Optical effect layer containing magnetic or magnetizable pigment particles, and method for producing the optical effect layer.

Abstract

The present invention relates to the field of protection of security documents, such as banknotes and identity documents, against counterfeiting and illegal duplication. In particular, the present invention provides security documents and decorative articles with one or more optical effect layers (OEL) comprising magnetically oriented plate-like magnetic or magnetisable pigment particles in an at least partially cured coating layer (x40), and a method for producing said OEL.

Description

Detailed description of the invention

[0001] [Field of Invention]

[0001] The present invention relates to the field of optical effect layers (OELs) comprising magnetically oriented magnetic or magnetizable pigment particles. In particular, the present invention provides security documents and decorative articles comprising one or more optical effect layers (OELs), a method for producing the OELs, ​​and the use of the OELs on security documents or security articles as an anti-counterfeiting means and for decorative purposes.

[0002] [Background of the Invention]

[0002] In the art, it is known, for example in the field of security documents, that security elements can be manufactured by using inks, compositions, coatings, or layers containing oriented magnetic or magnetizable pigment particles, particularly optically tunable magnetic or magnetizable pigment particles. Coatings or layers containing oriented magnetic or magnetizable pigment particles are disclosed, for example, in U.S. Patents 2,570,856, 3,676,273, 3,791,864, 5,630,877, and 5,364,689. Coatings or layers that exhibit particularly good optical effects by containing oriented magnetic color-changing pigment particles and are useful for protecting security documents are disclosed in International Publication Nos. 2002 / 090002 and International Publication Nos. 2005 / 002866.

[0003]

[0003] For example, security features of a security document can generally be classified into "secret" security features and "public" security features. Protection by secret security features relies on the principle that such measures are difficult to detect, and detection usually requires specialized equipment and knowledge. On the other hand, "public" security features are easily detectable by human senses alone, for example, such measures can be visualized and / or detected by touch, while manufacturing and / or copying remains difficult. However, the effectiveness of public security features largely depends on how easily they can be recognized as security features.

[0004]

[0004] Magnetic or magnetizable pigment particles in printing inks or coatings enable the generation of magnetically induced images, designs, and / or patterns by applying a magnetic field of the corresponding configuration to locally orient the magnetic or magnetizable pigment particles in an unsolidified / cured (i.e., wet) coating, and then solidifying the coating. The result is a fixed and stable magnetically induced image, design, or pattern. Materials and techniques for oriented magnetic or magnetizable pigment particles in coating compositions are disclosed, for example, in U.S. Patent Nos. 2,418,479, 2,570,856, 3,791,864, German Patent Publication No. 2006848, 3,676,273, 5,364,689, 6,103,361, European Patent No. 0406667, U.S. Patent Publication No. 2002 / 0160194, U.S. Patent Publication No. 2004 / 0009309, European Patent Publication No. 0710508, International Publication No. 2002 / 009002, International Publication No. 2003 / 000801, International Publication No. 2005 / 002866, and International Publication No. 2006 / 061301. In this way, a magnetic induction pattern with high resistance to counterfeiting can be obtained. The security element in question is achieved only by utilizing both magnetic or magnetizable pigment particles or corresponding inks, and specific techniques used for printing the ink and aligning the pigments in the printing ink.

[0005]

[0005] Depending on the magnetic orientation pattern of the magnetic or magnetizable pigment particles in the optical effect layer (OEL) and the viewing direction, the OEL may exhibit light and dark areas. The optical properties of a particular zone of the OEL depend directly on the orientation of the magnetic or magnetizable pigment particles in the coating layer constituting the OEL.

[0006]

[0006] European Patent No. 2024451 discloses a coating composition comprising a volatile component (S) and a non-volatile component particularly comprising a UV-curable compound, the latter comprising an ink vehicle (I) and a magnetically oriented optically variable interference pigment (P), characterized in that the ratio of the volume of the ink vehicle (V(I)) to the volume of the pigment (V(P)) is greater than 5.0 in order to generate a magnetically induced image (i.e., an optically effective layer). European Patent No. 2024451 further discloses that the optically effective layer is thicker than d50 / 3, where d50 is the average diameter of the magnetically oriented optically variable interference pigment. In particular, European Patent No. 2024451 discloses an improved method for generating an optically effective layer by using a specific ratio of the volume of the ink vehicle (V(I)) to the volume of the pigment (V(P)) and a specific ratio between the thickness and the d50 value, compared to conventional solvent-based compositions which are considered unsuitable due to the vertical shrinkage of the printing ink layer in the drying step.

[0007]

[0007] European Patent No. 1819525 and U.S. Patent No. 8,025,952 disclose optical effect layer particles that are magnetically oriented according to a pattern known as a Venetian blind. The optical effect layer of the disclosure comprises at least one zone of magnetically oriented plate-like magnetic or magnetizable pigment particles that are parallel to each other. The magnetically oriented pigment particles have their respective magnetic axes parallel to each other and parallel to a plane, the plane not parallel to the substrate on which the particles are coated, and having substantially the same elevation angle of at least 30° with respect to the plane of the substrate.

[0008]

[0008] International Publication No. 2020 / 173693 discloses a method of authentication by an optical effect layer of a portable device, as disclosed in European Patent No. 1819525 and U.S. Patent No. 8,025,952.

[0009]

[0009] The optical effect layers disclosed in European Patent No. 1819525, U.S. Patent No. 8,025,952, and International Publication No. 2020 / 173693 are typically produced by using the coating composition disclosed in European Patent No. 2024451.

[0010]

[0010] With regard to the efficiency and degree of freedom in selecting a magnetic field generator to orient particles in a coating layer such that adjacent magnetically oriented plate-shaped magnets or magnetizable pigment particles have one or more areas that are substantially parallel to each other, there is still a need for improved methods for producing an optical effect layer (OEL) containing magnetically oriented plate-shaped magnets or magnetizable pigment particles on a substrate.

[0011] [Overview of the prefecture]

[0011] Therefore, the present invention aims to overcome the shortcomings of the prior art.

[0012]

[0012] This is achieved by providing a method for producing an optical effect layer (OEL) as described herein and the resulting optical effect layer (OEL).

[0013]

[0013] The Specified herein describes a method for generating an optical effect layer (OEL) on a substrate (x20) having a two-dimensional surface, a) A step of applying a radiation-curable coating composition, which is in a first liquid state and contains plate-shaped magnetic or magnetizable pigment particles having a principal axis X and d50 value, to the surface of a substrate (x20) to form a coating layer (x10); b) One or more areas (A, A', A) of the magnetic field of the magnetic field generator (x30) i(x10), exposing the coating layer to the magnetic field to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles, wherein a substrate (x20) having the coating layer (x10) is provided in the one or more areas (A, A', A i '), and the angle α formed between the two-dimensional surface of the substrate (x20) at the position of the particles and the tangent to the magnetic field lines in the one or more areas (A, A', A i ') is 12° or more and about 75° or less (12° ≤ |α| ≤ 75°) or 105° or more and 168° or less (105° ≤ |α| ≤ 168°), the step; c) Simultaneously with part of step b) or after step b), at least partially curing the coating layer (x10) with a curing unit (x50) to fix the position and orientation of the plate-shaped magnetic or magnetizable pigment particles in the coating layer (x10), and generating at least a partially cured coating layer (x40) having a thickness T, wherein the thickness T of the at least partially cured coating layer (x40) is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles, and adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have a major axis X that is substantially parallel to each other in one or more regions (x40-a, x40-b) of the at least partially cured coating layer (x40), the step; A method is described that includes.

[0014]

[0014] Further, this specification describes an optical effect layer (OEL) comprising at least a partially cured layer (x40) composed of a radiation-curable coating composition containing magnetically oriented plate-shaped magnetic or magnetizable pigment particles having a thickness T, a major axis X, and a d50 value. The thickness T of the at least partially cured coating layer (x40) is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles, and adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have a major axis X that is substantially parallel to each other in one or more regions (x40-a, x40-b) of the at least partially cured layer (x40).

[0015] In contrast to the disclosure of European Patent No. 2024451, in addition to the specific relationship (T < d50) according to the claims between the thickness of the at least partially cured coating layer (x40) (i.e., the thickness of the optical effect layer) described herein and the d50 value of the plate-shaped magnetic or magnetizable pigment particles, and the value of the specific angle α according to the claims, preferably the relationship (T < d50*(sinα)) between the thickness of the method according to the claims and the value of the angle α, by using these, regardless of the uniformity / non-uniformity of each magnetic field, a magnetic field generating device can be freely selected to generate the optical effect layer including one or more regions (x40-a, x40-b) of the at least partially cured coating layer (x40) in which adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have at least a main axis X substantially parallel to each other. Further, the present invention is advantageous for enabling the generation of an optical effect layer (OEL) with uniform pigment orientation on a wide surface.

[0016]

[0016] Hereinafter, referring to the drawings and specific embodiments, the security document or article provided with one or more optical effect layers (OELs) described herein and the method described herein for generating the OEL on a substrate (x20) will be described in more detail.

[0017] FIG. 1 is a diagram schematically showing plate-shaped magnetic or magnetizable pigment particles having main axes X and Y. FIGS. 2A to 2H are diagrams showing cross-sections of an OEL provided with one or more at least partially cured coating layers (240, 241) having thicknesses T, T' and incorporating magnetically oriented plate-shaped magnetic or magnetizable pigment particles. FIG. 2A is a cross-section of an OEL provided with a single at least partially cured coating layer (240) having a thickness T and incorporating magnetically oriented plate-shaped magnetic or magnetizable pigment particles, in which substantially all plate-shaped magnetic or magnetizable pigment particles in one or more regions have substantially the same elevation angle γ and the particles have a d50 value larger than T, schematically showing the cross-section of the OEL. Figure 2B is a schematic diagram showing a cross-section of an OEL comprising a single, at least partially cured coating layer (240) having a thickness T, and containing plate-like magnetic or magnetizable pigment particles in one or more first regions (240-a) and plate-like magnetic or magnetizable pigment particles in one or more second regions (240-b), wherein substantially all plate-like magnetic or magnetizable pigment particles in one or more first regions (240-a) have substantially the same elevation angle γ, substantially all plate-like magnetic or magnetizable pigment particles in one or more second regions (240-b) have substantially the same other elevation angle γ', the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the particles have a d50 value greater than T. Figure 2C shows an OEL comprising: a first coating layer (240) having a thickness T and incorporating magnetically oriented first plate-shaped magnetic or magnetizable pigment particles, at least partially cured; and a second coating layer (241) having a thickness T' and incorporating magnetically oriented second plate-shaped magnetic or magnetizable pigment particles, wherein the second coating layer (241) at least partially overlaps the first coating layer (240), and substantially all of the particles in the first coating layer (240) This figure schematically shows a cross-section of an OEL, in which one plate-shaped magnetic or magnetizable pigment particle has substantially the same elevation angle γ, substantially all of the second plate-shaped magnetic or magnetizable pigment particles in at least a partially cured second coating layer (241) have substantially the same other elevation angle γ', the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, the first particle in at least a partially cured first coating layer (240) has a d50 value greater than T, and the second pigment particle in at least a partially cured second coating layer (241) has a d50 value greater than T'. Figure 2D shows an OEL comprising: a first coating layer (240) having a thickness T and incorporating magnetically oriented first plate-shaped magnetic or magnetizable pigment particles, at least partially cured; and a second coating layer (241) having a thickness T' and incorporating magnetically oriented second plate-shaped magnetic or magnetizable pigment particles, wherein the second coating layer (241) completely overlaps the first coating layer (240), and substantially all of the first coating layers (240) This figure schematically shows a cross-section of an OEL, in which plate-shaped magnetic or magnetizable pigment particles have substantially the same elevation angle γ, substantially all second plate-shaped magnetic or magnetizable pigment particles in at least a partially cured second coating layer (241) have substantially the same other elevation angle γ', the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, the first particles in at least a partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least a partially cured second coating layer (241) have a d50 value greater than T'. Figures 2E and 2F show an OEL comprising: a first coating layer (240) having a thickness T and incorporating magnetically oriented first plate-shaped magnetic or magnetizable pigment particles, which is at least partially cured; and a second coating layer (241) having a thickness T' and incorporating magnetically oriented second plate-shaped magnetic or magnetizable pigment particles, wherein the second coating layer (241) is at least partially cured and either adjacent to the first coating layer (240) (Figure 2E) or separated from the first coating layer (240) (Figure 2F). This figure schematically shows a cross-section of an OEL, where substantially all of the first plate-shaped magnetic or magnetizable pigment particles in the coating layer (240) have substantially the same elevation angle γ, substantially all of the second plate-shaped magnetic or magnetizable pigment particles in at least the partially cured second coating layer (241) have substantially the same other elevation angle γ', the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, the first particles in at least the partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least the partially cured second coating layer (241) have a d50 value greater than T'. Figures 2G and 2H show an OEL comprising: a first coating layer (240) having a thickness T and incorporating magnetically oriented first plate-shaped magnetic or magnetizable pigment particles, which is at least partially cured; and a second coating layer (241) having a thickness T' and incorporating magnetically oriented second plate-shaped magnetic or magnetizable pigment particles, wherein the second coating layer (241) is at least partially (Figure 2G) or completely (Figure 2H) overlapping the first coating layer (240), which is at least partially cured. This figure schematically shows a cross-section of an OEL, where substantially all of the first plate-like magnetic or magnetizable pigment particles in the first plate-like magnetic or magnetizable pigment particles have substantially the same elevation angle γ, substantially all of the second plate-like magnetic or magnetizable pigment particles in at least the partially cured second coating layer (241) have substantially the same other elevation angle γ', the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, the first particles in at least the partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least the partially cured second coating layer (241) have a d50 value greater than T'. Figures 3A, 3B, and 3D are schematic diagrams showing a cross-section of a suitable magnetic field generator (330) comprising a rod-shaped dipole magnet for orienting plate-shaped magnetic or magnetizable pigment particles in a coating layer (310) on a substrate (320), wherein the plate-shaped magnetic or magnetizable pigment particles are exposed in two areas to the magnetic field of the magnetic field generator (330) (magnetic field lines shown as arrowed lines pointing from the north pole to the south pole), and the magnetic field is substantially non-uniform (shown as A and A'). Figure 3C is a schematic diagram of a cross-section of a suitable magnetic field generator (330) comprising a single discontinuous coating layer (310) having two regions (310-a and 310-b) on a substrate (320), or a rod-shaped dipole magnet for aligning plate-shaped magnetic or magnetizable pigment particles in two coating layers (310-a and 310-b), wherein the plate-shaped magnetic or magnetizable pigment particles in the two regions (310-a and 310-b) are each exposed in one area to the magnetic field of the magnetic field generator (330) (magnetic field lines shown as arrowed lines pointing from the north pole to the south pole), and the magnetic field is substantially non-uniform (shown as A and A'). Figure 4 is a schematic diagram of a magnetic field generator (430) suitable for aligning plate-shaped magnetic or magnetizable pigment particles in a coating layer (410) on a substrate (420), comprising two rod-shaped dipole magnets (M1, M2) having the same magnetic field direction and an iron yoke (Y), wherein the plate-shaped magnetic or magnetizable pigment particles are exposed in one area to the magnetic field of the rod-shaped dipole magnets (430) (magnetic field lines shown as arrowed lines pointing from the N pole to the S pole), the magnetic field is substantially uniform (shown as a dotted rectangle A), and the substrate (420) having the coating layer (410) is provided in area A at a specific angle α. Figures 5A and 5B show the change in elevation angle γ of plate-shaped magnetic or magnetizable pigment particles that are magnetically oriented by the magnetic field of the magnetic field generator shown in Figure 3A, in at least partially cured coating layers (Examples E1, E2 and Comparative Examples C1, C2). The x-axis (mm) corresponds to the distance from the edge of the at least partially cured layer (x40), and the value of 15 mm corresponds to the center of the magnetic field generator shown in Figure 3A and the center of the at least partially cured layer (x40). Figure 6 is a schematic diagram of a magnetic field generator (630) disclosed in concurrently pending European Patent Application No. 20194060.8, the magnetic field generator (630) comprising a rod-shaped dipole magnet used for aligning plate-shaped magnetic or magnetizable pigment particles in a coating layer (610) on a substrate (620), wherein the plate-shaped magnetic or magnetizable pigment particles are exposed to the magnetic field of the magnetic field generator (630) (shown as magnetic field lines with arrows pointing from the north pole to the south pole) in one area (shown as B) where the magnetic field is substantially uniform, and the substrate (620) having the coating layer (610) is provided in the area B where the magnetic field is substantially uniform, and the angle α between the coating layer (610) and the tangent to the magnetic field lines of the magnetic field in the area B where the magnetic field is substantially uniform is about 30°. [Brief explanation of the drawing]

[0018]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 2E

Figure 2F

Figure 2G

Figure 2H

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4

Figure 5A

Figure 5B

Figure 6

[0019]

[0017] The magnetic field lines (shown as lines with arrows pointing from the north pole to the south pole) of the magnetic field generator (x30) shown in the drawing for illustrative purposes were obtained from a magnetic field simulation performed using the software Vizimag 3.19.

[0020] [Detailed explanation] (definition)

[0018] The meaning of terms used in this specification and in the claims shall be interpreted by the following definitions.

[0021]

[0019] In this specification, the term "at least one" means one or more (for example, one, two, or three).

[0022]

[0020] In this specification, the terms “about” and “substantially” mean that the quantity or value in question may be a specific value or another value in its vicinity. Generally, the terms “about” and “substantially” used to indicate a value are intended to indicate a range of ±5% of that value. For example, the expression “about 100” indicates a range of 100 ± 5, i.e., 95 to 105. Generally, when the term “about” is used, it can be expected that similar results or effects according to the present invention will be obtained within a range of ±5% of the specified value.

[0023]

[0021] The term "substantially parallel" means at least 1 mm 2 This indicates that the deviation from parallel alignment is 2° or less on the surface of the coating layer or on average across at least about 100 particles.

[0024]

[0022] In this specification, the term "and / or" means that all or just one of the elements of the group may be present. For example, "A and / or B" means "A only, 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 and not B."

[0025]

[0023] In this specification, the term “comprising” is intended to be non-exclusive and open-ended. Therefore, for example, a coating composition comprising compound A may also comprise compounds other than A. However, as a particular embodiment, the term “comprising” also encompasses the more restrictive meanings of “consisting essentially of” and “consisting of,” so for example, “a mixture comprising A, B, and optionally C” may consist (essentially) of A and B, or A, B, and C.

[0026]

[0024] In this specification, the term "optical effect layer (OEL)" refers to a coating layer comprising oriented magnetic or magnetizable pigment particles, wherein the magnetic or magnetizable pigment particles are oriented by a magnetic field, and the oriented magnetic or magnetizable pigment particles are fixed / stopped in their respective orientations and positions (i.e., after curing) to form a magnetically induced image.

[0027]

[0025] The term "coating composition" refers to any composition that can form an optical effect layer (OEL) on a solid substrate and can be suitably and non-exclusively applied by a printing method. The coating composition comprises plate-shaped magnetic or magnetizable pigment particles and a binder as described herein.

[0028]

[0026] In this specification, the term “wet” means a coating layer that is at least partially uncured (for example, a coating in which plate-like magnetic or magnetizable pigment particles can still change their position and orientation under the influence of external forces acting on them).

[0029]

[0027] The term "security document" refers to a document that is typically protected against forgery or fraud by at least one security feature. Examples of security documents include, but are not limited to, documents of value and goods of value.

[0030]

[0028] The term "security feature" is used to refer to an image, pattern, or graphic element that can be used for authentication purposes.

[0031]

[0029] When "preferred" embodiments / features are referred to in this specification, combinations of these "preferred" embodiments / features are also considered to be disclosed insofar as such combinations of "preferred" embodiments / features are technically significant.

[0032]

[0030] The present invention provides a method for producing one or more optical effect layers (OELs) and an optical effect layer (OEL) obtained therefrom, wherein the OEL comprises plate-shaped magnetic or magnetizable pigment particles on a substrate (x20) having a two-dimensional surface, and is based on magnetically oriented plate-shaped magnetic or magnetizable pigment particles incorporated into at least a partially cured coating layer (x40).

[0033]

[0031] The present invention further provides an OEL comprising at least a partially cured layer (x40) composed of a radiation-curable coating composition comprising magnetically oriented plate-shaped magnetic or magnetizable pigment particles having a thickness T and having a principal axis X and a d50 value, wherein the thickness T of the at least partially cured coating layer (x40) is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles, and adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have a principal axis X substantially parallel to each other in one or more regions (x40-a, x40-b) of the at least partially cured layer (x40).

[0034]

[0032] The present invention further provides security documents and decorative articles comprising a substrate (x20) as described herein and one or more optical effect layers (OEL) on the substrate (x20).

[0035]

[0033] Typical examples of decorative articles include, but are not limited to, luxury goods, cosmetic packaging, automotive parts, electronic / home appliances, furniture, and nail products. Alternatively, one or more OELs described herein may be provided on an auxiliary substrate, such as a label, and as a result transferred to the decorative article in a separate step.

[0036]

[0034] Examples of security documents include, but are not limited to, documents of value and goods of value. Typical examples of documents of value include banknotes, certificates, tickets, checks, vouchers, revenue stamps and tax stamps, contracts, etc., identification documents such as passports, identification cards, visas, driver's licenses, bank cards, credit cards, transaction cards, access documents or cards, admission tickets, public transport tickets, degree certificates, or deeds of title, etc. Banknotes, identification documents, documents granting rights, driver's licenses, and credit cards are preferred but are not limited to these. The term "value commercial good" refers particularly to packaging materials for items that should be protected against counterfeiting and / or illegal reproduction to guarantee the contents of the package, such as genuine medicine, including cosmetics, nutritional supplements, pharmaceuticals, alcohol, tobacco products, beverages or food products, electrical / electronic products, textiles or jewelry. Examples of these packaging materials include, but are not limited to, labels and seals such as certified brand labels and anti-fraud labels. The disclosed substrates, security documents, and decorative articles are shown solely for illustrative purposes and do not limit the scope of the present invention. Alternatively, one or more OELs described herein may be provided on an auxiliary substrate, such as a security thread, security stripe, foil, decal, window, or label, and as a result, be transferred to a security document in a separate step.

[0037]

[0035] The shapes of one or more OELs described herein may be continuous or discontinuous. According to one embodiment, the shapes of one or more OELs independently represent one or more seals, dots, and / or lines. In embodiments in which the security document and decorative article have two or more OELs, ​​i.e., two, three, etc., the OELs may be adjacent to each other, separated from each other, or partially or completely overlapping each other.

[0038]

[0036] Plate-shaped magnetic or magnetizable pigment particles are included in the radiation-curable coating composition, coating layer (x10), and at least partially cured coating layer (x40) described herein. As described herein, the method herein includes step c) at least partially curing the coating layer (x10) to a second state, so that the plate-shaped magnetic or magnetizable pigment particles are fixed in their current position and orientation and can no longer move or rotate within the layer. In this specification, “at least partially curing the coating layer (x10)” means that the plate-shaped magnetic or magnetizable pigment particles are fixed / stopped in their respective adopted position and orientation and can no longer move or rotate (also referred to in the art as “pinning” the particles).

[0039]

[0037] As described herein, one or more OELs described herein include magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least a partially cured coating layer (x40). The plate-shaped magnetic or magnetizable pigment particles described herein are preferably present in an amount of about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, the weight percentage being based on the total weight of at least the partially cured coating layer. The plate-shaped magnetic or magnetizable pigment particles described herein are preferably present in an amount of about 5% to about 40% by weight, more preferably about 10% to about 30% by weight, the weight percentage being based on the total weight of the radiation-curable coating layer described herein.

[0040]

[0038] The plate-shaped magnetic or magnetizable pigment particles described herein are non-spherical in shape and are specified to have anisotropic reflectivity to incident electromagnetic radiation in which at least a portion of the cured binder material is transparent. In this specification, the term "non-isotropic reflectivity" means that the proportion of incident radiation from a first angle reflected by the particle in a specific (viewing / observation) direction (second angle) is a function of the particle's orientation, that is, the magnitude of reflection in the viewing / observation direction may differ depending on the particle's orientation relative to the first angle. The plate-shaped magnetic or magnetizable pigment particles described herein have anisotropic reflectivity to incident electromagnetic radiation in part or all of the wavelength range, preferably about 200 to about 2500 nm, more preferably about 400 to about 700 nm, such that the reflection by the particle changes in a specific direction depending on the particle's orientation. As is known to those skilled in the art, while conventional pigment particles exhibit the same color and reflectivity regardless of particle orientation, the magnetic or magnetizable pigment particles described herein differ from conventional pigments in that they exhibit reflectivity, color, or both, determined by particle orientation. In contrast to needle-shaped pigment particles, which can be considered one-dimensional particles, plate-like pigment particles have x and y axes that define the main stretching plane of the particle (Figure 1). In other words, as shown in Figure 1, plate-like pigment particles may be considered two-dimensional particles due to their large aspect ratio, with dimensions X and Y substantially larger than dimension Z. In the art, plate-like pigment particles are also referred to as flattened particles or flakes. Such pigment particles may be described using a principal axis X corresponding to the longest dimension traversing each pigment particle, and a second principal axis Y perpendicular to X and also present within the pigment particle.

[0041]

[0039] The OEL described herein comprises magnetically oriented or plate-shaped magnetic or magnetizable pigment particles in at least a partially cured coating layer (x40) as described herein, wherein the orientation of the plate-shaped magnetic or magnetizable pigment particles is defined by a plate vector which is a vector parallel to the principal axis X of the particle, the plate vectors of adjacent plate-shaped magnetic or magnetizable pigment particles are substantially parallel to each other (see, for example, Figure 2A), and the plate vectors of the plate-shaped magnetic or magnetizable pigment particles have an elevation angle γ as described herein with respect to the two-dimensional surface of the substrate (x20) at the position of the particle.

[0042]

[0040] As described herein, the plate-shaped magnetic or magnetizable pigment particles in at least the partially cured coating layer (x40) are oriented at the elevation angle γ described herein. In other words, the elevation angle is the angle between the principal axis X of the plate-shaped magnetic or magnetizable pigment particles and the two-dimensional surface of the substrate (x20).

[0043]

[0041] In the embodiment where the plate-shaped magnetic or magnetizable pigment particles are uniaxially oriented, the orientation of the plate-shaped pigment particles is defined by a plate vector, which is a vector parallel to the principal axis X of the particle, and the plate vectors of adjacent plate-shaped magnetic or magnetizable pigment particles are substantially parallel to each other. That is, only the principal axes X of adjacent plate-shaped magnetic or magnetizable pigment particles are substantially parallel to each other (in other words, adjacent plate-shaped magnetic or magnetizable pigment particles have substantially the same elevation angle γ).

[0044]

[0042] In the embodiment in which the plate-shaped magnetic or magnetizable pigment particles are biaxially oriented, the orientation of the plate-shaped pigment particles is defined by a plate vector, which is a vector parallel to the principal axis X of the particle, and the plate vectors of adjacent plate-shaped magnetic or magnetizable pigment particles are parallel to each other. The orientation of the plate-shaped pigment particles is further defined by a second plate vector, which is a vector parallel to the second axis Y of the particle, and the plate vectors of adjacent plate-shaped magnetic or magnetizable pigment particles are parallel to each other, and the second plate vectors of the adjacent plate-shaped magnetic or magnetizable pigment particles are parallel to each other.

[0045]

[0043] Preferred examples of plate-shaped magnetic or magnetizable pigment particles described herein include, but are not limited to, magnetic metals selected from the group consisting of cobalt (Co), iron (Fe), and nickel (Ni), magnetic alloys of iron, manganese, cobalt, nickel, or mixtures of two or more thereof, magnetic oxides of chromium, manganese, cobalt, iron, nickel, or mixtures of two or more thereof, or pigment particles containing mixtures of two or more thereof. The term "magnetic" in relation to metals, alloys, and oxides applies to ferromagnetic or ferrimagnetic metals, alloys, and oxides. Magnetic oxides of chromium, manganese, cobalt, iron, nickel, or mixtures of two or more thereof may be pure or mixed oxides. Examples of magnetic oxides include hematite (Fe2O3), magnetite (Fe3O4), chromium dioxide (CrO2), magnetic ferrite (MFe2O4), magnetic spinel (MR2O4), magnetic hexaferrite (MFe 12 O 19 Examples include iron oxides such as magnetic orthoferrite (RFeO3) and magnetic garnet (M3R2(AO4)3), but are not limited to these. Here, M represents a divalent metal, R represents a trivalent metal, and A represents a tetravalent metal.

[0046]

[0044] Examples of plate-shaped magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles comprising a magnetic layer M composed of one or more magnetic metals such as cobalt (Co), iron (Fe), or nickel (Ni), and magnetic alloys of iron, cobalt, or nickel. The magnetic or magnetizable pigment particles may also have a multilayer structure comprising one or more other layers. One or more other layers are preferably one or more materials selected from the group consisting of metallic fluorides such as magnesium fluoride (MgF2), silicon oxide (SiO), silicon dioxide (SiO2), titanium oxide (TiO2), and aluminum oxide (Al2O3), more preferably layer A independently composed of silicon dioxide (SiO2), metals and metal alloys, preferably reflective metals and reflective metal alloys, more preferably one or more materials selected from the group consisting of aluminum (Al), chromium (Cr), and nickel (Ni), even more preferably layer B independently composed of aluminum (Al), or a combination of one or more layers A as described above and one or more layers B as described above. Common examples of plate-shaped magnetic or magnetizable pigment particles having the multilayer structure described above include, but are not limited to, A / M multilayer structures, A / M / A multilayer structures, A / M / B multilayer structures, A / B / M / A multilayer structures, A / B / M / B multilayer structures, A / B / M / B / A multilayer structures, B / M multilayer structures, B / M / B multilayer structures, B / A / M / A multilayer structures, B / A / M / B multilayer structures, B / A / M / B / A multilayer structures, and B / A / B / M / B / B / A / B multilayer structures. Here, layer A, magnetic layer M, and layer B are selected from the layers described above.

[0047]

[0045] According to one embodiment, it is preferable that at least a portion of the plate-shaped magnet or magnetizable particles is composed of plate-shaped optically variable magnet or magnetizable pigment particles. Optically variable pigments represent pigments that exhibit a change in brightness or a combination of a change in brightness and a change in hue with a change in viewing angle. According to one embodiment, at least a portion of the plate-shaped magnet or magnetizable particles is composed of particles exhibiting a metallic color, more preferably silver or gold.

[0048]

[0046] The open security provided by the color-changing properties of optically tunable magnetism or magnetizable pigment particles allows articles or security documents having an ink, coating composition, or coating layer containing the optically tunable magnetism or magnetizable pigment particles described herein to be easily detected, recognized, and / or distinguished from possible counterfeits by human senses alone. In addition, the optical properties of the optically tunable magnetism or magnetizable pigment particles may be used as a machine-readable tool for OEL recognition. Therefore, in an authentication process that analyzes the optical (e.g., spectral) properties of pigment particles, the optical properties of the optically tunable magnetism or magnetizable pigment particles may be used simultaneously as a confidential or semi-confidential security feature to improve resistance to counterfeiting.

[0049]

[0047] Using plate-shaped optically variable magnets or magnetizable pigment particles in the OEL enhances the significance of the OEL as a security feature in security document applications. This is because such materials are intended for the security document printing industry and are not generally available on the market.

[0050]

[0048] The plate-shaped magnetic or magnetizable pigment particles are more preferably selected from the group consisting of magnetic thin-film interference pigment particles, magnetic cholesteric liquid crystal pigment particles, interference-coated magnetic pigment particles, and mixtures of two or more of these.

[0051]

[0049] Magnetic thin-film interference pigment particles are known to those skilled in the art and are disclosed, for example, in U.S. Patent No. 4,838,648, International Publication No. 2002 / 073250, European Patent No. 0686675, International Publication No. 2003 / 000801, U.S. Patent No. 6,838,166, International Publication No. 2007 / 131833, European Patent No. 2402401, International Publication No. 2019 / 103937, International Publication No. 2020 / 006286, and the references thereof. Magnetic thin-film interference pigment particles preferably include pigment particles having a 5-layer Fabry-Perot multilayer structure, pigment particles having a 6-layer Fabry-Perot multilayer structure, pigment particles having a 7-layer Fabry-Perot multilayer structure, and / or pigment particles having a multilayer structure combining one or more multilayer Fabry-Perot structures.

[0052]

[0050] A preferred five-layer Fabry-Perot multilayer structure consists of a multilayer structure of absorber / dielectric / reflector / dielectric / absorber, where the reflector and / or absorber is also a magnetic layer, and preferably the reflector and / or absorber is a magnetic layer containing nickel, iron and / or cobalt, a magnetic alloy containing nickel, iron and / or cobalt, and / or a magnetic oxide containing nickel (Ni), iron (Fe), and / or cobalt (Co). Alternatively, a preferred five-layer Fabry-Perot multilayer structure consists of a multilayer structure of dielectric / reflector / magnetic material / reflector / dielectric, and preferably the magnetic layer contains nickel, iron and / or cobalt, a magnetic alloy containing nickel, iron and / or cobalt, and / or a magnetic oxide containing nickel (Ni), iron (Fe), and / or cobalt (Co).

[0053]

[0051] A preferred 6-layer Fabry-Perot multilayer structure consists of a multilayer structure of absorber / dielectric / reflector / magnetic / dielectric / absorber.

[0054]

[0052] A preferred seven-layer Fabry-Perot multilayer structure consists of an absorber / dielectric / reflector / magnetic / reflector / dielectric / absorber multilayer structure, as disclosed in U.S. Patent No. 4,838,648.

[0055]

[0053] Preferred pigment particles having a multilayer structure combining one or more Fabry-Perot structures are described in International Publication No. 2019 / 103937, which consist of a combination of at least two Fabry-Perot structures independently comprising a reflector layer, a dielectric layer, and an absorber layer, wherein each reflector and / or absorber layer may independently contain one or more magnetic materials, and / or the magnetic layer is sandwiched between the two structures. International Publication No. 2020 / 006 / 286 and European Patent Application Publication No. 3587500 disclose even more preferred pigment particles having a multilayer structure.

[0056]

[0054] The reflector layer described herein is 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 alloys thereof, and even more preferably composed independently of one or more materials selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), and alloys thereof, and most preferably aluminum (Al). The dielectric layer is preferably composed of one or more materials selected from the group consisting of magnesium fluoride (MgF2), aluminum fluoride (AlF3), cerium fluoride (CeF3), lanthanum fluoride (LaF3), sodium aluminum fluoride (e.g., Na3AlF6), neodymium fluoride (NdF3), samarium fluoride (SmF3), barium fluoride (BaF2), calcium fluoride (CaF2), lithium fluoride (LiF), and metal oxides such as silicon oxide (SiO2), silicon dioxide (SiO2), titanium oxide (TiO2), and aluminum oxide (Al2O3), more preferably magnesium fluoride (MgF2) independently. The absorber layer is preferably composed of one or more materials independently selected from the group consisting of aluminum (Al), silver (Ag), copper (Cu), palladium (Pd), platinum (Pt), titanium (Ti), vanadium (V), iron (Fe), tin (Sn), tungsten (W), molybdenum (Mo), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni), their metal oxides, metal sulfides, metal carbides, and metal alloys; more preferably selected from the group consisting of chromium (Cr), nickel (Ni), their metal oxides, and metal alloys; and even more preferably selected from the group consisting of chromium (Cr), nickel (Ni), and their metal alloys.The magnetic layer preferably contains a magnetic alloy comprising nickel (Ni), iron (Fe), and / or cobalt (Co), nickel (Ni), iron (Fe), and / or cobalt (Co), and / or a magnetic oxide comprising nickel (Ni), iron (Fe), and / or cobalt (Co). If magnetic thin-film interference pigment particles comprising a 7-layer Fabry-Perot structure are preferred, it is particularly preferred that the magnetic thin-film interference pigment particles comprise a 7-layer Fabry-Perot multilayer structure consisting of an absorber / dielectric / reflector / magnetic material / reflector / dielectric / absorber composed of a Cr / MgF2 / Al / Ni / Al / MgF2 / Cr multilayer structure.

[0057]

[0055] The magnetic thin-film interference pigment particles described herein are considered safe for human health and the environment and may be multilayer pigment particles based on, for example, a 5-layer Fabry-Perot multilayer structure, a 6-layer Fabry-Perot multilayer structure, and a 7-layer Fabry-Perot multilayer structure, wherein the pigment particles comprise one or more magnetic layers comprising a magnetic alloy with a substantially nickel-free composition including about 40% to about 90% by weight of iron, about 10% to about 50% by weight of chromium, and about 0% to about 30% by weight of aluminum. A general example of multilayer pigment particles considered safe for human health and the environment is found in European Patent No. 2402401, the entire contents of which are incorporated herein by reference.

[0058]

[0056] Suitable magnetic cholesteric liquid crystal pigment particles exhibiting optically tunable properties include, but are not limited to, magnetic single-layer cholesteric liquid crystal pigment particles and magnetic multilayer cholesteric liquid crystal pigment particles. Such pigment particles are disclosed, for example, in International Publication No. 2006 / 063926, U.S. Patent No. 6,582,781, and U.S. Patent No. 6,531,221. International Publication No. 2006 / 063926 discloses a single layer and pigment particles obtained from said single layer having specific properties such as high brightness and color change properties as well as magnetizability. The single layer and pigment particles obtained by grinding said single layer in this disclosure include three-dimensionally crosslinked cholesteric liquid crystal mixtures and magnetic nanoparticles. U.S. Patents No. 6,582,781 and U.S. Patent No. 6,410,130 describe arrangement A 1 / B / A2 discloses platelet-shaped cholesteric multilayer pigment particles. Here, A 1 and A 2 may be the same or different and each contain at least one cholesteric layer. B is an intermediate layer that absorbs all or part of the light sent from layer A 1 and A 2 and imparts magnetic properties. U.S. Patent No. 6,531,221 discloses platelet-shaped cholesteric multilayer pigment particles having an arrangement of A / B and optionally containing C. Here, A and C are absorbing layers containing pigment particles that impart magnetic properties, and B is a cholesteric layer.

[0059]

[0057] Suitable interference-coated magnetic pigment particles containing one or more magnetic materials include, but are not limited to, structures composed of a substrate selected from the group consisting of a core coated with one or more layers. Here, at least one of the core or one or more layers is magnetic. For example, suitable interference-coated pigment particles are cores composed of a magnetic material as described above, coated with one or more layers composed of one or more metal oxides, and include the core, or have a structure composed of a core composed of synthetic or natural mica, layered silicates (e.g., talc, kaolin, and sericite), glass (e.g., borosilicate), silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium oxide (TiO2), graphite, and mixtures of two or more of these. Further, one or more other layers such as a coloring layer may be present.

[0060]

[0058] The platelet-shaped magnetic or magnetizable pigment particles described herein may be surface-treated for protection against any deterioration that may occur in the coating composition and coating layer and / or to facilitate incorporation into the coating composition and coating layer, and usually, corrosion inhibitors and / or wetting agents may be used.

[0061]

[0059] The methods described herein include a) applying a radiation-curable coating composition comprising plate-shaped magnetic or magnetizable pigment particles as described herein to the surface of a substrate (x20) as described herein, wherein the radiation-curable coating composition is in a first liquid state that allows application as a coating layer (x10), and is at least partially uncured (i.e., wet) in which the pigment particles are movable and rotatable within the layer. The radiation-curable coating composition described herein, since it is provided on the surface of the substrate (x20), comprises at least a binder material and magnetic or magnetizable pigment particles, and is in a form that allows processing on a desired printing or coating equipment. Step a) is preferably performed by a printing process selected from the group consisting of screen printing, gravure printing, and flexographic printing, more preferably by a printing process selected from the group consisting of screen printing and flexographic printing, and even more preferably by flexographic printing.

[0062]

[0060] Depending on the printing process selected for the manufacture of one or more OELs described herein, a suitable viscosity value of the radiation-curable coating composition containing plate-shaped magnetic or magnetizable pigment particles is used. Screen printing inks have a viscosity of about 50 mPa·s to about 3000 mPa·s at 25°C, flexographic inks have a viscosity of about 50 mPa·s to about 2000 mPa·s at 25°C, and gravure inks have a viscosity of about 50 mPa·s to about 1000 mPa·s at 25°C. Viscosity measurements of security inks with viscosity values ​​from 100 mPa·s to 3000 mPa·s are performed using a Brookfield viscometer (model "RVDV-I Prime"). The spindle and rotation speed (rpm) are adjusted according to the viscosity range, with spindle 21 at 100 rpm for viscosity values ​​from 100 to 500 mPa·s, spindle 27 at 100 rpm for viscosity values ​​from 500 mPa·s to 2500 mPa·s, and spindle 27 at 50 rpm for viscosity values ​​from 2500 mPa·s to 3000 mPa·s. Viscosity measurements of security inks with viscosity values ​​from 10 mPa·s to 100 mPa·s are performed at 25°C and 1000 s. -1It is carried out by a TA Instruments rotational viscometer DHR-2 with a conical surface shape and a diameter of 40 mm.

[0063]

[0061] The method described in this specification is: b) in one or more areas (A, A', A i ’) of the magnetic field of the magnetic field generating device (x30) described in this specification, further including the step of orienting at least a part of the plate-shaped magnetic or magnetizable pigment particles by exposing the coating layer (x10) to the magnetic field. In step b) described in this specification, the substrate (x20) having the coating layer (x10) is provided in the one or more areas (A, A', A i ’ (i corresponds to 2, 3, 4, etc.)), and the angle α formed by the tangent of the magnetic field lines of the magnetic field in the one or more areas and the two-dimensional surface of the substrate (x20) at the position of the particles is 12° or more and 75° or less (12° ≤ |α| ≤ 75°) or 105° or more and 168° or less (105° ≤ |α| ≤ 168°).

[0064]

[0062] In addition to the requirement that the thickness T of the at least partially cured coating layer (x40) is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles (T < d50), the thickness T of the at least partially cured coating layer (x40) is preferably smaller than d50 * sin(α) (T < d50 * (sinα)).

[0065]

[0063] According to one embodiment, the orientation of the plate-shaped magnetic or magnetizable pigment particles and the elevation angle γ of the particles in the at least partially cured coating layer (x40) are obtained by exposing the plate-shaped magnetic or magnetizable pigment particles to the magnetic field of the magnetic field generating device (x30) described in this specification in one or more areas (shown as areas A and A' in FIGS. 3A to 3D), and this magnetic field is substantially non-uniform (that is, the magnetic field does not have a substantially constant magnitude and direction throughout the (one or more) areas of interest (in the case of uniaxial orientation)), or is not substantially confined to a plane (in the case of biaxial orientation), and the angle α is the two-dimensional surface of the substrate (x20) at the position of the particles and one or more areas (A, A', A iThe angle α is between 12° and 75° (12°≦|α|≦75°) or between 105° and 168° (105°≦|α|≦168°). If plate-shaped magnets or magnetizable pigment particles are exposed to the magnetic field of a magnetic field generator (x30) in two or more areas (for example, two areas shown in Figures 3A and 3C), two angles α and α' are described, where angle α' is between 12° and 75° (12°≦|α'|≦75°) or between 105° and 168° (105°≦|α'|≦168°), and α' is different from α, preferably α' and α differ by at least 30°. In one embodiment in which plate-shaped magnetic or magnetizable pigment particles are exposed to the magnetic field of a magnetic field generator (x30) in two or more areas (for example, two areas shown in Figures 3A and 3C), the substrate (x20) having a coating layer (x10) is provided in the two or more areas at angles α and α', and when angle α is 12° or more and 75° or less (12°≦|α'|≦75°), angle α' is 105° or more and 168° or less (105°≦|α'|≦168°).

[0066]

[0064] The OEL obtained by exposure of plate-shaped magnetic or magnetizable pigment particles to one or more areas where the magnetic field of the magnetic field generator (x30) is substantially non-uniform is based on the premise that, in the orientation step, the magnetically oriented plate-shaped magnetic or magnetizable pigment particles have different angles α as described herein (i.e., angle α in area A is different from angle α' in area A'), but these angles are within the range of values ​​described herein. An example of a magnetic field generator suitable for oriented plate-shaped magnetic or magnetizable pigments, where the magnetic field is substantially non-uniform in one or more areas indicated as A and A', is a rod-shaped dipole magnet whose magnetic axis is substantially parallel to the surface of the substrate (x20), as shown in Figure 3 and described later. Other examples of magnetic field generators suitable for oriented plate-like magnets or magnetizable pigments, where the magnetic field is substantially non-uniform in one or more areas, are disclosed in Figures 5A, 5B, 9B-9E, 10A, and 10B of U.S. Patent No. 7,047,883, as described below. The present invention is convenient because it provides a method for producing OEL with uniform pigment orientation over a large surface, even when the exposure step is performed under a non-uniform magnetic field.

[0067]

[0065] According to one embodiment, the orientation of plate-shaped magnetic or magnetizable pigment particles and the elevation angle γ of the particles in at least a partially cured coating layer (x40) are obtained by exposing the plate-shaped magnetic or magnetizable pigment particles to the magnetic field of a magnetic field generator (x30) described herein in one or more areas (shown as area A in Figure 4), wherein the magnetic field is substantially uniform (i.e., the magnetic field has substantially constant magnitude and direction throughout the area of ​​interest (in the case of uniaxial orientation)) or substantially confined to a plane (in the case of biaxial orientation), and the angle α is between the two-dimensional surface of the substrate (x20) at the position of the particles and one or more areas (A, A', A iThe tangent to the magnetic field lines of the magnetic field within the ') is such that the angle α is 12° or more and about 75° or less (12°≦|α|≦75°) or 105° or more and 168° or less (105°≦|α|≦168°). The OEL obtained by exposure of plate-shaped magnetic or magnetizable pigment particles in one or more areas where the magnetic field of the magnetic field generator (x30) is substantially uniform is such that, in the orientation step, the magnetically oriented plate-shaped magnetic or magnetizable pigment particles have substantially the same angle α as described herein.

[0068]

[0066] Step b) described herein is performed to uniaxially or biaxially orient at least a portion of the plate-like magnetic or magnetizable pigment particles described herein. In contrast to uniaxial orientation, in which the magnetic or magnetizable pigment particles are oriented so that only their principal axes are constrained by the magnetic field, performing biaxial orientation means oriented the plate-like magnetic or magnetizable pigment particles so that two principal axes X and Y are constrained. That is, each plate-like magnetic or magnetizable pigment particle is considered to have a major axis in the plane of the pigment particle and a minor axis perpendicular to the plane of the pigment particle. The axes Y and Y of the plate-like magnetic or magnetizable pigment particles are oriented according to the magnetic field. In practice, this makes closely adjacent plate-like magnetic pigment particles in space substantially parallel to each other. In other words, biaxial orientation aligns the planes of the plate-like magnetic or magnetizable pigment particles so that their planes are oriented substantially parallel to the planes of adjacent plate-like magnetic or magnetizable pigment particles (in all directions).

[0069]

[0067] According to one embodiment, step b) is performed to uniaxially orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles described herein. There are no limitations on suitable magnetic field generators for uniaxially orienting the plate-shaped magnetic or magnetizable pigment particles described herein.

[0070]

[0068] According to one embodiment shown in Figures 3A to 3D, a suitable magnetic field generator (330) for uniaxially oriented at least a portion of plate-shaped magnetic or magnetizable pigment particles comprises a rod-shaped dipole magnet whose magnetic axis is substantially parallel to the surface of the substrate (x20). As shown in Figures 3A to 3D, the plate-shaped magnetic or magnetizable pigment particles in the coating layer (310) on the substrate (320) are exposed in one or more areas (shown as areas A and A') to the magnetic field of the magnetic field generator (330) described herein (shown as magnetic field lines indicated as arrowed lines from the north pole to the south pole), the magnetic field being substantially non-uniform, and the substrate (320) having the coating layer (310) is provided in the one or more areas at the angle α described herein.

[0071]

[0069] According to one embodiment shown in Figure 4 and used in the following embodiments, a suitable magnetic field generator (430) for uniaxially oriented at least a portion of plate-shaped magnetic or magnetizable pigment particles comprises a rectangular assembly having two rod-shaped dipole magnets (M1, M2) and two magnetic pole pieces (P1, P2). The plate-shaped magnetic or magnetizable pigment particles in the coating layer (410) on the substrate (420) are exposed to the magnetic field of the magnetic field generator (430) (indicated as lines with arrows pointing from the north pole to the south pole) in one or more areas (indicated as dotted rectangle A), wherein the magnetic field is substantially uniform, the magnetic field lines are substantially parallel to each other in the area, and the substrate (420) having the coating layer (410) is provided in the one or more areas at the angle α described herein. The magnetic field generator (430) shown in Figure 4 comprises two spaced-apart rod-shaped dipoles (M1, M2) having the same magnetic field direction and length, and two spaced-apart magnetic pole pieces (P1, P2) having the same length, arranged as a rectangular assembly. M1 faces M2 but is not adjacent to it, P1 faces P2 but is not adjacent to it, and P1 is positioned at a distance from P2 corresponding to the length of M1 / M2.

[0072]

[0070] According to another embodiment, in a suitable magnetic field generator (430) for uniaxially oriented at least a portion of plate-shaped magnetic or magnetizable pigment particles as shown in Figures 5A, 5B, 9B-9E, 10A, and 10B of U.S. Patent No. 7,047,883, the plate-shaped magnetic or magnetizable pigment particles in a coating layer on a substrate are exposed to a magnetic field of the magnetic field generator in one or more areas, the magnetic field being substantially non-uniform, and the substrate having the coating layer (410) is provided in the one or more areas at an angle α as described herein. In particular, the magnetic field generator shown in Figures 5A and 5B of U.S. Patent No. 7,047,883 comprises two spaced magnets 84 arranged on a magnetic base 62 with their north poles facing the substrate; the magnetic field generator shown in Figure 9B of U.S. Patent No. 7,047,883 comprises a magnet 140, with the pigment article positioned at an offset position relative to the magnet axis; the magnetic field generator shown in Figure 9C of U.S. Patent No. 7,047,883 comprises two magnets 142 and one magnet 142' having a rhomboid cross-section, with the two magnets 142 facing their north poles toward the substrate, while the magnet 142' between them faces its south pole toward the substrate; the magnetic field generator shown in Figure 9D of U.S. Patent No. 7,047,883 comprises two magnets The magnetic field generator, shown in Figure 9E of U.S. Patent No. 7,047,883, comprises a stone 144 and a magnet 142' having one magnet 144' having a roof-shaped, hexagonal, circular, trapezoidal, or other cross-section, wherein the two magnets 144 orient their north poles toward the substrate, while the magnet 144' between them orients its south pole toward the substrate. The magnetic field generator comprises five magnets (a first magnet 142 which is a rhomboid magnet with its north pole toward the substrate, a second magnet 146 which is a rectangular magnet with its south pole toward the substrate, a third magnet 148 which is a circular top magnet with its north pole toward the substrate, a fourth magnet 150 which is a roof-shaped magnet with its south pole toward the substrate, and a fifth magnet 152 which is also a roof-shaped magnet with its north pole toward the substrate).

[0073]

[0071] According to another embodiment, step b) is performed to cause at least a portion of the plate-shaped magnetic or magnetizable pigment particles to be biaxially oriented. In embodiments in which the method described herein includes the step of causing at least a portion of the magnetic or magnetizable pigment particles to be biaxially oriented by exposing a coating layer (x10) to the magnetic field of a magnetic field generator (x30) described herein, the coating layer (x10) may be exposed to the magnetic field generator two or more times. There are no limitations on suitable magnetic field generators for biaxially oriented plate-shaped magnetic or magnetizable pigment particles as described herein. As those skilled in the art will see, biaxial orientation of plate-shaped magnetic or magnetizable pigment particles requires a dynamic magnetic field (i.e., a time-variable / time-dependent magnetic field) that vibrates the particles until both principal axes (X-axis and Y-axis) are aligned by changing direction and / or intensity. In other words, biaxial orientation requires the non-encompassing movement of the coating layer (x10) containing the plate-shaped magnetic or magnetizable pigment particles with respect to the magnetic field generator.

[0074]

[0072] According to one embodiment shown in Figures 10A and 10B of International Publication No. 2018 / 019594, a suitable magnetic field generator (430) for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles consists of a linear arrangement of at least four magnets (M1 to M4) arranged in a staggered or zigzag pattern, provided that a substrate having a coating layer is provided in one or more areas of the magnetic field of the device at an angle α value as described herein. European Patent Application Publication No. 2157141 discloses a similar suitable magnetic field generator in Figure 5, which may be used for biaxial orientation of at least a portion of plate-shaped magnets or magnetizable pigment particles, and consists of a linear arrangement of at least three, preferably at least four, magnets arranged in a staggered or zigzag pattern.

[0075]

[0073] According to one embodiment shown in Figures 8A and 8B of International Publication No. 2018 / 019594, a suitable magnetic field generator (430) for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles comprises two dipole magnets (M1, M2) with opposite magnetic field directions, provided that a substrate having a coating layer is located in one or more areas of the magnetic field of the device at an angle α value as described herein.

[0076]

[0074] According to one embodiment shown in Figures 7A and 7B of International Publication No. 2018 / 019594, a suitable magnetic field generator (430) for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles consists of two dipole magnets (M1, M2) with the same magnetic field direction, which is premised on the fact that a substrate having a coating layer is provided in one or more areas of the magnetic field of the device at an angle α value as described herein.

[0077]

[0075] According to one embodiment shown in Figure 3A of International Publication No. 2018 / 019594, a suitable magnetic field generator (430) for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles comprises a Halbach array including five dipole magnets (M1 to M5), which is based on the premise that a substrate having a coating layer is provided in one or more areas of the magnetic field of the device at an angular α value as described herein.

[0078]

[0076] According to one embodiment shown in Figure 12A of International Publication No. 2016 / 083259, a suitable magnetic field generator for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles comprises a Halbach cylindrical assembly including four structures (M1 to M4) each having a magnetic rod surrounded by a magnetic wire coil (not shown), provided that a substrate having a coating layer is provided in one or more areas of the magnetic field of the device at an angle α value as described herein.

[0079]

[0077] According to one embodiment shown in Figure 2A of concurrently pending European Patent Application No. 20176506.2, a suitable magnetic field generator (430) for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles comprises an assembly of eight bar-shaped dipole magnets (M1-M8), including a first assembly comprising a first bar-shaped dipole magnet (M4) and two second bar-shaped dipole magnets (M1, M6), a second assembly comprising a first bar-shaped dipole magnet (M5) and two second bar-shaped dipole magnets (M3, M8), and a first pair of third bar-shaped dipole magnets (M2, M7), provided that a substrate having a coating layer is provided in one or more areas of the magnetic field of the device at an angular α value as described herein.

[0080]

[0078] According to one embodiment shown in Figures 5A1 to 5A3 of concurrently pending European Patent Application No. 20194060.8, a suitable magnetic field generator for biaxially oriented at least a portion of plate-shaped magnets or magnetizable pigment particles comprises an assembly including nine rod-shaped dipole magnets (M1 to M5) arranged in a line with alternating NS magnetic field directions, provided that a substrate having a coating layer is provided in one or more areas of the magnetic field of the device at an angle α value as described herein.

[0081]

[0079] According to one embodiment, step b) described herein comprises two magnetic orientation steps described in International Publication No. 2015 / 086257, the steps comprising: i) oriented at least a portion of the plate-shaped magnetic or magnetizable pigment particles biaxially by exposing a coating layer (x10) containing plate-shaped magnetic or magnetizable pigment particles to a dynamic magnetic field of a first magnetic field generator as described above or in International Publication No. 2015 / 086257; and ii) oriented at least a portion of the plate-shaped magnetic or magnetizable pigment particles uniaxially by exposing the coating layer (x10) to a static magnetic field of a second magnetic field generator as described herein, provided that the substrate (x20) having the coating layer (x10) is located in one or more areas of the second magnetic field of the second magnetic field generator at an angle α value described herein. If these two steps i) and ii) are performed, at least a portion of the plate-shaped magnetic or magnetizable pigment particles are oriented by using at least the second step ii) to provide the substrate (x20) having the coating layer (x10) in one or more areas as specified herein at the angle α value specified herein.

[0082]

[0080] During the magnetic orientation of the magnetic or magnetizable pigment particles described herein, the substrate (x20) having the coating layer (x10) may be disposed on a non-magnetic support plate (x40) made of one or more non-metallic materials.

[0083]

[0081] The method described herein further includes the step of fixing the position and orientation of plate-like magnetic or magnetizable pigment particles in the coating layer (x10) by curing the coating layer (x10) at least partially with a curing unit (x50) described herein, either partially simultaneously with or after step b), thereby producing a partially cured coating layer (x40) having a thickness T. "Partially simultaneously" means that parts of both steps are performed at the same time, i.e., the timing of each step partially overlaps. In the context described herein, if curing is performed partially simultaneously with the orientation step b), it should be understood that curing is effective after orientation so that the pigment particles have time to orientation before the complete or partial curing or solidification of the OEL.

[0084]

[0082] If step c) is performed after step b) as described herein, the timing between the steps is preferably about 0.1 seconds to about 1.5 seconds, more preferably about 0.1 seconds to 0.5 seconds.

[0085]

[0083] The method described herein produces an OEL as described herein, wherein adjacent magnetically oriented plate-like magnetic or magnetizable pigment particles each have substantially parallel principal axes X in at least one or more regions (x40-a, x40-b) of at least partially cured coating layers (x40).

[0086]

[0084] A suitable curing unit (x50) includes an ultraviolet-visible light curing device equipped with an arc discharge lamp such as a high-power light-emitting diode (LED) lamp or a medium-pressure mercury arc (MPMA) or metal vapor arc lamp as a chemical radiation source. The selective curing units described herein may include one or more fixed or removable photomasks containing one or more voids corresponding to a pattern formed as part of the coating layer. One or more selective curing units may be addressable, such as a chemical radiation LED source including a scanning laser beam disclosed in European Patent Application Publication No. 2468423, an array of light-emitting diodes (LEDs) disclosed in International Publication No. 2017 / 021504, or an array of individually addressable chemical radiation emitters disclosed in International Publication No. 2020 / 148076.

[0087]

[0085] Figures 2A to 2E disclose cross-sections of the OEL described herein, which comprises one or more partially cured coating layers (240, 241) having thickness (T, T', etc.) and incorporating magnetically oriented plate-shaped magnets or magnetizable pigment particles.

[0088]

[0086] For example, according to one embodiment shown in Figure 2A, the OEL described herein comprises a single, at least partially cured coating layer (210) having a thickness T and incorporating magnetically oriented plate-shaped magnetic or magnetizable pigment particles, wherein substantially all plate-shaped magnetic or magnetizable pigment particles in one or more regions have substantially the same elevation angle γ, and the pigment particles have a d50 value greater than T.

[0089]

[0087] For example, according to one embodiment shown in Figure 2B, the OEL described herein comprises independently a single at least partially cured coating layer (240) having a thickness T and containing plate-like magnetic or magnetizable pigment particles in one or more first regions (240-a) and plate-like magnetic or magnetizable pigment particles in one or more second regions (240-b), wherein substantially all plate-like magnetic or magnetizable pigment particles in one or more first regions (240-a) have substantially the same elevation angle γ, substantially all plate-like magnetic or magnetizable pigment particles in one or more second regions (240-b) have substantially the same other elevation angle γ', the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the particles have a d50 value greater than T.

[0090]

[0088] For example, according to one embodiment shown in Figures 2C to 2F, the OEL described herein independently comprises a first partially cured coating layer (240) incorporating magnetically oriented plate-shaped magnets or magnetizable pigment particles, wherein substantially all plate-shaped magnets or magnetizable pigment particles have substantially the same elevation angle γ, and further comprises a second partially cured coating layer (241) incorporating a second magnetically oriented plate-shaped magnet or magnetizable pigment particle having a thickness T', wherein substantially all plate-shaped magnets or magnetizable pigment particles have substantially the same other elevation angle γ', the elevation angle γ and the other elevation angle γ' are different from and / or non-coplanar, the pigment particles in the at least partially cured coating layer (240) have a d50 value greater than T, and the pigment particles in the at least partially cured second coating layer (241) have a d50 value greater than T'. The second coating layer (241), which is at least partially cured, at least partially or completely overlaps the second coating layer (240) (see Figures 2C and 2D), is adjacent to the second coating layer (240) (see Figure 2E), or is separated from the second coating layer (x10) (see Figure 2F).

[0091]

[0089] Figure 2C schematically shows a cross-section of an OEL comprising a first coating layer (240) having a thickness T and incorporating a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle, which is at least partially cured, and a second coating layer (241) having a thickness T' and incorporating a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle, wherein the second coating layer (241) partially overlaps the first coating layer (240), which is at least partially cured. Substantially all first plate-shaped magnetic or magnetizable pigment particles in ) have substantially the same elevation angle γ, and substantially all second plate-shaped magnetic or magnetizable pigment particles in at least a partially cured second coating layer (241) have substantially the same other elevation angle γ', and the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the first particles in at least a partially cured first coating layer (240) have a d50 value greater than T, and the second pigment particles in at least a partially cured second coating layer (241) have a d50 value greater than T'.

[0092]

[0090] Figure 2D schematically shows a cross-section of an OEL comprising a first coating layer (240) having a thickness T and incorporating a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle, at least partially cured, and a second coating layer (241) having a thickness T' and incorporating a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle, wherein the second coating layer (241) completely overlaps the first coating layer (240), and the second coating layer (241) completely overlaps the first coating layer (240). In 40), substantially all of the first plate-like magnetic or magnetizable pigment particles have substantially the same elevation angle γ, and substantially all of the second plate-like magnetic or magnetizable pigment particles in at least the partially cured second coating layer (241) have substantially the same other elevation angle γ', and the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the first particles in at least the partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least the partially cured second coating layer (241) have a d50 value greater than T'.

[0093]

[0091] Figure 2E schematically shows a cross-section of an OEL comprising a first partially cured coating layer (240) having a thickness T and incorporating a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle, and a second partially cured coating layer (241) having a thickness T' and incorporating a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle, wherein the second partially cured coating layer (241) is adjacent to the first partially cured coating layer (240) and the first partially cured coating layer (240) Substantially all first plate-shaped magnetic or magnetizable pigment particles in ) have substantially the same elevation angle γ, and substantially all second plate-shaped magnetic or magnetizable pigment particles in at least a partially cured second coating layer (241) have substantially the same other elevation angle γ', and the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the first particles in at least a partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least a partially cured second coating layer (241) have a d50 value greater than T'.

[0094]

[0092] Figure 2F schematically shows a cross-section of an OEL comprising a first partially cured coating layer (240) having a thickness T and incorporating a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle, and a second partially cured coating layer (241) having a thickness T' and incorporating a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle, wherein the second partially cured coating layer (241) is separated from the first partially cured coating layer (240), and the second partially cured coating layer (241) is separated from the first partially cured coating layer (24 In (0), substantially all of the first plate-like magnetic or magnetizable pigment particles have substantially the same elevation angle γ, and substantially all of the second plate-like magnetic or magnetizable pigment particles in at least the partially cured second coating layer (241) have substantially the same other elevation angle γ', and the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the first particles in at least the partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least the partially cured second coating layer (241) have a d50 value greater than T'.

[0095]

[0093] Figure 2G schematically shows a cross-section of an OEL comprising a first coating layer (240) having a thickness T and incorporating a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle, which is at least partially cured, and a second coating layer (241) having a thickness T' and incorporating a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle, wherein the second coating layer (241) partially overlaps the first coating layer (240), which is at least partially cured. In (0), substantially all of the first plate-like magnetic or magnetizable pigment particles have substantially the same elevation angle γ, and substantially all of the second plate-like magnetic or magnetizable pigment particles in at least the partially cured second coating layer (241) have substantially the same other elevation angle γ', and the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the first particles in at least the partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least the partially cured second coating layer (241) have a d50 value greater than T'.

[0096]

[0094] Figure 2H schematically shows a cross-section of an OEL comprising a first partially cured coating layer (240) having a thickness T and incorporating a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle, and a second partially cured coating layer (241) having a thickness T' and incorporating a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle, wherein the second partially cured coating layer (241) completely overlaps the first partially cured coating layer (240), and the second partially cured coating layer (241) completely overlaps the first partially cured coating layer (24 In (0), substantially all of the first plate-like magnetic or magnetizable pigment particles have substantially the same elevation angle γ, and substantially all of the second plate-like magnetic or magnetizable pigment particles in at least the partially cured second coating layer (241) have substantially the same other elevation angle γ', and the elevation angles γ and the other elevation angle γ' are different from and / or non-coplanar, and the first particles in at least the partially cured first coating layer (240) have a d50 value greater than T, and the second particles in at least the partially cured second coating layer (241) have a d50 value greater than T'.

[0097]

[0095] According to one embodiment, the method herein for producing one or more OELs described herein (see, for example, Figure 2A) comprising a single at least partially cured coating layer (x40) is a) A step of applying a radiation-curable coating composition, which is in a first liquid state and contains plate-shaped magnetic or magnetizable pigment particles as described herein, to the surface of a substrate (x20) as described herein, to form a coating layer (x10); b) A step of exposing the coating layer (x10) described herein to the magnetic field of a magnetic field generator (x30) described herein, wherein the substrate (x20) having the coating layer (x10) is exposed to one or more areas (A, A', A) described herein. i A step provided in '), wherein the angle α described herein is 12° or more and approximately 75° or less (12°≦|α|≦75°) or 105° or more and 168° or less (105°≦|α|≦168°), c) Partially simultaneously with or after step b), the coating layer (x10) is cured at least partially with a curing unit (x50) to fix at least a portion of the plate-shaped magnetic or magnetizable particles in their respective adopted positions and orientations, thereby generating a single at least partially cured coating layer (x40) having a thickness T smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles. Includes.

[0098]

[0096] According to another embodiment, the method herein for producing one or more OELs described herein, which are independently composed of a single at least partially cured coating layer (x40) and comprising magnetically oriented plate-shaped magnets or magnetizable pigment particles in the single at least partially cured coating layer (x40), wherein the single at least partially cured coating layer (x40) comprises one or more first regions (x40-a) and one or more second regions (x40-b) (see, for example, Figure 2B), the method, a) Applying a radiation-curable coating composition, which is in a first liquid state and comprises plate-shaped magnetic or magnetizable pigment particles as described herein, to the surface of a substrate (x20) as described herein, to form a coating layer (x10) comprising one or more first regions (x10-a) and one or more second regions (x10-b); b) A step of exposing the coating layer (x10) described herein to the magnetic field of the magnetic field generator (x30-a) described herein, wherein the substrate (x20) having the coating layer (x10) is exposed to one or more areas (A, A', A) described herein. i A step provided in '), wherein the angle α described herein is 12° or more and approximately 75° or less (12°≦|α|≦75°) or 105° or more and 168° or less (105°≦|α|≦168°), c) A step of fixing at least a portion of plate-shaped magnetic or magnetizable particles to their respective adopted positions and orientations by selectively curing at least partially one or more first regions (x10a) of a single coating layer (x10) with a curing unit (x50) at least simultaneously with or after step b), d) A step of oriented at least a portion of plate-shaped magnetic or magnetizable pigment particles in one or more second regions (x10b) by exposing a single coating layer (x10) to the magnetic field of a second magnetic field generator (x30-b), wherein the substrate (x20) is one or more of the areas (A, A', A i A is provided in ') and the two-dimensional surface of the substrate (x20) at the position of the plate-shaped magnet or magnetizable pigment particles and one or more areas (A, A', A i The angle α' that the tangent to the magnetic field lines of the second magnetic field in step ') makes with the tangent is 12° or more and 75° or less (12°≦|α'|≦75°) or 105° or more and 168° or less (105°≦|α'|≦168°), and the second magnetic field generator (x30-b) is either the same as or different from the magnetic field generator (x30-a) of step b), and α' is different from α, preferably α' and α are different by at least 30°, in step b). e) A step of generating a single at least partially cured coating layer (x40) by curing a single coating layer (x10) at least partially with a curing unit (x50) described herein, at least simultaneously with or after step d), wherein adjacent magnetically oriented plate-like magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more first regions (x40-a) of the single at least partially cured coating layer (x40), and adjacent magnetically oriented plate-like magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more second regions (x40-b) of the single at least partially cured coating layer (x40), Includes.

[0099]

[0097] According to another embodiment, the method herein for producing one or more OELs described herein, comprising a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle comprising at least partially cured first coating layer (x40) and a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle comprising at least partially cured second coating layer (x41), wherein the at least partially cured second coating layer (x41) at least partially or completely overlaps the at least partially cured first coating layer (x40) (see, for example, Figures 2C, 2D, 2G, and 2H), the method is as follows: a) A step of applying a first radiation-curable coating composition, which is in a first liquid state and comprises a first plate-shaped magnetic or magnetizable pigment particle as described herein, to the surface of a substrate (x20) as described herein, b) A step of exposing the coating layer (x10) described herein to the magnetic field of the magnetic field generator (x30-a) described herein, wherein the substrate (x20) having the first coating layer (x10) is exposed to one or more areas (A, A', A) described herein. i A step provided in '), wherein the angle α described herein is 12° or more and approximately 75° or less (12°≦|α|≦75°) or 105° or more and 168° or less (105°≦|α|≦168°), c) A step of generating a partially cured first coating layer (x40) by curing the first coating layer (x10) with a curing unit (x50) at least partially simultaneously with or after step b), thereby fixing at least a portion of the first plate-shaped magnetic or magnetizable particles to their respective adopted positions and orientations, d) A step in which, after step c), a second radiation-curable coating composition, which is in a first liquid state and contains second plate-shaped magnetic or magnetizable pigment particles, and forms a second coating layer (x11), is applied partially (Figure 2C or Figure 2G) or completely (Figure 2D or Figure 2H) to at least partially cured first coating layer (x40), wherein the second radiation-curable coating composition is the same as or different from the radiation-curable coating composition of step a), e) One or more areas (A, A', A) of the second magnetic field of the second magnetic field generator (x30-b) i The step is to orient at least a portion of the second plate-shaped magnetic or magnetizable pigment particles by exposing the second coating layer (x11) to the second magnetic field, wherein the substrate (x20) having the second coating layer (x41) is one or more of the areas (A, A', A i ') is provided, and the two-dimensional surface of the substrate (x20) at the position of the second plate-shaped magnet or magnetizable pigment particle and one or more areas (A, A', A i The angle α' that the tangent to the magnetic field lines of the second magnetic field in step ') is between 12° and 75° (12°≦|α'|≦75°) or between 105° and 168° (105°≦|α'|≦168°), and the second magnetic field generator (x30-b) is either the same as or different from the magnetic field generator in step b), and α' is different from α, preferably α' and α are different by at least 30°, in step b). f) Exposing the second coating layer (x11) to a second magnetic field, and at least partially simultaneously with or after step e), curing the second coating layer (x11) with a curing unit (x50) thereby at least partially fixing the position and orientation of the second plate-shaped magnetic or magnetizable pigment particles in the second coating layer (x11) and generating a second coating layer (x41) that is at least partially cured, wherein at least each of the adjacent magnetically oriented first plate-shaped magnetic or magnetizable pigment particles is at least partially cured. In the coating layer (x40), adjacent magnetically oriented second plate-shaped magnetic or magnetizable pigment particles having substantially parallel principal axes X are at least each, and in the at least partially cured second coating layer (x41), the magnetically oriented first plate-shaped magnetic or magnetizable pigment particles in the at least partially cured coating layer (x40) have a different elevation angle from the magnetically oriented second plate-shaped magnetic or magnetizable pigment particles in the at least partially cured second coating layer (x41), and the step, Includes.

[0100]

[0098] According to another embodiment, the method herein for producing one or more OELs described herein, comprising a first magnetically oriented plate-shaped magnetic or magnetizable pigment particle in a first partially cured coating layer (x40) and a second magnetically oriented plate-shaped magnetic or magnetizable pigment particle in a second partially cured coating layer (x41), wherein the second partially cured coating layer (x41) is adjacent to the first partially cured coating layer (x40) (see, for example, Figure 2E) or separated from the first partially cured coating layer (x40) (Figure 2F), the method is as follows: a) A step of applying a first radiation-curable coating composition, which is in a first liquid state and comprises a first plate-shaped magnetic or magnetizable pigment particle as described herein, to the surface of a substrate (x20) as described herein, b) A step of exposing the first coating layer (x10) described herein to the magnetic field of a magnetic field generator (x30) described herein, wherein the substrate (x20) having the first coating layer (x10) is exposed to one or more areas (A, A', A) described herein. i A step provided in '), wherein the angle α described herein is 12° or more and approximately 75° or less (12°≦|α|≦75°) or 105° or more and 168° or less (105°≦|α|≦168°), c) A step of generating a partially cured first coating layer (x40) by curing the first coating layer (x10) with a curing unit (x50) at least partially simultaneously with or after step b), thereby fixing at least a portion of the first plate-shaped magnetic or magnetizable particles to their respective adopted positions and orientations, d) A step in which, after step c), a second radiation-curable coating composition is applied in a first liquid state, comprising a second plate-shaped magnetic or magnetizable pigment particle, to form a second coating layer (x11), wherein the second coating layer (x11) is adjacent to the coating layer (x40) (Figure 2E) or separated from the coating layer (x40) (Figure 2F), and the second radiation-curable coating composition is either the same as or different from the radiation-curable coating composition of step a), e) The second coating layer (x11) is placed in one or more areas (A, A', A) of the second magnetic field of the second magnetic field generator. i The step is to orient at least a portion of the second plate-shaped magnetic or magnetizable pigment particles by exposing the substrate (x20) having the second coating layer (x41) to the second magnetic field, wherein the substrate (x20) having the second coating layer (x41) is in the one or more areas (A, A', A i ') is provided, and the two-dimensional surface of the substrate (x20) at the position of the second plate-shaped magnet or magnetizable pigment particle and one or more areas (A, A', A iThe angle α' that the tangent to the magnetic field lines of the second magnetic field in step ') is between 12° and 75° (12°≦|α'|≦75°) or between 105° and 168° (105°≦|α'|≦168°), and the second magnetic field generator (x30-b) is either the same as or different from the magnetic field generator in step b), and α' is different from α, preferably α' and α are different by at least 30°, in step b). f) A step in which the second coating layer (x11) is exposed to a second magnetic field, and partly simultaneously with or after step e), the second coating layer (x11) is cured at least partially with a curing unit (x50) to at least partially fix the position and orientation of the second plate-shaped magnetic or magnetizable pigment particles in the second coating layer (x11) and to produce a second coating layer (x41) that is at least partially cured, wherein adjacent magnetically oriented first plate-shaped magnetic or magnetizable pigment particles are at least each In a partially cured first coating layer (x40), adjacent magnetically oriented second plate-shaped magnetic or magnetizable pigment particles have principal axes X substantially parallel to each other, and at least in a partially cured second coating layer (x41), the magnetically oriented particles in at least the partially cured coating layer (x40) have a different elevation angle from the magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least the partially cured second coating layer (x41), and the step, Includes.

[0101]

[0099] The OEL described herein optionally comprises at least a partially cured coating layer (x40) and at least a partially cured second coating layer (x41) containing magnetically oriented plate-shaped magnets or magnetizable pigment particles as described herein, wherein the thickness T of the at least partially cured coating layer (x40) (see, for example, Figures 2A to 2E) is less than the d50 value of the plate-shaped magnets or magnetizable pigment particles, and the thickness T' of the at least partially cured second coating layer (x41) (see, for example, Figures 2C to 2E) is less than the d50 value of the plate-shaped magnets or magnetizable pigment particles. Typically, the plate-shaped magnetic or magnetizable pigment particles described herein have a d50 size of approximately 5 μm to approximately 30 μm (when measured by direct optical particle size measurement), and at least the partially cured coating layer (x40) has a thickness of approximately 3 μm to approximately 30 μm (in particular, a thickness of approximately 6 μm to approximately 30 μm for layers coated by screen printing, a thickness of approximately 3 μm to approximately 20 μm for layers coated by gravure printing, and a thickness of approximately 3 μm to approximately 20 μm for layers coated by flexographic printing), provided that the said thickness is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles. The thickness (T, T', etc.) of at least the partially cured coating layer (x40, x41, etc.) directly affects the elevation angle γ of the plate-shaped magnetic or magnetizable pigment particles when exposed to the magnetic field of a magnetic field generator, by causing the particles to adopt the maximum elevation angle γ as a result of the said thickness and the d50 value of the particles. This is advantageous because it allows for the free selection of a magnetic field generator to produce the aforementioned OEL, regardless of the uniformity or non-uniformity of the magnetic field.

[0102]

[0100] As described herein, OEL comprises magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least a partially cured coating layer on a substrate. The substrate (x20) described herein is preferably selected from the group consisting of paper or cellulose, paper-containing materials, glass, metal, ceramic, plastic, and other fibrous materials such as polymers (including woven and nonwoven fibrous materials), metallized plastics or polymers, composites, and mixtures or combinations thereof. Typical paper, paper-like, or other fibrous materials consist of various fibers such as abaca, cotton, hemp, wood pulp, and mixtures thereof, but are not limited thereto. As is well known to those skilled in the art, cotton and cotton / hemp mixtures are preferred for banknotes, and wood pulp is commonly used for security documents other than banknotes. According to another embodiment, the substrate (x20) described herein is based on plastics and polymers, metallized plastics or polymers, composites, and mixtures or combinations thereof. Suitable examples of plastics and polymers include polyolefins such as polyethylene (PE) and polypropylene (PP), including biaxially oriented polypropylene (BOPP); polyamides; polyesters such as poly(ethylene terephthalate) (PET), poly(1,4-butylene terephthalate) (PBT), and poly(ethylene 2,6-naphthoate) (PEN); and polyvinyl chloride (PVC). As a base material, spunbond olefin fibers, for example, sold under the trademark Tyvek®, can also be used. Typical examples of metallized plastics or polymers include the aforementioned plastic or polymer materials having metals continuously or discontinuously arranged on their surface. Typical examples of metals include, but are not limited to, aluminum (Al), chromium (Cr), copper (Cu), gold (Au), silver (Ag), alloys thereof, and combinations of two or more of these metals. The metallization of the above-mentioned plastic or polymer materials may be carried out by an electrodeposition process, a high-vacuum coating process, or a sputtering process.Typical examples of composite materials include, but are not limited to, multilayer or laminated structures of paper and at least one plastic or polymer material as described above, and plastic and / or polymer fibers incorporated into paper-like or fibrous materials as described above. Naturally, the substrate may also contain other additives known to those skilled in the art, such as fillers, sizing agents, bleaching agents, processing aids, reinforcing or wetting enhancers. For example, when the OEL described herein is used for decorative or cosmetic purposes such as nail lacquer, the OEL may be formed on other types of substrates, including nails, artificial nails, or other parts of animals or humans. The substrate (x20) described herein may be in the form of a web, sheet, thread reel, film reel, roll of labels, or label stock.

[0103]

[0101] Where one or more OELs described herein are present on a security document, the substrate may further enhance the security level and resistance to forgery and illegal copying of the security document by comprising printing, coating, laser marking, or laser-punched markings, watermarks, security threads, fibers, planchettes, luminescent compounds, windows, foils, decals, and two or more combinations thereof. For the same purpose of further enhancing the security level and resistance to forgery and illegal copying of the security document, the substrate may comprise one or more marker materials or tracking additives and / or machine-readable materials (e.g., luminescent materials, UV / visible / IR absorbing materials, magnetic materials, and combinations thereof).

[0104]

[0102] According to one embodiment, the security document and decorative article comprising the substrate (x20) and one or more OELs described herein further comprises one or more undercoat layers, the one or more undercoat layers being located between the substrate (x20) and the one or more OELs. This may improve the quality of the one or more OELs described herein or promote adhesion. An example of such undercoat layers can be found in International Publication No. 2010 / 058026. According to one embodiment, the one or more OELs described herein may further include one or more printed seals located between the substrate (x20) and at least partially cured coating layers (x40) (in other words, one or more OELs at least partially overlap one or more seals). It is preferable that the one or more OELs and the one or more seals described herein each have the shape of the seal independently. In this specification, the terms “indicium and indicia” mean one or more continuous and discontinuous layers comprising an identification marking, sign, or pattern. The indiciums described herein are selected from the group consisting of codes, symbols, alphanumeric symbols, motifs, geometric patterns (e.g., circles, triangles, and regular or irregular polygons), letters, words, numbers, logos, drawings, portraits, and combinations thereof. Examples of codes include encoded alphanumeric data, one-dimensional barcodes, two-dimensional barcodes, QR codes, data matrices, and encoded marks such as IR read codes. One or more indiciums described herein may be solid indiciums and / or raster indiciums.

[0105]

[0103] The present invention provides a method for producing one or more printed mark present between one or more OELs and a substrate (x20) and at least partially cured coating layers (x40) as described herein, further comprising the steps of: applying a composition in the form of one or more mark as described herein, prior to step a) described herein; and at least partially curing or solidifying the composition. The step of applying a composition in the form of one or more mark as described herein may be carried out by a non-contact fluid microdispensing process such as curtain coating, spray coating, aerosol jet printing, electrohydrodynamic printing, and inkjet printing, or by a printing process selected from the group consisting of offset, screen printing, gravure printing, flexographic printing, and intaglio printing (also referred to in the art as copperplate intaglio printing and steel die intaglio printing). The present invention provides a method for producing one or more printed mark existing between the substrate (x20) and at least partially cured second coating layer (x41) in the case of an OEL having, for example, two at least partially cured coating layers (x40, x41) as shown in Figure 2E, in addition to the one or more OELs described herein and between the substrate (x20) and at least partially cured second coating layer (x41), further comprising the steps of applying a composition in the form of one or more mark described herein, prior to step a) described herein, and at least partially curing or solidifying the composition.

[0106]

[0104] For the purpose of improving the contamination resistance or chemical resistance and cleanliness and thus the service life of security documents or decorative articles having one or more OELs as described herein, or for the purpose of improving their aesthetic appearance (e.g., gloss), one or more protective layers may be applied to one or more OELs. If one or more protective layers are present, the layers are usually composed of a protective varnish. The protective varnish may be a radiation-curable composition, a heat-drying composition, or any combination thereof. One or more protective layers are preferably radiation-curable compositions, more preferably ultraviolet-visible light-curable compositions. The protective layers are usually applied after the formation of the OELs.

[0107]

[0105] The OEL described herein may be applied directly to a substrate (x20) to remain permanently (for example, in the case of banknote or label applications). Alternatively, the OEL may be applied to a temporary substrate for manufacturing purposes and then removed later.

[0108]

[0106] Alternatively, one or more adhesive layers may be present on one or more OELs or substrates (x20), and the one or more adhesive layers may be present on the substrate surface opposite to the surface on which the one or more OELs are provided and / or on the one or more OELs on the same surface as the one or more OELs. Thus, one or more adhesive layers may be applied to one or more OELs or substrates, and the one or more adhesive layers are applied after the completion of the curing step. Such objects may be able to be attached to any kind of document or other article without the need for machinery or labor-intensive processes such as printing. Alternatively, the substrates described herein, comprising one or more OELs, ​​may be in the form of transfer foils that can be applied to documents or articles in an independent transfer step. For this purpose, the substrate is provided with a release coating on which one or more OELs are generated. [Examples]

[0109]

[0107] The examples and comparative examples were carried out using the UV-visible curable flexographic printing inks of the formulations described in Table 1 and the first and second magnetic material assemblies described below. [Table 1]

[0110]

[0108] For each sample, the following methods were used to prepare Examples E1 to E3 and Comparative Examples C1 to C3. a) As described above, the UV-visible curable inks listed in Table 1 were applied to the substrate (x20) to form a coating layer (x10). b) In one or two areas (shown as A / A' in Figures 3A and 4), the coating layer (x10) was exposed to the magnetic field of the magnetic field generator (x30) described above, thereby orienting at least a portion of the plate-shaped magnetic or magnetizable pigment particles. c) After exposure to a magnetic field, either partially or afterward (see Table 2), the coating layer (x10) was cured to form an optical effect layer (OEL) (x40) containing magnetically oriented plate-shaped magnetic or magnetizable pigment particles having the elevation angle γ described in Table 2.

[0111]

[0109] Figures 3A and 4 schematically show different examples in which a substrate (x20) having a coating layer (x10) containing pigment particles is exposed to the magnetic field of a magnetic field generator (x30) in one or more areas (indicated as A and A') of the magnetic field, the magnetic field being non-uniform (Figure 3A) or substantially uniform (see Figure 4), and the angle α between the two-dimensional surface of the substrate (x20) at the particle locations and the tangents to the magnetic field lines of the magnetic field in the two areas A and A' in Figure 3A or one area A in Figure 4 is between 12° and 75° (12°≦|α|≦75°) or between approximately 105° and 168° (105°≦|α|≦168°). [Table 2]

[0112]

[0110] Figures 5A and 5B show the change in elevation angle γ of pigment particles in at least partially cured layer (x40), where the x-axis (mm) corresponds to the distance from the edge of at least partially cured layer (x40), and the value of 15 mm corresponds to the center of the magnetic field generator shown in Figure 3A and the center of at least partially cured layer (x40). As seen in the examples shown in Figures 5A and 5B, the corresponding angles γ of 0 mm to 2 mm and 28 mm to 30 mm could not be measured by conoscope scattering measurement.

[0113]

[0111] For the magnetic field generator shown in Figure 3A, the angle α between the two-dimensional surface of the substrate (x20) at the particle's position and the tangent to the magnetic field lines of the magnetic field in one or more areas was calculated using the software Vizimag 3.19, and this is shown in Table 3. [Table 3]

[0114] Step a)

[0112] The UV-visible curable inks listed in Table 1 were applied to PET (Folex BG71 OHP film for color laser printers and copiers (100 micrometers thick, 45 mm x 30 mm)) (x20) to form a coating layer (45 mm x 30 mm) (x10). The coating step was performed using a semi-automatic laboratory coater (K101 control coater (RK Print)) with coating bar Nr 4 (nominal coating layer thickness 36 μm, measured coating layer thickness of cured coating layer 24 μm) for C1 to C3 and coating bar Nr 2 (nominal coating layer thickness 12 μm, measured coating layer thickness of cured coating layer 8 μm) for E1 to E3.

[0115]

[0113] The inks used in Examples E1 to E3 and Comparative Examples C1 to C3 have a viscosity suitable for flexographic printing, so a coating method that mimics the flexographic process was used.

[0116] Step b) Magnetic field generator for orientation in a non-uniform magnetic field (Figure 3A)

[0114] The pigment particles were oriented using the magnetic field generator (330) shown in Figure 3A (not shown to scale for clarity of the drawing). The magnetic field generator (330) was made of NdFeB N42 and was a rod-shaped dipole magnet (M1) with dimensions of 30 mm (L1) × 30 mm (L2) × 6 mm (L3). The distance between the surface of the magnetic field generator (330) facing the substrate (320) and the coating layer (310) was 6 mm.

[0117] Magnetic field generator for orientation in a uniform magnetic field (Figure 4)

[0115] The pigment particles were oriented using the magnetic field generator (430) shown in Figure 4 (not shown to scale for clarity of the drawing). The magnetic field generator (430) was equipped with two rod-shaped dipole magnets (M1, M2) and two magnetic pole pieces (P1, P2).

[0118]

[0116] The two rod-shaped dipole magnets (M1, M2) are each made of NdFeB N42 and have dimensions of 40mm (L1) × 40mm (L2) × 10mm (L3).

[0119]

[0117] Two bar-shaped dipole magnets (M1, M2) were placed at a distance of approximately 40 mm from each other (d1). The magnetic axes of the two bar-shaped dipole magnets (M1, M2) were substantially parallel to the length of the magnet (L1), and the magnetic field directions of the two bar-shaped dipole magnets (M1, M2) were in the same direction.

[0120]

[0118] The two pole pieces (P1, P2) each had dimensions of 60 mm (L4) × 40 mm (L5) × 3 mm (L6). The two pole pieces (P1, P2) were made of iron (ARMCO (registered trademark)).

[0121]

[0119] The two bar-shaped dipole magnets (M1, M2) and the two pole pieces (P1, P2) are arranged to form a rectangular parallelepiped with a void in the center consisting of an area A where the magnetic field is substantially uniform and the magnetic field lines are substantially parallel to each other, so that the distance (d2) between the two pole pieces (P1, P2) is approximately 40 mm (i.e., the length (L1) of the two bar-shaped dipole magnets (M1, M2)), and the distance between the two bar-shaped dipole magnets (M1, M2) is 40 mm.

[0122]

[0120] The substrate (420) and the coating layer (410) were placed in the center of the void of the magnetic field generator (430) shown in Figure 4, such that the angle α between the two-dimensional surface of the substrate (420) at the particle position and the tangent to the magnetic field lines of the magnetic field in area A where the magnetic field is uniform is approximately 30°.

[0123] Step c)

[0121] Exposure to the magnetic field of the magnetic field generator (x30) and partially simultaneously with or after exposure to the magnetic field (see Table 2), Phoseon's UV-LED lamp (Type FireFlex (50 x 75 mm, 395 nm, 8 W / cm) 2 Exposure to the coating layer (x10) for approximately 0.5 seconds cured the coating layer, forming an optical effect layer (OEL) containing magnetically oriented plate-shaped magnetic or magnetizable pigment particles having the elevation angle γ described in Table 2.

[0124]

[0122] In Example E2 and Comparative Example C2, the UV-LED lamp was positioned at a distance of 10 cm from the edge of the magnetic field generator (330). That is, the substrate (320) was exposed to the UV-LED lamp at a distance from the magnetic field generator (330). The distance between the UV-LED lamp and the coating layer (320) was approximately 1 cm, and the exposure time was approximately 0.5 seconds.

[0125]

[0123] In the case of Example E3 and Comparative Example C3, after about 1 second, the curing unit (450) (UV-LED lamp (Phoseon FireFly (395nm, 4W / cm)) as shown in Figure 4 was cured. 2 The coating layer (610) was cured at least partially by ))).

[0126] Measurement of elevation angle using conoscope scattering method Conoscopic scattering measurements were performed using a conoscopic scattermeter (available from Eckhartd Optics LLC, 5430 Jefferson Ct, White Bear Lake, MN 55110 (http: / / eckop.com)) as shown in Figure 4A of International Publication No. 2019 / 038371. The elevation angle γ was approximately 1 mm. 2 The measurement was taken on the surface of the coating layer. In other words, the reported value is an average of approximately 1000 pigment particles. The measured cured coating layer thickness listed in Table 2 was determined by measuring the weight difference of the substrate before and after coating and dividing this by the surface area of ​​the coating layer and the density of the coating composition.

[0127]

[0125] As shown in Figures 5A and 5B, the optical effect layers (OELs) composed of samples E1 and E2 according to the present invention showed a change in the elevation angle γ of the pigment particles following a curve that reached a plateau value (regions A and A'). In the optical effect layers (OELs) obtained in this way, adjacent magnetically oriented plate-shaped magnets or magnetizable pigment particles each have substantially parallel principal axes X in at least the first region of the partially cured coating layer (x40) (corresponding to magnetic field area A), and adjacent magnetically oriented plate-shaped magnets or magnetizable pigment particles each have substantially parallel principal axes X in at least the second region of the partially cured coating layer (x40) (corresponding to magnetic field area A'), and the magnetically oriented plate-shaped magnets or magnetizable pigment particles have different elevation angles in the first and second regions.

[0128]

[0126] In contrast to the optical effect layer (OEL) composed of samples E1 and E2 according to the present invention, the optical effect layer (OEL) composed of comparative samples C1 and C2 showed a change in the elevation angle γ of the pigment particles following a constant increasing curve without a plateau absolute value.

[0129]

[0127] The optical effect layer (OEL) composed of sample E3 according to the present invention exhibited a constant elevation angle γ across the entire surface of the OEL as a result of exposure of the coating layer (410) to the magnetic field of a magnetic field generator (x40) in one area (shown as A) where the magnetic field was substantially uniform. The elevation angle γ was much smaller than the angle α as a result of the layer thickness (8 micrometers is smaller than the d50 value of the pigment particles (20 micrometers) (i.e., part of the present invention)).

[0130]

[0128] The optical effect layer (OEL) composed of comparative sample C3 exhibited a constant elevation angle γ across the entire surface of the OEL as a result of exposure of the coating layer (410) to the magnetic field of a magnetic field generator (x40) in one area (shown as A) where the magnetic field was substantially uniform. However, the elevation angle γ was similar to the angle α as a result of the layer thickness (24 micrometers is greater than the d50 value of the pigment particles (20 micrometers) (i.e., not part of the present invention)).

[0131]

[0129] For comparison purposes, Figure 6 discloses an example relating to concurrently pending European Patent Application No. 20194060.8, in which a coating layer (510) containing pigment particles is exposed to the magnetic field of a magnetic field generator (530) in an area (shown as B). This magnetic field is substantially uniform, and the substrate (520) having the coating layer (510) is provided such that, in the area where the magnetic field is substantially uniform, the angle α between the coating layer (510) and the tangents to the magnetic field lines of the magnetic field in area B where the magnetic field is substantially uniform is greater than 0° and less than 30° (0° < α < 30°) or greater than 150° and less than 180° (150° < α < 180°) (i.e., an angle significantly different from that used in the present invention). [Item 1] A method for generating one or more optical effect layers (OELs) containing magnetically oriented platelet-shaped magnetic or magnetizable pigment particles on a substrate (x20) having a two-dimensional surface, comprising: a) applying a radiation-curable coating composition in a first liquid state, which contains platelet-shaped magnetic or magnetizable pigment particles having a major axis X and a d50 value, to the surface of the substrate (x20) to form a coating layer (x10); b) exposing the coating layer (x10) to the magnetic field in one or more areas (A, A', A i ') of a magnetic field generating device (x30) to orient at least a part of the platelet-shaped magnetic or magnetizable pigment particles, wherein the substrate (x20) having the coating layer (x10) is provided in the one or more areas (A, A', A i '), and the angle α formed between the two-dimensional surface of the substrate (x20) at the position of the particles and the tangent to the magnetic field lines of the magnetic field in the one or more areas (A, A', A i ') is 12° or more and about 75° or less (12° ≤ |α| ≤ 75°) or 105° or more and 168° or less (105° ≤ |α| ≤ 168°); c) at least partially curing the coating layer (x10) with a curing unit (x50) either partially simultaneously with step b) or after step b) to fix the position and orientation of the platelet-shaped magnetic or magnetizable pigment particles in the coating layer (x10) and generate at least a partially cured coating layer (x40) having a thickness T, wherein the thickness T of the at least partially cured coating layer (x40) is smaller than the d50 value of the platelet-shaped magnetic or magnetizable pigment particles, and adjacent magnetically oriented platelet-shaped magnetic or magnetizable pigment particles each have a major axis X that is substantially parallel to each other in one or more regions (x40-a, x40-b) of the at least partially cured coating layer (x40). A method comprising the above steps. [Item 2] The method according to Item 1, wherein the thickness T of the at least partially cured coating layer (x40) is smaller than d50 * sin(α) (T < d50 * (sin α)). [Item 3] The method according to item 1 or 2, wherein step a) of applying the radiation-curable coating composition to the surface of the substrate (x20) is performed by a printing process selected from the group consisting of screen printing, gravure printing, and flexographic printing, preferably flexographic printing. [Item 4] The method according to any one of items 1 to 3, wherein at least a portion of the plate-shaped magnetic or magnetizable pigment particles is composed of plate-shaped optically tunable magnetic or magnetizable pigment particles. [Item 5] The method according to item 4, wherein the plate-shaped optically variable magnet or magnetizable pigment particles are selected from the group consisting of plate-shaped magnetic thin-film interference pigments, plate-shaped magnetic cholesteric liquid crystal pigments, interference-coated magnetic pigment particles, and mixtures thereof. [Item 6] The method according to item 4 or 5, wherein at least a portion of the plate-shaped magnetic or magnetizable particles is composed of plate-shaped magnetic or magnetizable pigment particles exhibiting a metallic color, preferably silver or gold. [Item 7] The magnetic field generator (x30) is a rod-shaped dipole magnet whose magnetic axis is substantially parallel to the two-dimensional surface of the substrate (x20), and step b) is the one or more areas (A, A', A) of the magnetic field of the magnetic field generator (x30) i The method according to any one of items 1 to 6, comprising exposing the coating layer (x10) to the magnetic field, wherein the magnetic field does not have substantially constant magnitude and direction across the one or more areas of interest, or is not substantially confined to a plane, and the magnetically oriented plate-like magnet or magnetizable pigment particles are at different angles α. [Item 8] Step b) is the one or more areas (A, A', A) of the magnetic field of the magnetic field generator (x30) i The method according to any one of items 1 to 6, comprising exposing the coating layer (x10) to the magnetic field, wherein the magnetic field has substantially constant magnitude and direction over the one or more areas of interest, or is substantially confined to a plane, and the magnetically oriented plate-like magnet or magnetizable pigment particles are substantially at the same angle α. [Item 9] The method according to any one of items 1 to 6 and 8, wherein step b) includes exposing the coating layer (x10) to a magnetic field having substantially constant size and direction over the one or more areas of interest, or substantially confined to a plane, the magnetic field generator (x30) comprises two spaced-apart rod-shaped dipole magnets (M1, M2) having the same magnetic field direction and the same length, and two spaced-apart pole pieces (P1, P2) having the same length and arranged as a rectangular assembly, wherein M1 faces M2 but is not adjacent, P1 faces P2 but is not adjacent, and P1 is positioned at a distance from P2 corresponding to the length of M1 / M2. [Item 10] The magnetic field lines are located in one or more areas (A, A', A i The method described in item 9, wherein the two are substantially parallel to each other. [Item 11] The method is such that the one or more optical effect layers (OELs) are independently composed of a single at least partially cured coating layer (x40), the single at least partially cured coating layer (x40) contains magnetically oriented plate-shaped magnets or magnetizable pigment particles, and the single at least partially cured coating layer (x40) includes one or more first regions (x40-a) and one or more second regions (x40-b), and the method is such that a) A step of generating a single coating layer (x10) comprising one or more first regions (x10-a) and one or more second regions (x10-b) by applying the radiation-curable coating composition comprising the plate-shaped magnetic or magnetizable pigment particles described herein to the surface of the substrate (x20) described herein, b) The substrate (x20) having the single coating layer (x10) described herein is one or more areas (A, A', A i The steps include: providing the single coating layer (x10) in the magnetic field of the magnetic field generator (x30) and exposing it to the magnetic field of the magnetic field generator (x30) when the angle α is 12° or more and approximately 75° or less (12°≦|α|≦75°) or 105° or more and 168° or less (105°≦|α|≦168°), c) A step of fixing at least a portion of the plate-shaped magnetic or magnetizable particles to their respective adopted positions and orientations by selectively curing at least partially one or more first regions (x10a) of the single coating layer (x10) with the curing unit (x50) at least simultaneously with or after step b), d) The step of oriented at least a portion of the plate-shaped magnetic or magnetizable pigment particles in one or more second regions (x10b) by exposing the single coating layer (x10) to the magnetic field of a second magnetic field, wherein the substrate (x20) is one or more areas (A, A', A i ') is provided, and the two-dimensional surface of the substrate (x20) at the position of the plate-shaped magnetic or magnetizable pigment particles and the one or more areas (A, A', A i The angle α' that the tangent to the magnetic field lines of the second magnetic field within step ') is between 12° and 75° (12°≦|α'|≦75°) or between 105° and 168° (105°≦|α'|≦168°), and the second magnetic field generator (x30-b) is either the same as or different from the magnetic field generator of step b), and α' is different from α, preferably α' and α are different by at least 30°, in step, e) A step of generating a single at least partially cured coating layer (x40) by curing the single coating layer (x10) at least partially with the curing unit (x50) described herein, at least simultaneously with or after step d), wherein adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more first regions (x40-a) of the single at least partially cured coating layer (x40), and adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more second regions (x40-b) of the single at least partially cured coating layer (x40), The method described in any one of items 1 through 10, including the method described in item 1 through 10. [Item 12] The one or more optical effect layers (OELs) include magnetically oriented plate-shaped magnets or magnetizable pigment particles in at least the partially cured coating layer (x40), and include magnetically oriented second plate-shaped magnets or magnetizable pigment particles in at least the partially cured second coating layer (x41), wherein the at least partially cured second coating layer (x41) at least partially or completely overlaps the at least partially cured coating layer (x40), is adjacent to the at least partially cured coating layer (x40), or is separated from the at least partially cured coating layer (x40), and the method is d) A step of applying, after step c), a second radiation-curable coating composition which is in a first liquid state and contains the second plate-shaped magnetic or magnetizable pigment particles, and which forms the second coating layer (x11), wherein the second radiation-curable coating composition is the same as or different from the radiation-curable coating composition of step a), e) One or more areas (A, A', A) of the second magnetic field of the second magnetic field generator (x30-b) i The step is to orient at least a portion of the second plate-shaped magnetic or magnetizable pigment particles by exposing the second coating layer (x11) to the second magnetic field, wherein the substrate (x20) having the second coating layer (x11) is one or more areas (A, A', Ai ') is provided, and the two-dimensional surface of the substrate (x20) at the position of the second plate-shaped magnetic or magnetizable pigment particle and the one or more areas (A, A', A i The angle α' that the tangent to the magnetic field lines of the second magnetic field within step ') is between 12° and 75° (12°≦|α'|≦75°) or between 105° and 168° (105°≦|α'|≦168°), and the second magnetic field generator (x30-b) is either the same as or different from the magnetic field generator of step b), and α' is different from α, preferably α' and α are different by at least 30°, in step, f) A step to generate the at least partially cured second coating layer (x41) by partially curing the second coating layer (x11) with a curing unit (x50) at least simultaneously with or after step e), thereby fixing at least partially the position and orientation of the second plate-shaped magnetic or magnetizable pigment particles in the second coating layer (x11), wherein adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles are at least each of the Steps include: In at least a partially cured coating layer (x40), adjacent magnetically oriented second plate-shaped magnetic or magnetizable pigment particles having substantially parallel principal axes X are at least each in the second coating layer (x41), and the magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least the partially cured coating layer (x40) have a different elevation angle than the magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least the partially cured second coating layer (x41); The method described in any one of items 1 through 10, including the method described in item 1 through 10. [Item 13] The method according to any one of items 1 to 12, further comprising the steps of applying a composition in the form of one or more marks, and at least partially curing or solidifying the composition, wherein the one or more marks are located between the substrate (x20) and the at least partially cured coating layer (x40), and the steps are performed prior to step a) of applying the radiation-curable coating composition to the surface of the substrate (x20). [Item 14] An optical effect layer (OEL) obtained by the method described in any one of items 1 to 13, comprising at least a partially cured layer (x40) composed of a radiation-curable coating composition having a thickness T and containing magnetically oriented plate-shaped magnetic or magnetizable pigment particles having a principal axis X and a d50 value, The thickness T of the at least partially cured coating layer (x40) is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles. An optical effect layer (OEL) in which adjacent magnetically oriented plate-like magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more regions (x40-a, x40-b) of the at least partially cured layer (x40). [Item 15] A security document or decorative article comprising the substrate (x20) and one or more optical effect layers (OELs) obtained by the method described in any one of items 1 to 13, or one or more optical effect layers (OELs) as described in item 14.

Claims

1. A method for generating one or more optical effect layers (OELs) containing magnetically oriented plate-shaped magnets or magnetizable pigment particles on a substrate (x20) having a two-dimensional surface, a) A step of applying a radiation-curable coating composition, which is in a first liquid state and contains plate-shaped magnetic or magnetizable pigment particles having a principal axis X and d50 value, to the surface of the substrate (x20), and forming a coating layer (x10); b) One or more areas (A, A', A) of the magnetic field of the magnetic field generator (x30) ｉ The step is to expose the coating layer (x10) to the magnetic field in the above-mentioned area (A, A', A) in order to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles, wherein the substrate (x20) having the coating layer (x10) is the one or more area (A, A', A) ｉ A is provided in the ') and the two-dimensional surface of the substrate (x20) at the position of the particle and the one or more areas (A, A', A ｉ The step is that the angle α made with the tangent to the magnetic field lines of the magnetic field within the ') is 12° or more and 75° or less (12° ≤ |α| ≤ 75°) or 105° or more and 168° or less (105° ≤ |α| ≤ 168°), c) A step in which, at least partially simultaneously with or after step b), the coating layer (x10) is cured at least partially with a curing unit (x50) to fix the position and orientation of the plate-shaped magnetic or magnetizable pigment particles in the coating layer (x10) and to produce a partially cured coating layer (x40) having a thickness T, wherein the thickness T of the partially cured coating layer (x40) is smaller than the d50 value of the plate-shaped magnetic or magnetizable pigment particles, and at least each adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particle has substantially parallel principal axes X in one or more regions (x40-a, x40-b) of the partially cured coating layer (x40), Includes, A method wherein the thickness T of the at least partially cured coating layer (x40) is less than d50*sin(α) (T < d50*(sinα)).

2. The method according to claim 1, wherein step a) of applying the radiation-curable coating composition to the surface of the substrate (x20) is performed by a printing process selected from the group consisting of screen printing, gravure printing, and flexographic printing.

3. The method according to claim 1 or 2, wherein at least a portion of the plate-shaped magnetic or magnetizable pigment particles is composed of plate-shaped optically tunable magnetic or magnetizable pigment particles.

4. The method according to claim 3, wherein the plate-shaped optically variable magnet or magnetizable pigment particles are selected from the group consisting of plate-shaped magnetic thin-film interference pigments, plate-shaped magnetic cholesteric liquid crystal pigments, interference-coated magnetic pigment particles, and mixtures thereof.

5. The method according to claim 3, wherein at least a portion of the plate-shaped magnetic or magnetizable particles is composed of plate-shaped magnetic or magnetizable pigment particles exhibiting a metallic color.

6. The method according to claim 5, wherein the metallic color is silver or gold.

7. The magnetic field generator (x30) is a rod-shaped dipole magnet whose magnetic axis is substantially parallel to the two-dimensional surface of the substrate (x20), and step b) is the one or more areas (A, A', A) of the magnetic field of the magnetic field generator (x30) ｉ The method according to claim 1 or 2, comprising exposing the coating layer (x10) to the magnetic field, wherein the magnetic field does not have substantially constant magnitude and direction across the one or more areas of interest, or is not substantially confined to a plane, and the magnetically oriented plate-like magnet or magnetizable pigment particles are at different angles α.

8. Step b) is the one or more areas (A, A', A) of the magnetic field of the magnetic field generator (x30) ｉ The method according to claim 1 or 2, comprising, in '), exposing the coating layer (x10) to the magnetic field, wherein the magnetic field has substantially constant magnitude and direction throughout the one or more areas of interest, or is substantially confined to a plane, and the magnetically oriented plate-like magnet or magnetizable pigment particles are substantially at the same angle α.

9. The method according to claim 1 or 2, wherein step b) includes exposing the coating layer (x10) to a magnetic field having substantially constant size and direction over the one or more areas of interest, or substantially confined to a plane, the magnetic field generator (x30) comprises two spaced-apart rod-shaped dipole magnets (M1, M2) having the same magnetic field direction and the same length, and two spaced-apart pole pieces (P1, P2) having the same length and arranged as a rectangular assembly, wherein M1 faces M2 but is not adjacent, P1 faces P2 but is not adjacent, and P1 is positioned at a distance from P2 corresponding to the length of M1 / M2.

10. The magnetic field lines are located in one or more areas (A, A', A ｉ The method according to claim 9, wherein the two sides are substantially parallel to each other.

11. The method is such that the one or more optical effect layers (OELs) are independently composed of a single at least partially cured coating layer (x40), the single at least partially cured coating layer (x40) contains magnetically oriented plate-shaped magnets or magnetizable pigment particles, and the single at least partially cured coating layer (x40) includes one or more first regions (x40-a) and one or more second regions (x40-b), and the method is such that a) A step of generating a single coating layer (x10) including one or more first regions (x10-a) and one or more second regions (x10-b) by applying the radiation-curable coating composition containing the plate-shaped magnetic or magnetizable pigment particles to the surface of the substrate (x20), b) The substrate (x20) having the single coating layer (x10) is one or more areas (A, A', A ｉ The steps include: providing the single coating layer (x10) in the magnetic field of the magnetic field generator (x30) when the angle α is 12° or more and 75° or less (12° ≤ |α| ≤ 75°) or 105° or more and 168° or less (105° ≤ |α| ≤ 168°), c) A step of fixing at least a portion of the plate-shaped magnetic or magnetizable particles to their respective adopted positions and orientations by selectively curing at least partially one or more first regions (x10a) of the single coating layer (x10) with the curing unit (x50) at least simultaneously with or after step b), d) exposing the single coating layer (x10) to the magnetic field of a second magnetic field to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles in the one or more second regions (x10b), wherein the substrate (x20) is provided in the one or more areas (A, A', A ｉ '), and the angle α' formed between the two-dimensional surface of the substrate (x20) at the position of the plate-shaped magnetic or magnetizable pigment particles and the tangent to the magnetic field lines of the second magnetic field in the one or more areas (A, A', A ｉ ') is 12° or more and 75° or less (12° ≤ |α'| ≤ 75°) or 105° or more and 168° or less (105° ≤ |α'| ≤ 168°), and the second magnetic field generating device (x30-b) is either the same as or different from the magnetic field generating device in step b), and α' is different from α, the step, e) A step of generating a single at least partially cured coating layer (x40) by curing the single coating layer (x10) at least partially with the curing unit (x50) at least simultaneously with or after step d), wherein adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more first regions (x40-a) of the single at least partially cured coating layer (x40), and adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles each have substantially parallel principal axes X in one or more second regions (x40-b) of the single at least partially cured coating layer (x40), The method according to claim 1 or 2, including the method described in claim 1 or 2.

12. The method according to claim 11, wherein α' and α differ by at least 30°.

13. The one or more optical effect layers (OELs) include magnetically oriented plate-shaped magnets or magnetizable pigment particles in at least the partially cured coating layer (x40), and include magnetically oriented second plate-shaped magnets or magnetizable pigment particles in at least the partially cured second coating layer (x41), wherein the at least partially cured second coating layer (x41) at least partially or completely overlaps the at least partially cured coating layer (x40), is adjacent to the at least partially cured coating layer (x40), or is separated from the at least partially cured coating layer (x40), and the method is d) A step of applying, after step c), a second radiation-curable coating composition in a first liquid state, which includes the second plate-shaped magnetic or magnetizable pigment particles and forms the second coating layer (x11), wherein the second radiation-curable coating composition is the same as or different from the radiation-curable coating composition of step a), e) One or more areas (A, A', A) of the second magnetic field of the second magnetic field generator (x30-b) ｉ The step is to orient at least a portion of the second plate-shaped magnetic or magnetizable pigment particles by exposing the second coating layer (x11) to the second magnetic field, wherein the substrate (x20) having the second coating layer (x11) is configured such that the one or more areas (A, A', A) ｉ ') is provided, and the two-dimensional surface of the substrate (x20) at the position of the second plate-shaped magnetic or magnetizable pigment particle and the one or more areas (A, A', A ｉ The angle α' that the tangent to the magnetic field lines of the second magnetic field within step ') is between 12° and 75° (12° ≤ |α'| ≤ 75°) or between 105° and 168° (105° ≤ |α'| ≤ 168°), and the second magnetic field generator (x30-b) is either the same as or different from the magnetic field generator of step b), and α' is different from α, in step, f) A step to generate the at least partially cured second coating layer (x41) by partially curing the second coating layer (x11) with a curing unit (x50) at least simultaneously with or after step e), thereby fixing at least partially the position and orientation of the second plate-shaped magnetic or magnetizable pigment particles in the second coating layer (x11), wherein adjacent magnetically oriented plate-shaped magnetic or magnetizable pigment particles are at least each of the above In at least a partially cured coating layer (x40), adjacent magnetically oriented second plate-shaped magnetic or magnetizable pigment particles each have principal axes X substantially parallel to each other, and in at least the second coating layer (x41), each has principal axes X substantially parallel to each other, and the magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least the partially cured coating layer (x40) have a different elevation angle than the magnetically oriented plate-shaped magnetic or magnetizable pigment particles in at least the partially cured second coating layer (x41), and The method according to claim 1 or 2, including the method described in claim 1 or 2.

14. The method according to claim 13, wherein α' and α differ by at least 30°.

15. The method according to claim 1 or 2, further comprising the steps of applying a composition in the form of one or more marks, and at least partially curing or solidifying the composition, wherein the one or more marks are located between the substrate (x20) and the at least partially cured coating layer (x40), and the steps are performed prior to step a) of applying the radiation-curable coating composition to the surface of the substrate (x20).

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