A method for producing a UV-Vis radiation-curable coating composition containing magnetic or magnetizable pigment particles and an optical effect layer.

Abstract

The present invention relates to a UV-Vis radiation-curable coating composition comprising magnetic or magnetizable pigment particles, a method for producing an optical effect layer (OEL) comprising magnetically oriented magnetic or magnetizable pigment particles, and its use as a means of preventing counterfeiting of security documents or security articles as well as for decorative purposes of the OEL. The UV-Vis radiation-curable coating composition comprises one or more (meth)acrylate monomers, one or more cyclic ether compounds, one or more vinyl ether compounds, one or more photoinitiators, one or more thermoplastic polymers, and non-spherical magnetic or magnetizable pigment particles.

Description

Detailed description of the invention

[0001] [Field of Invention]

[0001] The present invention relates to a UV-Vis radiation-curable coating composition comprising magnetic or magnetizable pigment particles, a method for producing an optical effect layer (OEL) comprising magnetically oriented magnetic or magnetizable pigment particles, and the field of use of the OEL as a means of preventing counterfeiting of security documents or security articles, as well as for decorative purposes.

[0002] [Background of the Invention]

[0002] For example, in the field of security documents, it is known in the art that inks, compositions, coatings, or layers containing oriented magnetic or magnetizable pigment particles, in particular optically variable magnetic or magnetizable pigment particles, may be used to create security elements. Coatings or layers containing oriented magnetic or magnetizable pigment particles are disclosed, for example, in U.S. Patent Nos. 2,570,856; 3,676,273; 3,791,864; 5,630,877; and 5,364,689. Coatings or layers containing oriented magnetic colorshift pigment particles provide particularly attractive optical effects and are useful for protecting security documents, and are disclosed in International Publication Nos. 2002 / 090002 and International Publication Nos. 2005 / 002866.

[0003]

[0003] For example, security features of security documents can generally be classified into "confidential" security features on the one hand and "public" security features on the other. The protection provided by confidential security features relies on the principle that such features are difficult to detect, typically requiring specialized equipment and knowledge for detection, while "public" security features rely on concepts that can be easily detected by human senses on their own, for example, such features may be visible and / or detectable by touch, while still difficult to fabricate and / or copy. However, the effectiveness of public security features largely depends on their easy recognition as security features.

[0004]

[0004] Magnetic or magnetizable pigment particles in printing inks or coatings enable the creation of magnetically induced images, designs, and / or patterns by applying a correspondingly configured magnetic field, causing local orientation of the magnetic or magnetizable pigment particles in an unsolidified (i.e., wet) coating, followed by solidification of 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 No. 2,418,479; U.S. Patent No. 2,570,856; U.S. Patent No. 3,791,864; German Patent Publication No. 2006848; U.S. Patent No. 3,676,273; U.S. Patent No. 5,364,689; U.S. Patent No. 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 / 09002; International Publication No. 2003 / 000801; International Publication No. 2005 / 002866; and International Publication No. 2006 / 061301. Such methods can be used to create magnetic induction patterns that are highly resistant to counterfeiting. The security element in question can only be created by accessing both magnetic or magnetizable pigment particles or corresponding pigment inks and specific techniques used to print the ink and to orient the pigment in the printed ink.

[0005]

[0005] However, there remains a need to provide a method for producing UV-Vis radiation-curable coating compositions and optical effect layers containing magnetic or magnetizable pigment particles, wherein the optical effect layer exhibits a noticeable effect and is mechanically robust.

[0006] [Overview of the prefecture]

[0006] Accordingly, the present invention aims to overcome the shortcomings of the prior art. This is a UV-Vis radiation-curable coating composition, i) Optionally, one or more (meth)acrylate oligomers in a total amount of about 0% to about 10% by weight, preferably about 1% to about 10% by weight; ii) one or more (meth)acrylate monomers, preferably selected from the group consisting of tri(meth)acrylate, tetra(meth)acrylate, and mixtures thereof, in a total amount of about 1% to about 20% by weight, wherein the monomer is different from the (meth)acrylate oligomer of i); iii) In a total amount of about 5% to about 40% by weight, preferably one or more cyclic ether compounds selected from the group consisting of epoxides, oxetanes, and mixtures thereof, more preferably alicyclic epoxides, oxetanes, and mixtures thereof; iv) One or more vinyl ether compounds in a total amount of approximately 10% to 50% by weight; v) One or more onium photoinitiators in a total amount of approximately 0.1% to 10% by weight; vi) One or more photoinitiators selected from the group consisting of alkoxyketones, acetophenone, benzophenone, ketosulfone, benzyl ketal, benzoin ether, phosphine oxide, phenylglyoxylate, coumarin, camphorquinone, and mixtures thereof, in a total amount of approximately 0.1% to approximately 10% by weight; vii) One or more thermoplastic polymers in a total amount of approximately 1% to approximately 20% by weight; and viii) Containing non-spherical magnetic or magnetizable pigment particles in a total amount of approximately 1% to 40% by weight, The weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition, and this is achieved by providing a UV-Vis radiation-curable coating composition.

[0007]

[0007] Preferably, the UV-Vis radiation-curable coating compositions described herein are i) One or more (meth)acrylate oligomers described herein, present in a total amount of approximately 2% to 5% by weight; ii) One or more (meth)acrylate monomers described herein, present in a total amount of approximately 2% to 15% by weight; iii) One or more cyclic ether compounds described herein, present in a total amount of approximately 10% to 35% by weight; iv) One or more vinyl ether compounds described herein present in a total amount of approximately 15% to 40% by weight; v) One or more onium photoinitiators described herein, present in a total amount of approximately 1% to 5% by weight; vi) One or more photoinitiators selected from the group consisting of alkoxyketones, acetophenones, benzophenones, ketosulfones, benzyl ketals, benzoin ethers, phosphine oxides, phenylglyoxylates, coumarins, camphorquinones, and mixtures thereof, in a total amount of approximately 1% to 5% by weight; vii) One or more thermoplastic polymers described herein in a total amount of approximately 3% to 15% by weight; and viii) Contains non-spherical magnetic or magnetizable pigment particles present in a total amount of approximately 3% to 35% by weight, The weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

[0008]

[0008] The UV-Vis radiation-curable coating compositions described herein, ix) Optionally, if present, one or more photosensitizers, preferably in a total amount of about 0.1% to about 5% by weight; and / or x) optionally, one or more fillers or extenders, when present, preferably present in a total amount of from about 0.1% by weight to about 10% by weight; and / or xi) optionally, one or more UV stabilizers, when present, preferably present in a total amount of from about 0.1% by weight to about 10% by weight; and / or xii) optionally, one or more color-constant coloring components, when present, preferably present in a total amount of from about 0.05% by weight to about 5% by weight; xiii) optionally, one or more solvents, when present, present in a total amount of less than about 15% by weight; and / or xiv) optionally, one or more marker substances or taggants and / or one or more machine-readable materials; and / or xv) optionally, may further comprise one or more additives selected from the group consisting of thickeners, surfactants, anti-settling agents, plasticizers, defoamers, waxes, and mixtures thereof, weight percentages are based on the total weight of the UV-Vis radiation-curable coating composition.

[0009]

[0009] A method for producing an optically effect layer (OEL) is also described herein, the method comprising the steps of: a) applying a UV-Vis radiation-curable coating composition onto a substrate, b) exposing the coating layer in a first state to a magnetic field from a magnetic field generating device, thereby orienting at least a portion of the non-spherical magnetic or magnetizable pigment particles described herein, and c) solidifying the coating layer to a second state to fix the non-spherical magnetic or magnetizable pigment particles in their adopted positions and orientations.

[0010]

[0010] Also described herein are optically effect layers (OELs) and security documents produced by the method described herein, as well as decorative elements and decorative bodies comprising one or more optical OELs described herein.

[0011]

[0011] The document also describes a method for manufacturing a security document or a decorative element or ornament, the method comprising a) providing a security document or a decorative element or ornament, and b) providing an optical effect layer, such as those described herein, in particular those obtained by the method described herein, which is included in the security document or decorative element or ornament.

[0012]

[0012] The UV-Vis radiation-curable coating compositions described herein are particularly suitable for producing mechanically and chemically resistant optical effect layers (OELs) on demanding documents such as banknotes and other valuable documents, which are subjected to mechanical constraints such as folding, creasing, and creases of their substrates, and chemical constraints that thus reduce their lifespan, thereby requiring an increased substitution rate at an additional cost. Furthermore, the UV-Vis radiation-curable coating compositions described herein enable the production of such highly durable optical effect layers (OELs) on valuable documents, and the OELs can be produced in an efficient manner with respect to speed and drying performance.

[0013]

[0013] Figures 1-4 schematically illustrate the present invention and are not to scale. Optical effect layers (OELs) prepared by UV-Vis radiation-curable coating compositions are described in more detail with reference to the drawings and specific embodiments. Figure 1 shows photographic images of OELs prepared with comparative compositions (C1-C3) and UV-Vis radiation-curable coating compositions according to the present invention (E1 and E2). Figure 2 shows photographic images of OELs prepared with comparative compositions (C2 and C3) and UV-Vis radiation-curable coating compositions according to the present invention (E1 and E2) after the dry wrinkle test (mechanical resistance test) described herein. Figure 3 shows photographic images of OELs prepared with the comparative composition (C2) and the UV-Vis radiation-curable coating compositions according to the present invention (E1 and E2) after the washing machine test (mechanical resistance test) described herein. Figure 4 schematically shows the magnetic assembly used to fabricate the OEL shown in Figure 1. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows photographic images of OELs prepared with comparative compositions (C1-C3) and UV-Vis radiation-curable coating compositions according to the present invention (E1 and E2). [Figure 2] Figure 2 shows photographic images of OELs prepared with comparative compositions (C2 and C3) and UV-Vis radiation-curable coating compositions according to the present invention (E1 and E2) after the dry wrinkle test (mechanical resistance test) described herein. [Figure 3] Figure 3 shows photographic images of OELs prepared with the comparative composition (C2) and the UV-Vis radiation-curable coating compositions according to the present invention (E1 and E2) after the washing machine test (mechanical resistance test) described herein. [Figure 4A] Figure 4 schematically shows the magnetic assembly used to fabricate the OEL shown in Figure 1. [Figure 4B] Figure 4 schematically shows the magnetic assembly used to fabricate the OEL shown in Figure 1. [Figure 4C] Figure 4 schematically shows the magnetic assembly used to fabricate the OEL shown in Figure 1.

[0015] [Detailed explanation] definition

[0014] The following definitions are considered in the detailed description and are used to interpret the meaning of the terms enumerated in the claims.

[0016]

[0015] As used herein, the term “at least one” is to define one or more, for example, 1, 2, or 3.

[0017]

[0016] As used herein, the term "about" means that the quantity or value in question is a specified value or any other value in its vicinity. Generally, the term "about" indicating a value is intended to indicate a range within ±5% of the 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 can be obtained within ±5% of the indicated value.

[0018]

[0017] As used herein, the terms "and / or" mean that all or only one of the elements of the group may be present. For example, "A and / or B" means "A only, or B only, or both A and B." In the case of "A only," the term also includes the possibility that B is not present, i.e., "A only and B not."

[0019]

[0018] The term “contains” as used herein is intended to be non-exclusive and non-restrictive. Thus, for example, a coating composition containing compound A may contain other compounds in addition to A. However, the term “contains” also encompasses, in its particular embodiments, the more restrictive meanings of “substantially from” and “consisting of,” so that, for example, “a dampening solution containing A, B and optionally C” may also consist of (substantially) A and B, or (substantially) A, B and C.

[0020]

[0019] As used herein, the term “Optical Effect Layer” (OEL) refers to a coating layer comprising oriented magnetic or magnetizable pigment particles, the magnetic or magnetizable pigment particles being oriented by a magnetic field, and the oriented magnetic or magnetizable pigment particles being fixed / frozen (i.e., after curing) in order to form a magnetically induced image.

[0021]

[0020] The term "coating composition" refers to any composition that can form an optical effect layer (OEL) on a solid substrate, and which can preferably be applied by a printing method, although this is not limited to the above.

[0022]

[0021] As used herein, the term “wet” refers to an uncured coating layer, for example, a coating layer in which non-spherical magnetic or magnetizable pigment particles can still change their position and orientation under the influence of external forces acting thereon.

[0023]

[0022] The term “security document” refers to a document that is typically protected from 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.

[0024]

[0023] The term "security feature" is used to describe an image, pattern, or graphic element that can be used for authentication purposes.

[0025]

[0024] Where this detailed description refers to “preferred” embodiments / features, any combination of these “preferred” embodiments / features shall also be deemed to be disclosed insofar as such combination of “preferred embodiments / features” is technically meaningful.

[0026]

[0025] The UV-Vis radiation-curable coating compositions described herein may include i) one or more (meth)acrylate oligomers, if present, in an amount of about 1% to 10% by weight, preferably about 2% to 5% by weight, where the weight percentage is based on the total weight of the radiation-curable coating composition. According to one embodiment, the UV-Vis radiation-curable coating composition described herein includes i) the amount of (meth)acrylate oligomer described herein. The (meth)acrylate oligomer used herein refers to a relatively high molecular weight compound with a weight-average molecular weight (MW) of ≥300 g / mol, preferably ≥500 g / mol. The (meth)acrylate oligomer may be branched or essentially linear, and the (meth)acrylate functional group or the number of (meth)acrylate functional groups may each be terminal groups and / or pendant side-chain groups attached to the oligomer skeleton. Preferably, the meth)acrylate oligomer is selected from the group consisting of (meth)acrylic oligomers, urethane (meth)acrylate oligomers, polyester (meth)acrylate oligomers, polyether-based (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, and mixtures thereof, and more preferably from the group consisting of epoxy (meth)acrylate oligomers and mixtures thereof.

[0027]

[0026] In the context of the present invention, the term "(meth)acrylate" refers to acrylate and the corresponding methacrylate.

[0028]

[0027] The UV-Vis radiation-curable coating compositions described herein include ii) one or more (meth)acrylate monomers in a total amount of about 1% to about 20% by weight, preferably about 2% to about 15% by weight, wherein, unlike the (meth)acrylate oligomers in i), the weight percentage of the one or more monomers is based on the total weight of the UV-Vis radiation-curable coating composition. Preferably, the one or more (meth)acrylates described herein are selected from the group consisting of epoxy (meth)acrylates, (meth)acrylated oils, polyesters, and polyether (meth)acrylates, aliphatic or aromatic urethane (meth)acrylates, silicone (meth)acrylates, acrylic (meth)acrylates, and mixtures thereof. Suitable examples of (meth)acrylates include tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof.

[0029]

[0028] Suitable examples of tri(meth)acrylates include, but are not limited to, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate; alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate; alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane trimethacrylate; alkoxylated (especially ethoxylated or propoxylated) glycerin triacrylate; pentaerythritol Examples include triacrylates; alkoxylated (especially ethoxylated or propoxylated) pentaerythritol triacrylates, and mixtures thereof; preferably selected from the group consisting of trimethylolpropane triacrylate; alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate; alkoxylated (especially ethoxylated or propoxylated) glycerin triacrylate; pentaerythritol triacrylate, and mixtures thereof.

[0030]

[0029] Suitable examples of tetra(meth)acrylate include, but are not limited to, ditrimethylolpropanetetra(meth)acrylate; pentaerythritoltetra(meth)acrylate; alkoxylated (e.g., ethoxylated or propoxylated) pentaerythritoltetra(meth)acrylate; and mixtures thereof; preferably selected from the group consisting of ditrimethylolpropanetetra(meth)acrylate; alkoxylated pentaerythritoltetra(meth)acrylate; and mixtures thereof.

[0031]

[0030] The UV-Vis radiation-curable coating compositions described herein may further comprise one or more UV-Vis curable diluents selected from the group consisting of mono(meth)acrylates; di(meth)acrylates and mixtures thereof. Suitable examples of mono(meth)acrylates include, but are not limited to, alkyl(meth)acrylates; cycloalkyl(meth)acrylates; benzyl(meth)acrylates; phenyl(meth)acrylates (including phenoxyalkyl(meth)acrylates such as phenoxyethyl acrylate); cyclic trimethylolpropaneformal acrylates; tetrahydrofurfuryl acrylates; aliphatic urethane(meth)acrylates; and alkoxylated (especially ethoxylated or propoxylated) compounds thereof.Appropriate examples of di(meth)acrylates include, but are not limited to, ethylene glycol diacrylate; ethylene glycol dimethacrylate; 1,4-butanediol diacrylate; 1,4-butanediol dimethacrylate; 1,3-butanediol diacrylate; 1,3-butanediol dimethacrylate; 2-methyl-1,3-propanediol diacrylate; 3-methyl-1,5-pentanediol diacrylate); 2-butyl-2-ethyl-1,3 -Propanediol diacrylate; 1,6-Hexanediol diacrylate; 1,6-Hexanediol dimethacrylate; Neopentyl glycol diacrylate; Neopentyl glycol dimethacrylate; 1,9-Nonanediol diacrylate; 1,9-Nonanediol dimethacrylate; 1,10-Decanediol diacrylate; 1,10-Decanediol dimethacrylate; Alkoxylation (especially ethoxylation and propoxylation) 1,6-Hexa Examples include dipropyl diacrylate; propoxylated neopentyl glycol diacrylate; ethoxylated 2-methyl-1,3-propanediol diacrylate; tricyclodecanedimethanol diacrylate; diethylene glycol diacrylate; diethylene glycol dimethacrylate; dipropylene glycol diacrylate; triethylene glycol diacrylate; triethylene glycol dimethacrylate; tripropylene glycol diacrylate; tripropylene glycol dimethacrylate; tetraethylene glycol diacrylate; tetraethylene glycol dimethacrylate; polyethylene glycol 200 / 400 / 600 diacrylate; polyethylene glycol 200 / 400 / 600 dimethacrylate; ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A diacrylate; and ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A dimethacrylate.

[0032]

[0031] The UV-Vis radiation-curable coating compositions described herein include, iii) one or more cyclic ether compounds selected from the group consisting of epoxides, oxetanes, and mixtures thereof, preferably in a total amount of about 5% to about 40% by weight, preferably about 10% to about 35% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

[0033]

[0032] According to one embodiment, the UV-Vis radiation-curable coating composition described herein comprises at least one cyclic ether compound, preferably at least one alicyclic epoxide, wherein the alicyclic epoxide may be bifunctional or polyfunctional. The UV-Vis radiation-curable coating composition described herein comprising at least one alicyclic epoxide may further comprise at least one oxetane described herein, wherein the at least one alicyclic epoxide and the at least one oxetane are present in a total amount of about 5% to about 40% by weight, preferably about 10% to about 35% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition. As is well known to those skilled in the art, the alicyclic epoxide comprises at least substituted or unsubstituted epoxycyclohexyl residues: [ka] It is a cationically curable monomer containing [a specific compound].

[0034]

[0033] Preferably, the alicyclic epoxides described herein comprise at least one cyclohexane ring and / or at least two epoxy groups, preferably at least one cyclohexane ring and at least two epoxy groups. Preferred alicyclic epoxides comprise more than one (i.e., at least two) cyclohexane groups and preferably have structural formula (I): [ka] In the formula, -X- represents a single bond or a divalent group containing one or more atoms. The alicyclic epoxide of general formula (I) is optionally substituted with one or more linear or branched alkyl radicals containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, and decyl), preferably one or more linear or branched alkyl radicals containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and i-propyl).

[0035]

[0034] According to one embodiment, -X- is a divalent hydrocarbon group which may be a linear or branched alkylene group containing 1 to 18 carbon atoms, and examples of such linear or branched alkylene groups include, but are not limited to, a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group.

[0036]

[0035] According to one embodiment, -X- is a divalent alicyclic hydrocarbon group, or a cycloalkylidene group such as a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a cyclopentylidene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, a 1,4-cyclohexylene group, and a cyclohexylidene group.

[0037]

[0036] According to one embodiment, -X- is a divalent group comprising one or more oxygen-containing bonding groups, the oxygen-containing bonding group being selected from the group consisting of -C(=O)-, -OC(=O)O-, -C(=O)O-, and -O-. Preferably, the alicyclic epoxide is an alicyclic epoxide of general formula (II), where -X- is a divalent group comprising one or more oxygen-containing bonding groups, the oxygen-containing bonding group being selected from the group consisting of -C(=O)-, -OC(=O)O-, -C(=O)O-, and -O-, and more preferably, an alicyclic epoxide of general formula (Ia), (Ib), or (Ic) as defined below. [ka] In the formula, X1 may be the same or different in each occurrence and is a linear or branched alkyl radical containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, and decyl), preferably a linear or branched alkyl radical containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and i-propyl); X2 may be the same or different in each occurrence and is a linear or branched alkyl radical containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, and decyl), preferably a linear or branched alkyl radical containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and i-propyl); l1 and l2 are independent integers between 0 and 9, preferably between 0 and 3, and more preferably 0; [ka] In the formula, X1 may be the same or different in each occurrence and is a linear or branched alkyl radical containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, and decyl), preferably a linear or branched alkyl radical containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and i-propyl); X2 may be the same or different in each occurrence and is a linear or branched alkyl radical containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, and decyl), preferably a linear or branched alkyl radical containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and i-propyl); l1 and l2 are independent integers between 0 and 9, preferably between 0 and 3, and more preferably 0; -X3- is a single bond, or a linear or branched divalent hydrocarbon group containing 1 to 10 carbon atoms, preferably 3 to 8 carbon atoms, such as an alkylene group containing trimethylene, tetramethylene, hexamethylene, and 2-ethylhexylene, and cycloalkylenes such as 1,2-cyclohexylene, 1,3-cyclohexylene, and 1,4-cyclohexylene, and cyclohexylidene; [ka] In the formula, X1 may be the same or different in each occurrence, and is a linear or branched alkyl radical containing 1 to 3 carbon atoms, such as methyl, ethyl, n-propyl, and i-propyl; x2 may be the same or different in each occurrence and is a linear or branched alkyl radical containing 1 to 3 carbon atoms, such as methyl, ethyl, n-propyl, and i-propyl; l1 and l2 are independent integers between 0 and 9, preferably between 0 and 3, and more preferably 0.

[0038]

[0037] Preferred alicyclic epoxides of general formula (Ia) include, but are not limited to, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate; 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate; 3,4-epoxy-2-methylcyclohexylmethyl-3,4-epoxy-2-methylcyclohexanecarboxylate; and 3,4-epoxy-4-methylcyclohexylmethyl-3,4-epoxy-4-methylcyclohexanecarboxylate.

[0039]

[0038] Preferred alicyclic epoxides of general formula (Ib) include, but are not limited to, bis(3,4-epoxycyclohexylmethyl) adipate; bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate, bis(3,4-epoxycyclohexylmethyl) oxalate; bis(3,4-epoxycyclohexylmethyl) pimelate; and bis(3,4-epoxycyclohexylmethyl) sebacate.

[0040]

[0039] Further examples of alicyclic epoxides include alicyclic epoxides of general formula (II-a) and alicyclic epoxides of general formula (II-b), which are optionally substituted with one or more linear or branched alkyl groups containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, and decyl), preferably one or more linear or branched alkyl groups containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and i-propyl). [ka]

[0041]

[0040] The alicyclic epoxides described herein may be hydroxylated or (meth)acrylate modified.

[0042]

[0041] It is known in the art that oxetane compounds accelerate curing and reduce tackiness, thereby limiting the risk of blocking and bleed-through when printed sheets are stacked immediately after curing. Preferred examples of oxetanes include trimethylene oxide; 3,3-dimethyloxetane; trimethylolpropaneoxetane; 2-ethyl-2-hydroxylmethyloxetane; 3-ethyl-3-hydroxymethyloxetane; 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane; 3,3-dicyclomethyloxetane; 3-ethyl-3-phenoxymethyloxetane; bis([1-ethyl(3-oxetanyl)]methyl ether; 1,4-bis[3-ethyl-3-oxetanylmethoxy)methyl]benzene; 3,3-dimethyl-2(p-methoxyphenyl)oxetane; 3-ethyl-[(tri-ethoxysilylpropoxy)methyl]oxetane; 4,4-bis(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl; and 3,3-dimethyl-2(p-methoxyphenyl)oxetane. One or more oxetanes described herein may be hydroxylated or (meth)acrylate modified. In the context of the present invention, the term "(meth)acrylate" refers to acrylate and the corresponding methacrylate.

[0043]

[0042] The UV-Vis radiation-curable coating compositions described herein contain iv) one or more vinyl ether compounds in a total amount of about 10% to about 50% by weight, preferably about 15% to about 40% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition. It is known in the art that vinyl ether compounds accelerate curing and reduce tackiness, thereby limiting the risk of blocking and back-printing when printed substrates are stacked immediately after curing.

[0044]

[0043] Examples of preferred vinyl ether compounds include methyl vinyl ether; ethyl vinyl ether; n-propyl vinyl ether; n-butyl vinyl ether; iso-butyl vinyl ether; ethylhexyl vinyl ether; octadecyl vinyl ether; dodecyl vinyl ether; isopropyl vinyl ether; tert-butyl vinyl ether; tert-amyl vinyl ether; cyclohexyl vinyl ether; cyclohexanedimethanol monovinyl ether; cyclohexanedimethanol divinyl ether; 4-(vinyloxymethyl)cyclohexylmethylbenzoate; phenyl vinyl ether; methylphenyl vinyl ether; methoxyphenyl vinyl ether; 2-chloroethyl vinyl ether; 2-hydroxyethyl vinyl ether; 4-hydroxybutyl vinyl ether; 1,6-hexanediol monovinyl ether; ethylene glycol divinyl ether; ethylene glycol monovinyl ether; 1,4-butanediol divinyl ether; 1,6-hexanediol divinyl ether; 4-(vinyloxymethyl) 4-(vinyloxy)butyl benzoate; bis[4-(vinyloxy)butyl]adipate; bis[4-(vinyloxy)butyl]succinate; bis[4-(vinyloxymethyl)cyclohexylmethyl]glutarate; 4-(vinyloxy)butyl stearate; trimethylolpropane trivinyl ether; propenyl ether of propylene carbonate; diethylene glycol monovinyl ether; diethylene glycol divinyl ether; ethylene glycol butyl vinyl ether; dipropylene glycol divinyl ether; triethylene glycol divinyl ether; triethylene glycol methyl vinyl ether; triethylene glycol monobutyl vinyl ether; tetraethylene glycol divinyl ether; poly(tetrahydrofuran) divinyl ether; polyethylene glycol-520 methyl vinyl ether; pluriol-E200 divinyl ether; tris[4-(vinyloxy)butyl]trimellitate; 1,4-bis(2-vinyloxyethoxy)benzene; 2,2-bis(4-vinyloxyethoxyphenyl)propane;bis[4-(vinyloxy)methyl]cyclohexyl]methyl] terephthalate and bis[4-(vinyloxy)methyl]cyclohexyl]methyl] isophthalate. According to one embodiment, the UV-Vis radiation-curable coating composition described herein comprises iv) two or more vinyl ether compounds in a total amount of about 10 wt% to about 50 wt%, preferably about 15 wt% to about 40 wt%, wherein the weight percentages are based on the total weight of the UV-Vis radiation-curable coating composition.;

[0045]

[0044] The UV-Vis radiation-curable coating composition described herein comprises v) one or more onium photoinitiators in a total amount of about 0.1 wt% to about 10 wt%, preferably about 1 wt% to about 5 wt%, wherein the weight percentages are based on the total weight of the UV-Vis radiation-curable coating composition. The one or more onium salts described herein are preferably selected from the group consisting of azonium salts, oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof, more preferably selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof, and still more preferably selected from the group consisting of iodonium salts, sulfonium salts, and mixtures thereof.

[0046]

[0045] The one or more iodonium salts described herein have a cation moiety and an anion moiety, and the anion moiety is preferably BF4 - , B(C6F5)4 - , PF6 - , (PF 6-m (CnF 2n-1 ) m ) - (wherein m is an integer from 1 to 5, and n is an integer from 1 to 4), AsF6 - , SbF6 - , CF3SO3 - , perfluoroalkyl sulfonate or pentafluorohydroxyantimonate, more preferably SbF6 - , PF6 - , or B(C6F5)4 -The cationic portion is preferably an aromatic iodonium ion, more preferably an iodonium ion containing two aryl groups, and the two aryl groups may be independently substituted with one or more alkyl groups (e.g., methyl, ethyl, isobutyl, tert-butyl, etc.), one or more alkoxy groups, one or more nitro groups, one or more halogen-containing groups, one or more hydroxyl groups, or a combination thereof.

[0047]

[0046] One or more sulfonium salts described herein have a cationic moiety and an anionic moiety, the anionic moiety preferably BF4 - , B(C6F5)4 - PF6 - , (PF 6-m (C n F 2n-1 ) m ) - (m is an integer from 1 to 5 and n is an integer from 1 to 4), AsF6 - SbF6 - CF3SO3 - , perfluoroalkyl sulfonate or pentafluorohydroxyantimonate, more preferably SbF6 - or PF6 - The cationic portion is preferably an aromatic sulfonium ion, more preferably a sulfonium ion containing two or more aryl groups, and the two or more aryl groups may be independently substituted with one or more alkyl groups (e.g., methyl, ethyl, isobutyl, tert-butyl, etc.), one or more alkoxy groups, one or more aryloxyl groups, one or more halogen-containing groups, one or more hydroxyl groups, or a combination thereof.

[0048]

[0047] The UV-Vis radiation-curable coating compositions described herein each comprise vi) one or more photoinitiators, one or more of which are selected from the group consisting of hydroxyketones (e.g., alpha-hydroxyketone), alkoxyketones (e.g., alpha-alkoxyketone), acetophenone, benzophenone, ketosulfone, benzyl ketal, benzoin ether, phosphine oxide, phenylglyoxylate, coumarin, camphorquinone, and mixtures thereof, and preferably contain hydroxyketones (e.g., alpha-hydroxyketone) in a total amount of about 0.1% to about 10% by weight, preferably about 1% to about 5% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition. Preferably, one or more photoinitiators vi) are selected from the group consisting of phosphine oxide, hydroxyketone, and mixtures thereof, and more preferably hydroxyketones (e.g., alpha-hydroxyketone).

[0049]

[0048] The UV-Vis radiation-curable coating compositions described herein may further comprise ix) one or more photosensitizers. The photosensitizers are activated by one or more wavelengths emitted by the UV-Vis light source and reach an excited state. The excited photosensitizers transfer energy to one or more photoinitiators or electrons. Either process sequentially initiates the polymerization process. The UV-Vis radiation-curable coating compositions described herein may further comprise one or more photosensitizers together with the one or more photoinitiators v) and vi) described herein to achieve efficient curing. Suitable examples of photosensitizers are known to those skilled in the art (e.g., Industrial Photoinitiators, WAGreen, CRC Press, 2010, Table 8.1 p.170). Preferably, one or more photosensitizers are selected from the group consisting of thioxanthone compounds, anthracene compounds, naphthalene compounds, titanocene compounds, and mixtures thereof, more preferably from the group consisting of thioxanthone compounds (but not limited to isopropyl-thioxanthone (ITX), 1-chloro-2-propoxy-thioxanthone (CPTX), 2-chloro-thioxanthone (CTX), 2,4-diethyl-thioxanthone (DETX), and mixtures thereof, in the form of oligomers or polymers thereof), anthracene compounds (such as 9,10-diethoxyanthracene and 9,10-dibutyloxyanthracene), naphthalene compounds (such as 1,4-diethoxynaphthalene), and mixtures thereof. If present, one or more photosensitizers are preferably present in a total amount of about 0.1% to about 5% by weight, more preferably 0.2% to about 1% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

[0050]

[0049] The UV-Vis radiation-curable coating compositions described herein contain, vii) one or more thermoplastic polymers in a total amount of about 1% to about 20% by weight, preferably about 3% to 15% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition. Preferably, one or more thermoplastic polymers are selected from the group consisting of polyvinyl butyral (PVB), polyamide, polyvinyl chloride (PVC), polyester, polyacetal, polyolefin, styrene polymer, polycarbonate, polyarylate, polyimide, polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyphenylene resin, polysulfone, and mixtures thereof, more preferably selected from the group consisting of polyvinyl butyral (PVB) and mixtures thereof. According to one embodiment, at least one of the one or more thermoplastic polymers is polyvinyl butyral (PVB) and / or polyvinyl chloride (PVC).

[0051]

[0050] The UV-Vis radiation-curable coating compositions described herein contain, in a total amount of, about 1% to about 40% by weight, preferably about 3% to about 35% by weight, and more preferably about 5% to about 30% by weight, non-spherical magnetic or magnetizable pigment particles, based on the total weight of the UV-Vis radiation-curable coating composition. The non-spherical magnetic or magnetizable pigment particles described herein are preferably elongated or flattened ellipsoidal, plate-like or needle-shaped magnetic or magnetizable pigment particles, or mixtures of two or more thereof, more preferably plate-like particles.

[0052]

[0051] The non-spherical magnetic or magnetizable pigment particles described herein are defined as having an anisotropic reflectance to incident electromagnetic radiation, such that the cured binder material is at least partially transparent, due to their non-spherical shape. The term “anisotropic reflectance” as used herein means that the ratio of incident radiation reflected by the particle from a first angle to a certain (observation) direction (second angle) is a function of the particle’s orientation, i.e., a change in the particle’s orientation relative to the first angle can cause a different magnitude of reflection in the observation direction. Preferably, the non-spherical magnetic or magnetizable pigment particles described herein have an anisotropic reflectance to incident electromagnetic radiation in part, or in the entire wavelength range of about 200 to about 2500 nm, more preferably about 400 to about 700 nm, such that a change in the particle’s orientation results in a change in the reflection by the particle in a certain direction. As is known to those skilled in the art, the magnetic or magnetizable pigment particles described herein differ from conventional pigments in that conventional pigment particles exhibit the same color and reflectance regardless of particle orientation, whereas the magnetic or magnetizable pigment particles described herein exhibit reflectance or color, or both, that depend on particle orientation.

[0053]

[0052] The UV-Vis radiation-curable coating compositions described herein, similar to the coating layers described herein, contain non-spherical, preferably plate-shaped, magnetic or magnetizable pigment particles as described herein, preferably in an amount of about 1% to about 40% by weight, preferably about 3% to about 35% by weight, and more preferably about 5% to about 30% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition or coating layer.

[0054]

[0053] Suitable examples of non-spherical, preferably 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 refers 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, but are not limited to, 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, where M represents a divalent metal, R represents a trivalent metal, and A represents a tetravalent metal.

[0055]

[0054] Examples of non-spherical, preferably plate-shaped, magnetic or magnetizable pigment particles described herein include, but are not limited to, magnetic metals such as cobalt (Co), iron (Fe), or nickel (Ni); and pigment particles comprising a magnetic layer M consisting of one or more magnetic alloys of iron, cobalt, or nickel, wherein the magnetic or magnetizable pigment particles may have a multilayer structure comprising one or more further layers. Preferably, one or more further layers are layer A, which is 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 independent of silicon dioxide (SiO2); or layer B, which is selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective alloys, more preferably selected from the group consisting of silver (Ag), aluminum (Al), chromium (Cr), and nickel (Ni), even more preferably independent of aluminum (Al); or a combination of one or more layers A, such as those described above, and one or more layers B, such as those described above. Representative examples of small, plate-shaped magnetic or magnetizable pigment particles having the above-mentioned multilayer structure 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 / A multilayer structures, A / B / M / B / A / multilayer structures, B / M multilayer structures, B / M / B multilayer structures, M / A / M multilayer structures, B / A / M / A multilayer structures, B / A / M / B / B multilayer structures, B / A / M / A / M / A / B / A / B multilayer structures, and A / B / A / B / A / M / A / B / A / B / A multilayer structures, where layer A, magnetic layer M, and layer B are selected from the above.

[0056]

[0055] The UV-Vis radiation-curable coating compositions described herein may include non-spherical, preferably plate-shaped, optically variable magnetic or magnetizable pigment particles, and / or non-spherical, preferably plate-shaped magnetic or magnetizable pigment particles that do not have optically variable properties. Preferably, at least a portion of the magnetic or magnetizable pigment particles described herein are composed of non-spherical, preferably plate-shaped, optically variable magnetic or magnetizable pigment particles. In addition to the public security provided by the color-shift properties of the optically variable magnetic or magnetizable pigment particles, which enable the use of human senses to easily detect, recognize and / or identify articles or security documents supporting the inks, coating compositions, or coating layers containing the optically variable magnetic or magnetizable pigment particles described herein from their possible counterfeits, the optical properties of the optically variable magnetic or magnetizable pigment particles may also be used as a machine-readable tool for OEL recognition. Therefore, the optical properties of optically variable magnetism or magnetizable pigment particles can be simultaneously used as confidential or semi-confidential security features in authentication processes where the optical (e.g., spectral) properties of the pigment particles are analyzed, thus improving resistance to counterfeiting.

[0057]

[0056] The use of non-spherical, preferably plate-shaped, optically variable magnetic or magnetizable pigment particles in the coating layer for producing OEL enhances the significance of OEL as a security feature in security document applications, since such materials are not available to the security document printing industry and are not generally commercially available.

[0058]

[0057] As described above, preferably, at least a portion of the non-spherical, preferably plate-shaped, magnetic or magnetizable pigment particles are composed of non-spherical, preferably plate-shaped, optically variable magnetic or magnetizable pigment particles. These are preferably selected from the group consisting of magnetic thin-film interference pigment particles, magnetic cholesteric liquid crystal pigment particles, magnetic materials, and interference-coated pigment particles comprising two or more mixtures thereof.

[0059]

[0058] Magnetic thin-film interference pigment particles are known to those skilled in the art, for example, 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; European Patent Application Publication No. 3587500, This is disclosed in European Patent Publication No. 3587501, European Patent Publication No. 3587502, European Patent Publication No. 3587503, International Publication No. 2020 / 006286, International Publication No. 2020 / 131700, U.S. Patent Publication No. 2021 / 0101402, U.S. Patent Publication No. 2021 / 038812, U.S. Patent Publication No. 2022 / 0282094, and the documents cited herein. Preferably, the magnetic thin-film interference pigment particles include pigment particles having a 5-layer Fabry-Perot multilayer structure, and / or pigment particles having a 6-layer Fabry-Perot multilayer structure, and / or pigment particles having a 7-layer Fabry-Perot multilayer structure, and / or pigment particles having a 9-layer Fabry-Perot multilayer structure, and / or pigment particles having an 11-layer Fabry-Perot multilayer structure, and / or pigment particles having a multilayer structure combining one or more multilayer Fabry-Perot structures.

[0060]

[0059] 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, and / or a magnetic alloy containing nickel, iron and / or cobalt, and / or a magnetic oxide containing nickel (Ni), iron (Fe), and / or cobalt (Co).

[0061]

[0060] A more preferred five-layer Fabry-Perot multilayer structure consists of a dielectric / reflector / magnetic / reflector / dielectric multilayer structure.

[0062]

[0061] A preferred 6-layer Fabry-Perot multilayer structure consists of a multilayer structure of absorber / dielectric / reflector / magnetic material / dielectric / absorber.

[0063]

[0062] A preferred 7-layer Fabry-Perot multilayer structure consists of an absorber / dielectric / reflector / magnetic / reflector / dielectric / absorber multilayer structure, such as disclosed in U.S. Patent No. 4,838,648.

[0064]

[0063] A preferred nine-layer Fabry-Perot multilayer structure consists of a multilayer structure of dielectric / absorber / dielectric / reflector / magnetic material / dielectric / absorber / dielectric.

[0065]

[0064] A preferred 11-layer Fabry-Perot multilayer structure consists of a multilayer structure of absorber / dielectric / absorber / dielectric / reflector / magnetic material / reflector / dielectric / absorber / dielectric / absorber.

[0066]

[0065] Preferably, the reflector layer described herein is selected from the group consisting of metals and metal alloys, preferably from the group consisting of reflective metals and reflective metal alloys, more preferably from the group consisting of aluminum (Al), silver (Ag), copper (Cu), gold (Au), platinum (Pt), tin (Sn), titanium (Ti), palladium (Pd), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni), and their alloys, even more preferably independent of one or more selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), and their alloys, and even more preferably independent of aluminum (Al). Preferably, the dielectric layer is independent of one or more materials selected from the group consisting of metal fluorides such as 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), and lithium fluoride (LiF), and metal oxides such as silicon oxide (SiO2), silicon dioxide (SiO2), titanium oxide (TiO2), and aluminum oxide (Al2O3), more preferably independently of magnesium fluoride (MgF2) and silicon dioxide (SiO2), and even more preferably independently of magnesium fluoride (MgF2). Preferably, the absorber layer is 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, their metal sulfides, their metal carbides, and their metal alloys; more preferably selected from the group consisting of chromium (Cr), nickel (Ni), their metal oxides, and their metal alloys; even more preferably independent from one or more selected from the group consisting of chromium (Cr), nickel (Ni), and their alloys.Preferably, the magnetic layer comprises nickel (Ni), iron (Fe), and / or cobalt (Co); and / or a magnetic alloy containing nickel (Ni), iron (Fe), and / or cobalt (Co); and / or a magnetic oxide containing nickel (Ni), iron (Fe), and / or cobalt (Co). When magnetic thin-film interference pigment particles comprising a 7-layer Fabry-Perot structure are preferred, the magnetic thin-film interference pigment particles particularly preferably comprise a multilayer structure of 7 layers of Fabry-Perot absorber / dielectric / reflector / magnetic material / reflector / dielectric / absorber consisting of a Cr / MgF2 / Al / M / Al / MgF2 / Cr multilayer structure, where M is Ni, Fe, or Co.

[0067]

[0066] The magnetic thin-film interference pigment particles described herein are considered safe for human health and the environment and may include, for example, multilayer pigment particles based on a 5-layer Fabry-Perot multilayer structure, a 6-layer Fabry-Perot multilayer structure, a 7-layer Fabry-Perot multilayer structure, a 9-layer Fabry-Perot multilayer structure, an 11-layer Fabry-Perot multilayer structure, and pigment particles having a multilayer structure combining one or more or two or more multilayer Fabry-Perot structures, wherein the pigment particles include one or more magnetic layers comprising a magnetic alloy having a substantially nickel-free composition containing 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 representative example of multilayer pigment particles considered safe for human health and the environment can be found in European Patent No. 2402401, the entirety of which is incorporated herein by reference.

[0068]

[0067] Suitable magnetic cholesteric liquid crystal pigment particles exhibiting optically variable 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 therefrom, which have high brightness and color shift properties and further specific properties such as magnetization. The disclosed single layer and pigment particles include a three-dimensionally crosslinked cholesteric liquid crystal mixture and magnetic nanoparticles obtained therefrom by grinding the single layer. U.S. Patent No. 6,582,781 and U.S. Patent No. 6,410,130 are sequence A 1 / B / A 2 Disclosed are plate-shaped cholesteric multilayer pigment particles containing A 1 and A 2 These may be the same or different, each comprising at least one cholesteric layer, where B is an intermediate layer that absorbs all or part of the light transmitted by layers A1 and A2 and imparts magnetic properties to the intermediate layer. U.S. Patent No. 6,531,221 also discloses suitable plate-shaped cholesteric multilayer pigment particles.

[0069]

[0068] Suitable interference-coated pigment particles comprising one or more magnetic materials include, but are not limited to, structures comprising a substrate selected from the group consisting of a core coated with one or more layers, wherein at least one or more layers of the core have magnetic properties. For example, suitable interference-coated pigment particles include a core made of a magnetic material such as those described above, wherein the core is coated with one or more layers made of one or more metal oxides, or they have a structure comprising a core made 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 two or more mixtures thereof, wherein the core is coated with one or more magnetic materials. Furthermore, one or more additional layers, such as a colored layer, may be present.

[0070]

[0069] The non-spherical, preferably plate-shaped, magnetic or magnetizable pigment particles described herein preferably have a size d50 of about 2 μm to about 50 μm (measured by direct optical particle size distribution).

[0071]

[0070] The non-spherical, preferably plate-shaped, magnetic or magnetizable pigment particles described herein may have surfaces that are treated to protect them from degradation that may occur in the coating composition and coating layer, and / or to facilitate their incorporation into the coating composition and coating layer, typically using corrosion inhibitors and / or wetting agents.

[0072]

[0071] The UV-Vis radiation-curable coating compositions described herein may further contain one or more fillers or fillers preferably selected from the group consisting of x) carbon fibers, talc, mica (muscovite), wollastonite, calcined clay, china clay, kaolin, carbonates (e.g., calcium carbonate, sodium aluminum carbonate), silicates (e.g., magnesium silicate, aluminum silicate), sulfates (e.g., magnesium sulfate, barium sulfate), titanates (e.g., potassium titanate), alumina hydrate, silica, fumed silica, montmorillonite, graphite, anatase, rutile, bentonite, vermiculite, zinc white, zinc sulfide, wood flour, quartz flour, natural fibers, synthetic fibers, and combinations thereof. If present, one or more fillers or extenders are preferably present in a total amount of about 0.1% to about 10% by weight, more preferably about 0.2% to about 5% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

[0073]

[0072] The UV-Vis radiation-curable coating compositions described herein may further include xi) one or more UV stabilizers, particularly UV canister stabilizers. If present, one or more UV stabilizers are preferably present in a total amount of about 0.1% to about 10% by weight, more preferably about 0.2% to about 5% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition. Examples of UV canister stabilizers, but not limited to, include glycerol alkoxylates (e.g., methoxylate, ethoxylate, propoxylate), polyacrylates, piperidine-1-oxyl, and hydroquinones (including hydroquinone, alkyl-substituted hydroquinone, and alkoxyalkyl-substituted hydroquinone). Suitable UV canister stabilizers are sold, for example, by Rahn under the trade name GENORAD, by Kromachem under the trade name FLORSTAB, by 3Dresyns under the name 3D-ADD STAB2 Bio, or by Sitech under the name SR-12UV.

[0074]

[0073] The UV-Vis radiation-curable coating compositions described herein may further include one or more color-constant coloring components (i.e., components that do not have optically variable properties) selected from the group consisting of organic pigment particles, inorganic pigment particles, and organic dyes. If present, one or more color-constant coloring components are preferably present in a total amount of about 0.05% to about 5% by weight, more preferably about 0.1% to about 3% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition. Optically variable (also referred to in the art as goniochromatic or color-shifting) pigment particles are known to exhibit color that depends on the viewing angle or angle of incidence. Optically variable pigment particles give different color impressions at various viewing angles. By “different color impressions”, this means that the elements show a difference in at least one parameter of the CIELAB (1976) system, preferably different “a * "Value, different "L" * " value, or different "b * Either show the value of "a" at various viewing angles. * "b * " and "L *This means that it represents two or three different values ​​selected from the values ​​of ". In contrast to optically variable pigment particles that exhibit various colors or color impressions depending on the viewing angle, a color-constant coloring component does not exhibit a color change or color impression change depending on the viewing angle. For example, a layer or coating containing optically variable pigment particles exhibits a color shift from a first color impression CI1 (e.g., green) to a second color impression CI2 (blue) as the viewing angle changes (e.g., from a viewing angle of about 90° to the surface of the layer or coating to a viewing angle of about 22.5° to the surface of the layer or coating). According to one embodiment, the UV-Vis radiation-curable coating composition described herein comprises non-spherical, preferably plate-shaped, optically variable magnetic or magnetizable pigment particles, and one or more color-constant coloring components. Preferably, the color of one or more color-constant coloring components is selected such that it is the same color as, or close to, the color of the optically variable magnetic or magnetizable pigment particles at a first viewing angle (e.g., the first color impression CI1 is green), or the same color as, close to, or an intermediate color of, the optically variable magnetic or magnetizable pigment particles at a second viewing angle (e.g., the second color impression CI2 is blue).

[0075]

[0074] The UV-Vis radiation-curable coating compositions described herein may further contain one or more solvents to fine-tune the viscosity of the ink. Preferred solvents are polar aproton solvents exhibiting high boiling points, such as carbonates. Preferred carbonates are alkylene carbonates (e.g., ethylene carbonate, propylene carbonate, and butylene carbonate). Propylene carbonate is particularly preferred, as it has a high boiling point and a favorable ecotoxicity profile. If present, one or more solvents are present in a total amount of less than about 15% by weight, more preferably less than about 5% by weight, where the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

[0076]

[0075] The UV-Vis radiation-curable coating compositions described herein may further include one or more marker substances or tagants and / or one or more machine-readable materials selected from the group consisting of xiv) magnetic materials (different from the non-spherical magnetic or magnetizable pigment particles described herein), luminescent materials, electroluminescent materials, upconverting materials, conductive materials, and Raman active materials (including surface-enhanced Raman spectroscopy SERS materials) and infrared absorbing materials. Alternatively, one or more marker substances or tagants and / or one or more machine-readable materials may be materials that can be authenticated by the use of a microscope. As used herein, “machine-readable material” means a material exhibiting at least one unique property that is detectable by an apparatus or machine and can be included in the coating to give a method of authenticating the coating or an article containing the coating by the use of a particular apparatus for detection and / or authentication.

[0077]

[0076] According to one embodiment, the UV-Vis radiation-curable coating composition described herein contains less than 5% by weight or about 5% by weight, preferably 0% by weight or about 0% to less than 5% by weight or about 5% by weight, of a polyol having three or more hydroxyl groups per molecule and a hydroxyl value of 550 to 750 mg of KOH / g.

[0078]

[0077] The UV-Vis radiation-curable coating compositions described herein may include, but are not limited to, one or more additives, which include compounds and materials used to adjust the physical, rheological, and chemical parameters of the coating composition, such as viscosity (e.g., thickeners and surfactants), consistency (e.g., anti-settling agents and plasticizers), foaming properties (e.g., defoamers), lubricity (waxes), adhesion, and antistatic properties. According to one embodiment, the UV-Vis radiation-curable coating compositions described herein further include one or more additives selected from the group consisting of thickeners, surfactants, anti-settling agents, plasticizers, defoamers, waxes, and mixtures thereof.

[0079]

[0078] The additives described herein may be present in the coating composition in amounts and forms known in the art, including so-called nanomaterials in which at least one of the dimensions of the additive is in the range of 1 to 1000 nm.

[0080]

[0079] According to one embodiment, the UV-Vis radiation-curable coating composition described herein is i) Optionally, one or more (meth)acrylate oligomers as described herein, in the total amount described herein, preferably one or more (meth)acrylate oligomers as described herein; ii) Preferably in the total amount described herein, one or more (meth)acrylate monomers selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof as described herein, wherein the one or more monomers are different from the (meth)acrylate oligomers of i); iii) One or more cyclic ether compounds selected from the group consisting of epoxides, oxetanes, and mixtures thereof, preferably alicyclic epoxides, oxetanes, and mixtures thereof, in total amounts as described herein; iv) One or more vinyl ether compounds as described herein in total amount; v) One or more onium photoinitiators as described herein in total amount; vi) One or more photoinitiators selected from the group consisting of alkoxyketones, acetophenones, benzophenones, ketosulfones, benzylketals, benzoin ethers, phosphine oxides, phenylglyoxylates, coumarins, camphorquinones, and mixtures thereof, in total amounts as specified herein; vii) One or more thermoplastic polymers as described herein, preferably polyvinyl butyral (PVB), in total amounts as described herein; viii) Non-spherical magnetic or magnetizable pigment particles, preferably non-spherical optically variable magnetic or magnetizable pigment particles, in the total amount specified herein; ix) Optionally, one or more photosensitizers, if present, preferably in the total amounts described herein; x) Optionally, one or more fillers or fillers in the total amount specified herein; xi) Optionally, one or more UV stabilizers in the total amount specified herein; xii) Optionally, one or more color-specific coloring components in the total amount described herein; xiii) Optionally, one or more solvents in the total amount described herein; xiv) optionally one or more marker substances or tagants and / or one or more machine-readable materials as described herein; and xv) Optionally, one or more additives selected from the group consisting of thickeners, surfactants, anti-settling agents, plasticizers, defoamers, waxes, and mixtures thereof.

[0081]

[0080] The UV-Vis radiation-curable coating compositions described herein may be prepared by dispersing or mixing all of the components described herein to form a liquid composition. Alternatively, one or more photoinitiators v) and vi), and any one or more photosensitizers ix), may be added to the composition during the dispersion or mixing step of all the other components, or at a later stage, i.e., after the formation of the liquid coating composition.

[0082]

[0081] Furthermore, a method for producing an optical effect layer (OEL) on a substrate is described herein, the OEL being based on magnetically oriented non-spherical magnetic or magnetizable pigment particles, such as those described herein. The method described herein includes a) applying the UV-Vis radiation-curable coating composition described herein onto a substrate, such as those described herein, to form a coating layer; b) exposing the coating layer in a first state to a magnetic field of a magnetic field generator, thereby oriented at least a portion of the non-spherical magnetic or magnetizable pigment particles described herein; and c) solidifying the coating layer in a second state, fixing the non-spherical magnetic or magnetizable pigment particles in their adopted positions and orientations.

[0083]

[0082] The method described herein comprises step a) applying the UV-Vis radiation-curable coating composition described herein onto a substrate described herein to form a coating layer, wherein the coating composition is in a first physical state that allows for its application as a layer and is not yet solidified (i.e., wet), and non-spherical magnetic or magnetizable pigment particles can move and rotate within the binder material. Preferably, step a) is performed by a printing process preferably selected from the group consisting of screen printing, gravure printing, flexographic printing, intaglio printing (also referred to in the art as stamped copper printing, stamped steel die printing), pad printing, and curtain coating, more preferably intaglio printing, screen printing, gravure printing, pad printing, and flexographic printing, and even more preferably selected from the group consisting of screen printing, gravure printing, pad printing, and flexographic printing.

[0084]

[0083] The UV-Vis radiation-curable coating compositions described herein may be applied to the substrates described herein in the form of one or more marks. As used herein, the term “mark” means discontinuous layers including, but not limited to, codes, symbols, alphanumeric symbols, motifs, geometric patterns (e.g., circles, triangles, and regular or irregular polygons), letters, words, numbers, logos, figures, portraits, and combinations thereof. Examples of codes include coded alphanumeric data, one-dimensional barcodes, two-dimensional barcodes, QR codes (registered trademarks), and coded marks such as data matrices. One or more marks described herein may be solid marks and / or raster marks.

[0085]

[0084] The method described herein includes step a) as described herein, followed by step b) of exposing the coating layer to the magnetic field of a magnetic field generator to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles.

[0086]

[0085] According to one embodiment, step b) is performed to orient at least a portion of the magnetic or magnetizable pigment particles described herein in a uniaxial direction.

[0087]

[0086] According to another embodiment, the pigment particles are plate-shaped magnetic or magnetizable pigment particles, and step b) is performed such that at least a portion of the plate-shaped magnetic or magnetizable pigment particles are oriented in two axes, preferably so that at least a portion of the plate-shaped magnetic or magnetizable pigment particles are oriented in two axes so that both their X and Y axes are substantially parallel to the substrate surface.

[0088]

[0087] According to another embodiment, the pigment particles are plate-shaped magnetic or magnetizable pigment particles, and step b) consists of two steps: a first step of exposing the coating layer to the magnetic field of a magnetic field generator to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles in two axes, and a second step of exposing the coating layer to the magnetic field of a second magnetic field generator to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles in one axis, wherein the second step is performed partially simultaneously with, simultaneously with, or after the first step.

[0089]

[0088] In embodiments of the method described herein, which includes the step of exposing a coating layer to the magnetic field of a magnetic field generator described herein to orient at least a portion of the magnetic or magnetizable pigment particles in two axes, the coating layer may subsequently be exposed to the magnetic field generator more than once.

[0090]

[0089] In contrast to uniaxial orientation, in which magnetic or magnetizable pigment particles are oriented so that only their principal axes are constrained by a magnetic field, performing biaxial orientation means oriented so that the two main axes of the plate-shaped magnetic or magnetizable pigment particles are constrained. That is, each plate-shaped magnetic or magnetizable pigment particle can be thought of as having a major axis on the surface of the pigment particle and an orthogonal minor axis on the surface of the pigment particle. The major and minor axes of the plate-shaped magnetic or magnetizable pigment particles are oriented according to the magnetic field, respectively. Effectively, this results in plate-shaped magnetic pigment particles that are adjacent to each other in close proximity with gaps in between, substantially parallel to each other. In other words, biaxial orientation aligns the surfaces of plate-shaped magnetic or magnetizable pigment particles so that the surfaces of the pigment particles are oriented substantially parallel to the surfaces of adjacent (in all directions) plate-shaped magnetic or magnetizable pigment particles. The biaxial orientation of the plate-shaped magnetic or magnetizable pigment particles described herein results in the plate-shaped magnetic or magnetizable pigment particles forming a sheet-like structure having their X and Y axes preferably substantially parallel to the substrate surface, and thus being planar in two dimensions.

[0091]

[0090] A magnetic field generator suitable for oriented the non-spherical magnetic or magnetizable pigment particles described herein in a uniaxial direction is not limited to, but examples include multipole magnets such as dipole magnets, quadrupole magnets, hexapole magnets, and octapole magnets, and combinations thereof. The following apparatus is provided herein as an example.

[0092]

[0091] An optical effect known as the flip-flop effect (also referred to in the art as the switch effect) comprises a first printed portion and a second printed portion separated by a transition, wherein the pigment particles are aligned parallel to a first surface in the first portion and the pigment particles in the second portion are aligned parallel to a second surface. A method and magnets that produce the effect are disclosed, for example, in U.S. Patent Application Publication 2005 / 0106367 and European Patent No. 1819525.

[0093]

[0092] An optical effect known as the rolling bar effect, as disclosed in U.S. Patent Application Publication No. 2005 / 0106367, may also be produced. The “rolling bar” effect is based on a pigment particle orientation that mimics a curved surface across the coating. The observer sees a specular reflection zone that moves away from or towards the observer when the image is tilted. The pigment particles are curved and aligned, following a convex surface (also referred to in the Art as a negative curve orientation) or a concave surface (also referred to in the Art as a positive curve orientation). Methods and magnets that produce the effect are disclosed, for example, in European Patent Application Publication No. 2263806, European Patent No. 1674282, European Patent Application Publication No. 2263807, International Publication No. 2004 / 007095, International Publication No. 2012 / 104098, and International Publication No. 2014 / 198905.

[0094]

[0093] An optical effect known as the Venetian blind effect may also be produced. The Venetian blind effect involves pigment particles oriented to make visible to the underlying substrate surface along a particular direction of observation, such that marks or other features present on or within the substrate surface become apparent to the observer while interfering with their visibility along other directions of observation. Methods and magnets for producing the effect are disclosed, for example, in U.S. Patent No. 8,025,952 and European Patent No. 1819525.

[0095]

[0094] An optical effect known as the moving ring effect may also be produced. The moving ring effect consists of optical illusion images of objects such as funnels, cones, bowls, circles, ellipses, and hemispheres that appear to move in any xy direction depending on the inclination angle of the optical effect layer. Methods and magnets for producing the effect are disclosed, for example, in European Patent Publication No. 1710756, U.S. Patent No. 8,343,615, European Patent Publication No. 2306222, European Patent Publication No. 2325677, International Publication No. 2011 / 092502, U.S. Patent Publication No. 2013 / 0084411, International Publication No. 2014108404, and International Publication No. 2014 / 108303.

[0096]

[0095] An optical effect may also be produced that gives an optical impression of the pattern of light and dark areas that move when the above effect is tilted. A method and magnet for producing the above effect are disclosed, for example, in International Publication No. 2013 / 167425.

[0097]

[0096] Optical effects may also be produced that produce an optical impression of a loop-shaped body having a size that changes when the above effect is tilted. Methods and magnets for producing these optical effects are disclosed, for example, in International Publication Nos. 2017 / 064052, 2017 / 080698, and 2017 / 148789.

[0098]

[0097] When the optical effect layer is tilted, an optical impression of one or more loop-shaped bodies whose shape changes may also be produced. A method and magnet for producing the said effect are disclosed, for example, in International Publication No. 2018 / 054819.

[0099]

[0098] When tilted, an optical effect may be produced that gives the optical impression of a crescent moon as it moves and rotates. A method and magnet for producing the said effect are disclosed, for example, in International Publication No. 2019 / 215148.

[0100]

[0099] An optical effect may be provided that gives the optical impression of a loop-shaped body whose size and shape change when tilted. A method and magnet for providing the said effect are disclosed, for example, in the concurrently pending PCT patent application, International Publication No. 2020 / 052862.

[0101]

[0100] The optical effect that produces the optical impression of the ortho parallax effect may be in the form of a bright reflective vertical bar that moves vertically when the substrate is tilted around the horizontal / latitude axis, or horizontally / latitude when the substrate is tilted around the longitudinal axis. A method and magnet for producing the effect is disclosed, for example, in International Publication No. 2020 / 160993.

[0102]

[0101] An optical effect may be produced that gives the optical impression of one loop shape surrounded by one or more loop shapes, the one or more loop shapes having shapes and / or luminances that change when tilted. A method and magnet for producing the effect is disclosed, for example, in International Publication No. 2020 / 193009.

[0103]

[0102] When the substrate is tilted around the vertical / longitudinal axis, an optical effect may be produced that produces an optical impression of multiple dark spots and multiple bright spots that move and / or appear and / or disappear in an oblique direction, as well as when the substrate is tilted. Methods and magnets for producing the said effect are disclosed, for example, in International Publication No. 2021 / 083808 and International Publication No. 2021 / 083809.

[0104]

[0103] Suitable magnetic field generating devices may also include magnetic plates supporting one or more reliefs, markings or notches. International Publication Nos. 2005 / 002866 and International Publication Nos. 2008 / 046702 are examples of such marking magnetic plates.

[0105]

[0104] A suitable magnetic field generator includes a soft magnetic plate supporting one or more marks in the form of recesses and / or protrusions, or a soft magnetic plate containing one or more spaces having the shape of one or more marks, wherein the orientation step is performed by forming an assembly of substrates supporting a coating layer on the soft magnetic plate, and the assembly is moved by a non-uniform magnetic field of a static magnetic field generator to orient at least a portion of plate-shaped magnetic or magnetizable pigment particles in two axes, as described in International Publication Nos. 2018 / 019594 and International Publication Nos. 2018 / 033512.

[0106]

[0105] A suitable magnetic field generator further includes a soft magnetic plate including one or more spaces for housing one or more dipole magnets, and one or more recesses and / or one or more protrusions forming one or more continuous loop-shaped markings and / or one or more discontinuous loop-shaped markings, as described in International Publication No. 2020 / 025218, or includes one or more spaces and one or more dipole magnets disposed within one or more spaces, and / or a soft magnetic assembly facing one or more pairs of two dipole magnets disposed at regular intervals from the one or more spaces and / or the soft magnetic plate.

[0107]

[0106] A magnetic field generator suitable for orienting the plate-shaped magnetic or magnetizable pigment particles described herein in two axial directions is not limited to this specification.

[0108]

[0107] A particularly preferred apparatus for orienting pigment particles in two axial directions is disclosed in European Patent Application Publication No. 2157141. In the operation of a substrate supporting a coating layer containing pigment particles, the apparatus disclosed in European Patent Application Publication No. 2157141 generates a dynamic magnetic field that rapidly vibrates the pigment particles by changing their direction until both of the principal axes (X and Y axes) are substantially parallel to the substrate surface, that is, the pigment particles are rotated until they become a stable sheet-like formation with their X and Y axes substantially parallel to the substrate surface, and are planarized in the two dimensions.

[0109]

[0108] Other particularly preferred apparatus for orienting pigment particles in two axial directions include a linear permanent magnet Halbach array, i.e., an apparatus comprising a plurality of magnets and a cylinder apparatus having different magnetization directions. A detailed description of Halbach permanent magnets is given by ZQZhu and D. Howe (Halbach permanent magnet machines and applications: a review, IEE. Proc. Electric Power Appl, 2001, 148, pp. 299-308). The magnetic field produced by such a Halbach array has the property that it is concentrated on one side while being weakened to almost zero on the other side. Linear Halbach arrays are disclosed, for example, in International Publication No. 2015 / 086257 and International Publication No. 2018 / 019594, and a Halbach cylinder apparatus is disclosed in European Patent No. 3224055.

[0110]

[0109] Another particularly preferred apparatus for orienting pigment particles in two axes is a rotating magnet, which includes a disc-shaped rotating magnet or magnetic field generator that is substantially magnetized along its diameter. A suitable rotating magnet or magnetic field generator is described in U.S. Patent Application Publication 2007 / 0172261, which generates a radially symmetric time-varying magnetic field that enables the bi-orientation of magnetic or magnetizable pigment particles in an uncured coating composition. These magnets or magnetic field generators are driven by an axis (or spindle) connected to an external motor. Chinese Patent No. 102529326 discloses an example of an apparatus including a rotating magnet that would be suitable for orienting magnetic or magnetizable pigment particles in two axes. In a preferred embodiment, a suitable apparatus for orienting magnetic or magnetizable pigment particles in two axes is a disc-shaped rotating magnet or magnetic field generator without an axis, contained in a housing made of a non-magnetic, preferably non-conductive material, and driven by one or more magnet wire coils wound around the housing. Examples of such axisless, disc-shaped rotating magnets or magnetic field generators are disclosed in International Publication Nos. 2015 / 082344, 2016 / 026896, and 2018 / 141547.

[0111]

[0110] Other particularly preferred apparatus for oriented pigment particles in two axial directions are shown in International Publication No. 2021 / 239607, Figure 3A, and include: a) at least a first set (S1) and a second set (S2), each of the first and second sets (S1, S2) comprising a first bar dipole magnet having a magnetic axis oriented substantially parallel to the substrate during magnetization orientation, and two bar dipole magnets having magnetic axes oriented substantially perpendicular to the substrate; and b) a third pair of bar dipole magnets (P1) having a magnetic axis oriented substantially parallel to the substrate, for example, as disclosed in International Publication No. 2021 / 239607.

[0112]

[0111] The method described herein includes step c) solidifying the coating layer into a second state so as to fix non-spherical magnetic or magnetizable pigment particles in their adopted positions and orientations. The solidification step is performed with one or more light sources to cure the coating layer, the one or more light sources being selected from the group consisting of mercury lamps (preferably medium-pressure mercury lamps), UV-LED lamps, and arrays thereof to form one or more optical effect layers (OELs) as described herein. A typical array includes the use of one or more UV-LED lamps in the first step and one or more medium-pressure mercury lamps in the second step to partially cure the UV-Vis radiation-curable coating composition. Mercury lamps advantageously emit a wide range of wavelengths in the UV-A, UV-B, and UV-C ranges. Step d) solidifying the coating layer as described herein may be performed partially simultaneously with or after step b) as described herein. "Partially simultaneously" means that both steps are performed partially simultaneously, i.e., the time spent performing each step partially overlaps. In the context described herein, if the hardening / curing step c) is performed partially simultaneously with the orientation step b), it should be understood that the hardening becomes effective after the orientation of the non-spherical magnetic or magnetizable pigment particles in the coating layer, before complete or partial hardening.

[0113]

[0112] The present invention provides the present invention for producing optical effect layers (OELs) and substrates comprising one or more obtained optical effect layers (OELs). The substrates described herein are preferably selected from the group consisting of paper or other fibrous materials (including woven and nonwoven fibrous materials), such as cellulose, paper-containing materials, glass, metals, ceramics, plastics and polymers, metallized plastics or polymers, composite materials, and two or more mixtures or combinations thereof. Typical paper, paper-like or other fibrous materials consist of various fibers, but are not limited to abaca, cotton, linen, wood pulp, and mixtures thereof. As is well known to those skilled in the art, cotton and cotton / linen mixtures are preferred for banknotes, while wood pulp is commonly used in non-banknote security documents. According to other embodiments, the substrates described herein are based on plastics and polymers, metallized plastics or polymers, composite materials, and two or more 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-naphthate) (PEN); and polyvinyl chloride (PVC). Spunbond olefin fibers, such as those sold under the trademark Tyvek®, may also be used as a base material. Typical examples of plated plastics or polymers include the above-mentioned plastic or polymer materials with metals arranged continuously or discontinuously on their surface. Typical examples of metals include, but are not limited to, aluminum (Al), chromium (Cr), copper (Cu), gold (Au), silver (Ag), their alloys, and combinations of two or more of the aforementioned metals. The metallization of the plastic or polymer material 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 paper structures and at least one plastic or polymer material such as those described above, as well as plastic and / or polymer fibers incorporated into paper-like or fibrous materials such as those described above. Naturally, the substrate may contain further additives known to those skilled in the art, such as fillers, adhesives, bleaching agents, processing aids, reinforcing agents, or wet strength enhancers. When the OEL is used for decorative or cosmetic purposes, for example, including nail lacquer, the OEL may be made on other types of substrates, including animal or human nails, artificial nails, or other parts.

[0114]

[0113] The Specified herein also describes a method for manufacturing a security document or a decorative element or ornament, the method comprising: a) preparing a security document or a decorative element or ornament; and b) preparing one or more optical effect layers as described herein, such as those obtained by the method described herein, to be included in the security document or a decorative element or ornament.

[0115]

[0114] If an OEL produced according to the present invention is on a security document or article, the substrate may include printing, coating, or laser marks or laser-punched marks, water level indicators, anti-counterfeiting threads, fibers, planchettes, luminescent compounds, windows, foils, decals, and two or more combinations thereof, for the purpose of further improving the security level and resistance to counterfeiting and illegal reproduction of the security document or article. For the same purpose of further improving the security level and resistance to counterfeiting and illegal reproduction of the security document and article, the substrate may include one or more marking substances or identification additives and / or machine-readable substances (e.g., luminescent substances, UV / visible / IR absorbing substances, magnetic materials, and combinations thereof).

[0116]

[0115] If necessary, a primer layer may be applied to the substrate before step a). This may improve the quality of the OEL described herein or promote adhesion. An example of such a primer layer can be found in International Publication No. 2010 / 058026.

[0117]

[0116] Substrates containing one or more OELs as described herein may be embossed, for example, by intaglio printing, as described in International Publication No. 2012 / 025206 and International Publication No. 2019 / 233624.

[0118]

[0117] The OELs described herein may be used in combination with holograms, microlenses and / or micromirrors as described in International Publication No. 2020 / 244805, European Patent Application Publication No. 3254863, U.S. Patent Application Publication No. 2008 / 0160226, U.S. Patent Application Publication No. 2005 / 0180020, and European Patent Application Publication No. 2284017.

[0119]

[0118] For the purpose of improving the durability against dirt or chemical resistance and cleanliness, and thus the cyclic life of security documents, articles, or decorative elements or ornaments containing OEL obtained by the method described herein, or for the purpose of altering their aesthetic properties (e.g., optical gloss), one or more protective layers may be applied to the OEL. If present, one or more protective layers typically consist of a protective varnish. The protective varnish may be a radiation-curable composition, a heat-curing composition, or any combination thereof. Preferably, one or more protective layers are a radiation-curable composition, more preferably a UV-Vis-curable composition. The protective layers are typically applied after the formation of the OEL.

[0120]

[0119] The OEL described herein may be provided directly on a permanent substrate (e.g., for banknote applications). Alternatively, the optical effect layer may also be provided on a temporary substrate for the purpose of production from which the OEL is subsequently removed. This can facilitate the formation of the optical effect layer (OEL), for example, while the binder material is still in its fluid state. After the coating composition for the production of the OEL has cured, the temporary substrate may be removed from the OEL.

[0121]

[0120] Alternatively, in other embodiments, the adhesive layer may be present on the substrate side including the OEL, and the adhesive layer may be on the substrate opposite to the side on which the OEL is provided, or on the same side as the OEL, and on the OEL. Thus, the adhesive layer may be applied to the OEL or the substrate, and the adhesive layer may be applied after the curing step is completed. Such articles may be attached to various types of documents or other articles or goods without machinery and printing and other processes with a fairly high effect. Alternatively, the substrate described herein, including the OEL as described herein, may be in the form of a transfer foil, which can be applied to documents or articles in separate transfer steps. For this purpose, the substrate is provided with a release coating, and the OEL is made thereon as described herein. One or more adhesive layers may be applied to the optical effect layer thus made.

[0122]

[0121] Furthermore, substrates having more than one optical effect layers (OELs), i.e., two, three, four, etc., obtained by the method described herein are also described herein.

[0123]

[0122] Articles, documents, in particular security documents, decorative elements, and decorative objects containing optical effect layers (OELs) produced by the present invention are also described herein. Articles, in particular security documents, decorative elements, or decorative objects may contain more than one (e.g., two, three, etc.) OELs produced by the present invention.

[0124]

[0123] As described above, the OEL produced by the present invention may be used for decorative purposes and for protecting and authenticating security documents.

[0125]

[0124] Representative examples of decorative elements or ornaments include, but are not limited to, luxury goods, cosmetic packaging, automotive parts, electronic / electrical appliances, furniture, and nails.

[0126]

[0125] Examples of security documents include, but are not limited to, value documents and value goods. Representative examples of value documents include, but are not limited to, banknotes, certificates, tickets, invoices, certificates, revenue stamps, and tax labels, agreements, etc., passports, identification cards, visas, driver's licenses, bank cards, credit cards, transaction cards, access documents or cards, admission tickets, public transport tickets, academic diplomas or rights, etc. Preferably, identity documents such as banknotes, identity documents, granting documents, driver's licenses, and credit cards. The term “value goods” refers in particular to cosmetics, nutritional supplements, pharmaceuticals, alcohol, tobacco products, beverages or food, electrical / electronic articles, textiles or jewelry, i.e., packaging materials for articles that are protected from counterfeiting and / or illegal reproduction in order to guarantee the contents of the packaging, such as for genuine pharmaceuticals. Examples of these packaging materials include, but are not limited to, labels such as authentication brand labels, tampa certification labels, and seals. Without limiting the scope of the present invention, it is noted that the disclosed substrates, value documents, and value goods are given solely for illustrative purposes.

[0127]

[0126] Alternatively, the optical effect layer (OEL) described herein may be made on an auxiliary substrate such as a security thread, security stripe, foil, decal, window, or label, and therefore transferred to the security document in separate steps.

[0128]

[0127] Those skilled in the art can anticipate several modifications from the above-described embodiments without departing from the spirit of the present invention. Such modifications are incorporated into the present invention.

[0129]

[0128] Furthermore, all references made throughout the specification are incorporated in their entirety by reference, so as to be fully described herein.

[0130] [Examples]

[0129] The present invention will be described in more detail below with reference to non-limiting examples. Examples (E1 and E2) and comparative examples (C1 to C3) were prepared with the UV-Vis radiation-curable coating compositions listed in Table 1, and the compositions according to the present invention will be described in more detail.

[0131]

[0130] The UV-Vis radiation-curable coating compositions shown in Table 1 were used to prepare two different sets of samples: a first set (Figure 1) prepared to evaluate different compositions and the magnetic orientation process imparted to the visual quality of the resulting OEL; and a second set of samples (Figures 2 and 3) prepared to evaluate the mechanical properties and resistance of the printed and solidified layers. [Table 1] JPEG2026530599000009.jpg131149

[0132] Sample from the first set: Magnetic orientation quality test (Figure 1)

[0131] In order to ensure the same process conditions for Examples E1 and E2 and Comparative Examples C1 to C3, the five UV-Vis radiation-curable coating compositions shown in Table 1 were applied in a straight line on white credit-printing paper (dimensions: 17.5 cm × 14.5 cm, from Louisenthal) using a pipette, manually forming a line (total length approximately 125 mm), and simultaneously oriented using a single magnetic assembly as shown in Figure 4.

[0133]

[0132] Approximately 1 ml of each of the UV-Vis radiation-curable coating compositions in Table 1 was applied separately as lines (approximately 25 mm in length) using disposable laboratory pipettes. The five UV-Vis radiation-curable coating compositions were then semi-automatically drawn using a K-Control Coater Model 101 and a K-bar HC3 (wet deposit approximately 24 μm thick) K-paint dispenser (RK PRINTCOAT INSTRUMENTS) (speed 3) simultaneously.

[0134]

[0133] A substrate supporting the applied layer, consisting of the five UV-Vis radiation-curable coating compositions of Table 1, is placed on the magnetic assembly described herein and schematically illustrated in Figure 4. The magnetic assembly comprised a non-magnetic holder and four dipole magnets. The four dipole magnets each had the following dimensions: length L4 of 30 mm, width L5 of 24 mm, and thickness L6 of 8.5 mm (plastic-bonded NdFeB magnets manufactured by molding, BMNpi-80 / 48 mold from Bomatec AG, CH-8181 Hori). Each of the four dipole magnets had a magnetic axis substantially parallel to its width and substantially parallel to the substrate surface. The four dipole magnets were arranged side by side in the non-magnetic holder, with their magnetic axes parallel to each other and their north poles pointing in the same direction. The non-magnetic holder had the following dimensions: length L1 of 140 mm, width L2 of 60 mm, and thickness L3 of 17.95 mm, and was made of polyphenylene sulfide (PPS). The top surface of the holder (i.e., the surface facing the substrate) was machined into a curved shape so that it would be flush with the surface of the magnetic cylinder when arranged on top of the magnetic cylinder.

[0135]

[0134] The distance (d) between the top surface of the dipole magnet and the top surface of the non-magnetic holder (which also corresponds to the distance between the top surface of the dipole magnet and the substrate) was 3.35 mm.

[0136]

[0135] The magnetic orientation pattern thus obtained for the magnetic pigment particles was then fixed by curing the layer containing the pigment particles using an Fe-doped Hg lamp (two passes at a speed of 150 W / cm; 100 m / min from IST) partially simultaneously with the orientation step (i.e., while the substrate supporting the coating layer consisting of five UV-Vis radiation-curable coating compositions was still in a magnetic field).

[0137]

[0136] Figure 1 shows the OELs obtained in the manner of Examples E1 and E2 and Comparative Examples C1 to C3. As illustrated in Figure 1, OELs E1 and E2 and C2 and C3 were clearly defined and showed a noticeable effect, exhibiting clear and sharp lines, while comparative OEL C1 was blurred and not clearly defined. As shown in Figure 1, comparative composition C1 is known to be used to provide security features including leafing pigments and is unsuitable for the production of OELs, ​​so no further evaluation of C1 was performed.

[0138] Sample of the second set

[0137] The UV-Vis radiation-curable coating compositions E1 and E2 and C2 and C3 of Table 1 were separately applied to white credit paper (6cm × 6cm, from Louisenthal) (x20), and the application was carried out by manual screen printing using a 90T screen to form a coating layer having a thickness of approximately 20 μm and having the shape of a disk surrounded by six circles with the following overall dimensions: 30 mm × 22 mm.

[0139]

[0138] Substrates supporting the coating layers made of UV-Vis radiation-curable coating compositions were separately placed on dipole magnets (plastic-bonded NdFeB magnets made by molding, BMNpi-80 / 48 mold from Bomatec AG, CH-8181 Hori) and had the following dimensions: length 30 mm, width 24 mm, thickness 8.5 mm, with a magnetic axis parallel to the substrate surface. The magnetic orientation patterns thus obtained for the magnetic pigment particles were then fixed by curing the layers containing the pigment particles using an Fe-doped Hg lamp (150 W / cm; two passes at a speed of 100 m / min from IST) in conjunction with the orientation step and partially simultaneously (i.e., while the substrates supporting each coating layer were still in the magnetic field).

[0140]

[0139] The OELs obtained in Examples E1 and E2 and Comparative Examples C2 and C3 exhibited a highly dynamic, clearly defined, and prominent effect, showing a clear and sharp line that moved up and down when the OEL was tilted. The OEL of Comparative Example C1 was not clearly defined and did not show a sharp line.

[0141] Mechanical resistance test: Dry wrinkle test (Figure 2)

[0140] Each sample consisting of compositions E1 and E2 and C2 and C3 was separately submitted for a dry wrinkle test using an IGT NBS wrinkle-forming apparatus from IGT Testing Systems according to the following process.

[0142]

[0141] Each sample was wound separately along one of its edges with the OEL facing the inside of the roll. The resulting reel was introduced into the creasing device and the device plunger was introduced. The sample was withdrawn from the device and the process was repeated along three opposite sides of the substrate.

[0143]

[0142] The OEL from Example E1 was evaluated as excellent, meaning no significant visible changes were observed, and the OEL remained unchanged after the test with no observable substrate within the layer (Figure 2). The OEL from Example E2 was evaluated as good, meaning only slight damage to the layer was observed. The OELs from Comparative Examples C2 and C3 were evaluated as poor, meaning significant damage to the layer was observed.

[0144] Mechanical resistance test: Washing machine test (Figure 3)

[0143] Each sample consisting of compositions E1 and E2 and C2 was submitted to a washing machine test according to the following process. C1 and C3 were not evaluated because they did not pass at least one of the previous tests.

[0145]

[0144] Each sample was inserted separately into a washing glove and secured with two needles. The washing gloves containing the samples were washed in a washing machine at 60°C for 1.5 hours with phosphate-free washing powder (spin drying speed of 800 rpm). The samples were removed from the washing gloves and dried in an oven at 60°C for 1 hour between two glass plates.

[0146]

[0145] The OEL consisting of Examples E1 and E2 was evaluated as good, meaning that only slight damage to the layer was observed. The OEL consisting of Comparative Example C2 was evaluated as poor, meaning that significant damage to the layer was observed (Figure 3).

Claims

1. A UV-Vis radiation-curable coating composition for producing an optical effect layer (OEL), wherein the composition comprises: i) Optionally, one or more (meth)acrylate oligomers in a total amount of about 0% to about 10% by weight, preferably about 1% to about 10% by weight; ii) one or more (meth)acrylate monomers, preferably selected from the group consisting of tri(meth)acrylate, tetra(meth)acrylate, and mixtures thereof, in a total amount of about 1% to about 20% by weight, wherein the monomer is different from the (meth)acrylate oligomer of i); iii) A total amount of about 5% to about 40% by weight of a cyclic ether compound, preferably an epoxide, an oxetane, and mixtures thereof, more preferably one or more cyclic ether compounds selected from the group consisting of alicyclic epoxides, oxetanes, and mixtures thereof; iv) One or more vinyl ether compounds in a total amount of approximately 10% to 50% by weight; v) One or more onium photoinitiators in a total amount of approximately 0.1% to approximately 10% by weight; vi) One or more photoinitiators selected from the group consisting of alkoxyketones, acetophenone, benzophenone, ketosulfone, benzyl ketal, benzoin ether, phosphine oxide, phenylglyoxylate, coumarin, camphorquinone, and mixtures thereof, in a total amount of about 0.1% to about 10% by weight; vii) One or more thermoplastic polymers in a total amount of about 1% to about 20% by weight; and viiii) Contains non-spherical magnetic or magnetizable pigment particles in a total amount of approximately 1% to 40% by weight, The aforementioned weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition, wherein the UV-Vis radiation-curable coating composition is a UV-Vis radiation-curable coating composition.

2. The one or more (meth)acrylate oligomers i) are present in a total amount of approximately 2% to 5% by weight; The one or more (meth)acrylate monomers ii) are present in a total amount of about 2% to 15% by weight; The one or more cyclic ether compounds iii) are present in a total amount of about 10% to 35% by weight; The one or more vinyl ether compounds iv) are present in a total amount of about 15% to 40% by weight; The one or more onium photoinitiators v) are present in a total amount of approximately 1% to 5% by weight; The one or more photoinitiators vi) are present in a total amount of about 1% to 5% by weight; The one or more thermoplastic polymers vii) are present in a total amount of about 3% to 15% by weight; The non-spherical magnetic or magnetizable pigment particles (viii) are present in a total amount of approximately 3% to 35% by weight; The UV-Vis radiation-curable coating composition according to claim 1, wherein the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

3. The UV-Vis radiation-curable coating composition according to claim 1 or 2, wherein at least one of the one or more thermoplastic polymers is polyvinyl butyral (PVB) and / or polyvinyl chloride (PVC).

4. The non-spherical magnetic or magnetizable pigment particles are non-spherical optically variable magnetic or magnetizable pigment particles, preferably the non-spherical optically variable magnetic or magnetizable pigment particles are selected from the group consisting of magnetic thin-film interference pigment particles, magnetic cholesteric liquid crystal pigment particles, interference coated pigment particles containing a magnetic material, and mixtures of two or more thereof, according to any one of claims 1 to 3.

5. The UV-Vis radiation-curable coating composition according to any one of claims 1 to 4, further comprising about 0.1% to about 5% by weight of one or more photosensitizers, wherein the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

6. The UV-Vis radiation-curable coating composition according to any one of claims 1 to 5, further comprising about 0.1% to about 10% by weight of one or more fillers or extenders, wherein the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

7. A UV-Vis radiation-curable coating composition according to any one of claims 1 to 6, further comprising about 0.1% to about 10% by weight of one or more UV stabilizers, wherein the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

8. The UV-Vis radiation-curable coating composition according to any one of claims 1 to 7, further comprising approximately 0.05% to approximately 5% by weight of one or more color-constant coloring components, wherein the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

9. A UV-Vis radiation-curable coating composition according to any one of claims 1 to 8, further comprising one or more marker substances or tagants and / or one or more machine-readable materials.

10. The UV-Vis radiation-curable coating composition according to any one of claims 1 to 9, further comprising one or more solvents in a total amount of less than 15% by weight, wherein the weight percentage is based on the total weight of the UV-Vis radiation-curable coating composition.

11. A UV-Vis radiation-curable coating composition according to any one of claims 1 to 10, further comprising one or more additives selected from the group consisting of thickeners, surfactants, anti-settling agents, plasticizers, defoamers, waxes, and mixtures thereof.

12. A method for fabricating an optical effect layer (OEL), a) A step of applying the UV-Vis radiation-curable coating composition according to any one of claims 1 to 11 onto a substrate to form a coating layer, b) Exposing the coating layer in the first state to the magnetic field of a magnetic field generator, thereby orienting at least a portion of the non-spherical magnetic or magnetizable pigment particles; c) A method comprising the step of solidifying the coating layer into a second state to fix the non-spherical magnetic or magnetizable pigment particles in their adopted positions and orientations.

13. The method according to claim 12, wherein the solidification step c) is performed partially simultaneously with step b).

14. Step b) of exposing the coating layer to the magnetic field of the magnetic field generator is performed such that at least a portion of the non-spherical magnetic or magnetizable pigment particles are oriented in a uniaxial direction, or The non-spherical magnetic or magnetizable pigment particles are plate-shaped magnetic or magnetizable pigment particles, and step b) of exposing the coating layer to the magnetic field of the magnetic field generator is performed such that at least a portion of the plate-shaped magnetic or magnetizable pigment particles are oriented in two axial directions, or The method according to claim 12 or 13, wherein the non-spherical magnetic or magnetizable pigment particles are plate-shaped magnetic or magnetizable pigment particles, and step b) of exposing the coating layer to the magnetic field of the magnetic field generator comprises two steps: a first step of exposing the coating layer to the magnetic field of the magnetic field generator to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles in two axes, and a second step of exposing the coating layer to the magnetic field of a second magnetic field generator to orient at least a portion of the plate-shaped magnetic or magnetizable pigment particles in one axis, wherein the second step is performed partially simultaneously with, simultaneously with, or subsequently with the first step.

15. The method according to any one of claims 12 to 14, wherein step a) of applying the UV-Vis radiation-curable coating composition is carried out by a process selected from the group consisting of screen printing, gravure printing, pad printing, and flexographic printing.

Images