Ultraviolet-visible radiation curable security ink

Abstract

The present invention relates to the field of security inks suitable for printing security features on substrates, especially security documents or articles, as well as security features made from said security inks and security documents comprising security features made from said security inks. In particular, the present invention provides UV-visible radiation cationically curable security inks and UV-visible radiation curable hybrid security inks comprising an ink vehicle and a pigment comprising a flaky non-metallic or metallic substrate comprising one or more at least partial coating layers and at least partial surface treatment layers made from one or more surface modifiers of the perfluoropolyether type.

Description

Detailed Description of the Invention

[0001] [Background Art]

[0001] The present invention relates to the field of security inks suitable for printing security functions on a substrate, particularly on a security document or an article.

[0002]

[0002] Due to the constantly improving quality of color copying and printing, and in attempts to protect security documents such as banknotes, valuable documents or cards, transportation tickets or cards, tax display strips, and product labels, etc., which have no replicable effects, from forgery, alteration or illegal replication, it has been conventionally practiced to incorporate various security means functions into these documents.

[0003]

[0003] For example, security functions for security documents can generally be classified into, on the one hand, "hidden" security functions and, on the other hand, "visible" security functions. The protection provided by hidden security functions relies on the concept that detection of such functions is difficult and typically requires special equipment and knowledge for detection, while "visible" security functions can be easily detected by the human senses without assistance. For example, such functions rely on the concept that they can be detected visually and / or tactilely, yet still be difficult to produce and / or reproduce. However, the effectiveness of visible security functions depends greatly on the fact that most users, and especially those without prior knowledge of the security functions of the protected document or article, will actually perform only the security checks based on such security functions if they have practical knowledge of the existence and nature of the security functions.

[0004]

[0004] Examples of visible security functions include a reflection function and an optically variable function, and the security functions exhibit a color shift or color change expressed by a change in brightness and / or chroma and / or hue due to a change in the observation angle. Typically, the security functions are made from inks containing platelet multilayer interference pigments.

[0005]

[0005] International Publication No. 2003 / 020834 discloses an aqueous security ink containing a flaky multilayer interference pigment for producing an optically variable security function. For the purpose of avoiding or reducing the corrosion of the pigment in the aqueous ink, the surface of the pigment is treated with a passivating agent such as a fluorinated organic ester of phosphoric acid. However, aqueous security inks can be difficult to print and the drying process can be long.

[0006]

[0006] International Publication No. 2006 / 117271 discloses a solvent security ink containing a flaky multilayer interference pigment for producing an optically variable security function. However, as the world's sensitivity to environmental problems and the necessary sensitivity to environmental regulations such as REACH and GHS in the chemical industry increases, inks containing significantly reduced amounts of organic solvents (volatile organic components, VOCs) have been formulated, promoting the development of industrially produced ultraviolet-visible radiation-curable screen printing inks containing the flaky pigment.

[0007]

[0007] It is known in the art that the perceived optical properties of the reflective and optically variable functions including the flaky pigment depend on the orientation of the flaky pigment in the dried ink on the substrate. The process of gradually drying an aqueous or solvent ink containing a flaky pigment reduces the thickness of the applied ink and aligns the flaky pigment substantially parallel to the substrate on which the ink is applied, thereby having the advantage of being able to produce a reflective function and an optically variable that exhibit good optical properties. Therefore, the process of immediately curing an ultraviolet-visible radiation-curable ink containing a flaky pigment and the thickness of the cured ink layer not substantially changing can cause random orientation of the pigment and may thereby produce a reflective function and an optically variable that exhibit inferior optical properties.

[0008]

[0008] For the purpose of improving the prominent effects and optical properties of the reflective function and the optically variable security function based on the flaky pigment, the pigment has been surface-treated with a hydrophobic compound so as to be more easily arranged in a plane substantially parallel to the substrate on which the ink containing the pigment is applied. In this document, the surface-treated pigment is called a leafing pigment.

[0009]

[0009] European Patent Application Publication No. 1090963 discloses a flaky nacreous pigment surface-treated with a fluorine-containing phosphate ester, and an ink, paint, plastic, or cosmetic containing the pigment. European Patent Application Publication No. 1090963 discloses a solvent gravure printing ink.

[0010]

[0010] U.S. Patent Application Publication No. 2002 / 0096087 discloses a platelet-shaped nacreous pigment based on platelet-shaped pigments containing at least one organic hydrophobic coupling agent such as a fluorine-containing silane, and the use of the pigment in paints, inks, plastics, coatings, and cosmetics.

[0011]

[0011] U.S. Patent Application Publication No. 2004 / 0069187 discloses a flaky pigment coated with a coupling agent and an organic compound having a perfluoroalkyl group, and the use of the pigment in printing inks.

[0012]

[0012] U.S. Patent Application Publication No. 2015 / 0166799 discloses a flaky effect pigment containing a fluoroalkyl group and a hydrophilic group and coated with an organic coating film formed from at least one siloxane and / or at least one silane, many uses of the pigment, and its use in paints, inks, plastics, coatings, and cosmetics.

[0013]

[0013] U.S. Patent Application Publication No. 2016 / 0207344 discloses a printed image composed of at least two region units on a substrate, wherein the first region unit contains a first flaky effect pigment having an outer layer containing a non-metallic inorganic material, and the second region unit contains a second flaky effect pigment having an outer layer containing an organic surface modifier such as an organofunctional siloxane containing a fluoroalkyl group and an aminoalkyl group. U.S. Patent Application Publication No. 2016 / 0207344 also discloses a printing ink which may be a solvent ink or an ultraviolet curable ink.

[0014]

[0014] International Publication No. 2013 / 119387 discloses an ultraviolet radiation radical curable metallic decorative composition containing leafing metallic pigment flakes, an acrylic oligomer and / or an acrylic monomer, an initiator or a mixture of initiators, and a curing accelerator which is a tertiary amine. The disclosed leafing metallic pigment flakes are surface-treated with a fatty acid, a phosphorus compound, a silane, or an aliphatic amine. The disclosed ultraviolet-visible radiation curable ink has drawbacks such as inferior optical properties including appearance and low chroma.

[0015]

[0015] Japanese Patent Application Laid-Open No. 2004244562 discloses an ultraviolet radiation cationic polymerizable ink containing a leafing aluminum pigment surface-treated with stearic acid, a cationic photoinitiator, and a hydroxyl group-containing fatty acid which improves the defoaming property of the ink. However, by using a cationic photoinitiator in a composition containing an aluminum pigment surface-treated with stearic acid, stearic acid is replaced by the acid generated by the cationic photoinitiator, and thereby the resulting leafing effect and optical properties are lost.

[0016]

[0016] Japanese Patent Application Laid-Open No. 2000273399 discloses an ultraviolet cationic or radical curable coating film-forming composition containing aluminum powder treated with an alkyl surfactant (stearic acid). Such treatment does not orient aluminum flakes parallel to the substrate surface at an industrial printing speed, and thus results in a cured coating film having low and inferior optical properties.

[0017]

[0017] Japanese Patent Application Laid-Open No. 2003-261817 discloses an ultraviolet cation-curable composition containing an aluminum pigment and an amine. The disclosed composition does not develop a metallic luster quickly enough in a high-speed industrial printing process, thus resulting in a cured coating film having poor optical properties.

[0018]

[0018] U.S. Patent No. 9,914,846 discloses a radiation-curable coating film composition containing a modified effect pigment, wherein the effect pigment is coated with at least one metal oxide layer and includes silicon dioxide, aluminum oxide, titanium dioxide, iron oxide, tin oxide, zinc oxide, or a mixture thereof, and at least one organic compound having one or more functional groups having a carbon-carbon multiple bond. Further, it is disclosed that the organic compound is bonded to the metal oxide layer and that a suitable modified effect pigment does not have an organic oligomer or polymer. U.S. Patent No. 9,914,846 discloses a coating film composition containing a conventional ultraviolet-curable compound, and both a radical-polymerizable binder and a cation-polymerizable binder can be used. The exemplified composition is an acrylic radical-curable ultraviolet printing ink containing an aluminum pigment coated with SiO2 and a methacryl-functional silane compound. Since the surface tension of the coating film base material is not optimized, a sufficiently fast orientation of the effect pigment cannot be obtained at an industrial printing speed, thus resulting in relatively poor optical properties.

[0019]

[0019] Therefore, there remains a need for a solvent-free or low-VOC-containing ultraviolet-visible radiation-curable security ink that is a cation-curable ink or a hybrid ink, especially in very demanding applications that require high resilience against counterfeiting and excellent optical properties. In particular, there is a need for an ultraviolet-visible radiation-curable security ink for producing a reflection function and an optically variable function based on a flaky multilayer interference pigment, wherein the security function exhibits improved optical properties with respect to chroma, lightness, and / or color shift properties.

[0020] [Summary]

[0020] Therefore, the object of the present invention is to overcome the deficiencies of the above-mentioned prior art.

[0021]

[0021] In a first aspect, the present invention provides an ultraviolet-visible radiation curable security ink, comprising: i) about 75% to about 99% by weight of an ink vehicle having a viscosity between about 200 and about 2000 mPas at 25°C, a) a1) about 45% to about 75% by weight of one or more alicyclic epoxides and a2) one or more cationic photoinitiators which are preferably onium salts selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof, about 2% to about 15% by weight, or b) b1) a mixture of about 45% to about 75% by weight of one or more alicyclic epoxides and one or more radical curable compounds selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof, b2) one or more cationic photoinitiators which are preferably onium salts selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof, and one or more radical photoinitiators which are preferably selected from the group consisting of hydroxyketones, alkoxyketones, acetophenone, benzophenone, ketosulfone, benzyl ketal, benzoin ether, phosphine oxide, phenylglyoxylate, thioxanthone, and mixtures thereof, more preferably selected from the group consisting of phosphine oxide, thioxanthone, alpha-hydroxyketone, and mixtures thereof, about 2% to about 15% by weight, c) Optionally, the ink vehicle contains less than about 20% by weight of one or more vinyl ethers, or less than about 30% by weight of one or more oxetanes, or less than about 15% by weight of a combination of one or more vinyl ethers and one or more oxetanes, wherein: The weight percentages of a), b), and c) are based on the total weight of the ink vehicle, and the ink vehicle and ii) about 1 to about 25% by weight of a pigment comprising a flaky non-metallic or metallic substrate, wherein the non-metallic or metallic substrate is one or more metal oxides, one or more metal hydroxides, one or more metal suboxides, or one or more at least partially formed from a mixture of these materials A coating layer, facing the environment, in direct contact with the upper layer of one or more at least partially formed coating layers, and at least partially formed from one or more surface modifiers selected from perfluoropolyethers A surface treatment layer, wherein the perfluoropolyether is functionalized with one or more phosphorus (P)-containing groups or one or more silicon (Si)-containing groups, a pigment An ultraviolet-visible radiation-curable security ink comprising An ultraviolet-visible radiation-curable security ink, wherein the weight percentages of i) and ii) are based on the total weight of the ultraviolet-visible radiation-curable security ink.

[0022]

[0022] Also described herein is the use of the ultraviolet-visible radiation-curable security ink described herein, preferably the ultraviolet-visible radiation-curable screen-printing security ink described herein, in the manufacture of one or more security features on a security document or article, and the security features obtained by its manufacture.

[0023]

[0023] Also described herein are the security features made from the ultraviolet-visible radiation-curable security ink described herein, preferably the ultraviolet-visible radiation-curable screen-printing security ink described herein.

[0024]

[0024] Also described herein is an article comprising a substrate and a radiation-cured coating film obtained by radiation curing of the ultraviolet-visible radiation-curable security ink described herein, preferably the ultraviolet-visible radiation-curable screen-printing security ink described herein.

[0025]

[0025] Also described herein is a method of making the article described herein, comprising a) Preferably, by a printing process selected from the group consisting of a rotary gravure process, a flexographic printing process, and a screen printing process, more preferably a screen printing process, the ultraviolet-visible radiation curable security ink described herein, preferably the ultraviolet-visible radiation curable screen printing security ink described herein, is printed on a substrate; b) curing the ultraviolet-visible radiation curable security ink to form one or more security features; A method including the above is also described.

[0026] [Detailed Description]

[0026] The following definitions are used to interpret the meaning of terms discussed in the description and recited in the claims.

[0027]

[0027] As used herein, the article "a" indicates one and more than one, and does not necessarily limit the noun being referred to to the singular.

[0028]

[0028] As used herein, the term "about" means that the quantity or value in question may be the specified particular value or another value in the vicinity. Generally, the term "about" indicating a value is intended to indicate a range of ±5% from that value. As an example, the phrase "about 100" indicates a range of 100 ± 5, that is, a range of 95 to 105. Preferably, the range indicated by the term "about" is within ±3% of that value, more preferably within ±1% of that value. Generally, when the term "about" is used, it can be expected that the same results or effects as those of the present invention can be obtained within the range of ±5% of the indicated value.

[0029] As used herein, the term "and / or" means that all or only one of the elements of the group may be present. For example, "A and / or B" means "only A, or only B, or both A and B". In the case of "only A", this term also encompasses the possibility that B is not present, i.e., "only A, not B".

[0030] As used herein, the term "at least" is intended to define one or two or more, for example one or two or three.

[0031] The term "comprising" as used herein is intended to be non-exclusive and open-ended. Thus, for example, a solution comprising compound A may also contain compounds other than A. However, since the term "comprising" also encompasses the more limiting meanings of "consisting essentially of" and "consisting of" as specific embodiments thereof, for example, a "solution comprising A, B, and optionally C" may (substantially) consist of A and B, or (substantially) consist of A, B, and C.

[0032] When this description refers to "preferred" embodiments or features, combinations of those "preferred" embodiments or features are also considered to be disclosed insofar as a particular combination of those "preferred" embodiments or features has technical meaning.

[0033] The term "security document" refers to a document that is normally protected from forgery or fraud by at least one security feature. Examples of security documents include, without limitation, valuable documents and valuable goods.

[0034] The terms "ultraviolet-visible curable" and "ultraviolet-visible curing" refer to radiation curing by photopolymerization under the influence of irradiation having wavelength components in the ultraviolet or ultraviolet and visible portions of the electromagnetic spectrum (typically between 100 nm and 800 nm, preferably between 150 and 600 nm, more preferably between 200 and 400 nm).

[0035]

[0035] The present invention provides a UV-visible radiation curable security ink, preferably selected from the group consisting of UV-visible radiation curable rotary gravure security ink, UV-visible radiation curable flexographic printing security ink, and UV-visible radiation curable screen printing security ink, more preferably a UV-visible radiation curable screen printing security ink.

[0036]

[0036] As is known to those skilled in the art, the term rotary gravure refers to a printing process described, for example, on page 48 of Handbook of Print Media, Helmut Kipphan, Springer Edition. Rotary gravure is a printing process in which image elements are engraved onto the surface of a cylinder. The non-image areas are at a constant original level. Before printing, the entire printing plate (non-printing and printing elements) is inked and immersed in ink. The ink is removed from the non-image areas by a wiper or blade before printing, and the ink remains only in the cells. The image is typically transferred from the cells to the substrate by pressure in the range of 2 to 4 bar and by the adhesive force between the substrate and the ink. The term rotary gravure does not include, for example, intaglio printing processes that depend on different types of ink (also called engraved steel die or copperplate printing processes in the art).

[0037]

[0037] The flexographic printing method preferably uses a unit having a chambered doctor blade, an anilox roller, and a plate cylinder. The anilox roller advantageously has small cells whose volume and / or density determine the application rate of the ink or varnish. The chambered doctor blade is placed on the anilox roller and fills the cells while scraping off the excess ink or varnish. The anilox roller transfers the ink to the plate cylinder, and the plate cylinder finally transfers the ink to the substrate. The plate cylinder can be made of a polymer or elastomer material. The polymer is mainly used as a photopolymer of the plate and sometimes as a seamless coating film on the sleeve. The photopolymer plate is made of a photosensitive polymer that is hardened by ultraviolet (UV) light. The photopolymer plate is cut to the required size and placed in a UV light exposure unit. One side of the plate is completely exposed to UV light to harden or cure the base of the plate. The plate is then reversed, the job negative is attached to the uncured side, and the plate is further exposed to UV light. This causes the plate in the image area to harden. The plate is then processed to remove the uncured photopolymer from the non-image areas, thereby lowering the plate surface in these non-image areas. After processing, the plate is dried and exposed to a post-exposure dose of UV light to cure the entire plate. The preparation of the plate cylinder for flexographic printing is described in Printing Technology, J.M. Adams and P.A. Dolin, Delmar Thomson Learning, 5th edition, pages 359-360.

[0038]

[0038] Screen printing (also called silk screen printing in the art) is a printing technique that typically uses a screen made of a mesh fabric to support an ink-blocking stencil. The attached stencil forms an opening area of the mesh that transfers the ink as a sharp-edged image onto a substrate. A squeegee is moved across the screen with the ink-blocking stencil, allowing the threads of the mesh fabric in the opening area to pass through the ink. A major feature of screen printing is that it can apply ink to the substrate in a thicker layer than other printing techniques. Therefore, screen printing is suitable even when it is necessary for the ink to be deposited at a thickness of more than about 10 to 50 μm, which cannot be (easily) achieved by other printing techniques. Generally, a screen is made of a piece of porous and fine-meshed woven fabric called a mesh stretched over a frame made of, for example, aluminum or wood. Currently, most meshes are made of artificial materials such as synthetic threads or steel wires. Suitable artificial materials are nylon threads or polyester threads.

[0039]

[0039] In addition to screens made based on mesh fabrics made of synthetic or metal threads, screens have been developed from solid metal sheets having a grid of holes. Such a screen is prepared by a process including a step of forming a metal screen by electrolysis by forming a screen skeleton on a base material provided with a separating agent in a first electrolytic cell, a step of peeling the formed screen skeleton from the base material, and a step of electrolyzing the screen skeleton in a second electrolytic cell to deposit metal on the skeleton.

[0040]

[0040] There are three types of screen printing machines: flatbed, cylinder, and rotary screen printing machines. Both flatbed and cylinder screen printing machines are similar in that they use a flat screen and a three-stage reciprocating process to perform the printing operation. First, the screen is moved to a position on the substrate, then the squeegee is pressed against the mesh and pulled across the image area, and then the screen is lifted from the substrate to complete the process. In a flatbed machine, the substrate used for printing is typically placed on a horizontal print bed parallel to the screen. In a cylinder machine, the substrate is placed on a cylinder. The flatbed and cylinder screen printing processes are discontinuous processes, so they are generally limited to a maximum speed of 45 m / min for web-fed processes or 3000 sheets / hour for sheet-fed processes.

[0041]

[0041] In contrast, rotary screen machines are designed for continuous high-speed printing. The screen used in a rotary screen machine is, for example, a thin metal cylinder that is usually obtained using the electroforming method described above or made of a fabric of steel wires. The open-end cylinder is capped at both ends and fitted into a block on the side of the device. During printing, ink is pumped into one end of the cylinder so that a fresh supply is constantly maintained. The squeegee is fixed inside the rotating screen, and the squeegee pressure is maintained and adjusted to allow for good and consistent print quality. The advantage of a rotary screen machine is the speed that can be easily achieved, which can reach 150 m / min for web-fed processes or 10000 sheets / hour for sheet-fed processes.

[0042]

[0042] Screen printing, for example, is further described in The Printing Ink Manual, R.H. Leach and R.J. Pierce, Springer Edition, 5th Edition, pages 58 - 62, Printing Technology, J.M. Adams and P.A.Dolin, Delmar Thomson Learning, 5th Edition, pages 293 - 328, and Handbook of Print Media, H. Kipphan, Springer, pages 409 - 422 and 498 - 499.

[0043]

[0043] According to one embodiment, the ultraviolet - visible radiation - curable security ink described herein, preferably the ultraviolet - visible radiation - curable screen - printing security ink, is an ultraviolet - visible radiation cation - curable security ink. According to another embodiment, the ultraviolet - visible radiation - curable security ink described herein, preferably the ultraviolet - visible radiation - curable screen - printing security ink, is an ultraviolet - visible radiation hybrid - curable security ink, i.e., an ink containing one or more cation - curable compounds and one or more radical - curable compounds.

[0044]

[0044] The cation - curable compound is cured by a cationic mechanism consisting of the activation of one or more photoinitiators that release cationic species such as acids by ultraviolet - visible light, and this cationic species in turn initiates the polymerization of the compound so as to form a cured binder. The radical - curable ink or composition is cured by a radical mechanism consisting of the activation of one or more photoinitiators that release radicals by ultraviolet - visible light, and this radical in turn initiates the polymerization process. Optionally, one or more photosensitizers may also be present. The photosensitizer is activated by one or more of the wavelengths emitted by the ultraviolet - visible light source and reaches an excited state. The excited photosensitizer transfers energy either to one or more photoinitiators (in radical polymerization) or to electrons (in cationic polymerization). Both processes then initiate the polymerization process. The light sources required to cure the ultraviolet-visible radiation curable security ink described in this specification are selected from the group consisting of mercury lamps (preferably medium-pressure mercury lamps), ultraviolet LED lamps, and their continuous use. Typical continuous use includes using one or more ultraviolet LED lamps in a first step to partially cure the ultraviolet-visible radiation composition and using one or more medium-pressure mercury lamps in a second step. Mercury lamps preferably emit wavelengths in a wide range of the UV-A, UV-B, and UV-C regions. Therefore, there is an abundance of photoinitiators or combinations of photoinitiators and photosensitizers having an absorption spectrum that matches at least one of the emission bands of the mercury lamp. Ultraviolet LEDs have a more limited wavelength range such that only a limited selection of photoinitiators or combinations of photoinitiators and photosensitizers are sufficiently efficient at industrial printing speeds. On the other hand, ultraviolet LEDs are lower in cost, require less energy (especially requiring a significantly less demanding heat dissipation system), are less likely to form ozone, and have a significantly longer lifespan.

[0045]

[0045] The ultraviolet-visible radiation curable security ink described in this specification, preferably the ultraviolet-visible radiation curable screen printing security ink, contains about 75 wt% to about 99 wt% of an ink vehicle having a viscosity of about 200 to about 2000 mPas as measured using a B-type viscometer (type "DV-I Prime") at 25°C (spindle S27 at 100 rpm for viscosities between 500 and 2500 mPas, spindle S21 at 100 rpm for viscosities below 500 mPas).

[0046]

[0046] According to one embodiment, the ink vehicle described in this specification is a cationically curable ink vehicle (i.e., a fully cationically curable ink vehicle that does not contain a radically curable compound) and contains a1) about 45 wt% to about 75 wt% of one or more of the alicyclic epoxides described in this specification and a2) about 2 wt% to about 15 wt% of one or more cationic photoinitiators, where the weight percentages are based on the total weight of the ink vehicle.

[0047]

[0047] According to another embodiment, the ink vehicle described herein is a hybrid ink vehicle, and thus b1) about 45% to about 75% by weight of a mixture comprising one or more alicyclic epoxides described herein and one or more radically curable compounds described herein, and b2) about 2% to about 15% by weight of a mixture of one or more cationic photoinitiators and one or more radical photoinitiators, wherein the weight percentages are based on the total weight of the ink vehicle.

[0048]

[0048] One or more of the alicyclic epoxides described herein may be bifunctional or polyfunctional. Preferably, one or more of the alicyclic epoxides described comprise independently at least one cyclohexane group and at least two epoxide groups. Suitable alicyclic epoxides contain two or more cyclohexane epoxide groups and have the structural formula (I).

Chemical formula

[0049]

[0049] According to one embodiment, X is a divalent hydrocarbon group which is a straight-chain or branched-chain alkylene group containing 1 to 18 carbon atoms. Examples of the straight-chain or branched-chain alkylene group 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.

[0050]

[0050] According to one embodiment, X is a divalent alicyclic hydrocarbon group or cycloalkylene 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.

[0051] According to one embodiment, X is a divalent group containing one or more oxygen-containing linking groups which are -CO-, -O-CO-O-, -COO-, and -O-. According to one embodiment, a preferred epoxy derivative containing two or more cyclohexane oxide groups and having the structural formula (I), wherein X is a divalent group containing one or more oxygen-containing linking groups which are -CO-, -O-CO-O-, -COO-, -O- has the structural formula (II), (III), or (IV).

Chemical formula

Chemical formula

Chemical formula

[0052]

[0052] According to one embodiment, one or more of the alicyclic epoxides described herein have the structural formula (V) or (VI).

Chemical formula

[0053] One or more of the alicyclic epoxides described herein may be modified with a hydroxyl group or (meth)acrylate. Examples are Cyclomer A400 (CAS: 64630-63-3) and Cyclomer M100 (CAS: 82428-30-6) from Daicel Corporation, or TTA15 and TTA16 commercially available under the names from TetraChem / Jiangsu.

[0054] For embodiments in which the ink vehicle described herein is a cationically curable ink vehicle (i.e., a fully cationically curable ink vehicle that does not contain a radically curable compound), the ink vehicle described herein contains about 2 wt% to about 15 wt%, preferably about 3 wt% to about 12 wt%, more preferably about 4 wt% to about 10 wt% of one or more cationic photoinitiators (also referred to as photoacid generators in the art) that are the onium salts described herein. The 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 even more preferably selected from the group consisting of iodonium salts, sulfonium salts, and mixtures thereof.

[0055] One or more of the iodonium salts described herein have a cationic part and an anionic part, and the anionic part is preferably BF4 - , B(C6F5)4 - , PF6 - , AsF6 - , SbF6 - , or CF3SO3 - , more preferably SbF6 - or PF6 -and the cation moiety is preferably an aromatic iodonium ion, more preferably an iodonium ion containing two aryl groups, and the two aryl groups may be independently substituted by one or more alkyl groups (such as 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. Particularly suitable examples of the iodonium salts of the present invention are commercially available under the names Omnicat 250 and 440 from IGM Resins and Speedcure 938 from Lambson.

[0056]

[0056] One or more of the sulfonium 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 (C n F 2n-1 ) m ) - (where m is an integer from 1 to 5 and n is an integer from 1 to 4), AsF6 - , SbF6 - , CF3SO3 - , a perfluoroalkyl sulfonate, or a pentafluoro hydroxy antimonate, more preferably SbF6 - or PF6 - and the cation moiety 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 by one or more alkyl groups (such as 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.

[0057] Suitable examples of sulfonium ions containing two or more aryl groups include, but are not limited to, triarylsulfonium ions, diphenyl[4-(phenylthio)phenyl]sulfonium ions, bis[4-(diphenylsulfonio)phenyl]sulfonium ions, triphenylsulfonium ions, and tris[4-(4-acetylphenyl)sulfanylphenyl]sulfonium ions.

[0058] Other examples of useful photoinitiators can be found in standard textbooks such as "Chemistry & Technology of UV & EB Formulation for Coatings, Inks & Paints", Volume 3, "Photoinitiators for Free Radical Cationic and Anionic Polymerization", 2nd Edition, by J.V. Crivello & K. Dietliker, edited by G. Bradley, published jointly by John Wiley & Sons and SITA Technology Limited in 1998.

[0059] In an embodiment where the ultraviolet-visible radiation curable security ink herein is an ultraviolet-visible radiation hybrid curable security ink, the vehicle of the ultraviolet-visible radiation hybrid curable security ink comprises one or more alicyclic epoxides described herein and one or more radically curable compounds selected from the group consisting of the tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof described herein, and the amount of the one or more radically curable compounds described herein is preferably about 30 wt% or less, with the weight percentages based on the total weight of the ink vehicle.

[0060]

[0060] One or more radically curable tri(meth)acrylates described herein are preferably selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane trimethacrylate, alkoxylated (especially ethoxylated or propoxylated) glycerol triacrylate, pentaerythritol triacrylate, alkoxylated (especially ethoxylated or propoxylated) pentaerythritol triacrylate, and mixtures thereof, and are preferably selected from the group consisting of trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) glycerol triacrylate, pentaerythritol triacrylate, and mixtures thereof.

[0061]

[0061] One or more radically curable tetra(meth)acrylates described herein are selected from the group consisting of ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, alkoxylated (especially ethoxylated or propoxylated) pentaerythritol tetraacrylate, and mixtures thereof, and are preferably selected from the group consisting of ditrimethylolpropane tetraacrylate, alkoxylated (especially ethoxylated or propoxylated) pentaerythritol tetraacrylate, and mixtures thereof.

[0062]

[0062] One or more radical photoinitiators are preferably selected from the group consisting of hydroxyketones (such as alpha-hydroxyketones), alkoxyketones (such as alpha-alkoxyketones), acetophenone, benzophenone, ketosulfone, benzyl ketal, benzoin ether, phosphine oxide, phenylglyoxylate, thioxanthone, and mixtures thereof, and more preferably are selected from the group consisting of phosphine oxide, hydroxyketone, thioxanthone, and mixtures thereof.

[0063]

[0063] Suitable examples of alpha-hydroxy ketones include (1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one), 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-2-methyl-1-(4-tert-butyl)phenylpropan-1-one, 2-hydroxy-1-[4-[[4-(2-hydroxy-2-methylpropanoyl)phenyl]methyl]phenyl]-2-methylpropan-1-one, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one, and oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], but are not limited thereto.

[0064]

[0064] Suitable examples of acetophenone include 2,2-diethoxyacetophenone and 2-methoxy-2-phenylacetophenone, but are not limited thereto.

[0065]

[0065] Suitable examples of benzophenone include benzophenone, polymeric benzophenone derivatives, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl-2-benzoylbenzoate, 4-(4-methylphenylthio)benzophenone, 4-hydroxybenzophenone laurate, and a mixture of 50% benzophenone and 50% 1-hydroxycyclohexyl phenyl ketone, but are not limited thereto.

[0066]

[0066] A suitable example of a ketosulfone is 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one, but is not limited thereto.

[0067]

[0067] Suitable examples of benzyl ketals include, but are not limited to, 2,2-dimethoxy-2-phenylacetophenone.

[0068]

[0068] Suitable examples of benzoin ethers include, but are not limited to, 2-ethoxy-1,2-diphenylethanone, 2-isopropoxy-1,2-diphenylethanone, 2-isobutoxy-1,2-diphenylethanone, 2-butoxy-1,2-diphenylethanone, 2,2-dimethoxy-1,2-diphenylethanone, and 2,2-diethoxyacetophenone.

[0069]

[0069] Suitable examples of phosphine oxides include, but are not limited to, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, substituted acyl-phosphine oxides, mixtures of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methylpropiophenone, mixtures of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methylpropiophenone, and mixtures of ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate and 2-hydroxy-2-methylpropiophenone.

[0070]

[0070] Suitable examples of thioxanthones include, but are not limited to, 2-methylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, and polymeric thioxanthone derivatives.

[0071]

[0071] Suitable examples of phenylglyoxylates include, but are not limited to, methyl benzoylformate, 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate, and a mixture of 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate and 2-[2-hydroxy-ethoxy]-ethyl ester of oxy-phenyl-acetic acid.

[0072]

[0072] According to one embodiment referred to herein, the UV-visible radiation curable security ink described herein is a UV-visible radiation hybrid curable security ink (i.e., the ink vehicle of the UV-visible radiation curable security ink comprises an alicyclic epoxide described herein, one or more cationic photoinitiators which are onium salts described herein, one or more radical curable compounds described herein, and one or more radical photoinitiators described herein), and the total amount of one or more cationic photoinitiators which are onium salts and one or more radical photoinitiators is between about 2 wt% and about 15 wt%, preferably between about 3 wt% and about 12 wt%, more preferably between about 4 wt% and about 10 wt%, and the weight percent is based on the total weight of the ink vehicle. Preferably, one or more cationic photoinitiators which are onium salts are present in an amount between about 1 wt% and about 10 wt%, and one or more radical photoinitiators are present in an amount between about 1 wt% and about 5 wt%, and the weight percent is based on the total weight of the ink vehicle, provided that the total amount of one or more cationic photoinitiators which are onium salts and one or more radical photoinitiators is between about 2 wt% and about 15 wt%, preferably between about 3 wt% and about 12 wt%, more preferably between about 4 wt% and about 10 wt%, and the weight percent is based on the total weight of the ink vehicle.

[0073]

[0073] The ink vehicle of the ultraviolet-visible radiation curable security ink described in this specification (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) may further contain c1) one or more vinyl ethers, or c2) one or more oxetanes, or c3) a combination of one or more vinyl ethers and one or more oxetanes.

[0074]

[0074] According to one embodiment, the ultraviolet-visible radiation curable security ink described in this specification (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) may further contain one or more vinyl ethers. In an embodiment where the ink vehicle of the ultraviolet-visible radiation curable security ink described in this specification contains one or more vinyl ethers described in this specification and does not contain one or more oxetanes described in this specification, the one or more vinyl ethers are present in an amount of less than about 20% by weight, preferably in an amount of about 5.0% by weight or more and about 15% by weight or less, and the weight percent is based on the total weight of the ink vehicle.

[0075]

[0075] Vinyl ethers are known in the art to promote curing, reduce tack, and thus limit the risk of blocking and back transfer when sheets printed immediately after printing and curing are stacked. Also, vinyl ethers improve the physical and chemical resistance of the printed security element and improve the flexibility of the printed and cured ink layer, which may be advantageous when printing the security ink of the present invention onto a plastic or polymer substrate. Also, vinyl ethers help reduce the viscosity of the ink while copolymerizing strongly with the ink vehicle.

[0076] Examples of suitable vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl 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)cyclohexylmethyl benzoate, 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-(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, bis[4-(vinyloxy)methyl]cyclohexyl]methyl]isophthalate may be mentioned. Suitable vinyl ethers are commercially available from BASF under the designations EVE, IBVE, DDVE, ODVE, BDDVE, DVE-2, DVE-3, CHVE, CHDM-di, HBVE. One or more of the vinyl ethers described herein may be hydroxy-modified or (meth)acrylate-modified (e.g., VEEA of Nippon Shokubai Co., Ltd., 2-(2-vinyloxyethoxy)ethyl acrylate (CAS: 86273-46-3)).

[0077]

[0077] According to another embodiment, the ink vehicle of the ultraviolet-visible radiation curable security ink described herein (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) contains one or more of the oxetanes described herein. In an embodiment where the ink vehicle of the ultraviolet-visible radiation curable security ink described herein contains one or more of the oxetanes described herein and does not contain one or more of the vinyl ethers described herein, the one or more oxetanes are present in an amount of about 30% by weight or less, preferably in an amount of about 5% by weight or more and about 25% by weight or less, and the weight percent is based on the total weight of the ink vehicle.

[0078]

[0078] Oxetane compounds are known in the art to promote curing, reduce tack, and thus limit the risk of blocking and back transfer when sheets printed immediately after printing and curing are stacked. Oxetane compounds also help reduce the ink viscosity while copolymerizing strongly with the ink vehicle.

[0079]

[0079] Suitable examples of oxetanes include trimethylene oxide, 3,3-dimethyloxetane, trimethylolpropane oxetane, 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-methoxy-phenyl)-oxetane, 3-ethyl-[(tri-ethoxysilylpropoxy)methyl]oxetane, 4,4-bis(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, and 3,3-dimethyl-2(p-methoxy-phenyl)oxetane. One or more of the oxetanes described herein may be hydroxy-modified or (meth)acrylate-modified (e.g., Lambson's UVi-Cure S170CAS (CAS: 37674-57-0)).

[0080]

[0080] According to another embodiment, the ink vehicle of the ultraviolet-visible radiation curable security ink described herein (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) comprises one or more of the vinyl ethers described herein and one or more of the oxetanes described herein. In embodiments where the ink vehicle of the ultraviolet-visible radiation curable security ink described herein comprises a combination of one or more of the vinyl ethers described herein and one or more of the oxetanes described herein, the combination is present in an amount of about 15 wt% or less, preferably in an amount of about 10 wt% or more and about 15 wt% or less, and the weight percent is based on the total weight of the ink vehicle.

[0081]

[0081] The selected balance of one or more vinyl ethers and one or more oxetanes described herein, within a specific range, helps to optimize the desirable properties of the security elements made from the security inks of the present invention, particularly the ease of processing (optimal viscosity, rapid hardening, no back transfer, no blocking) and strong chemical and physical resistance. Further, since vinyl ethers and oxetanes are generally less expensive than alicyclic epoxy compounds, it also helps to improve cost-effectiveness.

[0082]

[0082] The ink vehicle of the ultraviolet-visible radiation-curable security ink described herein (the ink vehicle of the ultraviolet-visible radiation cation-curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid-curable security ink) may further contain one or more polyhydroxy compounds, and the one or more polyhydroxy compounds are preferably present in an amount of about 25% by weight or less, more preferably in an amount between about 15% by weight and about 20% by weight, and the weight percentage is based on the total weight of the ink vehicle.

[0083]

[0083] Polyhydroxy compounds are known in the art to improve adhesion to substrates that exhibit poor adhesion, such as plastic or polymer substrates that have become widespread in the field of security documents, particularly banknotes.

[0084]

[0084] The one or more polyhydroxy compounds described herein preferably contain three or more hydroxy groups and may be linear, branched, or multi-branched (also referred to as dendritic in the art). Preferably, the one or more polyhydroxy compounds described herein are trifunctional, tetrafunctional, hexafunctional, or polyfunctional compounds.

[0085]

[0085] One or more of the polyhydroxy compounds described herein are preferably selected from the group consisting of polyhydroxy derivatives of aliphatic or aromatic polyethers, polyhydroxy derivatives of polyesters, polyhydroxy derivatives of polycarbonates, glycerol, trimethylolpropane, di-trimethylolpropane, pentaerythritol, dipentaerythritol, and mixtures thereof.

[0086]

[0086] One or more of the polyhydroxy compounds described herein may be at least partially alkoxylated. Thus, one or more of the polyhydroxy compounds described herein may have alkoxylated units, preferably ethoxylated and / or propoxylated units.

[0087]

[0087] According to one embodiment, one or more of the polyhydroxy compounds described herein are polyhydroxy derivatives of aliphatic or aromatic polyethers. Examples of polyhydroxy derivatives of aliphatic or aromatic polyethers include polyoxyalkylene polyols and polyalkoxylated polyols such as polyethylene glycol and polypropylene glycol.

[0088]

[0088] According to a preferred embodiment, one or more of the polyhydroxy compounds described herein are selected from the group consisting of trifunctional compounds, preferably glycerol and trimethylolpropane, tetrafunctional compounds, preferably di-trimethylolpropane and pentaerythritol, hexafunctional compounds, preferably dipentaerythritol, and mixtures thereof, and the compounds, preferably the trimethylolpropane, pentaerythritol, and dipentaerythritol may be alkoxylated (ethoxylated and / or propoxylated).

[0089]

[0089] Suitable examples of alkoxylated polyhydroxy compounds include those sold by Perstorp under the designations Polyol 3165, 3380, 3610, 3611, 3940, 3990, R3215, R3430, R3530, R3600, 4290, 4360, 4525, 4640, 4800, R4630, R4631, R4650, and R6405, where the first digit indicates the number of hydroxy groups per molecule and the following three digits indicate the hydroxy number.

[0090]

[0090] According to an embodiment, one or more of the polyhydroxy compounds described herein are polyhydroxy derivatives of polyesters such as polycaprolactone diol, triol, and tetraol. Such compounds are sold, for example, by Daicel Corporation as PLACCEL 200 Series, PLACCEL 300 Series, and PLACCEL 400 Series.

[0091]

[0091] According to a preferred embodiment, one or more of the polyhydroxy compounds described herein are multi-branched polyhydroxy derivatives of a polyester. As used herein, the term "multi-branched polymer" is also known as a dendrimer, highly branched polymer, dendron, or dendritic polymer (a three-dimensional highly branched molecule having a tree-like structure and containing one or more branched comonomer units). The branched comonomer units include a branching layer, one or more spacer layers, and / or a layer of chain-terminating molecules, and an optional core also known as a nucleus. By continuing the replication of the branching layer, the branching multiplicity, branching density, and the number of terminal functional groups are increased compared to other molecules. As described, for example, in U.S. Patent No. 5,418,301, the multi-branched polyhydroxy derivatives of a polyester are obtained in one or more subsequent steps by the controlled esterification of a polyhydroxy compound (e.g., trimethylolpropane, pentaerythritol, etc.), which is a central nucleating molecule, with an appropriate equimolar amount of dimethylolpropionic acid. Suitable examples of polyhydroxy compounds that are dendritic polyhydroxy derivatives of a polyester are sold by Perstorp under the designations Boltorn™ H20, Boltorn™ H2004, Boltorn™ H311, Boltorn™ P1000, and Boltorn™ P500.

[0092]

[0092] One or more of the polyhydroxy compounds described herein preferably have a hydroxy number between 100 and 1000 mg KOH / g.

[0093]

[0093] The ink vehicle of the ultraviolet-visible radiation curable security ink described in this specification (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) preferably comprises one or more fillers or extenders selected from the group consisting of carbon fiber, talc, mica (muscovite), wollastonite, fired clay, pottery 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), hydrated alumina, silica, fumed silica, montmorillonite, graphite, anatase, rutile, bentonite, vermiculite, zinc white, zinc sulfide, wood powder, quartz powder, natural fibers, synthetic fibers, and combinations thereof. When present, the one or more fillers or extenders are preferably present in an amount of about 0.1 wt% to about 20 wt%, more preferably in an amount of about 0.1 wt% to about 10 wt%, and the weight percent is based on the total weight of the ink vehicle.

[0094]

[0094] The ink vehicle of the ultraviolet-visible radiation curable security ink described in this specification (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) may further contain one or more photosensitizers together with one or more photoinitiators described in this specification in order to achieve efficient curing. Suitable examples of photosensitizers are known to those skilled in the art (for example, Industrial Photoinitiators, W.A. Green, CRC Press, 2010, Table 8.1, page 170). Suitable photosensitizers are those capable of achieving efficient rapid curing by an ultraviolet LED light source, such as thioxanthone derivatives, anthracene derivatives (for example, 9,10-diethoxyanthracene sold as Anthracure UVS-1101 and 9,10-dibutyloxyanthracene sold as Anthracure UVS-1331, both sold by Kawasaki Chemical Industry Co., Ltd.), and titanocene derivatives (for example, Irgacure784 sold by BASF). Thioxanthone derivatives including, but not limited to, isopropyl-thioxanthone (ITX), 1-chloro-2-propoxy-thioxanthone (CPTX), 2-chloro-thioxanthone (CTX), and 2,4-diethyl-thioxanthone (DETX), and mixtures thereof are particularly suitable. Alternatively, the thioxanthone photosensitizer may be used in the form of an oligomer or polymer (for example, Omnipol TX sold by IGM Resins, Genopol* TX-2 sold by Rahn, or Speedcure7010 sold by Lambson). When present, the one or more photosensitizers are preferably present in an amount of about 0.1 wt% to about 10 wt%, more preferably about 0.1 wt% to about 5 wt%, and even more preferably about 0.2 wt% to about 1 wt%, and the weight percent is based on the total weight of the ink vehicle.

[0095]

[0095] The ink vehicle of the ultraviolet-visible radiation curable security ink described herein (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) may further contain one or more solvents for fine-tuning the viscosity of the ultraviolet-visible radiation curable security ink described herein. Suitable solvents are polar aprotic solvents showing a high boiling point such as carbonates. Suitable carbonates are alkylene carbonates (for example, ethylene carbonate, propylene carbonate, and butylene carbonate). Propylene carbonate having a high boiling point and an advantageous ecotoxicity profile is particularly suitable. Preferably, the amount of one or more solvents in the ink vehicle is less than about 5% by weight, more preferably less than about 2% by weight, and the weight percent is based on the total weight of the ink vehicle.

[0096]

[0096] In embodiments where the ink vehicle of the ultraviolet-visible radiation curable security ink described herein is a hybrid curable ink vehicle, the ink vehicle may further contain one or more reactive diluents that are radical curable monomers selected from mono(meth)acrylates, di(meth)acrylates, and mixtures thereof.

[0097]

[0097] The ink vehicle of the ultraviolet-visible radiation curable security ink described in this specification (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) may further contain one or more marker substances and / or taggants including forensic markers and / or forensic taggants and / or one or more machine-readable materials selected from the group consisting of magnetic materials known in the art, luminescent materials and electroluminescent materials known in the art, conductive materials known in the art, infrared absorbing materials known in the art, and (surface-enhanced) Raman active compounds known in the art. As used herein, the term "machine-readable material" refers to a material that exhibits at least one characteristic property not perceptible to the naked eye and that, by being capable of being included in a layer, provides a method for authenticating the layer or an article provided with the layer by using a specific device for authentication. The one or more machine-readable materials are selected such that the detection of the machine-readable materials in the security function made of the ultraviolet-visible radiation curable security ink claimed and described herein is not impaired by pigments containing flaky non-metallic or metallic substrates contained in the security function. Selecting machine-readable materials for use in security inks taking into account the known properties of pigments containing flaky non-metallic or metallic substrates contained in the ink is within the scope of the general common knowledge of those skilled in the ink formulation art. The ultraviolet-visible radiation curable security ink claimed and described herein, preferably the ultraviolet-visible cationic radiation curable security ink claimed and described herein, is suitable, which contains one or more machine-readable materials selected from the group consisting of a pigment containing a flaky non-metallic substrate and an ink vehicle selected from the group consisting of magnetic materials known in the art, luminescent materials and electroluminescent materials known in the art, conductive materials known in the art, infrared absorbing materials known in the art, and (surface-enhanced) Raman active compounds known in the art, preferably selected from the group consisting of magnetic materials known in the art and infrared absorbing materials known in the art, more preferably selected from the group consisting of magnetic materials known in the art.The ultraviolet-visible radiation-curable security ink claimed and described herein, preferably the ultraviolet-visible cationic radiation-curable security ink claimed and described herein, also preferably includes a pigment containing a flaky metallic substrate and one or more machine-readable materials selected from the group consisting of magnetic materials known in the art, luminescent materials known in the art, electroluminescent materials known in the art, conductive materials known in the art, and (surface-enhanced) Raman active compounds known in the art, preferably selected from the group consisting of magnetic materials known in the art. Non-limiting examples of infrared-absorbing materials suitable for the ultraviolet-visible radiation-curable security ink claimed and described herein, which contains a pigment having a flaky non-metallic substrate, are described in International Publication No. WO 2007 / 060133 and International Publication No. WO 2019 / 219250. Non-limiting examples of magnetic materials suitable for the ultraviolet-visible radiation-curable security ink claimed and described herein include core-shell magnetic particles described in International Publication No. WO 2008 / 148201, International Publication No. WO 2010 / 115986, International Publication No. WO 2017 / 129666, and International Publication No. WO 2016 / 005158.

[0098] [

[0098] ]The ink vehicle of the ultraviolet-visible radiation curable security ink described in this specification (the ink vehicle of the ultraviolet-visible radiation cationic curable security ink and the ink vehicle of the ultraviolet-visible radiation hybrid curable security ink) may further contain one or more coloring components selected from the group consisting of organic pigment particles, inorganic pigment particles, organic dyes, and mixtures thereof, and / or one or more additives. The latter includes, but is not limited to, compounds and materials used for adjusting physical, rheological, and chemical parameters such as the consistency (e.g., anti-settling agents and plasticizers), foaming properties (e.g., anti-foaming agents and degassing agents), and lubricity (waxes) of the ultraviolet-visible radiation cationic curable security ink described in this specification, preferably the ultraviolet-visible radiation cationic curable screen printing security ink. The additives described in this specification may be present in known amounts and forms in the ink vehicle or the ultraviolet-visible radiation curable security ink described in this specification, preferably in the form of so-called nanomaterials in which at least one of the dimensions of the additives ranges from 1 to 1000 nm in the ultraviolet-visible radiation curable screen printing security ink.

[0099] [

[0099] ]The ultraviolet-visible radiation curable security ink described in this specification, preferably the ultraviolet-visible radical curable screen printing security ink, contains about 1 wt% to about 25 wt%, preferably about 5 wt% to about 20 wt%, more preferably about 10 wt% to about 20 wt% of a pigment containing the flaky non-metallic or metallic substrate described in this specification, wherein the flaky non-metallic or metallic substrate is at least partially coated with one or more at least partial coating layers described in this specification, faces the environment, and includes at least a partial surface treatment layer made of one or more surface modifiers described in this specification. "Facing the environment" means that the surface treatment layer is the outermost layer of the pigment and acts as the outer layer. The at least partial surface treatment layer is in direct contact with the upper layer of one or more at least partial coating layers described in this specification.

[0100]

[0100] The flaky non-metallic or metallic substrates of the pigments described herein include one or more metal oxides, one or more metal hydroxides, one or more metal suboxides, or one or more at least partial coatings independently made from a mixture of these materials. In other words, the non-metallic or metallic flakes described herein are at least partially coated with one or more layers made of one or more metal oxides, one or more metal hydroxides, one or more metal suboxides, or a mixture of these materials. The thickness of the metal oxide, metal hydroxide, metal suboxide, or their mixture is usually 5 - 1000 nm, preferably 10 - 800 nm, particularly 20 - 600 nm.

[0101]

[0101] As is known to those skilled in the art, one or more at least partial coatings may be applied to the flaky non-metallic or metallic substrates by precipitation method, wet chemical method, sol-gel method, physical vapor deposition (PVD) process, or chemical vapor deposition (CVD) process, and the method is selected according to the substrate material and coating material. Alternatively, one or more at least partial coatings made of metal oxides and / or hydroxides may be obtained on the flaky metallic substrates by chemically oxidizing the metal surface (e.g., by permanganate or other strong oxidants) or heating the flaky metallic pigments in air or a controlled atmosphere (e.g., rich in oxygen and / or water vapor) at a high temperature for a specified time. The time, temperature, and atmosphere composition depend on the desired thickness of the metal and at least partial coating. For example, the flaky metallic pigments may be baked in an oven at 300 °C in dry air for 30 minutes to obtain at least partial coatings made of metal oxides and / or metal hydrates.

[0102]

[0102] The size of the pigments used described herein, represented by the d50 value, is preferably in the range of about 1 μm to about 100 μm (microns), preferably in the range of about 5 μm to about 50 μm (microns). The thickness of the pigment is usually between about 0.1 μm and about 5 μm (microns), preferably between about 0.2 μm and about 4 μm (microns).

[0103]

[0103] According to one embodiment, the flaky non-metallic substrate of the pigment described herein is selected from the group consisting of natural mica, synthetic mica, talc, graphite, borosilicate (such as glass), and kaolin, more preferably selected from the group consisting of natural mica, synthetic mica, and glass, and even more preferably made of one or more materials selected from the group consisting of natural mica and synthetic mica.

[0104]

[0104] The flaky non-metallic substrate described herein is made independently of one or more metal oxides, one or more metal hydrated oxides, one or more metal suboxides, or a mixture of these materials, preferably one or more metal oxides and / or one or more metal hydrated oxides, and more preferably includes one or more at least partial coating films containing one or more metal oxides. Suitable examples of metal oxides include, but are not limited to, aluminum oxide, silicon oxide, iron oxide, tin oxide, cerium oxide, zinc oxide, zirconium oxide, chromium oxide, titanium oxide, and any mixture thereof. Preferably, the non-metallic substrate described herein is preferably made of natural mica or synthetic mica and consists of a non-metallic substrate including one or more at least partial coating films made independently of one or more metal oxides selected from the group consisting of titanium dioxide, tin oxide, iron oxide, chromium oxide, and mixtures thereof. A particularly preferred flaky non-metallic substrate for the pigment described herein consists of natural or synthetic mica containing two or more at least partial coating films, and also consists of natural mica or synthetic mica including one or more at least partial coating films made independently of titanium dioxide (i.e., flaky mica substrate + TiO2) or a mixture containing titanium dioxide, wherein one of the one or more at least partial coating films is made of titanium dioxide, and another one of the one or more at least partial coating films is made of tin oxide (i.e., flaky mica substrate + SnO2 + TiO2 or flaky mica substrate + TiO 2+ SnO2).

[0105]

[0105] According to one embodiment, the flaky metallic substrate of the pigment described herein preferably consists of a single layer made of one or more metals selected from the group consisting of aluminum, copper, zinc, tin, brass, iron, titanium, chromium, nickel, silver, gold, steel, their alloys, and mixtures thereof, preferably selected from the group consisting of aluminum, iron, and brass. The flaky metallic substrate described herein is independently made of one or more metal oxides, one or more metal hydrated oxides, one or more metal suboxides, or a mixture of these materials, preferably one or more metal oxides and / or one or more metal hydrated oxides, and more preferably includes one or more at least partial coatings containing one or more metal oxides. Suitable examples of metal oxides include, but are not limited to, aluminum oxide, silicon oxide, iron oxide, tin oxide, cerium oxide, zinc oxide, zirconium oxide, chromium oxide, and titanium oxide.

[0106]

[0106] According to one embodiment, the flaky metallic substrate of the pigment described herein consists of a multilayer including one or more metallic layers selected from the metals described herein and optionally one or more non-metallic layers.

[0107]

[0107] According to one preferred embodiment, the flaky metallic substrate of the pigment described herein consists of a multilayer comprising one or more metallic layers and optionally one or more non-metallic layers including a Fabry - Perot reflector / dielectric / absorber multilayer structure as disclosed in U.S. Patent No. 4,705,300, U.S. Patent No. 4,705,356, U.S. Patent No. 4,721,271, U.S. Patent No. 5,084,351, U.S. Patent No. 5,214,530, U.S. Patent No. 5,281,480, U.S. Patent No. 5,383,995, U.S. Patent No. 5,569,535, U.S. Patent No. 5,571624, and their related documents. Preferably, the multilayer comprising one or more metallic layers described herein is a thin - film interference pigment comprising a Fabry - Perot absorber / dielectric / reflector / dielectric / absorber multilayer structure, where the absorber layer partially transmits and partially reflects the incident light, the dielectric layer transmits it, and the reflector layer reflects it. Preferably, the reflector layer is selected from the group consisting of metals, metal alloys, and combinations thereof, preferably selected from the group consisting of reflective metals, reflective metal alloys, and combinations thereof, more preferably selected from the group consisting of aluminum, chromium, nickel, and mixtures thereof, and even more preferably aluminum. Preferably, the dielectric layer is independently selected from the group consisting of magnesium fluoride, silicon dioxide, and mixtures thereof, and more preferably magnesium fluoride. Preferably, the absorber layer is independently selected from the group consisting of chromium, nickel, metallic alloys, and mixtures thereof, and more preferably chromium. A particularly preferred thin - film interference multilayer comprises a Fabry - Perot absorber / dielectric / reflector / dielectric / absorber multilayer structure including a Cr / MgF2 / Al / MgF2 / Cr multilayer structure. The flaky metallic substrate of the pigment described herein consisting of a thin - film interference multilayer further comprises one or more metal oxides, one or more metal hydrated oxides, one or more metal sub - oxides, one or more metal fluorides, or a mixture of these materials, preferably made from one or more metal oxides and / or one or more metal hydrated oxides, more preferably further comprising at least a partial coating containing one or more metal oxides.Suitable metal oxides are aluminum oxide, silicon oxide, iron oxide, tin oxide, cerium oxide, zinc oxide, zirconium oxide, chromium oxide, and titanium oxide, preferably chromium oxide and mixtures thereof.

[0108]

[0108] The flaky non-metallic or metallic substrate further comprises at least a partial surface treatment layer described herein, the surface treatment layer facing the environment and being in direct contact with the upper layer of one or more at least partial coating layers. In other words, the at least partial surface treatment layer described herein is present on the coating upper layer of one or more at least partial coatings. The at least partial surface treatment layer described herein is made from one or more surface modifiers selected from perfluoropolyethers, the perfluoropolyethers being functionalized with one or more phosphorus (P)-containing compounds or one or more silicon (Si)-containing compounds. The functionalized perfluoropolyethers described herein are preferably functionalized with one or more phosphoric acid-containing groups, one or more silane-containing groups, or one or more siloxane-containing groups.

[0109]

[0109] Surface modification can occur in various ways. For example, one or more surface modifiers described herein may be dissolved in an organic solvent and / or water and then applied by mixing to a flaky non-metallic or metallic substrate comprising one or more at least partial coating layers described herein, and the resulting pigment is then dried. Alternatively, surface treatment with one or more surface modifiers may occur immediately after the flaky non-metallic or metallic substrate has been at least partially coated with one or more at least partial coating layers described herein by a one-pot process. An optional firing step may be performed on the flaky non-metallic or metallic substrate comprising one or more at least partial coating layers described herein prior to the surface treatment.

[0110]

[0110] One or more surface modifiers described herein preferably have a weight average molecular weight of less than about 2000 g / mol eq PS as measured by the method described herein.

[0111]

[0111] According to one embodiment, one or more of the surface modifiers described herein are perfluoropolyethers functionalized with one or more phosphorus (P)-containing groups or one or more silicon (Si)-containing groups (i.e., -CH2O-(CF2) m -(CF2-CF2-O) n -CF2-structure), in particular perfluoropolyethers having one or more phosphate groups or perfluoropolyether compounds having one or more silanes.

[0112]

[0112] According to one embodiment, one or more of the surface modifiers described herein are monofunctionalized or difunctionalized with one or more phosphate groups, preferably phosphoric acid or phosphonate ester groups (perfluoropolyethers, more preferably alkoxylated perfluoropolyether compound derivatives having a phosphate group, preferably phosphoric acid or phosphonate ester group. Preferably, one or more of the surface modifiers described herein are perfluoropolyethers of the following formula (VII). (OH)2(O)P-[(OCH2CH2) p -OCH2-R f -CH2O-(CH2CH2O) p P(O)OH] q OH (VII) wherein p = 1 to 2, q = 1 to 4, and R f is CH2O-(CF2) m -(CF2-CF2-O) n -CF2. A particularly suitable example of the surface modifier of the present invention is commercially available from Solvay under the name Fluorolink (trademark) P54.

[0113] According to another embodiment, one or more surface modifiers described herein are perfluoropolyethers functionalized with one or more silane groups, preferably alkoxylated silane groups. Preferably, one or more surface modifiers described herein consist of perfluoropolyethers of the following formula (VIII). (OH) 3-n -(R II O) n Si-R I -NH-C(O)-CF2O-(CF2-CF2-O) p -(CF2O) q -CF2-C(O)-NH-R I -Si(OR II ) n (OH) 3-n (VIII) In the formula, R I is an alkylene having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, and R II is a linear or branched alkyl group having 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms, n is an integer from 0 to 3, preferably 3, and p and q are numbers such that the q / p ratio is between 0.2 and 4, and p is different from 0. Preferably, one or more surface modifiers described herein are perfluoropolyethers of the following formula (IX) functionalized with silane groups. (EtO)3-Si-R I -NH-C(O)-CF2O-(CF2-CF2-O) p -(CF2O) q -CF2-C(O)-NH-R I -Si(OEt)3 (IX) In the formula, R I is an alkylene having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, and p and q are numbers such that the q / p ratio is between 0.2 and 4, and p is different from 0. A particularly suitable example of the surface modifier of the present invention is commercially available from Solvay under the name Fluorolink (trademark) S10 having the following formula (X). (EtO)3-Si-CH2CH2CH2-NH-C(O)-CF2O-(CF2-CF2-O) p -(CF2O) q -CF2-C(O)-NH-CH2CH2CH2-Si(OEt)3 (X) In the formula, p = 2 to 6 and q = 2 to 4.

[0114]

[0114] The present invention further provides a method for producing an ultraviolet-visible radiation curable ink described herein, preferably an ultraviolet-visible radiation curable screen printing ink, and an ink obtained by the method. The ultraviolet-visible radiation curable ink described herein, preferably an ultraviolet-visible radiation curable screen printing ink, may be prepared by dispersing or mixing the components of the ink vehicle described herein, namely one or more alicyclic epoxides, one or more radically curable compounds if present, a cationic photoinitiator which is an onium salt, one or more radical photoinitiators if present, and optional additives described herein, with the pigments described herein. The compounds may all be dispersed or mixed in a single step, or the ink vehicle may first be prepared and then the pigments described herein added and the resulting mixture dispersed or mixed. One or more photoinitiators described herein may be added at any of the dispersion or mixing steps of all other components, or at a later stage, namely after ink formation.

[0115]

[0115] The ultraviolet-visible radiation curable ink described herein, preferably an ultraviolet-visible radiation curable screen printing ink, is applied to a substrate described herein for producing security functions by a printing process preferably selected from the group consisting of a rotogravure process, a flexographic printing process, and a screen printing process, more preferably by a screen printing process.

[0116]

[0116] The present invention further provides a method for producing a security function described herein and a security function obtained therefrom. By a printing process selected from the group consisting of a rotogravure process, a flexographic printing process, and a screen printing process, more preferably a screen printing process, step a) of printing an ultraviolet-visible radiation curable security ink described herein onto a substrate described herein, and step b) of curing the ultraviolet-visible radiation curable security ink in the presence of ultraviolet-visible radiation. The method comprising is carried out to form one or more security functions as described herein. Preferably, by a screen printing process, step a) of printing an ultraviolet-visible radiation curable screen printing security ink described herein onto a substrate described herein, and step b) of curing the ultraviolet-visible radiation curable screen printing security ink in the presence of ultraviolet-visible radiation. The method described herein comprising is carried out to form one or more security functions as described herein. Preferably, the curing step b) described herein is carried out using one or more light sources selected from the group consisting of a mercury lamp (preferably a medium pressure mercury lamp), an ultraviolet LED lamp, and their continuous use. Contrary to a medium pressure mercury lamp having emission bands in the UV-A, UV-B, and UV-C regions of the electromagnetic spectrum, an ultraviolet LED lamp emits radiation in the UV-A region (365 - 405 nm). As mentioned herein, typical continuous use includes using one or more ultraviolet LED lamps in a first step to partially cure an ultraviolet-visible radiation composition and using one or more medium pressure mercury lamps in a second step. A mercury lamp advantageously emits wavelengths in a wide region of the UV-A, UV-B, and UV-C regions.

[0117]

[0117] The present invention further provides a security function on a substrate described herein produced by an ultraviolet-visible radiation curable security ink described herein, preferably an ultraviolet-visible radiation curable screen printing security ink.

[0118]

[0118] The substrate described herein is preferably selected from the group consisting of paper or other fibrous materials (including woven and non-woven fibrous materials), such as cellulose, paper-containing materials, glass, metal, ceramic, plastic and polymer, metallized plastic or polymer, composite materials, and mixtures or combinations of two or more thereof. Typical papers, paper-like, or other fibrous materials are made from a variety of fibers including, without limitation, manila hemp, cotton, linen, wood pulp, and blends thereof. As is well known to those skilled in the art, cotton and cotton / linen blends are preferred for banknotes, while wood pulp is commonly used in security documents other than banknotes. Typical examples of plastics and polymers include polyolefins such as polypropylene (PP) including polyethylene (PE) and biaxially oriented polypropylene (BOPP), polyamides, polyesters such as poly(ethylene terephthalate) (PET), poly(1,4-butylene terephthalate) (PBT), poly(ethylene 2,6-naphthalate) (PEN), and polyvinyl chloride (PVC). Spunbond olefin fibers such as those sold under the trademark Tyvek™ may also be used as the substrate. Typical examples of metallized plastics or polymers include the plastic or polymer materials described above having metal disposed continuously or discontinuously on the surface. Typical examples of metals include, but are not limited to, aluminum, chromium, copper, gold, silver, their alloys, and combinations of two or more of the above metals. Metallization of the plastic or polymer materials described above may be performed by an electroplating process, a high vacuum coating process, or a sputtering process. Typical examples of composite materials include, without limitation, multi-layer structures or laminates of paper and at least one plastic or polymer material such as those described above, and plastics and / or polymer fibers incorporated into paper-like or fibrous materials such as those described above. Of course, the substrate may contain additional additives known to those skilled in the art, such as fillers, sizing agents, whitening agents, processing aids, reinforcing or wet strength enhancers, etc.

[0119] When the UV-visible radiation curable security ink described herein is printed on a substrate made of plastic or polymer, particularly when printed on a transparent or translucent window area of the substrate, the ink preferably contains one or more polyhydroxy compounds described herein to improve the adhesion of the UV-visible radiation curable security ink to the substrate, and contains one or more vinyl ether compounds described herein to improve the flexibility of the printed and cured layer. In this case, one or more vinyl ether compounds are present in an amount of less than about 20% by weight, preferably in an amount of about 5.0% to about 15% by weight, and one or more polyhydroxy compounds are present in an amount of 25% by weight or less, more preferably in an amount between about 15% and about 20% by weight, and the weight percentages are based on the total weight of the ink vehicle.

[0120]

[0120] The present invention further provides a substrate described herein and a security document having the security function described herein, or a security document having two or more of the security functions described herein. The security document includes, without limitation, valuable documents and valuable goods. Typical examples of valuable documents include, without limitation, banknotes, certificates, coupons, checks, tickets, revenue stamps and tax stamps, contracts, etc., passports, ID cards, visas, driver's licenses, bank cards, credit cards, transaction cards, identity documents such as access documents or cards, tickets, tickets for public transportation, or documents conferring rights, etc. The term "valuable goods" refers to packaging materials for the pharmaceutical, cosmetic, electronic, or food industries, which can be protected from forgery and / or illegal replication, for example, to guarantee the contents of the packaging of genuine drugs, etc. Examples of these packaging materials include, without limitation, labels, such as authentication brand labels, anti-counterfeiting labels, and seals. Preferably, the security document described herein is selected from the group consisting of banknotes, identity documents, documents conferring rights, driver's licenses, credit cards, access cards, rights documents for transportation, tickets, and product warranty labels. Alternatively, the security function described herein may be produced on an auxiliary substrate, such as a security thread, security stripe, foil, decal, window, or label, etc., and consequently transferred to the security document in a separate step.

[0121]

[0121] For the purpose of further increasing the security level of the security document and its resistance to forgery and illegal replication, the substrate described herein may contain printing, coating, or laser marking or laser-perforated marks, watermark patterns, security threads, fibers, planchets, luminescent compounds, windows, foils, decals, primers, and combinations of two or more of them.

[0122]

[0122] For the purpose of increasing the durability or chemical resistance to soiling and cleanliness, and thus the circulation durability of security documents, or for the purpose of modifying their aesthetic appearance (e.g., optical gloss), one or more protective layers may be applied on the security features or security documents described in this specification. If present, the one or more protective layers are typically made of a protective varnish that may be transparent or slightly colored or tinted, and may also have some gloss. The protective varnish may be a radiation-curable composition, a heat-drying composition, or any combination thereof. Preferably, the one or more protective layers are made of a radiation-curable material. More preferably, an ultraviolet-visible radiation-curable composition.

[0123]

[0123] The security features described in this specification may be applied directly on a substrate on which the security features should remain permanently (e.g., in the case of banknotes). Alternatively, the security features may also be applied on a temporary substrate for manufacturing purposes, and then the security features are removed therefrom. Thereafter, after the hardening or curing of the ultraviolet-visible radiation-curable security ink, preferably the ultraviolet-visible radiation-curable screen-printing security ink, described in this specification for the production of the security features, the temporary substrate may be removed from the security features.

[0124]

[0124] Alternatively, in another embodiment, the adhesive layer may be present on top of the security function or on a substrate having the security function. The adhesive layer is on a substrate on the side opposite to the side where the security function is imparted or on top of the security function on the same side as the security function. Thus, the adhesive layer may be applied to the security function or to the substrate, and the adhesive layer is applied after the curing step is completed. Such an article may be attached to all kinds of documents, or other articles or items without printing or other processes involving machinery and some high labor. Alternatively, the substrate described herein having the security function described herein may be in the form of a transfer foil that can be applied to a document or article in a separate transfer step. For this purpose, the substrate is provided with a release coating on which the security function is fabricated as described herein. One or more adhesive layers may be applied on top of the security function thus fabricated.

[0125]

[0125] Two or more, i.e., two, three, four, etc., substrates having the security function described herein, security documents, decorative elements, and objects are also described herein. Articles having the security function described herein, particularly security documents, decorative elements, or objects are also described herein.

[0126]

[0126] As mentioned above, the security function described herein can be used for the protection and authentication of security documents or decorative elements.

[0127]

[0127] Typical examples of decorative elements or objects include, without limitation, luxury goods, cosmetic packaging, automotive parts, electronic / electrical products, furniture, and nail items.

[0128]

[0128] The security document includes, without limitation, valuable documents and valuable goods. Typical examples of valuable documents include, without limitation, banknotes, certificates, coupons, checks, tickets, revenue stamps and tax stamps, contracts, etc., passports, ID cards, visas, driver's licenses, bank cards, credit cards, transaction cards, access documents, or identity documents such as cards, tickets, public transportation tickets, graduation certificates, or title deeds, etc., preferably including banknotes, identity documents, documents conferring rights, driver's licenses, and credit cards. The term "valuable goods" refers to, in particular, cosmetics, dietary supplements, medical supplies, alcohol, tobacco products, beverages, or foodstuffs, electrical / electronic goods, fabrics, or gemstones, i.e., packaging materials for articles that should be protected from forgery and / or illegal replication in order to guarantee the contents of the packaging such as, for example, genuine drugs. Examples of these packaging materials include, without limitation, labels, such as authentication brand labels, anti-counterfeiting labels, and seals. It is pointed out that the disclosed base materials, valuable documents, and valuable goods are listed only for illustrative purposes and do not limit the scope of the present invention.

[0129]

[0129] Those skilled in the art can envision some modifications to the above-described specific embodiments without departing from the spirit of the present invention. Such modifications are encompassed by the present invention.

[0130]

[0130] Furthermore, all documents referred to throughout this specification are hereby incorporated by reference in their entirety as fully described herein.

Examples

[0131]

[0131] Here, the present invention will be described in more detail with reference to non-limiting examples. The following examples show in more detail the preparation and properties of ultraviolet-visible radiation-curable screen-printing security inks and the security functions obtained thereby.

[0132]

[0132] Two series of screen-printing security inks were prepared and applied to the substrate. E1 to E4 were prepared using different flakes, and the surfaces of the flakes were independently treated with different compounds so as to provide a surface treatment layer on the flakes. Table 1 describes the flakes. Table 3A-1 describes the solvent ink vehicle S0 used for the preparation of comparative solvent screen printing security inks (C1, C7, and C9) according to the prior art such as U.S. Patent No. 8,147,932. Table 3A-2 describes the ultraviolet-visible radiation curable ink vehicle used for the preparation of the ultraviolet-visible radiation curable screen printing security inks (E1 to E4) according to the present invention and the preparation of comparative ultraviolet-visible radiation curable screen printing security inks (C2 to C6, C8, and C10). Table 3B shows the optical properties of the security functions made from the ultraviolet-visible radiation curable screen printing security inks (E1 to E4) according to the present invention, the functions made from the comparative solvent screen printing security inks, and the functions made from the comparative ultraviolet-visible radiation curable screen printing security inks (C1 to C10). E5 to E30 and C11 to C16 were prepared using flakes which are five-layer thin film interference pigments (i.e., optically variable pigments) (ChromaFlair (trademark)), and the surfaces of the flakes were treated with FluoroLink (trademark) P54 (a phosphorus (P)-containing compound, particularly a perfluoropolyether functionalized with a phosphate-containing group) so as to provide a surface treatment layer on the flakes. Tables 4A to 11A describe the ink vehicles used for the preparation of the ultraviolet-visible radiation curable screen printing security inks (E5 to E30) according to the present invention and the preparation of comparative ultraviolet-visible radiation curable screen printing security inks (C11 to C16). Tables 4B to 11B show the optical properties of the security functions made from the ultraviolet-visible radiation curable screen printing security inks (E5 to E30) according to the present invention and the functions made from the comparative ultraviolet-visible radiation curable screen printing security inks (C11 to C16).

[0133] [Preparation of surface treatment of flakes (P1 to P4) with different compounds (b to g)]

Table 1

[0134] (Method 1a (for the treatment of Chromaflo (trademark) (Viavi Solutions) flakes with Fluorolink (trademark) P54))

[0133] Fluorolink (trademark) P54 (Solvay, 20 wt% in water) was dissolved in an equivalent amount of isopropanol (Brenntag-Schweizer, 99%) so as to obtain a 10 wt% solution.

[0135]

[0134] In a 1-liter polypropylene beaker, 50 g of flakes were added to 440 g of isopropanol (Brenntag-Schweizer, 99%), and dispersed at 600 rpm for 10 minutes at room temperature using a Dispermat (LC220-12). 10 g of the 10 wt% solution of Fluorolink (trademark) P54 was added to the dispersion, and further dispersed at 600 rpm for 15 minutes at room temperature. The obtained dispersion was poured into a Buchner funnel equipped with filter paper under vacuum (water pump), and washed three times using 200 g of isopropanol (Brenntag-Schweizer, 99%) and finally 200 g of acetone (Brenntag-Schweizer, 99%). Finally, the surface-treated high aspect ratio pigment was dried under vacuum for 5 minutes.

[0136] (Method 1b (for the treatment of Pyrisima (trademark) Yellow T30-20 (Merck) and Lumina (trademark) Turquoise 9T30D (BASF) flakes with Fluorolink (trademark) P54))

[0135] In a 50 mL polypropylene test tube, 2 g of flakes were added to 17.2 g of isopropanol (Brenntag-Schweizer, 99%) at room temperature. 0.8 g of the 10 wt% solution of Fluorolink (trademark) P54 (procedure described for Method 1a) was added, and the tube was shaken vigorously for 2 minutes. After the sedimentation of the flakes, the upper layer of the solvent was removed with a pipette, and then the flakes were washed twice with 20 g of isopropanol (Brenntag-Schweizer, 99%) and once with 20 g of acetone (Brenntag-Schweizer, 99%). The surface-treated flakes thus obtained were dried on filter paper at room temperature for 30 minutes.

[0137] (Method 2 (Fullorink (trademark) S10 for the treatment of ChromaFlare (trademark) (Viavi Solutions) wafers))

[0136] A mixture of a) 0.5 g of acetic acid (Sigma-Aldrich, 99.8%), 2 g of deionized water, and 97 g of isopropanol (Brenntag-Schweizer, 99%) and b) 0.5 g of Fullorink (trademark) S10 was mixed at room temperature to prepare 100 g of a solution containing Fullorink (trademark) S10 (Solvay). The solution thus obtained was dispersed at 600 rpm for 30 minutes using a Dispermat (LC220-12) so as to obtain a 0.5 wt% solution of Fullorink (trademark) S10.

[0138]

[0137] In a 50 mL polypropylene test tube, 2 g of wafers were added to 15 g of a 0.5 wt% Fullorink (trademark) S10 solution, and the tube was shaken vigorously for 2 minutes. The surface-treated wafers were filtered under vacuum (water pump) on a Buchner funnel, placed in a glassware while the wafers contained moisture, and dried in an oven at 100 °C for 30 minutes before use.

[0139] (Method 3 (Dynasilane (trademark) F8815 for the treatment of ChromaFlare (trademark) (Viavi Solutions) wafers))

[0138] To prepare 100 g of a solution containing Dynasilane (trademark) F8815, 2 g of Dynasilane (trademark) F8815 (Evonik, >99%) was mixed with 98 g of a 50 / 50 mixture of water and isopropanol (Brenntag-Schweizer, 99%) so as to obtain a 2 wt% solution of Dynasilane (trademark) F8815.

[0140] [

[0139] ]In a 50 mL polypropylene test tube, 2 g of the flakes were added to 13 g of isopropanol (Brenntag-Schweizer, 99%). 5 g of a 2 wt% solution of Dynasilane™ F8815 was added to the dispersion, and the tube was shaken vigorously for 2 minutes. The surface-treated flakes were filtered under vacuum (water pump) on a Büchner funnel, placed in a glassware while the flakes still contained moisture, and dried in an oven at 100 °C for 30 minutes before use.

[0141] (Method 4 (for treating Chromafire™ (Viavi Solutions) flakes with Dynasilane™ F8261)) [

[0140] ]100 g of a solution containing Dynasilane™ F8261 was prepared by mixing 0.5 g of Dynasilane™ F8261 (Evonik, >99%), 97.5 g of isopropanol (Brenntag-Schweizer, 99%), and 2.0 g of water so as to obtain a 0.5 wt% solution of Dynasilane™ F8261.

[0142] [

[0141] ]In a 50 mL polypropylene test tube, 2 g of the flakes were added to 20 g of a 0.5 wt% solution of Dynasilane™ F8261, and the tube was shaken vigorously for 2 minutes. The surface-treated flakes were filtered under vacuum (water pump) on a Büchner funnel, placed in a glassware while the flakes still contained moisture, and dried in an oven at 100 °C for 30 minutes before use.

[0143] (Method 5 (for treating Chromafire™ (Viavi Solutions) flakes with Polyfox™ 156A)) [

[0142] ]100 g of a solution containing Polyfox™ 156A was prepared by mixing 22.2 g of Polyfox™ 156A (Omnova Solutions, 30 wt% in water) and 77.8 g of a 50 / 50 mixture of water and isopropanol (Brenntag-Schweizer, 99%) so as to obtain a 6.67 wt% solution of Polyfox™ 156A.

[0144]

[0143] In a 50 mL polypropylene test tube, 2 g of the flakes were added to 17.4 g of isopropanol (Brenntag - Schweizer, 99%) at room temperature. 0.6 g of a 6.67 wt% solution of Polyfox (trademark) 156A was added to the dispersion, and the tube was shaken vigorously for 2 minutes. The surface - treated flakes were filtered under vacuum (water pump) on a Büchner funnel, placed in a glassware while the flakes still contained moisture, and dried in an oven at 100 °C for 30 minutes before use.

[0145] (Method 6 (for the treatment of Chromafire (trademark) (Viavi Solutions) flakes with Lakeland PAE - 185))

[0144] To obtain a 2.2 wt% solution of Lakeland PAE - 185, 2.4 g of Lakeland PAE - 185 (Lakeland Laboratories Ltd, >90%) and 97.6 g of a 50 / 50 mixture of water and isopropanol (Brenntag - Schweizer, 99%) were mixed to prepare 100 g of a solution containing Lakeland PAE - 185.

[0146]

[0145] In a 50 mL polypropylene test tube, 2 g of the flakes were added to 16.2 g of isopropanol (Brenntag - Schweizer, 99%). 1.8 g of a 2.2 wt% solution of Lakeland PAE - 185 was added to the dispersion, and the tube was shaken vigorously for 2 minutes. The surface - treated flakes were filtered under vacuum (water pump) on a Büchner funnel, placed in a glassware while the flakes still contained moisture, and dried in an oven at 100 °C for 30 minutes before use.

[0147] [Explanation of the components of the ultraviolet - visible radiation - curable screen - printing ink vehicle V0 - V32]

Table 2

[0148] [Preparation of inks (E1 - E4 and C1 - C10) and the printed security functions obtained from those inks] (A0. Preparation of Solvent Ink Vehicle S0 (Table 3A-1) and Ultraviolet Visible Curing Ink Vehicle V0 (Table 3A-2))

Table 3

[0149]

[0146] To prepare 100 g of ink vehicle S0, the components of ink vehicle S0 shown in Table 3A-1 were mixed and dispersed at 1000 - 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0150]

[0147] For about 15 g of the ink vehicle, the viscosity values shown in Table 3A-1 were independently measured at 25°C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm).

[0151]

Table 4

[0152]

[0148] To prepare 100 g of ink vehicle, the components of ink vehicle V0 shown in Table 3A-2 were mixed and dispersed at 1000 - 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0153]

[0149] For about 15 g of the ink vehicle, the viscosity values shown in Table 3A-2 were measured at 25°C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm).

[0154] (A1-1. Preparation of Comparative Solvent Screen Printing Security Inks (C1, C7, and C9))

[0150] Using the solvent ink vehicle S0 described in Table 3A-1 and each of the thin sheets P1a, P2a, and P3a (i.e., those used as commercially available ones without further surface treatment), comparative solvent screen printing security inks (C1, C7, and C9) were prepared.

[0155]

[0151] To obtain 20 g of the comparative solvent screen printing security ink independently, 17% by weight of flakes P1a, P2a, and P3a were independently added to 83% by weight of ink vehicle S0, and dispersed at 800 - 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0156] (A1-2. Preparation of Comparative Ultraviolet-Visible Radiation-Curable Screen Printing Security Inks (C2 - C6, C8, and C10) and Ultraviolet-Visible Radiation-Curable Screen Printing Security Inks (E1 - E4) According to the Present Invention)

[0152] Using the ink vehicle V0 described in Table 3A-2 and each of the flakes P1a, P2a, and P3a (i.e., used as those commercially available without further surface treatment), comparative ultraviolet-visible radiation-curable screen printing security inks (C2, C8, and C10) were prepared.

[0157]

[0153] Using the ink vehicle V0 described in Table 3A and each of the flakes P1d, P1e, P1f, and P1g (i.e., including a surface treatment based on a perfluoropolyether functionalized with one or more phosphate-containing groups or one or more silane-containing groups), comparative ultraviolet-visible radiation-curable screen printing security inks (C3 - C6) were prepared.

[0158]

[0154] Using the ink vehicle V0 described in Table 3A-2 and each of the surface-treated flakes P1b, P1c, P2b, and P3b, ultraviolet-visible radiation-curable screen printing security inks (E1 - E4) according to the present invention were prepared.

[0159]

[0155] To obtain 20 g of the comparative ultraviolet-visible radiation-curable screen printing security inks (C2 - C6, C8, and C10) and the ultraviolet-visible radiation-curable screen printing security inks (E1 - E4) according to the present invention independently, 17% by weight of flakes were independently added to 83% by weight of ink vehicle V0, and dispersed at 800 - 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0160] (Preparation of security functions using inks (E1 to E4 and C1 to C10))

[0156] Comparative solvent screen printing security inks (C1, C7, and C9), comparative ultraviolet-visible radiation curable screen printing security inks (C2 to C6, C8, and C10), and the ultraviolet-visible radiation curable screen printing security inks (E1 to E4) according to the present invention were manually and independently applied onto credit paper (BNP paper manufactured by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh). The printed pattern had a size of 6 cm × 10 cm.

[0161]

[0157] After the printing step, the security functions produced by the ultraviolet-visible radiation curable screen printing security inks were independently cured by exposing the functions twice to ultraviolet-visible light under a dryer manufactured by IST Metz GmbH at a speed of 100 m / min (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ).

[0162] (A3. Optical properties of security functions produced from inks E1 to E4 and C1 to C10 (Table 3B))

[0158] A3-a. The optical properties of the security functions described herein, determined by a goniometer (Goniospektrometer Codec WI-10 5&5 manufactured by Phyma GmbH, Austria), are shown in Table 3B below.

[0163]

[0159] The evaluation was performed as follows. The L*a*b* values of the printed security functions were determined for two angles, 22.5° with respect to the normal under illumination at 22.5° (hereinafter, denoted as 22.5° / 22.5° in Table 3C-1) and 45° with respect to the normal under illumination at 45° (hereinafter, denoted as 45° / 45° in Table 3C-1). The C* (chroma) value was calculated from the a* and b* values according to the CIELAB (1976) color space, where

Number

[0164] A3-b. Relative visual evaluation was also performed according to the criteria for chroma and color label (Table 3B). The sample to be observed was held perpendicular to the diffused light source, and an angle was selected such that the diffused light was not blocked by the observer's head (i.e., an elevation angle between about 25° and about 45°), and the chroma (corresponding to a measure of the vividness or saturation of the color) was observed under diffused illumination (e.g., light entering through a window without direct sunlight). Grades of excellent, good, sufficient, and insufficient were used. Insufficient chroma refers to a sample that is not suitable for use as a security function for very demanding end uses. The color label (corresponding to the change in color or hue as a function of the viewing angle) was observed by first viewing the sample at the same elevation angle as the chroma observation while holding the sample perpendicular to the diffused light source. Next, while observing the change in color, the angle between the sample and the diffused light source was changed back and forth. Grades of excellent, good, sufficient, and insufficient were used. Insufficient color label means that the color difference when changing the viewing angle is not easily perceptible or not perceptible at all to the naked eye, and thus the security function is not suitable for very demanding end uses.

[0165]

Table 5

[0166] As shown in Table 3B, the security functions produced from inks E1 to E4 according to the present invention showed strongly improved optical performance compared to the security functions produced from comparative ultraviolet-visible radiation-curable screen-printing security inks C2, C8, and C10 (thin films used as commercially available) and the security functions produced from ultraviolet-visible radiation-curable screen-printing security inks C3 to C6 (different surface treatments based on compounds that are not composed of perfluoropolyethers functionalized with one or more phosphate-containing groups or one or more silane-containing groups). The security functions produced from inks E1 to E4 according to the present invention showed similar or improved optical performance compared to the security functions produced from comparative solvent inks C1, C7, and C9 while avoiding problems related to solvent inks (difficulty in complying with environmental regulations such as VOC, REACH, and GHS, and complex equipment for recovering and purifying evaporated solvents).

[0167] [Preparation of Inks (E5 to E6 and C11) and Printed Security Functions Obtained from Such Inks] (B0. Preparation of Ultraviolet-Visible Radiation-Curable Ink Vehicles V1 to V3 (Table 4A))

Table 6

[0168]

[0161] To prepare 100 g of each ink vehicle, the components of ink vehicles V1 to V3 shown in Table 4A were mixed and dispersed at 1000 to 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0169]

[0162] For about 15 g of each ink vehicle, the viscosity values shown in Table 4A were independently measured at 25°C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm for V1 to V2, and spindle S21 at 100 rpm for V3).

[0170] (Preparation of UV-visible radiation curable screen printing security ink (E5 - E6 and C11))

[0163] Using each ink vehicle V1 - V3 and flake P1b described in Table 4A, a comparative UV-visible radiation curable screen printing security ink (C11) and the UV-visible radiation curable screen printing security ink (E5 - E6) according to the present invention were prepared. Security ink E5 is the same as ink E1 in Table 3B and was prepared simultaneously with the UV-visible radiation curable screen printing security ink (E6) according to the present invention and the comparative UV-visible radiation curable screen printing security ink (C11).

[0171]

[0164] To obtain 20 g each of the UV-visible radiation curable screen printing security ink (E5 - E6) according to the present invention and the comparative UV-visible radiation curable screen printing security ink (C11) independently, 17% by weight of flake P1b was independently added to 83% by weight of each ink vehicle V1 - V3, and dispersed at 800 - 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0172] (Preparation of security functions and optical properties made from inks E5 - E6 and C11 (Table 4B))

[0165] The comparative UV-visible radiation curable screen printing security ink (C11) and the UV-visible radiation curable screen printing security ink (E5 - E6) according to the present invention were manually applied independently onto credit paper sheets (BNP paper made by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0173]

[0166] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security function made from the UV-visible radiation curable screen printing security ink was exposed to UV-visible light twice under a dryer made by IST Metz GmbH at a speed of 100 m / min (two lamps: iron-doped mercury lamp 200 W / cm 2+ 200 W / cm mercury lamp 2 ) and cured independently thereby.

[0174]

[0167] The optical properties of the above-described security function determined by both visual inspection and the use of the same gonimeter as described in items A3-a and A3-b are shown in Table 4B.

[0175] (B3. Results)

Table 7

[0176]

[0168] As shown in Table 4B, the security function produced by Comparative Ink C11 containing an aliphatic epoxide instead of an alicyclic epoxide showed a poorer appearance and a lower value of chroma measured by a gonimeter.

[0177] [Preparation of Inks (E7 to E10) and Printed Security Functions Obtained from Those Inks] (C0. Preparation of UV-Visible Radiation-Curable Ink Vehicles V4 to V7 (Table 5A))

Table 8

[0178]

[0169] To prepare 100 g of each ink vehicle, the components of each ink vehicle V4 to V7 shown in Table 5A were mixed and dispersed at 1000 to 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0179]

[0170] For about 15 g of the ink vehicle, the viscosity values shown in Table 5A were independently measured at 25 °C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm for V4 and V6, spindle S21 at 100 rpm for V5 and V7).

[0180] (Preparation of UV-visible radiation curable screen printing security ink (E7 - E10))

[0171] Using each ink vehicle V4 - V7 and the flake P1b described in Table 5A, the UV-visible radiation curable screen printing security ink (E7 - E10) according to the present invention was prepared. Security ink E9 is the same as ink E1 in Table 3B and was prepared simultaneously with inks E7 - E10.

[0181]

[0172] To independently obtain 20 g of the UV-visible radiation curable screen printing security ink (E7 - E10) according to the present invention, 17 wt% of the flake P1b was independently added to 83 wt% of each ink vehicle V4 - V7, and dispersed at 800 - 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0182] (Preparation of security functions and optical properties made from inks E7 - E10 (Table 5B))

[0173] The UV-visible radiation curable screen printing security ink (E7 - E10) according to the present invention was manually applied independently onto credit paper pieces (BNP paper made by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0183]

[0174] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security functions made from the UV-visible radiation curable screen printing security ink were independently cured by exposing the functions twice to UV-visible light under a dryer made by IST Metz GmbH at a speed of 100 m / min (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ).

[0184]

[0175] Table 5B shows the optical properties of the above-mentioned security functions determined by both visual inspection and the use of the goniometer described in items A3-a and A3-b.

[0185] (C3. Results)

Table 9

[0186]

[0176] As shown in Table 5B, the ultraviolet-visible radiation curable screen printing security ink according to the present invention containing either a combination of an alicyclic epoxide and a cationic photoinitiator (E7) (i.e., an ink containing a cationically curable ink vehicle) or a tetraacrylate having an alicyclic epoxide, a cationic photoinitiator, and a radical photoinitiator (E8 to E10) (an ink containing a hybrid curable ink vehicle) showed sufficient to excellent appearance and high values in gonimeter measurement.

[0187] [Preparation of Inks (E11 to E13 and C12) and Printed Security Functions Obtained from the Inks] (D0. Preparation of Ultraviolet-Visible Radiation Curable Inks V8 to V11 (Table 6A))

Table 10

[0188]

[0177] To prepare 100 g of each ink vehicle, the components of each ink vehicle V8 to V11 shown in Table 6A were mixed and dispersed at 1000 to 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0189]

[0178] For about 15 g of the ink vehicle, the viscosity values shown in Table 6A were independently measured at 25 °C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm for V8 to V11).

[0190] (D1. Preparation of Ultraviolet-Visible Radiation Curable Screen Printing Security Inks (E11 to E13 and C12)) Using each of the ink vehicles V8 to V11 and the flakes P1b described in Table 6A, a comparative ultraviolet-visible radiation-curable screen printing security ink (C12) and the ultraviolet-visible radiation-curable screen printing security inks (E11 to E13) according to the present invention were prepared. The security ink E12 is the same as the ink E1 in Table 3B and was prepared simultaneously with the inks E11 to E13 and C12.

[0191]

[0180] 17% by weight of the flakes P1b was independently added to 83% by weight of each of the ink vehicles V8 to V11 so that 20 g of the ultraviolet-visible radiation-curable screen printing security inks (E11 to E13) according to the present invention and the comparative ultraviolet-visible radiation-curable screen printing security ink (C12) could be independently obtained, and dispersion was carried out at 800 to 1000 rpm for 5 minutes using a Dispermat (CV-3 type) at room temperature.

[0192] (D2. Preparation of security functions and optical properties made from the inks E11 to E13 and C12 (Table 6B))

[0181] The ultraviolet-visible radiation-curable screen printing security inks (E11 to E13) according to the present invention and the comparative ultraviolet-visible radiation-curable screen printing security ink (C12) were independently manually applied onto a credit paper sheet (BNP paper manufactured by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0193]

[0182] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security functions made from the ultraviolet-visible radiation-curable screen printing security inks were independently cured by exposing the functions twice to ultraviolet-visible light under a dryer manufactured by IST Metz GmbH at a speed of 100 m / min (two lamps: an iron-doped mercury lamp of 200 W / cm 2 + a mercury lamp of 200 W / cm 2 ).

[0194]

[0183] The optical properties of the above security function determined by both visual inspection and the use of the gonimeters described in Items A3-a and A3-b are shown in Table 6B.

[0195] (D3. Results)

Table 11

[0196]

[0184] As shown in Table 6B, for the weight percentages based on the total weight of the ink vehicle, the ultraviolet-visible radiation-curable screen printing security ink according to the present invention, in which the total amount of the alicyclic epoxide and tetraacrylate is within the claimed range, showed improved optical performance compared to Comparative Ink C12 in which the total amount of the alicyclic epoxide and tetraacrylate is 77.85% by weight.

[0197] [Preparation of Inks (E14 to E17 and C13) and Printed Security Functions Obtained from Those Inks) (E0. Preparation of Ultraviolet-Visible Radiation-Curable Ink Vehicles V12 to V16 (Table 7A))

Table 12

[0198]

[0185] To obtain 100 g of each ink vehicle, the components of each ink vehicle V12 to V16 shown in Table 7A were mixed and dispersed at 1000 to 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0199]

[0186] For about 15 g of the ink vehicle, the viscosity values shown in Table 7A were independently measured at 25°C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm for V12 to V14, spindle S21 at 100 rpm for V15 and V16).

[0200] (Preparation of UV-visible radiation curable screen printing security ink (E14 to E17 and C13))

[0187] Using each ink vehicle V12 to V16 and the flake P1b described in Table 7A, the UV-visible radiation curable screen printing security ink (E14 to E17) according to the present invention and the comparative UV-visible radiation curable screen printing security ink (C13) were prepared. 17% by weight of the flake P1b was independently added to 83% by weight of each ink vehicle V12 to V16 so that 20 g of the UV-visible radiation curable screen printing security ink (E14 to E17) according to the present invention and the comparative UV-visible radiation curable screen printing security ink (C13) could be independently obtained, and they were dispersed at 800 to 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0201] (Preparation of security functions and optical properties made from inks E14 to E17 and C13 (Table 7B))

[0188] The UV-visible radiation curable screen printing security ink (E14 to E17) according to the present invention and the comparative UV-visible radiation curable screen printing security ink (C13) were manually applied independently onto credit paper pieces (BNP paper made by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0202]

[0189] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security functions made from the UV-visible radiation curable screen printing security ink were independently cured by exposing the functions to UV-visible light twice under a dryer made by IST Metz GmbH at a speed of 100 m / min (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ).

[0203]

[0190] The optical properties of the above-described security function determined by both visual inspection and the use of the gonimeters described in Items A3-a and A3-b are shown in Table 7B.

[0204] (E3. Results)

Table 13

[0205]

[0191] As shown in Table 7B, the ultraviolet-visible radiation-curable screen printing security ink according to the present invention in which the amount of vinyl ether is within the claimed range contains vinyl ether in an amount of 20% by weight (weight percent is based on the total weight of the ink vehicle) and showed improved performance compared to Comparative Ink C13, which has the disadvantage that its optical properties are poor and insufficient.

[0206] [Preparation of Inks (E18 to E22) and Printed Security Functions Obtained from the Inks] (F0. Preparation of Ultraviolet-Visible Radiation-Curable Inks V17 to V21 (Table 8A))

Table 14

[0207]

[0192] To prepare 100 g of each ink vehicle, the components of each ink vehicle V17 to V21 shown in Table 8A were mixed and dispersed at 1000 to 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0208]

[0193] For about 15 g of the ink vehicle, the viscosity values shown in Table 8A were independently measured at 25 °C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm for V17 and V18, spindle S21 at 100 rpm for V19 to V21).

[0209] (F1. Preparation of Ultraviolet-Visible Radiation-Curable Screen Printing Security Inks (E18 to E22))

[0194] Using each of the ink vehicles V17 to V21 and the flake P1b described in Table 8A, the ultraviolet-visible radiation curable screen printing security ink (E18 to E22) according to the present invention was prepared.

[0210]

[0195] 17% by weight of the flake P1b was independently added to 83% by weight of each of the ink vehicles V17 to V21 so that 20 g of the ultraviolet-visible radiation curable screen printing security ink (E18 to E22) according to the present invention could be independently obtained, and dispersed at 800 to 1000 rpm for 5 minutes using a Dispermat (CV-3 type) at room temperature.

[0211] (F2. Preparation of Security Functions and Optical Properties from Inks E18 to E22 (Table 8B))

[0196] The ultraviolet-visible radiation curable screen printing security ink (E18 to E22) according to the present invention was manually applied independently onto a credit paper sheet (BNP paper manufactured by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0212]

[0197] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security function produced by the ultraviolet-visible radiation curable screen printing security ink was exposed to ultraviolet-visible light twice (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ) under a dryer manufactured by IST Metz GmbH at a speed of 100 m / min to be independently cured.

[0213]

[0198] Table 8B shows the optical properties of the above-described security function determined by both visual inspection and the use of the goniometer described in Items A3-a and A3-b.

[0214] (F3. Results)

Table 15

[0215]

[0199] As shown in Table 8B, the ultraviolet-visible radiation-curable screen printing security ink according to the present invention containing one or more oxetanes showed good to excellent appearance and high values in goniometer measurements.

[0216] [Preparation of Inks (E23 - E24 and C14 - C16) and Printed Security Functions Obtained from Those Inks] (G0. Preparation of Ultraviolet-Visible Radiation-Curable Ink Vehicles V22 - V26 (Table 9A))

Table 16

[0217]

[0200] To prepare 100 g of each ink vehicle, the components of each ink vehicle V22 - V26 shown in Table 9A were mixed and dispersed at 1000 - 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0218]

[0201] For about 15 g of the ink vehicle, the viscosity values shown in Table 9A were independently measured at 25°C using a B-type viscometer (type "DV-I Prime", spindle S27 at 100 rpm for V22, spindle S21 at 100 rpm for V23 - V26).

[0219] (G1. Preparation of Ultraviolet-Visible Radiation-Curable Screen Printing Security Inks (E23 - E24 and C14 - C16))

[0202] Using each ink vehicle V22 - V26 and flake P1b described in Table 9A, a comparative ultraviolet-visible radiation-curable screen printing security ink (C14 - C16) and the ultraviolet-visible radiation-curable screen printing security ink according to the present invention (E23 - E24) were prepared. Security ink E23 is the same as ink E1 in Table 3B and was prepared simultaneously with inks E23 - E24 and C14 - C16.

[0220]

[0203] 83 wt% of each ink vehicle V23 - V27 was independently added with 17 wt% of flakes P1b so that 20 g each of the UV - visible radiation - curable screen - printing security inks (E23 - E24) according to the present invention and the comparative UV - visible radiation - curable screen - printing security inks (C14 - C16) shown in Table 9B could be obtained independently, and they were dispersed at 800 - 1000 rpm for 5 minutes at room temperature using a Dispermat (CV - 3 type).

[0221] (G2. Preparation of security functions and optical properties from inks E21 - E22 and C14 - C16 (Table 9B))

[0204] The UV - visible radiation - curable screen - printing security inks (E23 - E24) according to the present invention and the comparative UV - visible radiation - curable screen - printing security inks (C14 - C16) were independently applied by hand using a 90 lines / cm screen (230 mesh) onto credit paper sheets (BNP paper made by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm).

[0222]

[0205] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security functions made from the UV - visible radiation - curable screen - printing security inks were independently cured by exposing the functions to UV - visible light twice under a dryer made by IST Metz GmbH at a speed of 100 m / min (two lamps: iron - doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ).

[0223]

[0206] The optical properties of the above - mentioned security functions determined by both visual inspection and the use of the gonimeter described in Items A3 - a and A3 - b are shown in Table 9B.

[0224] (G3. Results)

Table 17

[0225] As shown in Table 9B, the ultraviolet-visible radiation curable screen printing security ink according to the present invention containing one or more vinyl ethers and one or more oxetanes in an amount of 15% by weight or less (weight percent is based on the total weight of the ink vehicle) showed sufficient to excellent appearance and high values in goniometer measurements.

[0226] [Preparation of Ink (E25 - E28) and Printed Security Function Obtained from the Ink] (H0. Preparation of Ultraviolet-Visible Radiation Curable Ink Vehicle V27 - V30 (Table 10A))

Table 18

[0227]

[0208] To prepare 100 g of each ink vehicle, the components of each ink vehicle V27 - V30 shown in Table 10A were mixed and dispersed at 1000 - 1500 rpm for 15 minutes at room temperature using a Dispermat (CV-3 type).

[0228]

[0209] For about 15 g of the ink vehicle, the viscosity values shown in Table 10A were independently measured at 25°C using a B-type viscometer (type "DV-I Prime", spindle S21 at 100 rpm).

[0229] (H1. Preparation of Ultraviolet-Visible Radiation Curable Screen Printing Security Ink (E25 - E28))

[0210] Using each ink vehicle V27 - V30 and flake P1b described in Table 10A, the ultraviolet-visible radiation curable screen printing security ink (E25 - E28) according to the present invention was prepared. Security ink E26 is the same as ink E1 in Table 3B and was prepared simultaneously with inks E25 - E28.

[0230]

[0211] So that 20 g of the ultraviolet-visible radiation-curable screen-printing security ink (E25 to E28) according to the present invention shown in Table 10B can be independently obtained, 17% by weight of the flake P1b was independently added to each of the ink vehicles V23 to V27 at 83% by weight, and dispersed at 800 to 1000 rpm for 5 minutes using a Dispermat (CV-3 type) at room temperature.

[0231] (H2. Preparation of security functions and optical properties from inks E25 to E28 (Table 10B))

[0212] The ultraviolet-visible radiation-curable screen-printing security ink (E25 to E28) according to the present invention was manually applied independently onto credit paper pieces (BNP paper manufactured by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0232]

[0213] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security functions produced by the ultraviolet-visible radiation-curable screen-printing security ink were exposed to ultraviolet-visible light twice (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ) under a dryer manufactured by IST Metz GmbH at a speed of 100 m / min for independent curing.

[0233]

[0214] Table 10B shows the optical properties of the above-described security functions determined by both visual inspection and the use of the goniometer described in Items A3-a and A3-b.

[0234] (H3. Results)

Table 19

[0235] As shown in Table 10B, the ultraviolet-visible radiation-curable screen printing security ink according to the present invention containing one or more polyhydroxy compounds having three or more hydroxy groups in an amount of 25% by weight or less (weight percent is based on the total weight of the ink vehicle) showed sufficient to excellent appearance and high values in goniometer measurement.

[0236] [Preparation of Ink (E29 - E30) and Printed Security Function Obtained from the Ink] (I0. Preparation of Ultraviolet-Visible Radiation-Curable Ink Vehicle V31 - V32 (Table 11A))

Table 20

[0237]

[0216] To prepare 100 g of each ink vehicle, the components of each ink vehicle V31 - V32 shown in Table 11A were mixed and dispersed at 1000 - 1500 rpm for 15 minutes at room temperature using a Dispermat (CV - 3 type).

[0238]

[0217] For about 15 g of the ink vehicle, the viscosity values shown in Table 11A were independently measured at 25°C using a B-type viscometer (「DV-I Prime」 type, spindle S27 at 100 rpm).

[0239] (I1. Preparation of Ultraviolet-Visible Radiation-Curable Screen Printing Security Ink (E29 - E30))

[0218] Using each ink vehicle V31 - V32 and the flake P1b described in Table 11A, the ultraviolet-visible radiation-curable screen printing security ink (E29 - E30) according to the present invention was prepared. Security ink E29 is the same as ink E1 in Table 3B and was prepared simultaneously with ink E30.

[0240] So that 20 g of the ultraviolet-visible radiation-curable screen printing security ink (E29 - E30) according to the present invention can be obtained independently, 17% by weight of the flakes P1b was independently added to 83% by weight of each ink vehicle V31 - V32, and dispersed at 800 - 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0241] (I2. Preparation of security functions and optical properties made from inks E29 - E30 (Table 11B))

[0220] The ultraviolet-visible radiation-curable screen printing security ink (E29 - E30) according to the present invention was manually applied independently onto credit paper sheets (BNP paper made by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0242]

[0221] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security functions made from the ultraviolet-visible radiation-curable screen printing security ink were independently cured by exposing the functions to ultraviolet-visible light twice under a dryer made by IST Metz GmbH at a speed of 100 m / min (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ).

[0243]

[0222] Table 11B shows the optical properties of the above-described security functions determined by both visual inspection and the use of the goniometer described in Items A3-a and A3-b.

[0244] (I3. Results)

Table 21

[0245] As shown in Table 11B, the ultraviolet-visible radiation-curable screen printing security ink according to the present invention containing either a tetrafunctional polyhydroxy compound (Perstorp POLYOL R4631 / E29) or a dendritic polyhydroxy derivative of polyester (Perstorp Boltorn (trademark) P1000 / E30) in an amount of 25% by weight or less (weight percent is based on the total weight of the ink vehicle) showed good to excellent appearance and high values in goniometer measurements.

[0246] [Preparation of Inks (E31 - E40) and Printed Security Functions Obtained from Such Inks] (J1. Preparation of Ultraviolet-Visible Radiation-Curable Screen Printing Security Inks (E31 - E40))

[0224] The ultraviolet-visible radiation-curable screen printing security inks E31, E33, E35, E37, and E39 according to the present invention were prepared using the ink vehicle V4 described in Table 5A (ultraviolet-visible radiation cation-curable security ink).

[0247]

[0225] The ultraviolet-visible radiation-curable screen printing security inks E32, E34, E36, E38, and E40 according to the present invention were prepared using the ink vehicle V0 described in Table 3A-2 (ultraviolet-visible radiation hybrid-curable security ink).

[0248]

[0226] The security inks E31 - E32 and E35 - E38 contained the pigment P2b (treated Pyrisma (trademark) Yellow, Table 1). The security inks E33 - E34 and E39 - E40 contained the pigment P1b (treated Chromaflare (trademark) Blue-to-Red, Table 1).

[0249]

[0227] The security inks E35 and E36 additionally contained an infrared absorption compound, enabling the preparation of an infrared-detectable security function.

[0250]

[0228] Security inks E37 to E40 additionally contain a soft magnetic and brightly colored material, enabling the preparation of a magnetically detectable security function.

[0251]

[0229] To prepare security inks E31 to E34, 17 wt% of each treated flake (P1b or P2b) was independently added to 83 wt% of each ink vehicle V0 and V4 so that 20 g of an ultraviolet-visible radiation curable screen printing security ink (E31 to E34) was independently obtained, and dispersion was carried out at 800 to 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0252]

[0230] To prepare security inks E35 to E36, 17 wt% of treated flake P2b and 9 wt% of an infrared absorbing compound were independently added to 74 wt% of each ink vehicle V0 and V4 so that 20 g of an ultraviolet-visible radiation curable screen printing security ink (E35 to E36) containing an infrared absorbing compound was independently obtained, and dispersion was carried out at 800 to 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0253]

[0231] To prepare security inks E37 to E40, 17 wt% of each treated flake (P1b or P2b) and 6 wt% of a soft magnetic and brightly colored material were independently added to 77 wt% of each ink vehicle V0 and V4 so that 20 g of an ultraviolet-visible radiation curable screen printing security ink (E37 to E40) containing a soft magnetic and brightly colored material was independently obtained, and dispersion was carried out at 800 to 1000 rpm for 5 minutes at room temperature using a Dispermat (CV-3 type).

[0254]

[0232] The composition of the inks is summarized in Table 12A below.

Table 22

[0255] (J2. Preparation and properties of security functions made from inks E31 to E40 (Table 12B))

[0233] The ultraviolet-visible radiation-curable screen printing security ink (E31 to E40) according to the present invention was manually and independently applied onto a credit paper sheet (BNP paper manufactured by Louisenthal, 100 g / m 2 , 14.5 cm × 17.5 cm) using a 90 lines / cm screen (230 mesh).

[0256]

[0234] The printed pattern had a size of 6 cm × 10 cm. After the printing step, the security function produced by the ultraviolet-visible radiation-curable screen printing security ink was exposed to ultraviolet-visible light twice under a dryer manufactured by IST Metz GmbH at a speed of 100 m / min (two lamps: iron-doped mercury lamp 200 W / cm 2 + mercury lamp 200 W / cm 2 ) to be independently cured.

[0257]

[0235] The visible-infrared reflection spectra of the security functions produced by inks E31, E32, E35, and E36 were independently measured between 400 nm and 1100 nm using a DC45 manufactured by Datacolor. The 100% reflectance was measured using the internal standard of the device. The reflectance values [%] at the selected wavelengths are shown in Table 12B. As shown in Table 12B, the reflectance values shown by the security functions obtained from inks E35 and E36 containing the treated Pylisma (trademark) Yellow pigment and IR-A absorbing compound in the wavelength range of 400 to 600 nm are equivalent to the reflectance values shown by the security functions obtained from inks E31 and E32 lacking the infrared absorbing compound. In the wavelength range of 700 to 1100 nm, the reflectance shown by the security functions obtained from inks E35 and E36 containing the treated Pylisma (trademark) Yellow pigment and IR-A absorbing compound is significantly lower than the reflectance shown by the security functions obtained from inks E31 and E32 lacking the infrared absorbing compound, thereby enabling the authentication of the security functions obtained by inks E35 and E36 based on the property of absorbing infrared rays characteristic of the infrared absorbing compounds contained in inks E35 and E36.

[0258]

Table 23

[0259]

[0236] The magnetic moment (unit: emu) as a function of the applied magnetic field (unit: Oe) shown by each of the security functions obtained from Inks E31 to E34 (lacking a soft magnetic and brightly colored pigment) and E37 to E40 (containing a soft magnetic and brightly colored pigment) was measured using a vibrating sample magnetometer (Lake Shore Cryotronics Inc., 575 McCorkle Blvd, Westerville, OH 43082, USA, 7400 Series). The measurement was performed by applying a magnetic field that changes between 0 and 10,000 Oe to a Φ5 mm surface sample punched out from the security function and reading the saturation magnetization value at 10,000 Oe. As expected, the security functions obtained from Inks E31 to E34 lacking a soft magnetic and brightly colored material did not show a magnetic signal. The security functions obtained from Inks E37 to E40 containing a soft magnetic and brightly colored material showed a magnetic signal characteristic of the soft magnetic and brightly colored material, thereby enabling authentication of the security function based on the magnetic properties characteristic of the soft magnetic and brightly colored material contained in Inks E37 to E40. Inks E37 to E40 exhibit magnetic properties similar to those of inks used for producing security functions that can be authenticated by a banknote acceptor.

[0260]

[0237] The optical properties of the above security function were determined by both visual inspection and the use of the goniometer described in Items A3-a and A3-b. Both the infrared-absorbing compound and the soft magnetic and brightly colored material are completely hidden in the ink layer and cannot be detected by the naked eye. The optical properties exhibited by the security function obtained from Inks E31 to E32 containing the treated Pyrisma (trademark) Yellow pigment are better than those exhibited by the security function obtained from Inks E35 to E36 containing the treated Pyrisma (trademark) Yellow pigment and the IR-A absorbing compound. However, despite the change in the optical properties due to the infrared-absorbing compound, the optical performance of the security function obtained from Inks E35 to E36 is resistant to use as a reflective security function. The optical properties of the security function obtained from Inks E37 to E40 containing either the treated Pyrisma Yellow (trademark) pigment and the soft magnetic and brightly colored material or the treated Chromaflare (trademark) Blue-to-Red pigment and the soft magnetic and brightly colored material are equivalent to the optical properties exhibited by the corresponding security function obtained from Inks E31 to E34 lacking the soft magnetic and brightly colored material. [Item 1] i) Approximately 75 wt% to approximately 99 wt% of an ink vehicle having a viscosity between approximately 200 and approximately 2000 mPas at 25°C, a) a1) 45 wt% to approximately 75 wt% of one or more alicyclic epoxides and a2) one or more cationic photoinitiators which are preferably onium salts selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof, approximately 2 wt% to approximately 15 wt%, or b) b1) a mixture containing 45 wt% to approximately 75 wt% of one or more alicyclic epoxides and one or more radically curable compounds selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof, and b2) one or more cationic photoinitiators which are preferably onium salts selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof, and one or more radical photoinitiators preferably selected from the group consisting of hydroxyketones, alkoxyketones, acetophenone, benzophenone, ketosulfone, benzyl ketal, benzoin ether, phosphine oxide, phenylglyoxylate, thioxanthone, and mixtures thereof, more preferably one or more radical photoinitiators selected from the group consisting of phosphine oxide, thioxanthone, alpha-hydroxyketone, and mixtures thereof, approximately 2 wt% to approximately 15 wt%, c) The ink vehicle optionally contains less than approximately 20 wt% of one or more vinyl ethers, or less than or equal to approximately 30 wt% of one or more oxetanes, or less than or equal to approximately 15 wt% of a combination of one or more vinyl ethers and one or more oxetanes, The weight percentages of a), b), and c) are based on the total weight of the ink vehicle, the ink vehicle, and ii) about 1 to about 25% by weight of a pigment comprising a flaky non-metallic or metallic substrate, wherein the non-metallic or metallic substrate is one or more metal oxides, one or more metal hydroxide oxides, one or more metal suboxides, or one or more at least partial coating layers independently formed from a mixture of these materials, facing the environment, in direct contact with the upper layer of one or more at least partial coating layers, and at least a partial surface treatment layer formed from one or more surface modifiers selected from perfluoropolyethers, wherein the perfluoropolyethers are functionalized with one or more phosphorus (P)-containing groups or one or more silicon (Si)-containing groups, the pigment comprising wherein the weight percentages of i) and ii) are based on the total weight of the ultraviolet-visible radiation curable security ink ultraviolet-visible radiation curable security ink [Item 2] The ultraviolet-visible radiation curable security ink according to Item 1, which is an ultraviolet-visible radiation curable screen printing security ink [Item 3] The ultraviolet-visible radiation cationically curable security ink according to Item 1 or 2, wherein the ink vehicle further comprises c) one or more vinyl ethers in an amount of less than about 20% by weight, or one or more oxetanes in an amount of about 30% by weight or less, or a combination of one or more vinyl ethers and one or more oxetanes, wherein the combination is present in an amount of about 15% by weight or less, and the weight percentages of a), b), and c) are based on the total weight of the ink vehicle [Item 4] The ultraviolet-visible radiation cationically curable security ink according to any one of Items 1 to 3, wherein the ink vehicle further comprises one or more polyhydroxy compounds, preferably one or more polyhydroxy compounds containing three or more hydroxy groups, and the one or more polyhydroxy compounds are present in an amount of about 25% by weight or less, and the weight percentage is based on the total weight of the ink vehicle [Item 5] The ink vehicle contains 45 to about 75% by weight of a mixture comprising one or more alicyclic epoxides and one or more radically curable compounds selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof, wherein the one or more radically curable compounds are present in an amount of 35% by weight or less, preferably 30% by weight or less, and the weight percentages are based on the total weight of the ink vehicle. The ultraviolet-visible radiation cation-curable security ink according to any one of items 1 to 4. [Item 6] The pigment contains a flaky metallic substrate comprising a multilayer including one or more metallic layers, preferably a thin-film interference multilayer having a Fabry-Perot absorber / dielectric / reflector / dielectric / absorber structure, and the pigment contains one or more at least partial coatings independently made from one or more metal oxides. The ultraviolet-visible radiation cation-curable security ink according to any one of items 1 to 5. [Item 7] The ink vehicle further contains one or more machine-readable materials selected from the group consisting of magnetic materials. The ultraviolet-visible radiation cation-curable security ink according to item 6. [Item 8] The pigment contains a flaky non-metallic substrate made from one or more materials selected from the group consisting of natural mica, synthetic mica, and glass. The ultraviolet-visible radiation cation-curable security ink according to any one of items 1 to 5. [Item 9] The non-metallic substrate contains one or more at least partial coatings independently made from one or more metal oxides. The ultraviolet-visible radiation cation-curable security ink according to item 8. [Item 10] The ink vehicle further contains one or more machine-readable materials selected from the group consisting of magnetic materials and infrared absorbing materials. The ultraviolet-visible radiation cation-curable security ink according to item 8 or 9. [Item 11] The perfluoropolyether is functionalized with one or more phosphate-containing groups or one or more silane-containing groups. The ultraviolet-visible radiation cation-curable security ink according to any one of items 1 to 10. [Item 12] Use of the ultraviolet-visible radiation cation-curable security ink according to any one of items 1 to 11 in the manufacture of one or more security features on a security document or article. [Item 13] The security function produced from the ultraviolet-visible radiation curable security ink according to any one of Items 1 to 11. [Item 14] An article comprising a substrate selected from the group consisting of a substrate, preferably paper or other fibrous material, paper-containing material, glass, metal, ceramic, plastic and polymer, metallized plastic or polymer, composite material, and a mixture or combination of two or more thereof, and a radiation-cured coating film obtained by ultraviolet-visible radiation curing of the ultraviolet-visible radiation curable screen printing ink according to any one of Items 1 to 11. [Item 15] a. Printing the ultraviolet-visible radiation curable security ink according to any one of Items 1 to 11 on the substrate by a printing process selected from the group consisting of a rotogravure process, a flexographic printing process, and a screen printing process, preferably a screen printing process; b. Curing the ultraviolet-visible radiation curable security ink using one or more light sources selected from the group consisting of preferably a mercury lamp, an ultraviolet LED lamp, and continuous use thereof so as to form one or more security functions A method for producing the article according to Item 14, comprising:

Claims

1. i) 75% to 99% by weight of an ink vehicle having a viscosity between 200 and 2000 mPa·s at 25 °C, a) a1) 45% to 75% by weight of one or more alicyclic epoxides and a2) 2% to 15% by weight of one or more cationic photoinitiators which are onium salts, or b) b1) 45% to 75% by weight of a mixture comprising one or more alicyclic epoxides and one or more radically curable compounds selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof, and b2) 2% to 15% by weight of a mixture of one or more cationic photoinitiators which are onium salts and one or more radical photoinitiators, c) the ink vehicle optionally contains less than 20% by weight of one or more vinyl ethers, or up to 30% by weight of one or more oxetanes, or up to 15% by weight of a combination of one or more vinyl ethers and one or more oxetanes, the weight percentages of a), b), and c) are based on the total weight of the ink vehicle, of the ink vehicle and ii) 1% to 25% by weight of a pigment comprising a flaky non-metallic or metallic substrate, the non-metallic or metallic substrate being one or more metal oxides, one or more metal hydroxides, one or more metal hypoxides, or one or more at least partial coating layers independently formed from a mixture of these materials, facing the environment, in direct contact with the upper layer of one or more at least partial coating layers, and at least partial surface treatment layers formed from one or more surface modifiers selected from perfluoropolyethers, the perfluoropolyethers being functionalized by one or more phosphorus (P)-containing groups or one or more silicon (Si)-containing groups, a pigment and the weight percentages of i) and ii) are based on the total weight of the ultraviolet-visible radiation curable security ink, an ultraviolet-visible radiation curable security ink. **Claim 2**: The ultraviolet-visible radiation curable security ink according to claim 1, wherein the one or more cationic photoinitiators are selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts, and mixtures thereof. **Claim 3**: The ultraviolet-visible radiation curable security ink according to claim 1, wherein the one or more radical photoinitiators are selected from the group consisting of hydroxyketones, alkoxyketones, acetophenones, benzophenones, ketosulfones, benzyl ketals, benzoin ethers, phosphine oxides, phenylglyoxylates, thioxanthones, and mixtures thereof. **Claim 4** The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 3, which is an ultraviolet-visible radiation curable screen printing security ink. **Claim 5** The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 4, wherein the ink vehicle further comprises c) one or more vinyl ethers in an amount of less than 20% by weight, or one or more oxetanes in an amount of 30% by weight or less, or a combination of one or more vinyl ethers and one or more oxetanes, the combination being present in an amount of 15% by weight or less, and the weight percentages of a), b), and c) are based on the total weight of the ink vehicle. **Claim 6** The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 5, wherein the ink vehicle further comprises one or more polyhydroxy compounds, the one or more polyhydroxy compounds being present in an amount of 25% by weight or less, and the weight percentage is based on the total weight of the ink vehicle. **Claim 7**: The ultraviolet-visible radiation curable security ink according to claim 6, wherein the one or more polyhydroxy compounds are one or more polyhydroxy compounds containing three or more hydroxy groups. **Claim 8** The ink vehicle contains 45 to 75% by weight of a mixture containing one or more alicyclic epoxides and one or more radically curable compounds selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof, and the one or more radically curable compounds are present in an amount of 35% by weight or less, and the weight percentages are based on the total weight of the ink vehicle. The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 7.

9. The pigment contains a flaky metallic substrate composed of a multilayer containing one or more metallic layers, and the pigment contains one or more at least partial coating films independently made from one or more metal oxides. The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 8.

10. The ultraviolet-visible radiation curable security ink according to claim 9, wherein the multilayer is a thin film interference multilayer having a Fabry-Perot absorber / dielectric / reflector / dielectric / absorber structure.

11. The ink vehicle further contains one or more machine-readable materials selected from the group consisting of magnetic materials. The ultraviolet-visible radiation curable security ink according to claim 9 or 10.

12. The pigment contains a flaky non-metallic substrate made from one or more materials selected from the group consisting of natural mica, synthetic mica, and glass. The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 8.

13. The non-metallic substrate contains one or more at least partial coating films independently made from one or more metal oxides. The ultraviolet-visible radiation curable security ink according to claim 12.

14. The ink vehicle further contains one or more machine-readable materials selected from the group consisting of magnetic materials and infrared absorbing materials. The ultraviolet-visible radiation curable security ink according to claim 12 or 13.

15. The ultraviolet-visible radiation curable security ink according to any one of claims 1 to 14, wherein the perfluoropolyether is functionalized with one or more phosphoric acid-containing groups or one or more silane-containing groups.

16. Use of the ultraviolet-visible radiation curable security ink according to any one of claims 1 to 15 in the production of one or more security functions on a security document or article.

17. A security function produced from the ultraviolet-visible radiation curable security ink according to any one of claims 1 to 15.

18. An article comprising a substrate and a radiation-cured coating film obtained by ultraviolet-visible radiation curing of the ultraviolet-visible radiation curable security ink according to any one of claims 1 to 15.

19. The article according to claim 18, wherein the substrate is selected from the group consisting of paper or other fibrous materials, paper-containing materials, glass, metal, ceramic, plastic and polymer, metallized plastic or polymer, composite materials, and mixtures or combinations of two or more thereof.

20. a. Printing the ultraviolet-visible radiation curable security ink according to any one of claims 1 to 15 on the substrate by a printing process selected from the group consisting of a rotary gravure process, a flexographic printing process, and a screen printing process; b. Curing the ultraviolet-visible radiation curable security ink to form one or more security functions A method for producing the article according to claim 18, comprising:

21. The method according to claim 20, wherein the curing is performed using one or more light sources selected from the group consisting of a mercury lamp, an ultraviolet LED lamp, and continuous use thereof.

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