a two-step orientation step, and wherein the substrate (610) carrying the first coating (620') obtained by screen printing (640') (step a') is first exposed to the first magnetic field of the magnetic component (630'-a) (step b'-1)), and then subsequently exposed to the combined magnetic field of the second magnetic component (630'-a) and the third magnetic component (630'-c) (step b'-2) and wherein the coating (620') is at least partially cured simultaneously with the first curing unit (650') and step b') (step c')).

[0033] Figure 6B illustrates the industrial two-step orientation step b' shown in Figure 6A, wherein the coating (620') is first exposed to the magnetic field of the first 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), wherein the first magnetic component (630'-a) is placed outside the rotating magnetic cylinder, the second magnetic component (630'-b) is mounted on the rotating magnetic cylinder, and the third magnetic component (630'-c) is placed outside the rotating magnetic cylinder.And the first coating (620') is at least partially cured simultaneously with step b') using the curing unit (650') (step c')).

[0034] FIG7A schematically illustrates the second set of steps (S2) described herein, wherein the orientation step b'') is an orientation step, and wherein the substrate (710) carrying the first coating (720') and the second coating (720'') obtained by screen printing (740'') (step a'') on the same side as the first coating (720') is exposed to the magnetic field of the magnetic component (730'') to cause the pigment particles to be biaxially oriented, and wherein the second coating (720'') is at least partially cured simultaneously with step b'') using the second curing unit (750'') (step c'')).

[0035] FIG7B schematically illustrates the second set of steps (S2) described herein, wherein the orientation step b'') is an orientation step, and wherein the substrate (710) carrying the first coating (720') and the second coating (720'') obtained by screen printing (740'') (step a'') on the side of the substrate (710) without the first coating (720') is exposed to the magnetic field of the magnetic component (730'') to cause the pigment particles to be biaxially oriented, and wherein the second coating (720'') is at least partially cured simultaneously with the second curing unit (750'') and step b'') (step c'') with the second curing unit (750'').

[0036] FIG7C shows a step b'' of the industrial orientation shown in FIG7A, wherein the second coating (720'') is exposed to the magnetic field of the magnetic component (730''), wherein the magnetic component (730'') is placed outside the rotating cylinder (two optional positions are shown in FIG7C), and wherein the second coating (720'') is at least partially cured with the curing unit (750') (step c'')).

[0037] FIG8A schematically illustrates the second set of steps (S2) described herein, wherein the orientation step b'') is a one-step orientation step, and wherein the substrate (810) carrying the first coating (820') and the second coating (820'') obtained by screen printing (840'') (step a'') on the same side as the first coating (820') is exposed to the magnetic field of the rotating magnetic assembly (830'') to cause the pigment particles to be biaxially oriented (step b''), and wherein the second coating (820'') is at least partially cured simultaneously with the second curing unit (850'') in step b'') (step c'') with the second curing unit (850'').

[0038] FIG8B schematically illustrates the second set of steps (S2) described herein, wherein the orientation step b'') is a one-step orientation step,And the substrate (810) carrying the first coating (820') and the second coating (820'') obtained by screen printing (840'') (step a'') on the side of the substrate (810) without the first coating (820') is exposed to the magnetic field of the rotating magnetic assembly (830'') to cause the pigment particles to be biaxially oriented (step b''), and the second coating (820'') is at least partially cured simultaneously with the portion of step b'') by the second curing unit (850'') (step c'')).

[0039] FIG8C shows the industrial orientation step b'') shown in FIG8A, wherein the second coating (820'') is exposed to the magnetic field of the rotating magnetic assembly (830''), wherein the magnetic assembly (830'') is mounted on a rotating magnetic cylinder, and wherein the second coating (820'') is at least partially cured simultaneously with the portion of step b'') by the curing unit (850'') (step c'')).

[0040] FIG9 schematically illustrates the third set of steps (S3) described herein that occur after the second set of steps (S2), wherein the orientation step b''') is an orientation step, and wherein the substrate (910) carrying the first and second coatings (920' and 920'') and the third coating (920''') obtained by screen printing (940''') (step a''') on the opposite side to the first and second coatings (920' and 920'') is exposed to the magnetic field of the rotating magnetic component (930''') to cause the pigment particles to be biaxially oriented (step b'''), and wherein the third coating (920''') is at least partially cured simultaneously with the third curing unit (950''') (step c''') with the portion of step b''').

[0041] FIG10 schematically illustrates the magnetic assembly (1030) used in steps b') of embodiments E1-E5 and step b'') of embodiment E1 provided therein for biaxially orienting pigment particles.

[0042] FIG11 schematically illustrates the magnetic assembly (1130) used in steps b') of embodiments E1-E5 provided therein and adapted to produce a pattern exhibiting dynamic movement of reflective strips that move when the pattern is tilted.

[0043] FIG12 schematically illustrates the magnetic assembly (1230) used for biaxially orienting pigment particles and in steps b'') of embodiments E2 and E4 and step b''') of embodiment E4 provided therein.

[0044] FIG13 schematically illustrates the magnetic assembly (1330) used in steps b'') of embodiments E3 and E5 and step b''') of embodiment E5 provided therein for biaxially orienting pigment particles.

[0045] The distances provided in the figures are merely illustrative.Instead of being drawn to scale. Specification 5 / 46 Page 9 CN 122422063 A Detailed Description

[0046] Definitions

[0047] The following definitions are used to clarify the meaning of terms defined in the discussion and claims of the specification.

[0048] As used herein, the indefinite article “a(a)” means one and greater than one, and does not necessarily limit its noun to the singular.

[0049] As used herein, the term “at least” is intended to define one or greater than one, for example, one, two, or three.

[0050] As used herein, the term “about” means that the quantity or value in discussion may be a specified particular value or some other value near it. 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, that is, 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.

[0051] 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 “A only, or B only, or both A and B.” In the case of “A only,” the term also covers the possibility that B is not present, i.e., “A only, but not B.”

[0052] As used herein, the term “comprising” is intended to be non-exclusive and open-ended. Thus, a coating composition comprising, for example, compound A may comprise other compounds besides A. However, as in particular embodiments thereof, the term “comprising” also covers the more restrictive meanings of “consisting substantially of” and “consisting of”, such that, for example, “a dampening solution comprising A, B, and optionally C” may also consist (substantially) of A and B, or (substantially) of A, B, and C.

[0053] As used herein, the term “Optical Effect Layer (OEL)” 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.

[0054] The term “coating composition” refers to any composition capable of forming an optical effect layer (EOL) 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.

[0055] As used herein, the term “wet” refers to a coating that has not yet cured, for example, a coating in which the sheet-like magnetic or magnetizable pigment particles are still capable of changing their position and orientation under the influence of an external force acting thereon.

[0056] As used herein, the term “marking” should refer to a discontinuous layer, such as a pattern.Including but not limited to symbols, alphanumeric symbols, motifs, letters, words, numbers, signs, and pictures.

[0057] The term "curing" is used to refer to a method in which the viscosity of a coating composition in a first physical state that has not yet hardened (i.e., wet) is increased so as to transform it into a second physical state, i.e., a hardened or solid state, in which the sheet-like magnetic or magnetizable pigment particles are fixed / frozen in their current position and orientation and cannot be moved or rotated again.

[0058] The term "secure document" refers to a document that is generally 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.

[0059] The term "security feature" is used to refer to an image, pattern, or graphic element that can be used for authentication purposes.

[0060] 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.

[0061] The present invention provides a method for producing an optical effect layer (OEL) suitable as a security feature against counterfeiting or fraud, and comprising magnetically oriented sheet-like magnetic or magnetizable pigment particles on a substrate. As shown in FIG1 AB, 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'', wherein 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 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.

[0062] As shown in Figure 1C, the OEL comprises a first pattern in the form of a cured first coating 120', a second pattern in the form of a cured second coating 120'', and a third pattern in the form of a cured third coating 120'''. The first pattern comprises sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern, the second pattern comprises sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern, and the third pattern comprises sheet-like magnetic or magnetizable pigment particles oriented according to a third magnetic pattern. At least a portion of the third pattern is adjacent to and appropriately registered with at least a portion of the first pattern and / or adjacent to and appropriately registered with at least a portion of the second pattern (i.e., the third pattern is at least partially adjacent to and appropriately registered with the first pattern and / or at least partially adjacent to and appropriately registered with the second pattern).Preferably, it is adjacent to and properly registered with at least a portion of the first pattern and adjacent to and properly registered with at least a portion of the second pattern (i.e., at least partially adjacent to and properly registered with the first pattern and at least partially adjacent to and properly registered with the second pattern).

[0063] The first and second patterns, in the form of a cured first coating (x20')' and a second coating (20''), may independently comprise a single sub-pattern, or may comprise more than one sub-pattern as shown in FIG. 1, wherein the more than one sub-pattern independently forms the first and second patterns respectively. If the first and / or second patterns described herein independently comprise a first sub-pattern and a second sub-pattern (as shown, for example, in FIG. 1), then the OEL is obtained by a combination of multiple or all sub-patterns.

[0064] As described herein, the first magnetic pattern of the first graphic and the second magnetic pattern of the second graphic are obtained by independently exposing the first radiation-curable coating composition of step a') and the second radiation-curable coating composition of step a'') to the magnetic field of the magnetic component (x30') during step b') to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles, and independently exposing them to the magnetic field of the magnetic component (x30'') during step b'') to biaxially orient at least a portion of the sheet-like magnetic or magnetizable pigment particles.

[0065] The method described herein includes at least two sets of steps, namely a first set (S1) including steps a'), b') and c') and a second set (S2) including steps a''), b'') and c'') (optionally including a'''), b''') and c''') and a third set of steps (S3), optional including a''''), b'''') and c''') and a fourth set of steps (S4), etc., wherein the last set of steps includes biaxially oriented at least a portion of the sheet-like magnetic or magnetizable pigment particles such that i) their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) their XY plane is parallel to the surface of an imaginary sphere. For an embodiment comprising three sets of steps, preferably, step b') of the first set (S1) includes orienting at least a portion of the pigment particles such that the first pattern exhibits a dynamic effect; steps b'') of the second set (S2) and the last set (S3) include biaxially orienting at least a portion of the pigment particles such that i) both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) their XY plane is parallel to the surface of an imaginary sphere. Alternatively, for an embodiment comprising three sets of steps, preferably, step b') of the first set (S1) includes orienting at least a portion of the pigment particles such that the first pattern exhibits a dynamic effect; and step b'') of the first set (S2) includes orienting at least a portion of the pigment particles such that the second pattern exhibits a dynamic effect.And the last group (S3) step b''') includes biaxially oriented at least a portion of the pigment particles such that i) both their X-axis and Y-axis are substantially parallel to the substrate (x10) surface, or ii) their XY plane is parallel to the surface of an imaginary sphere; for embodiments including n groups of steps, preferably the (n-1) group (S(n-1)) step b(n-1)') and the last group (Sn) step bn') include biaxially oriented at least a portion of the pigment particles such that i) both their X-axis and Y-axis are substantially parallel to the substrate (x10) surface, or ii) their XY plane is parallel to the surface of an imaginary sphere. Therefore, the method described herein is a sequential method, meaning that the second set of steps (S2) is performed directly after the first set (S1) (in other words, step a'' of the second set is performed directly after step c' of the first set). For embodiments comprising n sets of steps, step an'' of the nth set (S(n)) is performed directly after step c(n-1') of the (n-1)th set. In other words, the multi-set step method described herein is a sequential method using a single machine that allows for the application, preferably printing, of a coating composition, exposure of the composition to a magnetic field, and at least partial curing of the composition. The method allows for the preparation of an OEL comprising the first and second patterns described herein that 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, wherein an observer sees a highly bright effect, preferably a highly bright and dynamic effect, 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.

[0066] As shown in FIG1 AB, the OEL described herein includes a first and a second pattern (i.e., first and second cured coatings 120' and 120'') on the same side of a substrate (110) (see FIG1 A) or on the opposite side of the substrate (110) (i.e., the side of the substrate without the first pattern) (see FIG1 B), wherein the substrate (110) is preferably transparent, and 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 such that an observer perceives the OEL as highly bright (in FIG1 A when viewed from the side of the substrate (110) carrying the first and second coatings (120' and 120''), or in FIG1 B when viewed from the side of the substrate (110) carrying the second layer (120''), see the eye in FIG1 AB), and in perspective viewing mode, reflection viewing mode, or transparent viewing mode, the OEL is perceived as a bright, continuous feature.

[0067] As shown in FIG1 C,The OEL described herein includes first, second, and third patterns (i.e., first, second, and third cured coatings 120', 120'', and 120'''), wherein the first and second patterns (120' and 120'') are on the same side of the substrate (110), and the third pattern (120''') is on the side of the substrate (110) excluding both the first and second patterns (120''), wherein the substrate (110) is preferably transparent, and 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, and 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 (i.e., in Figure 1C, the third graphic is at least partially adjacent to and properly registered with the first graphic and at least partially adjacent to and properly registered with the second graphic), such that the observer perceives the OEL as highly bright (Figure 1C when viewed from the side of the substrate (110) carrying the first and second coatings (120' and 120'') and / or when viewed from the side of the substrate (110) carrying the third layer (120'''), see the eye in Figure 1C), and the OEL is perceived as a continuous feature in perspective viewing mode, reflection viewing mode, or transparent viewing mode.

[0068] The term "adjacent" means that the first and second patterns are superimposed, encompassing both the second coating (x20'') being in direct contact with the first coating (x20') (see Figures 1A and 1C) and the second coating (x20'') being in direct contact with the first coating (x20') through a substrate (i.e., the substrate is present therebetween and they are in indirect contact) (see Figure 1B). In other words, the second pattern is present on top of and in direct contact with the first pattern, or the second pattern faces the first pattern through a substrate.

[0069] The method described herein comprises at least two independent steps a') and a''), which include: applying a first radiation-curable coating composition to form a first coating (x20') (step a'), and including: registering 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.

[0070] By registering and applying in step a''), it is meant that the radiation-curable coating composition is 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'), such that the obtained OEL appears to the naked eye as a continuous layer (i.e.,The registration application 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. The registration application is permitted using a single machine via a claimed continuous method.

[0071] 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 engraved copperplate printing and engraved 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.

[0072] Screen printing (also known in the art as silkscreen printing) is a stencil method in which ink is transferred through a stencil to a surface supported by a finely woven mesh of silk, such as monofilaments or multifilaments or metal wires made of synthetic fibers like 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 pores 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.

[0073] 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, unpainted level. Before printing, the entire printing plate (both non-printed and printed elements) is inked and filled with ink. Before printing, the ink is removed from the non-image areas by a wiper or doctor blade.This ensures that the ink remains only 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 provided 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.

[0074] Flexographic printing preferably uses a cell having a doctor blade, preferably a cavity doctor blade, an anilox roller and a printing cylinder. The anilox roller advantageously has small cells whose volume and / or density determine the ink application rate. The doctor blade is placed against the anilox roller and simultaneously scrapes off excess ink. An anilox roller transfers ink to a plate cylinder, which in turn transfers the ink onto a substrate. Specific designs can be achieved using a designed photopolymer plate. The plate cylinder can be made of polymer or elastomer materials. Polymers are primarily used as photopolymers in the plate and sometimes as a seamless coating on a sleeve. Photopolymer plates are made of photosensitive polymers that are cured by ultraviolet (UV) light. The photopolymer plate is cut to the desired size and placed in a UV light exposure unit. One side of the plate is fully exposed to UV light to harden or cure the base of the plate. The plate is then flipped over, the film for the job is mounted on the uncured side, and the plate is further exposed to UV light. This hardens the plate in the image area. The plate is then treated to remove the uncured photopolymer from the non-image areas, which lowers the plate surface in these non-image areas. After treatment, the plate is dried and given a post-exposure dose of UV light to cure the entire plate. The preparation of the printing cylinder for flexographic printing is described in Printing Technology, J.M. Adams and P.A. Dolin, Delmar Thomson Learning, 5th edition, pp. 359-360 and The Printing Ink Manual, RH Leach and RJ Pierce, Springer, 5th edition, pp. 33-42.

[0075] The first and second radiation-curable coating compositions are applied independently during steps a') and a'').Thus, a first coating (x20') and a second coating (x20'') are formed, as described on page 9 / 46 of CN 122422063 A. The first and second radiation-curable coating compositions independently comprise a binder and the sheet-like magnetic or magnetizable pigment particles described herein. During step a'), the first radiation-curable coating composition is applied to the substrate (x10) to form the first coating (x20'), and the second radiation-curable coating composition can be applied during step a'') to the same side as the first coating (x20') (see Figures 7A and 8A) or the opposite side, i.e., the side of the substrate (x10) without the first coating (x20') (see Figures 7B and 8B), to form the second coating (x20'').

[0076] According to one embodiment, 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. According to one embodiment, the first and second radiation-curable coating compositions have different binders but contain the same flake-like magnetic or magnetizable pigment particles, such that they appear to the naked eye the same color. 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 flake-like magnetic or magnetizable pigment particles. According to one embodiment, wherein the OEL includes a third pattern, the first radiation-curable coating composition exhibits a color, the second radiation-curable coating composition exhibits the same color as seen to the naked eye, and the third radiation-curable coating composition exhibits the same color as seen to the naked eye of the first and second compositions.

[0077] According to one embodiment, the first radiation-curable coating composition exhibits a first color, and the second radiation-curable coating composition exhibits a second color, the second color being different from the first color as observed to the naked eye. According to one embodiment, the first and second radiation-curable coating compositions have the same binder but contain different flake-like magnetic or magnetizable pigment particles, such that they appear to the naked eye the same color. According to the embodiments described, the OEL thus obtained not only exhibits a striking effect due to its dynamic and highly bright effect, but also demonstrates a high level of anti-counterfeiting due to the complex adjacent patterns of different colors.

[0078] According to one embodiment, the first and second radiation-curable coating compositions contain the same sheet-like magnetic or magnetizable pigment particles, but contain different binders, the binder of the first composition containing dyes and / or colorants, such that the compositions exhibit different colors visible to the naked eye. According to one embodiment, the first and second radiation-curable coating compositions contain the same sheet-like magnetic or magnetizable pigment particles, but contain different binders, the binder of the second composition containing dyes and / or colorants,This results in the compositions exhibiting different colors visible to the naked eye. According to one embodiment, the first and second radiation-curable coating compositions contain the same flake-like magnetic or magnetizable pigment particles, but contain different binders. The binder of the first composition contains dyes and / or colorants, and the binder of the second composition contains dyes and / or colorants of different colors, resulting in the compositions exhibiting different colors visible to the naked eye. For optically variable flake-like magnetic or magnetizable pigment particles, i.e., pigments that exhibit different colors when tilted (i.e., exhibiting a face color and different angular colors), "different colors" refers to different face colors or different angular colors or different face colors and angular colors. According to one embodiment, the first radiation-curable coating composition contains optically variable flake-like magnetic or magnetizable pigment particles having a first face color and a first angular color, and the second radiation-curable coating composition contains optically variable flake-like magnetic or magnetizable pigment particles having a second face color and a second angular color, wherein the first face color is different from the second face color, and the first angular color is different from the second angular color. According to one embodiment, a first radiation-curable coating composition comprises optically variable flaky magnetic or magnetizable pigment particles having a first face color and a first angular color, and a second radiation-curable coating composition comprises optically variable flaky magnetic or magnetizable pigment particles having a second face color and a second angular color, wherein the first face color is the same as the second face color, and the first angular color is different from the second angular color. According to another embodiment, the first radiation-curable coating composition comprises optically variable flaky magnetic or magnetizable pigment particles having a first face color and a first angular color, and the second radiation-curable coating composition comprises optically variable flaky magnetic or magnetizable pigment particles having a second face color and a second angular color, wherein one face color is different from the second face color, and the first angular color is the same as the second angular color.

[0079] According to one embodiment, the OEL includes a third pattern, a first radiation-curable coating composition exhibits a color, a second radiation-curable coating composition exhibits the same color visible to the naked eye, and a third radiation-curable coating composition exhibits a different color visible to the naked eye; or the first radiation-curable coating composition exhibits a color, the third radiation-curable coating composition exhibits the same color visible to the naked eye, and the second radiation-curable coating composition exhibits a different color visible to the naked eye; or the second radiation-curable coating composition exhibits a color, the third radiation-curable coating composition exhibits the same color visible to the naked eye, and the first radiation-curable coating composition exhibits a different color visible to the naked eye. According to one embodiment, the OEL includes a third pattern, a first radiation-curable coating composition exhibits a color, and a second radiation-curable coating composition exhibits a different color visible to the naked eye.Furthermore, the third radiation-curable coating composition exhibits a different color visible to the naked eye (or in other words, the first, second, and third compositions have different colors).

[0080] The first and second coating compositions described herein, as well as the first coating layer (x20') and the second coating layer (x20'') described herein, contain 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 because of 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, and the Z dimension is ignored.

[0081] 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 the 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.

[0082] 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, which independently contain a hardened binder material that fixes the orientation of the 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. Hereinafter, the term “transparent” means that, at the relevant wavelength, electromagnetic radiation has a transmittance of at least 50% through a 20 μm layer of the hardened binder material present in the OEL (excluding flake-like magnetic or magnetizable pigment particles, but all other optional components of the OEL in the presence of these components).More preferably at least 60%, even more preferably at least 70%. This can be determined, for example, by measuring the transmittance of a test piece of hardened binder material (excluding sheet-like magnetic or magnetizable pigment particles) according to well-established test methods, such as DIN 5036-3 (1979-11).

[0083] 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 (see specification 11 / 46 pages 15 CN 122422063 A). 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.

[0084] The first and second radiation-curable coating compositions and the first and second coatings (x20', x20'') described herein independently 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.%.Weight percentages are based on the total weight of the radiation-curable coating composition or coating.

[0085] 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.

[0086] Examples of the sheet-like magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles comprising a magnetic layer M, wherein the magnetic layer M is 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 the magnetic or magnetizable pigment particles may be a multilayer structure comprising one or more additional layers. Preferably,One or more additional layers are layers A, independently made of one or more of the group consisting of metal fluorides such as magnesium fluoride (MgF2), silicon oxide (SiO), silicon dioxide (SiO2), titanium oxide (TiO2), and aluminum oxide (Al2O3), more preferably silicon dioxide (SiO2); or layers B, independently made of one or more of the group consisting of metals and metal alloys, preferably consisting of reflective metals and reflective metal alloys, more preferably consisting of one or more of the group consisting of silver (Ag), aluminum (Al), chromium (Cr), and nickel (Ni), and even more preferably aluminum (Al); or combinations of one or more of the layers A as described above and one or more of the layers B as described above. 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.

[0087] 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 inks, coating compositions, or coatings containing the optically variable magnetic or magnetizable pigment particles described herein (page 12 / 46, CN 122422063 A), and their potential counterfeits, 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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).

[0092] A further preferred five-layer Fabry-Perot multilayer structure is composed of a dielectric / reflector / magnetic material / reflector / dielectric multilayer structure.

[0093] A preferred six-layer Fabry-Perot multilayer structure is composed of an absorber / dielectric / reflector / magnetic material / dielectric / absorber multilayer structure.

[0094] A preferred seven-layer Fabry-Perot multilayer structure is composed of an absorber / dielectric / reflector / magnetic material / reflector / dielectric / absorber multilayer structure as disclosed in US 4,838,648.

[0095] A preferred nine-layer Fabry-Perot multilayer structure is composed of a dielectric / absorber / dielectric / reflector / magnetic material / dielectric / absorber / dielectric multilayer structure.

[0096] 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.

[0097] 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 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 other metal fluorides, as well as 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.

[0098] 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.

[0099] 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.

[0100] The flake-like magnetic or magnetizable pigment particles of the first and second coatings described herein preferably have a size d50 (measured by direct optical particle size analyzer) between about 2 μm and about 50 μm.

[0101] The flake-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-inhibiting materials and / or wetting agents may typically be used.

[0102] 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', x30'', respectively) to independently magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles (steps b') and b'', respectively).

[0103] The method described herein includes at least two separate steps b') and b''), which include exposing the first and second radiation-curable coating compositions described herein to a magnetic field of a magnetic component to magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles, wherein step b'') is performed by exposing the second radiation-curable coating composition of step a'') to a magnetic field of a magnetic component (x30'') to biaxially orient the pigment particles.

[0104] During the orientation steps b') and b'') described herein, the substrate (x10) may be independently configured on a nonmagnetic support plate (x70) made of one or more nonmagnetic materials.

[0105] 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, or an assembly containing a magnet and one or more pole pieces or containing two or more magnets and one or more pole pieces.The magnetic components (x30' and x30'') are selected according to the design of the orientation pattern of the first and second graphics of the OEL to be produced. If the magnetic components (x30' and x30'') contain more than one component, the sheet-like magnetic or magnetizable pigment particles are exposed to the combined magnetic field of the more than one component.

[0106] The method described herein includes the orientation step b' described herein.

[0107] According to an embodiment shown, for example, FIG. 3A, the orientation step b') of the first set of steps (S1) is an orientation step in which the substrate (310) carrying the first coating (320') obtained by screen printing (340') (step a') is exposed to the magnetic field of the magnetic component (330'), and wherein the first coating (320') is at least partially cured simultaneously with the first curing unit (350') and step b') (step c').

[0108] According to one embodiment, for example, shown in FIG4A, the orientation step b') of the first set of steps (S1) is an orientation step in which an assembly of a substrate (410) carrying the first coating (420') described herein is placed on a first magnetic assembly (430'-a), and the assembly is simultaneously moved in the vicinity of a static second magnetic assembly (430'-b).

[0109] According to one embodiment, for example, shown in FIG. 4B, the method described herein allows for the preparation of OEL, wherein step b') comprises the following steps: placing a substrate (410) carrying a first 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 the sheet-like magnetic or magnetizable pigment particles are subjected to the first magnetic field vector component, and simultaneously moving the substrate (410) carrying the first 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.More preferably, the value is between about 1.5 and about 0.5. The first magnetic component (430'-a) on which the substrate (410) bearing the first coating (420') is exposed is preferably selected from the magnetic component described above for orienting pigment particles and the soft magnetic plate described above. The second magnetic component (430'-b) is preferably selected from the magnetic component described above for biaxially orienting pigment particles. Such methods are disclosed in WO 2019 / 14142 A1 and WO 2019 / 141453 A1.

[0110] According to one embodiment, for example, shown in FIG5A, the orientation step b') of the first set of steps (S1) is a two-step orientation step comprising two steps: a first orientation step (b'-1) to biaxially orient the sheet-like magnetic or magnetizable pigment particles as described herein, followed by a second orientation step to reorient the sheet-like magnetic or magnetizable pigment particles as described herein (b'-2), wherein the substrate (510) carrying the first coating (520') is exposed to the magnetic field of the magnetic component (530'-a) and subsequently exposed to the magnetic field of the magnetic component (530'-b), the two magnetic components (530'-a and 530'-b) being located on a second side of the substrate (i.e., the side without the first coating (520')). Figure 5B (not drawn to scale) illustrates a method in which orientation step b') comprises a two-step orientation step in which the first radiation-curable coating composition described herein is first exposed to the magnetic field of a first magnetic component (530'-a) and subsequently exposed to the magnetic field of a second magnetic component (530'-b), wherein the second magnetic component (530'-b) is mounted on a rotating magnetic cylinder.

[0111] According to one embodiment, for example, shown in Figures 6A-6B, the orientation step b') of the first set of steps (S1) is a two-step orientation step, which includes two steps: a first orientation step (b'-1) to biaxially orient the sheet-like magnetic or magnetizable pigment particles as described herein, followed by a second orientation step to reorient the sheet-like magnetic or magnetizable pigment particles as described herein (b'-2), wherein the substrate (610) carrying the first coating (620') is 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), which are located on the side without the first coating (620').

[0112] Figure 6B (not drawn to scale) illustrates a method in which the orientation step b') of the first set of steps (S1) is a two-step orientation step, which includes two steps: the first orientation step (b'-1) oriented the sheet-like magnetic or magnetizable pigment particles as described herein in a biaxial manner.The subsequent second orientation step reorients the sheet-like magnetic or magnetizable pigment particles as described herein (b'-2), wherein the substrate (610) carrying the first coating (620') is exposed to the magnetic field of the magnetic component (630'-a), and subsequently to the combined magnetic field of the second magnetic component (630'-b) and the third magnetic component (630'-c), the magnetic components 630'-a and 630'-b being located on the side without the first coating (620'), and the magnetic component 630'-c being located on the side containing the first coating (620'), wherein the magnetic component 630'-b is mounted on a rotating magnetic cylinder, and the magnetic component 630'-c is placed outside the rotating magnetic cylinder. A suitable method for the orientation step b') comprising two orientation steps is disclosed in WO 2015 / 086257 A1.

[0113] According to one embodiment, the method described herein allows for the preparation of an OEL in which a first graphic exhibits more than one mark, wherein step b') 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 more than one 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, general-purpose magnetic garnet, including 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 comprising 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).

[0114] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein a first pattern exhibits dynamic movement when the OEL is tilted and displays more than one mark, wherein step b') comprises exposing a radiation-curable coating composition to a magnetic assembly (x30) comprising a rod-shaped dipole magnet and an engraved magnetic plate, wherein the engraved magnetic plate comprises more than one engraving having more than one mark shape.The engraved magnetic plate is placed above the rod-shaped dipole magnet.

[0115] According to one embodiment, the method herein includes step b'), which includes exposing a first radiation-curable coating composition to those 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 comprising two magnets 144 and one magnet 144' having a roof-shaped, hexagonal, circular, trapezoidal, or other cross-section, wherein the north poles of the two magnets 144 face the substrate, and the south pole of the intermediate magnet 144' faces the substrate. Figure 9E of 7,047,883 discloses a magnetic assembly comprising five magnets: a first magnet 142 is a rhomboid magnet with its north pole facing the substrate; a second magnet 146 is a rectangular magnet with its south pole facing the substrate; a third magnet 148 is a magnet with a rounded top and its north pole facing the substrate; a fourth magnet 150 is a roof-shaped magnet with its south pole facing the substrate; and a 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 (magnetic field lines are shown as lines with arrows pointing from the north pole to the south pole) in more than one region (shown as dashed rectangle A), 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. WO 2022 / 0490241 Figure 4A2 of A discloses a magnetic assembly comprising two rod-shaped dipole magnets (M1, M2) having the same magnetic orientation and an iron yoke (Y), wherein the particles are exposed to the magnetic field of the magnetic assembly in more than one region (shown as dashed rectangle A) (the 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.Furthermore, the magnetic field lines are substantially parallel to each other in the 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 the particle is exposed to the magnetic field of the magnetic assembly (magnetic field lines are shown as lines with arrows pointing from the North Pole to the South Pole) in more than one region (shown as dashed rectangle A), wherein the magnetic field is substantially uniform, and wherein the magnetic field lines are substantially parallel to each other in the region.

[0116] According to an embodiment shown, for example, in Figure 11 (Examples E1-E5, during step b'), the method described herein allows for the preparation of an OEL in which a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being bright reflective stripes moving in the vertical direction (up / down) as the OEL is tilted about a horizontal axis; wherein step b') comprises exposing a first radiation-curable coating composition to a rod-shaped dipole magnet having a magnetic axis oriented substantially parallel to the substrate and substantially parallel to the machine feed direction. 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 / strips that move away from or toward the observer as the OEL is tilted.

[0117] According to another embodiment, the method described herein allows for the preparation of an OEL in which a first 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 vertical axis; wherein step b') comprises exposing a first radiation-curable coating composition to a rod-shaped dipole magnet having a magnetic axis oriented substantially parallel to the substrate and substantially perpendicular to the machine feed direction. This effect is the so-called "rolling bar" effect, as disclosed in US 2005 / 0106367.

[0118] According to another embodiment, the method described herein allows for the preparation of an OEL in which a first 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 step b') comprises exposing a first radiation-curable coating composition to magnetic components such as those disclosed in WO 2020 / 160993 A1. Figure 2-5 of WO 2020 / 160993 A1 discloses 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 rod-shaped dipole magnets, where n is an integer equal to or greater than 1, wherein the north-south magnetic axis of each of the rod-shaped dipole magnets (x30-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 in the range of about 5° to about 175° or in the range of about 185° to about 355°. (Description 17 / 46, page 21, CN 122422063 A) Angle α, wherein a combination of n groups of spaced-a1, x30-a2 rod-shaped dipole magnets is positioned below or above at least one dipole magnet (x40), and wherein the combination of at least one dipole magnet (x40) and the n groups of spaced-a1, x30-b2 rod-shaped dipole magnets is substantially centered relative to each other (see, for example, Figures 2-5 of WO 2020 / 160993 A1).

[0119] According to another embodiment, the method described herein allows for the preparation of an OEL in which a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement of the OEL being a bright reflective bar moving in the vertical direction (up / down) when the OEL is tilted about a horizontal axis; wherein step b') comprises exposing a first radiation-curable coating composition to those magnetic components disclosed in WO 2014 / 198905 A2. Figures 5-9 of WO 2014 / 198905 A2 disclose a magnetic assembly comprising:

[0120] a) a rod-shaped dipole magnet (M1) and a pair of rod-shaped dipole magnets (M2) and (M3), the north-south axes of said rod-shaped dipole magnets (M1), (M2) and (M3) being substantially parallel to the substrate and having the same magnetic north-south direction, wherein a1) said rod-shaped dipole magnet (M1) is disposed below the substrate, and said pair of rod-shaped dipole magnets (M2) and (M3) are disposed separately below said rod-shaped dipole magnet (M1); or a2) said pair of rod-shaped dipole magnets (M2) and (M3) are disposed below the substrate and are separated from each other, and said rod-shaped dipole magnet (M1) is disposed below said pair of rod-shaped dipole magnets (M2) and (M3); or

[0121] b) A pair of rod-shaped dipole magnets (M4) and (M5) and a pole piece (Y), wherein the north-south axis of the pair of rod-shaped dipole magnets (M4) and (M5) is substantially parallel to the substrate and has the same magnetic north-south direction.The pole piece (Y) is disposed between the rod-shaped dipole magnet (M4) and the rod-shaped dipole magnet (M5); or

[0122] c) a pair of rod-shaped dipole magnets (M4) and (M5), a pole piece (Y) and a magnetic plate (M6), wherein the north-south axis of the pair of rod-shaped dipole magnets (M4) and (M5) is substantially parallel to the substrate and has the same magnetic north-south direction, the north-south axis of the magnetic plate (M6) is substantially perpendicular to the substrate, and the pole piece (Y) is disposed between the rod-shaped dipole magnets (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.

[0123] 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 pattern of light and dark areas moving as the OEL is tilted; wherein step b') comprises exposing a radiation-curable coating composition to magnetic components such as those disclosed in WO 2013 / 167425 A1 and WO 2021 / 083809 A1. WO 2021 / 083809 The disclosed magnetic component of 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, wherein the magnetic axes of the additional dipole magnets are oriented substantially parallel to the substantially parallel lines αi, and wherein at least one dipole magnet (x40) is arranged below the combination comprising at least four dipole magnets (x31). According to one embodiment, the vector H of the magnetic axis 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 tilting direction. According to another embodiment, the vector H of the magnetic axis 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 wherein the vector and H of the magnetic axis of each straight line αi and at least one dipole magnet (x41) form an angle γ.The angle γ 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 in the range of 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 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 axis). Suitable magnetic components are those shown in Figures 6-8 of WO 2021 / 083809 A1.

[0124] 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 pattern of light and dark areas moving when the OEL is tilted; wherein step b') comprises exposing a radiation-curable coating composition to magnetic components such as those disclosed in WO 2021 / 083808 A1. WO 2021 / 083808 A1 discloses a magnetic assembly comprising 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 said at least four additional dipole magnets (x31) pointing in the same direction and their magnetic axes 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, wherein the magnetic axes of the additional dipole magnets (x31) are substantially parallel to the substrate. The straight line αi is oriented such that at least one dipole magnet (x41) is disposed below a combination comprising at least four first dipole magnets (x31), wherein on each straight line αi, and on each straight line βj, the north poles of adjacent additional dipole magnets (x31) point in opposite directions, wherein the vector H of the magnetic axis of each straight line αi and at least one dipole magnet (x41) is substantially non-parallel and substantially non-perpendicular to each other OEL, preferably wherein the vector and H of the magnetic axis of each straight line αi and at least one dipole magnet (x41) form 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 axis, but also diagonally when the substrate carrying the OEL is tilted relative to the 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 relative to both vertical axes, namely the horizontal axis and the vertical axis). Suitable magnetic components are those shown in Figures 5-7 of WO 2021 / 083808 A1.

[0125] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein a first 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 step b') comprises exposing a first 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 a 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 having radial magnetization (i.e., its magnetic north-south axis extending radially from the center of the ring magnet to the outer periphery) (see, for example, Figure 6 of WO 2014 / 108404 A2); Or c) at least one dipole magnet, which is three or more dipole magnets arranged in a ring with radial magnetization (i.e., the magnetic axis of each of the three or more dipole magnets is oriented substantially parallel to the substrate, and their magnetic axes are aligned such that they extend substantially radially from the center of symmetry of the ring arrangement, wherein the north-south direction of the three or more dipole magnets all points or all moves 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 b) at least two rod-shaped dipole magnets.Their magnetic axes are substantially perpendicular to the substrate and have opposite magnetic orientations (see Figure 10 of WO 2014 / 108404 A2).

[0126] According to one embodiment, the method described herein allows for the preparation of an OEL in which a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a multi-ringed body that moves when the OEL is tilted; wherein step b') comprises exposing a first radiation-curable coating composition to those magnetic components disclosed in WO 2014 / 108303 A2. The magnetic component disclosed in WO 2014 / 108303 A2 comprises one of the following:

[0127] 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

[0128] 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

[0129] c) having at least one dipole magnet oriented substantially perpendicular to a magnetic axis of the substrate, plate-shaped pole pieces disposed below and in contact with at least one dipole magnet, and one or more annular pole pieces disposed on top of at least one dipole magnet, wherein the central pole piece of one or more annular pole pieces is in contact with at least one dipole magnet, and wherein the plate-shaped pole pieces may include one or more spaced-apart protrusions laterally surrounding at least one dipole magnet (see, for example, WO 2014 / 108303 A2). 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 comprising b) at least four rod-shaped dipole magnets whose magnetic axes are substantially parallel to the substrate (see Figures 11, 12, and 15 of WO 2014 / 108303 A2).

[0130] According to one embodiment,The method described herein allows for the preparation of an OEL, wherein a first pattern 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 step b') comprises exposing a first radiation-curable coating composition to 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:

[0131] - 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

[0132] - 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 (see page 20 / 46 of specification 24 CN 122422063 A), 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

[0133] - 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, 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 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 north pole of the single ring magnet (x31) or two or more dipole magnets (x31) forming the 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 the single ring magnet (x31) or two or more dipole magnets (x31) forming the 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, WO). Figures 1-14 of 2017 / 148789 A1).

[0134] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a ring-shaped body whose shape changes when the OEL is tilted; wherein step b') comprises exposing a first radiation-curable coating composition to those magnetic components 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 (x20), 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 two or more dipole magnets (x31) arranged in a ring, and wherein the ring-shaped magnetic field generating device (x31) is formed When the north pole of a single ring magnet (x31) or two or more dipole magnets (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 surface of the substrate, or when the south pole of the 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 toward the substrate surface.

[0135] According to one embodiment, the method herein allows for the preparation of an OEL, wherein a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a crescent that moves and rotates when the OEL is tilted; wherein step b') comprises exposing a first radiation-curable coating composition to those magnetic components 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 surface of a substrate 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 orientation (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, WO 2017 / 148789). Figures 1-12 of A1).

[0136] According to one embodiment, the method described herein allows for the preparation of an OEL in which a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a ring surrounded by a substantially annular body, the shape and / or brightness of which change as the OEL is tilted; wherein step b') comprises exposing a first radiation-curable coating composition to those magnetic components disclosed in WO 2020 / 193009 A1. WO 2020 / 193009 A1 discloses a magnetic assembly comprising 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 axes of the first dipole magnets (x31-ai) are 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 lies at a projection point within the ring, wherein the at least one second dipole magnet (x41) is disposed above the combination of the three or more first dipole magnets (x31-ai).An angle αi is formed between each vector ( , , ) and the vector ( , , , ...) of the magnetic axis of the corresponding first dipole magnet (x31-ai), wherein when measured in the 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 the 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).

[0137] According to one embodiment, the method described herein allows for the preparation of an OEL in which a first pattern 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 step b') comprises exposing a first radiation-curable coating composition to magnetic components disclosed in Figures 1, 3, and 6 of US 2005 / 0106367.

[0138] According to one embodiment, the method described herein allows for the preparation of an OEL in which a first pattern exhibits dynamic movement when the OEL is tilted, the dynamic movement being a comet-shaped point rotating around the center of rotation when the OEL is tilted, wherein step b') comprises exposing a first 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:

[0139] -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 mutually inclined magnetic axes, 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 projections of the magnetic axes of the first magnetic field generating device (x30) and the second magnetic field generating device (x40) form an angle (Ω) along the rotation axis in a plane perpendicular to the rotation axis, 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 rotation axis; or two or more rod-shaped dipole magnets, each of which has a north-south magnetic axis substantially perpendicular to the rotation axis.And all of the two or more rod-shaped dipole magnets have the same magnetic field direction; or a ring-shaped dipole magnet, the north-south magnetic axis of which is substantially perpendicular to the rotation axis; Specification 22 / 46 pages 26 CN 122422063 A or a disc-shaped dipole magnet nested inside the ring-shaped dipole magnet, the north-south magnetic axis of each of the disc-shaped dipole magnets and the ring-shaped dipole magnets being substantially perpendicular to the rotation axis and having the same magnetic field direction; or two or more nested ring-shaped dipole magnets, the north-south magnetic axis of each of the two or more nested ring-shaped dipole magnets being substantially perpendicular to the rotation axis, and all of the two or more nested ring-shaped magnets having the same magnetic field direction; and wherein the second magnetic field generating device (x40) includes a disc-shaped dipole magnet, the north-south magnetic axis of which is substantially perpendicular to the rotation axis; or a ring-shaped dipole magnet, the north-south magnetic axis of which is substantially perpendicular to the rotation axis; or a rod-shaped dipole magnet, the north-south magnetic axis of which is substantially perpendicular to the rotation axis;

[0140] 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) at least partially or completely embedded in a support base (x32), the north-south magnetic axis of each of the rod-shaped dipole magnets (x31) being substantially parallel to the axis of rotation, the at least pair of the two rod-shaped dipole magnets (x31) having opposite magnetic field directions and arranged symmetrically along line (α) about the axis of rotation, and

[0141] The second magnetic field generating device (x40) comprises 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 two rod-shaped dipole magnets (x41) have opposite magnetic field directions and are arranged around the rotation axis along line (β). 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

[0142] - 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.The disk-shaped dipole magnet (x31), annular, preferably circular, or rod-shaped dipole magnet (x31) of the magnetic field generating device (x30) includes at least one pair of indentations (I) and / or at least one pair of gaps (V) and / or at least one pair of protrusions (P), wherein the at least one pair of indentations (I), at least one pair of gaps (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 circular, or rod-shaped dipole magnet (x31) of the magnetic field generating device (x30) and including the axis of rotation.

[0143] According to one embodiment, the method described herein allows for the preparation of an OEL, wherein step b') comprises independently exposing a first radiation-curable coating composition to a combined magnetic field of a combination of a magnetic component (described later) 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, pp. 189-241, Elsevier.1999; (4) Electric and Magnetic Properties of Metals, C. Moosbrugger, Chapter 8, Soft Magnetic 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, Soft Magnetic Materials, pp. 20-9 to 20-16, Butterworth-Heinemann Ltd, 1992. The soft magnetic plates described herein may be plates made of one or more metals, alloys or compounds with high permeability (hereinafter referred to as “soft magnetic metal plates”), or plates made of composite materials containing soft magnetic particles dispersed in non-magnetic materials (hereinafter referred to as “soft magnetic composite plates”). 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.

[0144] According to one embodiment, the method described herein includes a biaxial orientation step b'', comprising an orientation step.

[0145] In contrast to uniaxial orientation, in which plate-like magnetic or magnetizable pigment particles are oriented such that only their principal axes are magnetically constrained, biaxial orientation means oriented such that plate-like magnetic or magnetizable pigment particles are constrained by both of their principal axes. Unlike needle-like pigment particles, which can be considered one-dimensional particles, plate-like pigment particles have an X-axis and a Y-axis defining the principal extension plane of the particle. In other words,Flaky 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, flaky pigment particles can be considered as two-dimensional structures where dimensions X and Y are substantially larger than dimension Z. Flaky pigment particles are also referred to in the art as flat 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. Performing a biaxial orientation results in flaky magnetic or magnetizable pigment particles having two constrained principal axes, i.e., 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.

[0146] The biaxially oriented sheet-like magnetic or magnetizable pigment particles described herein are composed of sheet-like magnetic or magnetizable pigment particles forming a sheet-like structure, wherein their X-axis and Y-axis are preferably substantially parallel to the substrate (x10) surface and are planarized in said two dimensions.

[0147] According to another embodiment, the magnetic component described below allows the biaxial orientation of the sheet-like magnetic or magnetizable pigment particles described herein, such that both the X-axis and Y-axis of the sheet-like magnetic or magnetizable pigment particles are substantially parallel to the substrate (x10) surface.

[0148] According to another embodiment, the magnetic component described below allows the 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.

[0149] According to another embodiment, the magnetic component described herein allows the sheet-like magnetic or magnetizable pigment particles to be biaxially oriented, such that the sheet-like magnetic or magnetizable pigment particles have a first axis substantially parallel to the surface of the substrate (x10) in the XY plane and a second axis 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 an imaginary spherical surface.

[0150] According to one embodiment, the method herein includes an orientation step b'') comprising an orientation step that biaxially oriented the magnetic or magnetizable pigment particles described herein, such that i) both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) their XY plane is parallel to an imaginary spherical surface.

[0151] According to an embodiment, for example, shown in FIG. 7A, the orientation step b'') of the second set of steps (S2) is a one-step orientation step.A substrate (710) bearing a first coating (720') and a second coating (720'') on the same side is exposed to the magnetic field of a magnetic component (730'') located on the side of the substrate (710) excluding the first and second coatings (720' and 720''). Figure 7C (not drawn to scale) illustrates a method in which orientation step b'') includes an orientation step in which a substrate (710) bearing a first and second coating (720' and 720'') on the same side is exposed to the magnetic field of a static magnetic component (730''), wherein the magnetic component (730'') is arranged near a rotating cylinder (two locations shown in Figure 7C), wherein the second coating (720'') is exposed to one and / or the other of the magnetic components (730'').

[0152] According to one embodiment, for example, shown in FIG. 7B, the orientation step b'') of the second set of steps (S2) is an orientation step in which the substrate (710) bearing the first coating (720') on a first side and the second coating (720'') on a second side of the substrate (710) (i.e., the side of the substrate (710) without the first coating (720')) is exposed to the magnetic field of a magnetic component (730'') located on the side containing the cured first coating (720').

[0153] According to one embodiment, for example, shown in FIG. 8A, the orientation step b'') of the second set of steps (S2) is an orientation step in which the substrate (810) bearing the first coating (820') and the second coating (820'') on the same side is exposed to the magnetic field of a rotating magnetic component (830'') located on the side of the substrate (810) without the first and second coatings (820' and 820''). Figure 8C (not drawn to scale) illustrates a method in which orientation step b'') includes an orientation step in which a substrate (810) bearing the first and second coatings (820' and 820'') described herein is exposed to the magnetic field of a rotating magnetic assembly (830'') mounted on a rotating cylinder.

[0154] According to an embodiment, for example, shown in Figure 8B, orientation step b'') of the second set of steps (S2) is an orientation step in which a substrate (810) bearing the first coating (820') on a first side and the second coating (820'') on a second side of the substrate (810) (i.e., the side of the substrate (810) without the first coating (820')) is exposed to the magnetic field of a rotating magnetic assembly (830'') located on the side containing the cured first coating (820').

[0155] According to one embodiment shown in FIG9, the method herein includes a third set of steps (S3), which occurs after the second set (S2).The third set of steps (S3) includes an orientation step b'''), wherein a substrate (910) bearing a first coating (920') and a second coating (920'') on a first side and the same side, and a third coating (920'') on a second side of the substrate (910) (i.e., the side of the substrate that does not contain the first and second coatings (920' and 920'')), is exposed to a magnetic field of a rotating magnetic assembly (930''') located on the side of the substrate (910) containing the first and second cured coatings (920' and 920'').

[0156] Suitable magnetic assemblies for biaxially oriented sheet-like magnetic or magnetizable pigment particles described herein are provided below as non-limiting examples.

[0157] According to one embodiment shown, for example, Figure 10 (Examples E1-E5, step b') and the magnetic component (1030) used in Example E1, step b''), biaxial orientation is performed by exposing the radiation-curable coating composition to those magnetic components disclosed in WO 2021 / 239607 A1. The magnetic component disclosed in WO 2021 / 239607 A1, pages 25 / 46, CN 122422063 A, comprises:

[0158] 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 whose magnetic axis is oriented substantially parallel to the substrate; and ii) two second rod-shaped dipole magnets (x32a and x32b) having a second thickness (L2), a second length (L6), and a second width (L7), the uppermost surfaces of the two second rod-shaped dipole magnets (x32a, x32b) being flush with each other, and their magnetic axes being oriented substantially perpendicular to the substrate, wherein 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 magnetic orientation of the first rod-shaped dipole magnets (x31) in the first group (S1) and the second group (S2) is spaced apart by a first distance (d1). The first rod-shaped dipole magnets (x31) in the first group (S1) and the first rod-shaped dipole magnets (x31) in the second group (S2) have substantially the same first length (L4) and first width (L5). The two second rod-shaped dipole magnets (x32a and x32b) in the first group (S1) and the two second rod-shaped dipole magnets (x32a and x32b) in the second group (S2) have substantially the same second length (L6) and second width (L7). The first rod-shaped dipole magnets (x31) and the second rod-shaped dipole magnets (x32a and x32b) in each of the first group (S1) and the second group (S2) are aligned to form a column.The first rod-shaped dipole magnets (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). The first width (L5) and the second length (L6) are substantially 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 to the first plane, while the north pole of the first rod-shaped dipole magnet (x31) points to the second rod-shaped dipole magnet (x32a and x32b). 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 to 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

[0159] The first pair (P1) consists of third rod-shaped dipole magnets (x33a and x33b) with 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) in the first group (S1) and the second group (S2) has a value substantially the same as the third width (L9) of the third rod-shaped dipole magnets (x33a and x33b). Each of the third rod-shaped dipole magnets (x33a and x33b) has a value similar to that of one second rod-shaped dipole magnet (x32a and x32b) in the first group (S1) and one second rod-shaped dipole magnet (x32a and x32b) in the second group (S2). Aligned with x32b to form two lines, the third rod-shaped dipole magnets (x33a and x33b) are placed between and spaced apart from the respective second rod-shaped dipole magnets (x32a and x32b) by a third distance (d3). 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 magnets (x33a and x33b) points toward the second rod-shaped dipole magnets (x32a and x32b), respectively; 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 magnets (x33a and x33b) points toward the second rod-shaped dipole magnets (x32a and x32b), respectively.

[0160] According to one embodiment, the method described herein includes i) step b'') or ii) both steps b'') and b') or iii) both steps b'') and b'''), which independently includes exposing the radiation-curable coating composition to those magnetic components as described in EP 2 157 141 A1. The magnetic components disclosed in EP 2 157 141 A1 provide a magnetic field that changes the orientation of sheet-like magnetic or magnetizable pigment particles as they move through the component.The sheet-like magnetic or magnetizable pigment particles are forced to oscillate rapidly until the two principal axes become parallel to the substrate, i.e., the sheet-like magnetic or magnetizable pigment 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, which is opposite to the polarity of magnets on opposite sides of the alternating feed path. 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 (movement direction: 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 magnet and the third magnet on a second opposite side of the feed path, wherein the first magnet and the third magnet have the same polarity, and wherein the second magnet has a polarity complementary to that of the first magnet and the third magnet. According to another embodiment, the magnetic assembly further includes a fourth magnet on the same side of the feed path as the second magnet, which has the polarity of the second magnet and is complementary to the polarity of the third magnet.

[0161] According to one embodiment, biaxial orientation is achieved by exposing a radiation-curable coating composition to a magnetic assembly comprising a linear permanent magnet Helbeck array, i.e., an assembly comprising a plurality of magnets with different magnetization directions and a cylindrical device. A detailed description of Halbach permanent magnets is given by ZQ Zhu and D. Howe (Halbach permanent magnet machines and applications: a review), IEE. Proc. Electric Power Appl., 2001, 148, pp. 299-308. The magnetic field generated by such a Halbach array has the property that it is concentrated on one side and weakens to almost zero on the other side. Linear Halbach arrays are disclosed, for example, in WO 2015 / 086257 A1 and WO 2018 / 019594 A1, and Halbach cylindrical devices are disclosed in EP 3 224 055 B1.

[0162] According to one embodiment,Biaxial orientation is achieved by exposing the radiation-curable coating composition to a rotating magnetic assembly at an appropriate rate. Examples of rotating magnetic assemblies are those comprising one or more disc-shaped rotating magnets or magnetic assemblies magnetized substantially along their diameter. Magnetic assemblies comprising rotating magnets or magnetic field generating devices are described in US 2007 / 0172261 A1, which generate radially symmetrical time-varying magnetic fields, allowing biaxial orientation of pigment particles. These magnetic assemblies are driven by a shaft (or spindle) connected to an external motor. CN 102529326 B discloses examples of magnetic assemblies comprising rotating magnets suitable for biaxial orientation of pigment particles. In a preferred embodiment, a suitable magnetic assembly is a shaftless disc-shaped rotating magnetic assembly 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 and WO 2016 / 026896 A1.

[0163] According to one embodiment, for example shown in Figures 12-13, a biaxial orientation step is performed by exposing a radiation-curable coating composition at an appropriate rate to the rotating magnetic component disclosed in WO2018 / 141547 A1. The magnetic assembly (x30) disclosed in WO2018 / 141547 A1 comprises

[0164] a) a first block (A) comprising a1) a retainer (1a) having a stator mounted thereon, the stator comprising n magnetic coils (1b) arranged in n annular slots in a circular arrangement around an axis guiding a magnetic field stator core (1c); and

[0165] b) a second block (B) comprising:

[0166] b1) a housing (4)

[0167] b2) a rotor comprising m permanent magnet poles (3a) of alternating polarities arranged in a circular arrangement in or on one side of a rotor disk (3b), wherein the m permanent magnet poles (3a) face a rotor protection plate (2);

[0168] b3) Rotor protection plate (2), preferably titanium rotor protection plate (2), wherein the rotor protection plate (2) covers the rotor (3a+3b); and

[0169] b4) Permanent magnet assembly (PMA) (5) driven by the rotor (3a+3b), wherein the permanent magnet assembly (PMA) (5) is disposed on the opposite side of the rotor disk (3b),

[0170] wherein the stator (1b+1c) and the rotor (3a+3b) together serve as a brushless DC (BLDC) motor, Specification 27 / 46 pages 31 CN 122422063 A

[0171] wherein n is a multiple of 3 and m is a multiple of 2,The condition is that n / m is 3 / 2, 3 / 4, 6 / 4, 6 / 8, 9 / 8, 9 / 10, 12 / 10, or 12 / 14, and

[0172] wherein the first block (A) is configured to be removably fixed to the base of a rotating magnetic alignment cylinder (RMC) or flat plate (FB) magnetic alignment printing unit, and

[0173] wherein the second block (B) is removably fixed to the first block (A).

[0174] According to one embodiment, the alignment step b'') of the second set of steps (S2) is a two-step alignment step, wherein the first step biaxially aligns at least a portion of the sheet-like magnetic or magnetizable pigment particles as described herein, and the second step biaxially aligns at least a portion of the sheet-like magnetic or magnetizable pigment particles as described herein, wherein the magnetic components (x30'') used in the two steps may be the same or may be different.

[0175] According to one embodiment, the method herein includes a third set of steps (S3), wherein the orientation step b''') comprises: exposing the third radiation-curable coating composition of step a''') to the magnetic field of the magnetic component (x30''') to 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) their XY plane is parallel to the surface of an imaginary sphere, and forming a third coating (x20''') and a third magnetic pattern, said third coating (x20''') being adjacent to and properly registered with at least a portion of the first pattern and / or adjacent to and properly registered with at least a portion of the second pattern (i.e., the third pattern being at least partially adjacent to and properly registered with the first coating (x20') and / or adjacent to and properly registered with at least a portion of the second coating (x20''), wherein said third magnetic pattern may be the same as or different from the second magnetic pattern.

[0176] According to one embodiment, the orientation step b''') of the third set of steps (S3) is one-step or two-step orientation step as described for step b') or for step b''). Preferably, the orientation step b''') of the third set of steps (S3) is one-step orientation step as described for step b'') of the second set of steps (S2), wherein the third magnetic pattern thus obtained is the same as or different from the second magnetic pattern.

[0177] The following combinations of multiple sets of steps are also described herein:

[0178] - a first set of steps (S1) including step b') and a second set of steps (S2) including step b''), both independently including one-step orientation steps as described herein;

[0179] - a first set of steps (S1) including step b') including two-step orientation steps as described herein, preferably independently including a first orientation step that biaxially orients the sheet-like magnetic or magnetizable pigment particles,This is followed by a two-step orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles described herein, and a second set of steps (S2) comprising a step b'') including a one-step orientation step as described herein of biaxially oriented the sheet-like magnetic or magnetizable pigment particles; and

[0180] - a first set of steps (S1) including step b'') and a second set of steps (S2) including step b''), both independently comprising two orientation steps, step b'') comprising a first orientation step of biaxially oriented the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles described herein, and step b'') comprising a first orientation step of biaxially oriented the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of biaxially oriented the sheet-like magnetic or magnetizable pigment particles described herein,

[0181] - a first set of steps (S1) including step b''), a second set of steps (S2) including step b'''), and a second set of steps (S2) including step b'''). The third set of steps (S3), each of which independently includes a one-step orientation step as described herein;

[0182] - The first set of steps (S1), which includes step b') including a two-step orientation step as described herein, preferably independently 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 as described herein; the second set of steps (S2) including step b'') of the one-step orientation step as described herein (page 28 / 46, CN 122422063 A); and the third set of steps (S3) including step b''') of the one-step orientation step as described herein;

[0183] - The first set of steps (S1) including step b') and the second set of steps (S2) including step b'') each independently include a two-step orientation step, step b') including a first orientation step that biaxially orients the sheet-like magnetic or magnetizable pigment particles, This is followed by a second orientation step that reorients the sheet-like magnetic or magnetizable pigment particles described herein, and step b'') includes a first orientation step that biaxially orients the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step that biaxially orients the sheet-like magnetic or magnetizable pigment particles described herein, and a third set of steps (S3) includes step b''') including a one-step orientation step as described herein; and

[0184] - a first set of steps (S1) including step b''), a second set of steps (S2) including step b'''), and a third set of steps (S3) including step b'''), the three steps independently including two orientation steps, step b') including a first orientation step that biaxially orients the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step that reorients the sheet-like magnetic or magnetizable pigment particles described herein,Step b'') includes a first orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles as described herein, and a third set of steps (S3) includes step b'''), which includes a first orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of biaxially orienting the sheet-like magnetic or magnetizable pigment particles as described herein.

[0185] 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', step c'') and optional step c''')). Therefore, it is noteworthy that the first and second coating compositions, and optionally the third coating composition, 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, such that the flake-like magnetic or magnetizable pigment particles dispersed in the composition can move, rotate, and orient freely when exposed to a magnetic field, and a second hardened (e.g., solid or solid state) state, in which the flake-like magnetic or magnetizable pigment particles are fixed or frozen in their respective positions and orientations.

[0186] Such 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 flake-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 solidifies, the binder material transforms into a second state, i.e., a hardened or solid state, in which the flake-like magnetic or magnetizable pigment particles are fixed in their current positions and orientations and can no longer move or rotate within the binder material. As is known to those skilled in the art, the components contained in an ink or coating composition to be applied directly or indirectly to a 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 contained 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.

[0187] The curing steps (step c'), c''), and optional 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 secure documents. The terms “curing” or “curability” refer to a method of chemical reaction, crosslinking, or polymerization including at least one component of the applied coating composition.In this manner, it is transformed into a polymeric material with a molecular weight larger than that of the starting material. Preferably, curing results in the formation of a stable three-dimensional polymer network. Such curing is typically induced by (i) after the application of the composition (step a'), step a'') and optional step a''')) and (ii) after or partially simultaneously with the application of external stimuli to the composition (step c'), step c'') and optional step c''')) of the orientation of at least a portion of the sheet-like magnetic or magnetically oriented pigment particles (step b'), step b'') and optional step b'''))). Advantageously, the curing steps (step c', step c'') and optional step c''') of the first and second coatings (x20' and x20'') and the optional third coating (x20''') described herein are performed independently and simultaneously with the orientation (step b', step b'') and optional step b''') of at least a portion of the sheet-like magnetic or magnetizable pigment particles (step c', step c'') and optional step 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 information loss after the magnetic orientation step. Preferably, the curing steps (step c'), c''), and optionally 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.

[0188] Preferably, the first or second or optionally third radiation-curable coating composition, preferably the first and second and third 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. Cationic curable compounds cure via a cationic mechanism, which typically involves activation by irradiation of one or more photoinitiators. These photoinitiators release cationic substances, such as acids, which in turn initiate curing, causing monomers and / or oligomers to react and / or crosslink, thereby hardening the coating composition. Radical curable compounds cure via a radical mechanism, which typically involves activation by irradiation of one or more photoinitiators, generating free radicals that in turn initiate polymerization.To allow the coating composition to harden. Depending on the monomer, oligomer, or prepolymer used to prepare the binder contained in the first and second radiation-curable coating compositions described herein, different photoinitiators may be used. Suitable examples of free 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. For effective curing, a sensitizer combined with one or more photoinitiators may also be advantageously 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. One or more photoinitiators included in the UV-Vis curable coating composition are preferably present in a total amount of about 0.1% by weight to about 20% by weight, more preferably about 1% by weight to about 15% by weight, based on the total weight of the first and second radiation-curable coating compositions, respectively.

[0189] The first, second, and third radiation-curable coating compositions described herein may further independently contain one or more additives, including but not limited to compounds and materials used to adjust 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, etc. The additives described herein may be present in the coating compositions described herein in amounts and forms known in the art, including in the form of so-called nanomaterials, wherein at least one particle size is in the range of 1 to 1000 nm.

[0190] 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.That is, it is added after the formation of the liquid coating composition.

[0191] The method for generating OEL described herein includes a curing step c (step c') and / or c'') and / or optional step c''')) of the radiation-curable coating composition, preferably partially simultaneous with or after step b (step b') and / or b'') and / or optional step c''')). 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 the orientation step b (step b') and / or b'') and / or optional step b''')) to the start of the curing step c (step c') and / or c'') and / or optional step 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 / or optional step b''')) and the start of step c)(step c') and / or c'') and / or optional step c''')) is less than 1 minute, preferably less than 20 seconds, and more preferably less than 5 seconds. Particularly preferably, there is substantially no time interval between the end of orientation step b)(step b') and / or b'')) and the start of curing step c)(step c') and / or c'') and / or optional step c'''))), i.e., 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 step (step c) (step c') and / or c'') and / or optional step c''') can be carried out by different means or methods depending on the binder material contained in the coating composition, which also contains flake magnetic or magnetizable pigment particles.

[0192] 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 may include a chemical reaction,The curing, polymerization, or crosslinking of binders and optional initiator compounds and / or optional crosslinking compounds contained in radiation-curable coating compositions. Such chemical reactions 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.

[0193] 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. Therefore, 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', x50'', and optional x50''') for curing steps (step c') and c'') and / or optional 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 as described on pages 31 / 46 of the specification, CN 122422063 A. 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, meaning they emit only at one wavelength, such as 365nm, 385nm, 395nm, 405nm, or 450nm. Preferably,The first coating (x20'), the second coating (x20''), and optionally the third coating (x20''') are exposed to UV light, preferably to one or more wavelengths between about 355 nm and about 415 nm, more preferably by exposure to UV light of 365 nm and / or 385 nm and / or 395 nm emitted from the LED curing units (x50', x50'', x50'''), at least one of the steps described herein (c') and c'') and optionally c'''), more preferably steps c') and c'') and optional c'''), and even more preferably steps c') and c'') and optional c''').

[0194] The method described herein may further include a customization step during the first set of steps to produce an OEL containing a first graphic that further exhibits one or more markings, wherein the customization step occurs after step b') and before step c'). The customization step is preferably performed by independently applying the 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 disclosed in WO 2021 / 259527 A1.

[0195] The present invention provides a method for producing the OEL described herein on a substrate (x10) described herein. The substrate described herein is 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 of 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 generally 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), and polyamides.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, multilayer structures or laminates of paper and at least one plastic or polymeric material, such as those described above, and the incorporation of paper-like or fibrous materials, such as the plastic and / or polymeric fibers described above. 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 present invention is used for decorative or cosmetic purposes, including, for example, nail polish, the OEL can be produced on other types of substrates including animal or human nails, artificial nails, or other parts.

[0196] According to one embodiment, the substrate (x10) described herein is a transparent substrate, preferably selected from the group consisting of: transparent polyolefins (such as polyethylene (PE) and polypropylene (PP) including biaxially oriented polypropylene (BOPP)), transparent polyamides, transparent polyesters (such as polyethylene terephthalate (PET), polybutanediol terephthalate (PBT), polyethylene 2,6-naphthalenedicarboxylate (PEN), and transparent polyvinyl chloride (PVC), more preferably biaxially oriented polypropylene; or specification 32 / 46 pages 36 CN 122422063 A It is a partially opaque substrate, particularly a transparent polymer that is at least partially opaque, preferably selected from the group consisting of: transparent polyolefins (such as polyethylene (PE) and polypropylene (PP) including biaxially oriented polypropylene (BOPP)), transparent polyamides, transparent polyesters (such as polyethylene terephthalate (PET), polybutane terephthalate (PBT), polyethylene 2,6-naphthalene glycol (PEN), and transparent polyvinyl chloride (PVC),More preferably, biaxially oriented polypropylene. According to one embodiment, the OEL described herein is present on banknotes and on those transparent substrates as described herein, preferably in the form of a window or foil, or on those at least partially opaque substrates as described herein, preferably in the form of a non-opaque area, in the form of a window or foil.

[0197] The substrate (x10) described herein may be in the form of a web, sheet, thread reel, film reel, labels of the roll, or label material, preferably in sheet form.

[0198] If the OEL produced according to the invention is on a security document, and for the purpose of further improving the security level of the security document and its resistance to counterfeiting and illegal copying, the substrate may include 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 enhancing the security level of secure documents and their resistance to forgery and illegal copying, the substrate may contain more than one marker or tracer and / or machine-readable material. According to one embodiment, the substrate (x10) comprises a printed pattern, preferably an offset printed pattern, wherein at least one of the radiation-curable coating compositions of steps a') and a'') and optionally a''') is at least partially applied on top of the printed pattern, and the method described herein includes the step of printing ink onto the substrate (x10) described herein, wherein, as appropriate, the step occurs before steps a') and a'') and optionally a''') described herein.

[0199] If desired, a primer layer may be applied to the substrate (x10) before step a') or before step a'') or optionally before 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.

[0200] For the purpose of improving durability through stain resistance or chemical resistance and cleanliness, thereby increasing the cycle life of articles, security documents, or decorative elements or objects containing an OEL obtained by the methods described herein, or for the purpose of altering their aesthetic appearance (e.g., optical gloss), one or more protective layers may be applied on top of the OEL. When present, one or more protective layers are typically made of a protective varnish. These may be transparent or slightly tinted or colored, and may be more or less glossy. The protective varnish may 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, a UV-Vis curable composition is used. A protective layer is typically applied after the OEL is formed.

[0201] 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.

[0202] The OEL described herein may 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, which are applied at locations spaced apart from or at least partially applied on top of or below the OEL.

[0203] The present invention further provides an optical effect layer (OEL) produced by the method according to the invention.

[0204] According to one embodiment shown in Examples E4-E5, the OEL comprises a first pattern, a second pattern, and a third pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a first magnetic pattern as described herein, the second pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a second magnetic pattern as described herein, and the third pattern comprising sheet-like magnetic or magnetizable pigment particles oriented according to a third magnetic pattern as described herein, wherein the first and second patterns are different from each other, the third and second patterns are the same as or different from each other, wherein the second pattern is at least partially adjacent to and properly registered with the first pattern, and wherein the third pattern is at least partially adjacent to and properly registered with the first pattern and / or at least partially adjacent to and properly registered with the second pattern. This document also describes a method for producing an OEL having the three patterns described herein, wherein the method includes the first set of steps (S1) a'), b') and c') described herein, the second set of steps (S2) a''), b'') and c'') described herein, and the third set of steps (S3) a'''), b''') and c''') described herein, wherein the third set of steps (S3), particularly step a''') is performed after and consecutively with step c'').

[0205] According to one embodiment shown in C of FIG1, the method described herein includes the two sets of steps (S1 and S2) described herein, and further includes a third set of steps (S3) to produce an optical effect layer (OEL) comprising a first pattern, a second pattern and a third pattern, wherein the first pattern comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a first magnetic pattern orientation described herein.The second pattern comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to the second magnetic pattern orientation described herein, and the third pattern comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to the third magnetic pattern orientation, wherein the substrate (x10) comprises a first coating (x20') and a second coating (x20'') present on the same side of the substrate (x10), and the third set of steps (S3) comprises:

[0206] a''') applying a third radiation-curable coating composition comprising sheet-like magnetic or magnetizable pigment particles, preferably a third UV-Vis curable coating composition, to the side of the substrate (x10) that does not contain the first coating (x20') and does not contain the second coating (x20'') to form a third coating (x20'''), the coating composition being in a first state, and at least a portion of the third coating (x20''') being adjacent to the first coating (x20'').

[0207] b''') The third radiation-curable coating composition of step a''') is adjacent to and / or adjacent to at least a portion of the second coating (x20'') (see, for example, C and 9 of FIG1);

[0208] c''') The third radiation-curable coating composition of step a''') is exposed to the magnetic field of the magnetic component (x30''') to cause at least a portion of the sheet-like magnetic or magnetizable pigment particles to be biaxially oriented; and

[0209] c''') The second 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 third pattern.

[0209] According to one embodiment, the method described herein includes the two sets of steps (S1 and S2) described herein, and further includes a third set of steps (S3) to produce an optical effect layer (OEL) comprising a first pattern, a second pattern, and a third pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a first magnetic pattern orientation described herein, the second pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a second magnetic pattern orientation described herein, and the third pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a third magnetic pattern orientation, wherein the first coating (x20') is present on a first side of a substrate (x10) and the second coating (x20'') is present on a second side (i.e., the opposite side) of the substrate (x10), and the third set of steps (S3) includes:

[0210] a A third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to a side of a substrate (x10) containing a first coating (x20') in a cured state and excluding a second coating (x20''), to form a third coating (x20'''), wherein the coating composition is in the first state.And at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20'');

[0211] b''') exposing the third radiation-curable coating composition of step a''') to the magnetic field of the magnetic component (x30''') to cause at least a portion of the sheet-like magnetic or magnetizable pigment particles to be biaxially oriented; and

[0212] c''') curing at least a portion of the third 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 as described herein, and to produce a third figure (34 / 46 pages, 38 CN 122422063 A).

[0213] According to one embodiment, the method described herein includes the two sets of steps (S1 and S2) described herein, and further includes a third set of steps (S3) to produce an optical effect layer (OEL) comprising a first pattern, a second pattern, and a third pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a first magnetic pattern orientation described herein, the second pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a second magnetic pattern orientation described herein, and the third pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a third magnetic pattern orientation, wherein the first coating (x20') is present on a first side of the substrate (x10) and the second coating (x20'') is present on a second side (i.e., the opposite side) of the substrate (x10), and the third set of steps (S3) includes:

[0214] a b) Applying a third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles to a side of a substrate (x10) containing a second coating (x20'') in a cured state and excluding a first coating (x20''), to form a third coating (x20'''), wherein the coating composition is in a first state, and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20'') and / or adjacent to at least a portion of the second coating (x20'');

[0215] b) Exposing the third radiation-curable coating composition of step a'''') to the magnetic field of a magnetic component (x30''') to cause at least a portion of the flake-like magnetic or magnetizable pigment particles to biaxial orientation; and

[0216] c''') The third radiation-curable coating composition of step b''') is at least partially cured to the second state to fix the flake-like magnetic or magnetizable pigment particles in their adopted positions and orientations as described herein, and to produce a third pattern.

[0217] According to one embodiment, the method herein comprises the two sets of steps (S1 and S2) described herein,And further includes a third set of steps (S3) to produce an optical effect layer (OEL) comprising a first pattern, a second pattern, and a third pattern, wherein the first pattern comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a first magnetic pattern orientation as described herein, the second pattern comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a second magnetic pattern orientation as described herein, and the third pattern comprises sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a third magnetic pattern orientation, wherein the substrate (x10) comprises a first coating (x20') and a second coating (x20'') present on the same side of the substrate (x10), and the third set of steps (S3) includes:

[0218] a b) Applying a third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles to one side of a substrate (x10) comprising a first coating (x20') and a second coating (x20'') in a cured state to form a third coating (x20'''), wherein the coating composition is in a first state and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20'');

[0219] b) Exposing the third radiation-curable coating composition of step a) to the magnetic field of the magnetic component (x30''') to cause at least a portion of the flake-like magnetic or magnetizable pigment particles to be biaxially oriented; and

[0220] c''') The third radiation-curable coating composition of step b''') is at least partially cured to the second state to fix the flake-like magnetic or magnetizable pigment particles in their adopted positions and orientations as described herein, and to produce a third pattern.

[0221] The OEL described herein can be directly applied to the substrate (x10), which will be permanently retained on the substrate (x10) (e.g., for banknote applications). Alternatively, the OEL can also be applied to a temporary substrate for production purposes, from which the OEL is subsequently removed. This can, for example, facilitate the generation of the OEL, particularly when the adhesive material is still in its fluid state. Thereafter, after curing the radiation-curable composition used to generate the OEL, the temporary substrate can be removed from the OEL. Specification 35 / 46 pages 39 CN 122422063 A

[0222] 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 items without printing or other processes involving machinery and a considerable amount of work. Alternatively, the substrate described herein that contains the OEL can be in the form of transfer foil.It can be applied to a document or article in a separate transfer step. For this purpose, the substrate is provided with a release coating, on which an OEL is produced, as described herein.

[0223] This document also describes substrates comprising more than one, i.e., two, three, four, etc. (x10). Each of the OELs obtained by the methods described herein independently comprises first and second patterns as described herein in the form of first and second coatings (x20', x20''). The method described herein for generating more than one OEL on a substrate (x10) may include: a first set of steps (S1) a'), b') and c') for generating a first pattern of a first OEL; a second set of steps (S2) a''), b'') and c'') for generating a second pattern of the first OEL; a third set of steps (S3) a'''), b''') and c''') for generating a first pattern of a second OEL; and a fourth set of steps (S4) a''''), b'''') and c'''') for generating a second pattern of a second OEL. Alternatively, the method described herein for generating more than one OEL on a substrate (x10) may include: a first set of steps (S1) a'), b') and c') for generating a first graphic of a first OEL; a second set of steps (S2) a''), b'') and c'') for generating a first graphic of a second OEL; a third set of steps (S3) a'''), b''') and c''') for generating a second graphic of the first OEL; and a fourth set of steps (S4) a''''), b'''') and c'''') for generating a second graphic of the second OEL.

[0224] This document also describes articles comprising OELs generated 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 generated according to the invention.

[0225] As described above, OELs generated according to the invention can be used for decorative purposes as well as for protecting and authenticating security documents.

[0226] 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.

[0227] 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, etc.Preferred items include banknotes, identification documents, grant documents, driver's licenses, and credit cards. The term "goods of value" refers to packaging materials, particularly those used for cosmetics, nutritional products, pharmaceuticals, alcoholic beverages, tobacco products, soft drinks or food, electrical / electronic products, textiles, or jewelry—items that should be protected against counterfeiting and / or illegal reproduction to ensure the contents of the package are genuine, such as medicine. 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, documents of value, and goods of value are given for illustrative purposes only and do not limit the scope of the invention.

[0228] 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.

[0229] 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 present invention.

[0230] Furthermore, all documents mentioned in the entire specification are incorporated herein by reference in their entirety, as fully described on pages 36 / 46 of this specification, CN 122422063 A.

[0231] Embodiments

[0232] 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 generating optical effect layers (OELs).

[0233] OELs obtained by the method of Examples E1-E5 are prepared on laboratory equipment according to a method comprising two sets of steps (E1-E3) or three sets of steps (E4-E5), wherein

[0234] the first orientation step b') of the first set is shown in FIG5A to simulate an industrial method (E1-E5) comprising two orientation steps as shown in FIG5B;

[0235] wherein the orientation step b'') of the second set is shown in FIG7A to simulate an industrial method (e.g., E1) comprising one orientation step as shown in FIG7C, or shown in 8A to simulate an industrial method (e.g., E2-E5) comprising one orientation step as shown in FIG8C; and

[0236] wherein the orientation step b''') of the third set is shown in FIG9,To simulate an industrial method (e.g., E4-E5) including a one-step orientation step similar to step b'' shown in Figure 8C.

[0237] Precise registration of the first pattern, the second pattern, and, if present, the third pattern (i.e., the first, second, and third cured coatings (x20', x20'', x20''') is ensured by using a screen containing guide marks in addition to the pattern to be printed.

[0238] Examples E1-E3 were prepared independently using the UV-curable screen printing inks of Table 1, wherein the first UV-curable screen printing ink I1 was applied in step a') to a first side of a transparent substrate (x10) (polymer BOPP substrate, GuardianTM from CCL) to form a first coating (x20'), and the second UV-curable screen printing ink I1 (step a'') was applied (step a'') to the same side of the substrate (x10) and partially on top of and in direct contact with the first coating (x20') (see Figure 1A and Figure 7).

[0239] Examples E4-E5 were independently prepared using the UV-curable screen printing inks in Table 1, wherein a first UV-curable screen printing ink I1 was applied to a first side of a transparent substrate (x10) in step a') to form a first coating (x20'); a second UV-curable screen printing ink I1 was applied (step a'') to the same side of the substrate (x10) in a manner registered with the first coating (x20') and partially on top of and in direct contact with the first coating (x20'); and a third UV-curable screen printing ink I2 was applied (step a'') in a manner registered with the first and second coatings (x20' and x20''). On the opposite side of the substrate (x10) (i.e., the side of the substrate (x10) that does not contain the first and second coatings (x20' and x20'') and on top of it, and in indirect contact with the first coating (x20') and the second coating (x20'') (through the substrate (x10) (see Figure 1 C and Figure 9).

[0240] A first UV-curable screen printing ink is applied (step a') 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.

[0241] A second UV-curable screen printing ink (step a'') is applied to the first side of the substrate (x10), precisely registered with the first coating (x20') applied in step a'), the application being performed by manual screen printing using a second T90 screen (x40'') to form a second coating (x20'') with a thickness of approximately 20 μm and having the shape shown in Table 2.

[0242] A third UV-curable screen printing ink (step a''') is applied to the second side of the substrate (x10) (i.e.,On the side of the substrate (x10) excluding the first and second coatings (x20' and x20''), a third coating (x20'') is precisely registered with the first coating (x20') applied in step a'') and precisely registered with the second coating (x20''), which is applied by manual screen printing using a third T90 screen (x40''), to form a third coating (x20''') with a thickness of about 20 μm and having the shape shown in Table 2.

[0243] Two-step orientation steps for the first coating / first pattern (Figure 5A of Examples E1-E5, steps b'-c')) Specification 37 / 46 pages 41 CN 122422063 A

[0244] The substrate (510) carrying the first coating (520') is moved over the static magnetic assembly (530'-a) (see the gray arrow in Figure 5A) (step b'-1)) and then placed on the second magnetic assembly (530'-b), which is the magnetic assembly 1130 of Figure 11. Then, simultaneously with the orientation step b'-2) (i.e., while the substrate (510) carrying the first coating (520') is still in the magnetic field of the magnetic component (530'-b), the magnetic orientation pattern of the thus obtained sheet-like magnetic pigment particles is fixed by exposing the layer containing the pigment particles to UV curing (step c') for about 1.5 seconds using a first UV-LED lamp (550') from Phoseon (model FireFlex 50× 75mm, 395nm, 8W / cm2).

[0245] One-step orientation step for applying the second coating / second pattern to the side of the substrate carrying the first coating / first pattern (Figure 7A of Example E1, steps a''-c'')

[0246] A second UV-curable screen printing ink (step a'') is applied to the same side of the substrate (710) carrying the first coating (720') to form a second coating (720'') precisely registered with the first coating (720'). The substrate (710) bearing the first and second coatings (720' and 720'') is placed above the static magnetic component (730'') of the magnetic component 1030 in FIG. 10 (step b'') and moved back and forth ten times at a linear velocity of about 1 m / s in the magnetic field generated by the component (step b'-1) with the side of the substrate (710) without the first and second coatings (720' and 720'') facing the static magnetic component (730''). Then, partially simultaneously with the orientation step b'') (i.e., while the substrate (710) bearing the first and second coatings (720' and 720'') is still in the magnetic field of the magnetic component (730''),The magnetic orientation pattern of the flake-like magnetic pigment particles thus obtained is fixed by exposing the layer containing the pigment particles to UV curing for about 1.5 seconds using a second UV-LED lamp (750'') from Phoseon (model FireFlex 50×75mm, 395nm, 8W / cm2) (step c'').

[0247] One-step orientation of the second coating / second pattern for application on the side of the substrate carrying the first coating / first pattern (Figure 8A of Examples E2-E5, steps a'')-c'')

[0248] A second UV-curable screen printing ink is applied (step a'') to the same side of the substrate (810) carrying the first coating (820') to form a second coating (820'') precisely registered with the first coating (820'). The substrate (810) bearing the first and second coatings (820' and 820'') is placed above the rotating magnetic assembly (830'') (step b'') with the side of the substrate (810) without the first and second coatings (820' and 820'') facing the rotating magnetic assembly (830''). Then, simultaneously with the orientation step b'') (i.e., while the substrate (810) bearing the first and second coatings (820' and 820'') is still in the magnetic field of the magnetic assembly (830''), the magnetic orientation pattern of the thus obtained sheet-like magnetic pigment particles is fixed by exposing the layer containing the pigment particles to UV curing for about 1.5 seconds using a second UV-LED lamp (850'') from Phoseon (model FireFlex 50×75mm, 395nm, 8W / cm2) for about 1.5 seconds.

[0249] One-step orientation for applying a third coating / third pattern to the side of the substrate that does not contain the first and second coatings (Figure 9 of Examples E4-E5, steps a''')-c'''))

[0250] The substrate carrying the first coating (920') and the second coating (920'') on the same side is flipped / rotated, and a third UV-curable screen printing ink is applied (step a''')) to the side of the substrate that does not contain the first and second coatings (920', 920'') to form a third coating (920''') that is precisely registered with the first coating (920') and precisely registered with the second coating (920''). A substrate (910) bearing the first, second, and third coatings (920', 920'', 920''') is placed above a rotating magnetic assembly (930''), wherein one side of the substrate (910) containing the first and second coatings (920' and 920'') in a cured state faces the rotating magnetic assembly (930'''). Then, simultaneously with the orientation step b''') (i.e.,While the substrate (910) bearing the first, second, and third coatings (920', 920'', 920''') is still in the magnetic field of the rotating magnetic component (930'''), the magnetic orientation pattern of the thus obtained flake-shaped magnetic pigment particles is fixed by exposing the layer containing the pigment particles to UV curing for about 1.5 seconds using a second UV-LED lamp (950''') from Phoseon (model FireFlex 50×75mm, 395nm, 8W / cm2). Specification 38 / 46 pages 42 CN 122422063 A

[0251] Table 1

[0252]

[0253] ( ) Gold to green color-changing magnetic pigment particles (flake-shaped pigment particles) in the shape of flakes with a diameter d50 of about 11μm and a thickness of about 1μm.

[0254] ( ) Green to blue color-changing magnetic pigment particles (flaky pigment particles) in the shape of a sheet with a diameter d50 of about 11 μm and a thickness of about 1 μm.

[0255] Magnetic assembly of FIG10

[0256] A magnetic assembly (1030) for biaxially oriented pigment particles according to the method of the invention is disclosed in FIG3A of WO 2021 / 239607 A1. The magnetic assembly (1030) comprises (530'-a) when used in the first step b'-1 of FIG5A, or comprises (730'') when used in the step of FIG7A.

[0257] The magnetic assembly (1030) comprises a) a first group (S1) comprising a first rod-shaped dipole magnet (1531-a) and two second rod-shaped dipole magnets (1032-a and 1032-d); a second group (S2) comprising a first rod-shaped dipole magnet (1031-b) and two second rod-shaped dipole magnets (1032-b and 1032-e); and a third group (S3).It includes a first rod-shaped dipole magnet (1031-c) and two second rod-shaped dipole magnets (1032-c and 1032-f); and b) a first pair (P1) of third rod-shaped dipole magnets (1033-a and 1033-b); and a second pair (P2) of third rod-shaped dipole magnets (1033-c and 1033-f).

[0258] The uppermost surfaces of the first rod-shaped dipole magnets (1031-a, 1031-b and 1031-c) of the first group, the second group and the third group (S1, S2, S3), the second rod-shaped dipole magnets (1032-a to 1032-f) of the first group, the second group and the third group (S1, S2, S3), and the third rod-shaped dipole magnets (1033-a to 1033-d) of the first pair and the second pair (P1 and P2) are flush with each other.

[0259] The third rod-shaped dipole magnet (1033-a) of the first pair (P1) is aligned with the second rod-shaped dipole magnet (1032-a) of the first group (S1), the second rod-shaped dipole magnet (1032-b) of the second group (S2), the third rod-shaped dipole magnet (1033-c) of the second pair (P2), and the second rod-shaped dipole magnet (1032-c) of the third group (S3), thereby forming a line. The third rod-shaped dipole magnet (1033-b) is aligned with the second rod-shaped dipole magnet (1032-d) of the first group (S1), the second rod-shaped dipole magnet (1032-e) of the second group (S2), the third rod-shaped dipole magnet (1033-d) of the second pair (P2), and the second rod-shaped dipole magnet (1032-f) of the third group (S3), thereby forming a line. For each line described herein,The third rod-shaped dipole magnets (1033-a, 1033-b, 1033-c and 1033-d) and the second rod-shaped dipole magnets (1032-a to 1032-f) are spaced 2 mm apart by a distance (d2). The first rod-shaped dipole magnets (1031-a) of the first group (S1), the first rod-shaped dipole magnets (1031-b) of the second group (S2), and the first rod-shaped dipole magnets (1031-c) of the third group (S3) are spaced 24 mm apart by a distance (d3).

[0260] The first rod-shaped dipole magnets (1031-a, 1031-b, and 1031-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 (1032-a to 1032-f) of the first, second, and third groups (S1, S2, S3) has the following dimensions: a second length (L4) of 40 mm, a second width (L5) of 10 mm, and a second thickness (L6) of 10 mm. Each of the third rod-shaped dipole magnets (1033-a to 1033-d) of the first and second pairs (P1, P2) has the following dimensions: a third length (L7) of 20 mm, a third width (L8) of 10 mm, and a third thickness (L9) of 10 mm.

[0261] The first rod-shaped dipole magnet (1031-a) of the first group (S1) and the second rod-shaped dipole magnet (1032-a and 1032-d) of the first group (S1) are aligned to form a column; and the first rod-shaped dipole magnet (1031-b) of the second group (S2) and the second rod-shaped dipole magnet (1032-b and 1032-e) of the second group (S2) are aligned to form a column; and the first rod-shaped dipole magnet (1031-c) of the third group (S3) and the second rod-shaped dipole magnet (1032-c and 1032-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 (1031-a, 1031-b and 1031-c) and the two second rod-shaped dipole magnets (1032-a and 1032-d; 1032-b and 1032-e; and 1032-c and 1032-f, respectively) are spaced apart by a second distance (d1) of 2 mm.

[0262] The magnetic axis orientation of the first rod-shaped dipole magnets (1031-a, 1031-b and 1031-c) in the first, second and third groups (S1, S2, S3) is substantially parallel to the substrate (1010) and substantially parallel to the substrate (1010).The magnetic direction of the first rod-shaped dipole magnet (1031-a) in the first group (S1) is opposite to that of the first rod-shaped dipole magnet (1031-b) in the second group (S2), and the magnetic direction of the first rod-shaped dipole magnet (1031-b) in the second group (S2) is opposite to that of the first rod-shaped dipole magnet (1031-c) in the third group (S3). The first rod-shaped dipole magnet (1031-a) in the first group (S1) and the first rod-shaped dipole magnet (1031-b) in the second group (S2), as well as the first rod-shaped dipole magnet (1031-b) in the second group (S2) and the first rod-shaped dipole magnet (1031-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)).

[0263] The magnetic axes of the two second rod-shaped dipole magnets (1032-a to 1032-f) in the first, second, and third groups (S1, S2, S3) are oriented substantially perpendicular to the surface of the substrate (1010). The south pole of the second rod-shaped dipole magnet (1032-a) in the first group (S1), the south pole of the second rod-shaped dipole magnet (1032-e) in the second group (S2), and the south pole of the second rod-shaped dipole magnet (1032-c) in the third group (S3) point towards the substrate (1010). The north pole of the second rod-shaped dipole magnet (1032-d) in the first group (S1), the north pole of the second rod-shaped dipole magnet (1032-b) in the second group (S2), and the north pole of the second rod-shaped dipole magnet (1032-f) in the third group (S3) point towards the substrate (1010). The north pole of the first rod-shaped dipole magnet (1031-a) in the first group (S1) points to the second rod-shaped dipole magnet (1032-d) in the first group (S1), the north pole of the second rod-shaped dipole magnet (1031-b) in the second group (S2) points to the first rod-shaped dipole magnet (1032-b) in the second group (S2), and the north pole of the first rod-shaped dipole magnet (1031-c) in the third group (S3) points to the second rod-shaped dipole magnet (1032-f) in the third group (S3). The south pole of the third rod-shaped dipole magnet (1033-a) of the first pair (P1) points towards the second rod-shaped dipole magnet (1032-a) of the first group (S1), and the south pole of the second rod-shaped dipole magnet (1032-a) points towards the substrate (1010); the south pole of the third rod-shaped dipole magnet (1033-d) of the second pair (P1) points towards the second rod-shaped dipole magnet (1032-e) of the second group (S2), and the south pole of the second rod-shaped dipole magnet (1032-e) points towards the substrate (1010); the north pole of the third rod-shaped dipole magnet (1033-b) of the first pair (P1) points towards the second rod-shaped dipole magnet (1032-d) of the first group (S1).The north pole of the second rod-shaped dipole magnet (1032-d) points toward the substrate (1010); and the north pole of the third rod-shaped dipole magnet (1033-c) of the second pair (P2) points toward the second rod-shaped dipole magnet (1032-b) of the second group (S2), the north pole of the second rod-shaped dipole magnet (1032-b) pointing toward the substrate (1010). Instruction manual, pages 40 / 46, CN 122422063 A

[0264] The first rod-shaped dipole magnets (1031-a, 1031-b and 1031-c) of the first, second and third groups (S1, S2, S3) and the second rod-shaped dipole magnets (1032-a to 1032-f) of the first, second and third groups (S1, S2, S3) are made of NdFeB N42; the third rod-shaped dipole magnets (1033-a, 1033-b, 1033-c and 1033-d) of the first pair and the second pair (P1, P2) are made of NdFeB N48. All magnets (1031-a to 1031-c, 1032-a to 1032-f, and 1033-a to 1033-d) are embedded in a non-magnetic support substrate (not shown) made of POM with the following dimensions: 200 mm × 120 mm × 12 mm.

[0265] Magnetic assembly of FIG11

[0266] The magnetic assembly (1130) for reorienting pigment particles according to the method of the invention is shown in FIG11. The magnetic assembly (1130) includes (530'-b) when used in the second step b'-2) of FIG5A. The magnetic assembly (1130) includes a rod-shaped dipole magnet (1130-1) and a holding box (1170). The rod-shaped dipole magnet (1130-1) has a length and width of about 30 mm and a thickness of about 8.5 mm. The north-south magnetic axis of the rod-shaped dipole magnet (1130-1) is parallel to the surface of the substrate (1110), parallel to its length (L1), and parallel to the machine feed direction (shown by the arrow in Figure 11). The rod-shaped dipole magnet (1130-b1) is made of NdFeB BMnPi 80 / 48.

[0267] The retaining box (1170) is made of a hollow top and bottom cover with curved surfaces. The hollow top has a length of about 40 mm, a width of about 40 mm, and 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, and a thickness of about 3 mm.It is made of POM. The curved surface is suitable for matching the surface of a rotating magnetic cylinder of an industrial printing press. The hollow top is suitable for receiving a rod-shaped dipole magnet (1130-1).

[0268] The distance (h) between the top surface of the rod-shaped dipole magnet (1130-1) and the bottom surface of the substrate (1110) is about 3.35 mm.

[0269] Magnetic assembly of FIG12

[0270] The magnetic assembly (1230) is a rotating magnet similar to the assembly disclosed in FIG1 of WO 2018 / 151547 A1. When used in step b'') of FIG8A, the magnetic assembly (1230) includes (830'') and when used in step b'') of FIG9, the magnetic assembly (1230) includes (930''). The magnetic assembly (1230) comprises:

[0271] i) a retainer (1a) made of aluminum (external dimensions: 60mm × 40mm × 25mm), which includes a rectangular recess (40mm × 40mm × 12.5mm) for receiving the “H”-shaped housing (4) and the cover (8), and a square cavity (36.5mm × 36.5mm × 6mm) for receiving the magnetic field guided stator core (1c);

[0272] ii) the magnetic field guided stator core (1c) (36mm × 36mm × 5mm; see details in Figures 3A-B of WO 2018 / 151547 A1), which is milled from pure iron (Armco) and insulated with a layer of polyurethane varnish dried at 80°C for 2 hours. The magnetic field-guided stator core (1c) comprises n (n=6) annular winding slots (outer diameter = 10mm, inner diameter = 5mm, depth = 4mm) configured in a circular (diameter = 25mm) shape and a center hole for mounting purposes. N (n=6) magnetic coils (1b) of 120 turns of enameled 0.20mm self-adhesive copper wire (POLYSOL 155 1 ​​x 02 MM HG from Distrerec AG) are wound and fixed to a self-standing state by hot air treatment at 250°C for approximately two minutes, and inserted into the n (n=6) winding slots. The magnetic coils (1b) are wired together to form a three-phase Y-scheme stator winding (u, v, w, u', v, w'), where every two opposing magnetic coils (u, u'), (v, v'), and (w, w') are electrically connected together to produce the same magnetic polarity at radially opposite positions. The stator winding is connected to the aforementioned motor driver via four wires (U, V, W, GND);

[0273] iii) a sensorless BLDC motor driver (DRV11873EVM, from Texas Instruments) operating at 12V DC power;

[0274] iv) a winding protection plate (7) (36mm × 36mm × 0.5mm) made of titanium, which includes a central mounting hole (10mm diameter) and is disposed on top of the magnetic field guided stator core (1c).Thus protecting the magnetic coil (1b) and the magnetic field guiding stator core, page 41 / 46 of the specification, 45 CN 122422063 A (1c);

[0275] v) a single “H”-shaped housing (4) made of titanium and having four corner posts (height = 12.5 mm, width = 10 mm) (see Figures 4A-B of WO 2018 / 151547 A1) (30 mm × 30 mm × 12.5 mm). The “H”-shaped housing (4) contains a first cavity and a second cavity defined by a horizontal intermediate plate, which is 2 mm thick and located 7 mm from the top surface of the “H”-shaped housing (4) and 3.5 mm from the bottom surface of the “H”-shaped housing (4). The “H”-shaped housing (4) includes a central circular hole (diameter = 10 mm) for receiving a ceramic ball bearing (3c) (outer diameter = 10 mm, inner diameter = 5 mm, height = 3 mm) fixed in the hole with epoxy resin;

[0276] vi) a rotor protection plate (2) (30 mm × 30 mm × 0.5 mm) made of titanium for closing the first cavity of the “H”-shaped housing (4);

[0277] vii) a rotor disk (3b) (see Figures 2A-B of WO 2018 / 151547 A1) (diameter = 30 mm, thickness 2 mm), which is made of iron (Armco) and includes a central hub or protrusion with M3 threaded holes (as shown in Figure 2A of WO 2018 / 151547 A1) on its upper surface; the rotor disk (3b) includes m (m = 8) cavities (diameter = 7 mm, depth = 1.2 mm) on its lower surface. Among them, m (m=8) permanent magnet poles (NdFeB N45 disk-shaped axially magnetized dipole magnets (3a) (diameter=6mm, thickness=1mm)) are glued together in an alternating north and south pole manner to produce the eight-pole circular lower surface of the rotor disk (3b). The rotor disk (3b) is inserted into the first cavity of the “H”-shaped housing (4) in such a way that the hub or protrusion protrudes through the ceramic ball bearing (3c);

[0278] viii) a disc magnet support (6) (diameter = 30 mm, thickness = 2 mm) with a 3 mm mounting hole, which is made of aluminum and fixed to the hub or protrusion of the rotor disk (3b) with M3 screws;

[0279] ix) a permanent magnet assembly (5), which is a radially magnetized NdFeB N40 disc dipole magnet (diameter = 25 mm, thickness = 2 mm), and glued to the disc magnet support (6); and

[0280] x) a cover (8) (40 mm × 40 mm × 15 mm) made of PPS (polyphenylene sulfide),It is fitted into the rectangular recess of the retainer (A) and includes a recess (30mm × 30mm × 13mm) to accommodate the “H”-shaped housing (4).

[0281] The magnetic gap (G) given by the distance between the top surface of the stator (1b+1c), i.e. the top surface of the magnetically guided stator core (1c), and the lowest surface of the rotor is about 2.0mm, including the combined thickness (2 × 0.5mm) of the notable winding protection plate (7) and the titanium protection plate (2) and the free air gap of about 1mm between the lower surface of the rotor and the upper surface of the rotor protection plate (2).

[0282] During the orientation step, the permanent magnet assembly (5) is used at a rotational speed of about 200 rpm for about 2 seconds.

[0283] The distance between the top surface of the permanent magnet assembly (5) and the bottom surface of the substrate (1210) is about 3mm.

[0284] Magnetic assembly of FIG13

[0285] The magnetic assembly (1330) is a rotating magnet similar to the assembly disclosed in FIG1 of WO 2018 / 151547 A1. When used in step b'') of FIG8A, the magnetic assembly (1330) includes (830'') and when used in step b'') of FIG9, the magnetic assembly (1330) includes (930''). Except that the permanent magnet assembly (5) comprises a radially magnetized annular dipole magnet (5-1) made of NdFeB N40 and having an outer diameter of about 25 mm, an inner diameter of about 14 mm and a thickness of about 2 mm, and a radially magnetized disk dipole magnet (5-2) made of NdFeB N40 and having a diameter of about 25 mm and a thickness of about 2 mm, the magnetic assembly (1330) is the same as the magnetic assembly (1230) shown in FIG12. The annular dipole magnet (5-1) is directly disposed on top of the disk dipole magnet (5-2) and centered with the disk dipole magnet (5-1). During the alignment step, the assembly (1330) is used at a rotation rate of about 200 rpm for about 2 seconds.

[0286] The distance between the top surface of the annular dipole magnet (5-1) and the top surface of the substrate (1310) is about 4.5 mm.

[0287] Table 2A Specification 42 / 46 pages 46 CN 122422063 A

[0288]

[0289] Table 2B

[0290] The OEL shown in Table 2, i.e., the combination of the first pattern, the second pattern and the third pattern when present, has the following dimensions: a length of about 25 mm and a height of about 20 mm.

[0291] When viewed from the side of the substrate bearing the first and second coatings, the OEL of Example E1 provides a highly reflective image of a turtle with a dynamic effect in the form of a rolling bar, which is particularly visible in the head and leg areas of the turtle when the substrate is tilted about a horizontal axis.The dynamic effect moves in the vertical direction.

[0292] When viewed from the side of the substrate bearing the first and second coatings, the OEL of Examples E2-E3 provides a highly reflective image of a turtle with a dynamic effect in the form of a rolling bar, which is particularly visible in the head and leg regions of the turtle, and the particularly highly reflective shell region of the turtle has a scintillation dynamic effect. When the substrate is tilted about a horizontal axis, the dynamic and brightening effects move in the vertical direction, while when the substrate is tilted about the same horizontal axis, the scintillation dynamic effect moves across the shell of the turtle.

[0293] The OEL of Examples E1-E3 is the same when viewed from the right page side (front side) and the left page side (back side) of the substrate, although there is less reflection and brightness when viewed from the left page side.

[0294] When viewed from the side of the substrate bearing the first and second coatings and from the side of the substrate bearing the third coating, the OEL of Examples E4-E5 provides a highly reflective image of a turtle with a dynamic effect in the form of a rolling bar, which is particularly visible in the head and leg regions of the turtle, and the particularly highly reflective shell region of the turtle has a scintillation dynamic effect. When the substrate is tilted about a horizontal axis, the dynamic and brightening effects move vertically, while when the substrate is tilted about the same horizontal axis, the shimmering point dynamic effect moves across the turtle's shell. The OELs of Examples E4-E5 exhibit a gold-to-green color progression effect when viewed from the right side of the substrate in both front and side views; when viewed from the left side, the OELs of Examples E4-E5 exhibit a gold-to-green color progression effect in the head and leg areas of the turtle, and primarily a green-to-blue color progression effect in the shell area of ​​the turtle.

[0295] The following items also form part of this disclosure:

[0296] 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 with a magnetic orientation according to a first magnetic pattern orientation, and the second pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a second magnetic pattern orientation,

[0297] the method comprising:

[0298] a first set of steps comprising:

[0299] a') applying a first radiation-curable coating composition, preferably a first UV-Vis curable coating composition 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,

[0300] b') exposing the first radiation-curable coating composition of step a') to a magnetic field of a magnetic component (x30'),To magnetically orient at least a portion of the sheet-like magnetic or magnetizable pigment particles;

[0301] c') Curing at least partially the first 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

[0302] A second set of steps, comprising:

[0303] a'') Applying a second radiation-curable coating composition, preferably a second UV-Vis curable coating composition, containing sheet-like magnetic or magnetizable pigment particles to form a second coating (x20''), 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');

[0304] b'') Exposing the second radiation-curable coating composition of step a'') to the magnetic field of the magnetic component (x30''). To 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) their XY plane is parallel to the surface of an imaginary sphere;

[0305] c'') the second 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. Specification 44 / 46 pages 48 CN 122422063 A

[0306] Item 2. The method according to item 1, wherein step b') is a one-step orientation step or a two-step orientation step including a first orientation step of biaxially oriented sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles.

[0307] Item 3. The method according to Item 2, wherein step b') is a two-step orientation step comprising a first orientation step of biaxially oriented sheet-like magnetic or magnetizable pigment particles, followed by a second orientation step of reorienting the sheet-like magnetic or magnetizable pigment particles.

[0308] Item 4. The method according to any one of Items 1 to 3, wherein the first orientation step of the two-step orientation step b') is performed to 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.

[0309] Item 5. The method according to any one of Items 1 to 4,The first radiation-curable coating composition and the second radiation-curable coating composition exhibit the same color.

[0310] Item 6. The method according to any one of items 1 to 4, wherein the first radiation-curable coating composition and the second radiation-curable coating composition exhibit different colors.

[0311] Item 7. The method according to any one of items 1 to 6, 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.

[0312] Item 8. The method according to any one of items 1 to 7, wherein steps c') and b') are performed simultaneously and / or steps c'') and b'') are performed simultaneously.

[0313] Item 9. The method according to any one of items 1 to 8, 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.

[0314] Item 10. The method according to any one of items 1 to 9, 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.

[0315] Item 11. The method according to any one of items 1 to 10, 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.

[0316] Item 12. The method according to item 11, wherein the substrate (x10) is a transparent substrate.

[0317] Item 13. The method according to any one of Items 1 to 12, wherein the optical effect layer (OEL) comprises a first pattern, a second pattern and a third pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a first magnetic pattern orientation, the second pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a second magnetic pattern orientation, the third pattern comprising sheet-like magnetic or magnetizable pigment particles with a magnetic orientation according to a third magnetic pattern orientation, the method further comprising a third set of steps including the following:

[0318] a''') applying a third radiation-curable coating composition comprising sheet-like magnetic or magnetizable pigment particles, preferably a third UV-Vis curable coating composition, to a side of a substrate (x10) that does not contain the first coating (x20') and does not contain the second coating (x20''), the coating composition being in a first state,And at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or, as per specification page 45 / 46, page 49, CN 122422063 A

[0319] a''') applies a third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, to the side of the substrate (x10) containing the first coating (x20') in a cured state and excluding the second coating (x20''), to form a third coating (x20'''), the coating composition being in a first state, and at least a portion of the third coating (x20''') being adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or

[0320] a A third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to a side of a substrate (x10) containing a second coating (x20'') in a cured state and excluding a first coating (x20'), to form a third coating (x20'''), wherein the coating composition is in a first state, and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or

[0321] a b) Applying a third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles to one side of a substrate (x10) comprising a first coating (x20') and a second coating (x20'') in a cured state to form a third coating (x20'''), wherein the coating composition is in a first state and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20'');

[0322] b) Exposing the third radiation-curable coating composition of step a) to the magnetic field of the magnetic component (x30''') to cause at least a portion of the flake-like magnetic or magnetizable pigment particles to be biaxially oriented; and

[0323] c''') The second 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 third pattern.

[0324] Item 14. The method according to any one of items 1 to 15, wherein the substrate (x10) comprises a printed pattern, preferably an offset printed pattern,And at least one of the radiation-curable coating compositions of steps a') and a'') is applied at least partially to the printed pattern.

[0325] 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, pages 46 / 46, 50 CN 122422063 A, Figure 1, Figure 2, Figure 3A, Figure 3B; Instruction manual drawings, pages 1 / 7, 51 CN 122422063 A, Figure 3C, Figure 4A, Figure 4B, Figure 5A; Instruction manual drawings, pages 2 / 7, 52 CN 122422063 A, Figure 5B, Figure 6A, Figure 6B, Figure 7A; Instruction manual drawings, pages 3 / 7, 53 CN 122422063 A, Figure 7B, Figure 7C, Figure 8A, Figure 8B; Instruction manual drawings, pages 4 / 7, 54 CN 122422063 A, Figure 8C, Figure 9, Figure 10; Instruction manual drawings, pages 5 / 7, 55 CN 122422063 A, Figure 11, Figure 12; Instruction manual drawings, pages 6 / 7, 56 CN 122422063 A, Figure 13; Instruction manual drawings, pages 7 / 7, 57 CN 122422063 A.

Claims

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 magnetically oriented according to a first magnetic pattern, and the second pattern comprising sheet-like magnetic or magnetizable pigment particles magnetically oriented according to a 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, containing 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 first radiation-curable coating composition of step a') to the 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 first 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'') A second radiation-curable coating composition, preferably a second UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is registered and applied to form a second coating (x20''), 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'') Expose the second radiation-curable coating composition of step a'') to the magnetic field of the magnetic component (x30'') to cause at least a portion of the sheet-like magnetic or magnetizable pigment particles to be biaxially oriented such that i) both their X-axis and Y-axis are substantially parallel to the surface of the substrate (x10), or ii) their XY plane is parallel to the surface of an imaginary sphere. c'') The second 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 graphics are superimposed.

2. The method of claim 1, wherein step b') is a one-step orientation step 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.

3. The method of claim 2, wherein step b') 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.

4. The method according to any one of claims 1 to 3, wherein the first orientation step of the two-step orientation step b') is performed to 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.

5. The method according to any one of claims 1 to 4, wherein the first radiation-curable coating composition and the second radiation-curable coating composition exhibit the same color.

6. The method according to any one of claims 1 to 4, wherein the first radiation-curable coating composition and the second radiation-curable coating composition exhibit different colors.

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

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 of claim 9, wherein the substrate (x10) is a transparent substrate.

11. The method according to any one of claims 1 to 10, wherein the optical effect layer (OEL) comprises a first pattern, a second pattern, and a third pattern, the first pattern comprising sheet-like magnetic or magnetizable pigment particles magnetically oriented according to a first magnetic pattern orientation, the second pattern comprising sheet-like magnetic or magnetizable pigment particles magnetically oriented according to a second magnetic pattern orientation, the third pattern comprising sheet-like magnetic or magnetizable pigment particles magnetically oriented according to a third magnetic pattern orientation, the method further comprising a third set of steps including: a''') A third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to a side of a substrate (x10) that does not contain a first coating (x20') and does not contain a second coating (x20'') to form a third coating (x20'''), wherein the coating composition is in a first state, and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or a''') A third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to a side of a substrate (x10) containing a first coating (x20') in a cured state and excluding a second coating (x20''), to form a third coating (x20'''), wherein the coating composition is in a first state, and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or a''') A third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to a side of a substrate (x10) containing a second coating (x20'') in a cured state and excluding the first coating (x20'), to form a third coating (x20'''), wherein the coating composition is in a first state, and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''), or a''') A third radiation-curable coating composition, preferably a third UV-Vis curable coating composition, comprising flake-like magnetic or magnetizable pigment particles, is applied to one side of a substrate (x10) comprising a first coating (x20') and a second coating (x20'') in a cured state to form a third coating (x20'''), wherein the coating composition is in a first state and at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20''); b''') Expose the third radiation-curable coating composition of step a''') to the magnetic field of the magnetic component (x30''') to cause at least a portion of the sheet-like magnetic or magnetizable pigment particles to be biaxially oriented; and c''') The second 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 third pattern. Wherein, at least a portion of the third coating (x20''') is adjacent to at least a portion of the first coating (x20') and / or adjacent to at least a portion of the second coating (x20'') means that the third pattern is superimposed on the first pattern and / or the second pattern.

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, 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.

14. The method according to any one of claims 1 to 13, 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.

15. The method according to any one of claims 1 to 14, wherein step b') of the first set of steps comprises orienting at least a portion of the sheet-like magnetic or magnetizable pigment particles such that the first pattern exhibits a dynamic effect.

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