Uv-vis curable security inks comprising tags and security features obtained thereof

Abstract

The present invention relates to the technical field of security features comprising markers by means of surface enhanced Raman spectroscopy (SERS) and the detection thereof. Furthermore, the present invention relates to the field of UV-Vis curable security inks comprising SERS tags for printing security features on substrates, in particular security documents or articles, in which the ink comprises one or more surface enhanced Raman spectroscopy (SERS) tags, one or more radiation curable compounds and one or more photoinitiators, and wherein the ink does not contain a vinyl ether-containing compound.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480056777.1 (22) Application Date 2024.09.02 (30) Priority Data 23195678.0 2023.09.06 EP (85) PCT International Application Entering National Phase Date 2026.03.05 (86) PCT International Application Application Data PCT / EP2024 / 074411 2024.09.02 (87) PCT International Application Publication Data WO2025 / 051658 EN 2025.03.13 (71) Applicant: Sikbay Holding Ltd. Address: Switzerland (72) Inventors: C. Basguier, D. Espinosa, A. Molina, T. Martini, C. Adler, C. Rohde (74) Patent Agency: Beijing Linda Liu Intellectual Property Agency (General Partnership) 11277 Patent Attorneys: Li Maojia, Duan Ran (51) Int.Cl. C09D 11 / 101 (2006.01) C09D 11 / 322 (2006.01) C09D 11 / 037 (2006.01) C09D 11 / 38 (2006.01) C09D 11 / 03 (2006.01) B41M 3 / 14 (2006.01) (54) Title of Invention: UV-VIS Curable Safety Ink Containing Labels and Safety Features Obtained Therefrom (57) Abstract: This invention relates to the technical field of safety features containing labels by means of surface-enhanced Raman spectroscopy (SERS) and their detection. Furthermore, this invention relates to the field of UV-Vis curable safety inks containing SERS labels, said inks for printing safety features on substrates, particularly on security documents or articles, said inks containing one or more surface-enhanced Raman spectroscopy (SERS) labels, one or more radiation-curing compounds, and one or more photoinitiators, and said inks do not contain compounds containing vinyl ethers. Claims 2 pages, Description 34 pages, Drawings 21 pages, CN 121773169 A 2026.03.31 CN 1 21 77 31 69 A 1. A UV-Vis radiation-curable printing ink comprising: i) one or more surface-enhanced Raman spectroscopy (SERS) labels, the total amount of which is about 0.01 wt.% to about 1 wt.%, preferably about 0.02 wt.% to about 1 wt.%, preferably the one or more surface-enhanced Raman spectroscopy (SERS) labels are nanoparticles, and more preferably at least one of the one or more SERS labels contains gold (Au) as a SERS reinforcing material;ii) one or more radiation-curable compounds, in total of about 50 wt.% to about 95 wt.%, preferably about 60 wt.% to about 95 wt.%; and iii) one or more photoinitiators, in total of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%, wherein the UV-Vis radiation-curable printing ink does not contain compounds containing vinyl ethers, the weight percentages being based on the total weight of the UV-Vis radiation-curable printing ink. 2. The UV-Vis radiation-curable printing ink according to claim 1, wherein the one or more SERS labels are present in the form of a dispersion, preferably a dispersion comprising an alkyd resin and about 10 wt.% to about 30 wt.%, for example 20 wt.%, of the surface-enhanced Raman spectroscopy (SERS) label, the weight percentages being based on the total weight of the dispersion. 3. The UV-Vis radiation-curable printing ink according to claim 1 or 2, selected from the group consisting of: screen printing inks, flexographic printing inks, and non-contact fluid microdistribution technology inks. 4. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 3, wherein the one or more radiation-curable compounds are cationic curable compounds selected from the group consisting of: propylene ethers, cyclic ethers, lactones, cyclic sulfides, propylene sulfides, silanes and mixtures thereof, preferably cyclic ethers, more preferably epoxides, oxetanes and mixtures thereof, and the one or more photoinitiators are one or more cationic photoinitiators, wherein the cationic photoinitiator is an onium salt, preferably selected from the group consisting of: oxonium salts, iodonium salts, sulfonium salts and mixtures thereof. 5. The UV-Vis radiation-curable printing ink according to claim 4, wherein the cationic curable compound is selected from the group consisting of: epoxides, oxetanes and mixtures thereof, preferably alicyclic epoxides, oxetanes and mixtures thereof. 6. The UV-Vis radiation-curable printing ink according to claim 4 or 5, further comprising one or more free radical curing compounds selected from the group consisting of: tri(meth)acrylates, tetra(meth)acrylates and mixtures thereof, and one or more free radical photoinitiators selected from the group consisting of: hydroxy ketones, alkoxy ketones, acetophenones, benzophenones, ketone sulfones, benzyl ketals, benzoyl ethers, coumarins, camphorquinones, phosphine oxides, phenyl glyoxylates and mixtures thereof, preferably selected from the group consisting of: phosphine oxides, hydroxy ketones and mixtures thereof. 7. The UV-Vis radiation-curable printing ink according to claim 4 or 5, which is a cationic UV-Vis radiation-curable screen printing ink, and further comprising one or more polyhydroxy compounds and / or one or more fillers or extenders.8. The UV-Vis radiation-curable printing ink according to claim 6, which is a mixed UV-Vis radiation-curable screen printing ink, and further comprises one or more polyhydroxy compounds, one or more fillers or extenders and / or one or more solvents and / or one or more photosensitizers. 9. The UV-Vis radiation-curable printing ink according to claim 4 or 5, which is a cationic UV-Vis radiation-curable inkjet printing ink, and further comprises one or more cationic curable epoxy siloxane compounds and / or one or more photosensitizers and / or one or more solvents. Claims 1 / 2 Page 2 CN 121773169 A 10. The UV-Vis radiation-curable printing ink according to claim 6, which is a mixed UV-Vis radiation-curable inkjet printing ink, and further comprises one or more cationic curable epoxy siloxane compounds and / or one or more solvents. 11. Use of the UV-Vis radiation-curable printing ink according to any one of claims 1 to 10 for manufacturing one or more safety features on a substrate. 12. A safety feature made of the UV-Vis radiation-curable printing ink according to any one of claims 1 to 10. 13. A safety article comprising a substrate and a radiation-cured coating obtained by UV-Vis radiation curing of the UV-Vis radiation-curable printing ink according to any one of claims 1 to 10, wherein the substrate is preferably selected from the group consisting of: paper or other fibrous materials, paper-containing materials, glass, metal, ceramics, plastics and polymers, composite materials, and mixtures or combinations thereof. 14. A method for producing the safety article of claim 13, comprising the steps of: a. printing the UV-Vis radiation-curable printing ink according to any one of claims 1 to 10 onto a substrate, preferably by a printing method selected from the group consisting of screen printing, flexographic printing, or non-contact fluid micro-dispensing technology; and b. UV-Vis radiation curing the UV-Vis radiation-curable printing ink, preferably by one or more light sources selected from the group consisting of mercury lamps, UV-LED lamps, and sequences thereof, to form one or more safety features. 15. A method for identifying one or more security features as claimed in claim 12 and a security article as claimed in claim 13, comprising the following steps: a. providing a security article as claimed in claim 13 and comprising one or more security features as claimed in claim 12, said one or more security features being made of a radiation-cured layer made of UV-Vis radiation-curable printing ink as claimed in any one of claims 1 to 10; b. irradiating one or more security features with visible light and / or near-IR light and measuring the SERS spectrum; and c.The SERS spectrum obtained in step b is compared with a pre-recorded reference Raman spectrum. Claims 2 / 2 Page 3 CN 121773169 A UV-VIS curable security ink containing a label and security features obtained therefrom Technical Field

[0001] This invention relates to the technical field of security features containing markers obtained by surface-enhanced Raman spectroscopy (SERS) and their detection. Furthermore, this invention relates to the field of UV-Vis curable security inks containing SERS labels for printing security features on substrates, particularly on security documents or articles. Background Art

[0002] With the continuous improvement in the quality of color photocopies and printed matter, and the attempt to protect security articles and documents that do not have reproducibility effects, such as banknotes, valuable documents or cards, transportation tickets or cards, tax banders, and merchandise labels, from counterfeiting, alteration, or illegal copying, it is conventional to introduce various security features into or onto these documents.

[0003] For example, security features used for security documents and articles can be classified as "overt" and "covert" security features. Explicit security features are easily detectable using independent human senses; for example, such features may be visible and / or detectable via tactile senses, while remaining difficult to produce and / or reproduce. Implicit security features, on the other hand, typically require specialized equipment and knowledge for their detection.

[0004] Machine-readable inks, such as magnetic inks, luminescent inks, and infrared (IR) absorbing inks, have been widely used in the field of security documents, particularly for banknote printing, to produce implicit security features.

[0005] Machine-readable inks containing SERS-type or SERRS-type markers (referred to herein as SERS tags and SERRS tags) have been developed for the protection of security articles and documents. Surface-enhanced Raman scattering is called SERS, and surface-enhanced resonant Raman scattering is called SERRS. SERS and SERRS tags have unique characteristic surface-enhancing features (i.e., surface-enhanced Raman scattering features or surface-enhanced resonant Raman scattering features, respectively), which allow for their detection and identification using a standard Raman spectrometer.

[0006] As is well known to those skilled in the art, SERS and SERRS tags comprise nanoparticles exhibiting a plasmonic surface and aggregates of Raman-active reporter molecules adsorbed on the surface of the nanoparticles. Surface-enhanced Raman scattering is a laser-based optical spectroscopy that generates fingerprint-like vibrational spectra for molecules or other materials with characteristics much narrower than typical fluorescence. The nanoparticles exhibiting a plasmonic surface are responsible for generating the electric field required for Raman amplification, while the Raman-active reporter molecules provide the unique vibrational fingerprint of the SERS tag.

[0007] SERS tags comprise a metal or other reinforcing surface that is electromagnetically coupled to the incident electromagnetic radiation and generates localized radiation.A large electromagnetic field causes a 10² to 10⁹-fold or greater increase in Raman scattering by SERS-active molecules located on or near the enhanced surface. The output of a SERS experiment is a fingerprint-like Raman spectrum of the SERS-active molecules.

[0008] SERS tags and other types of optical detection tags can be manufactured in various sizes and shapes, and have some control over the selected configuration elements.

[0009] Raman spectroscopy is obtained by measuring the intensity distribution of Raman scattered photons received from a sample containing the substance of interest and irradiated by a light source as a function of wavelength. Quantitative determination is based on the fact that the concentration of the substance of interest is proportional to the integral intensity of its characteristic Raman band.

[0010] As mentioned above, machine-readable inks containing SERS markers have been developed for protecting security articles and documents. For example, EP 0 806 460 A1 discloses security inks, particularly oxidative drying inks, which contain SERS-active metal aggregates containing Raman-active compounds. WO 91 / 11492 A1 discloses security inks containing Raman-active compounds, such as offset printing, letterpress printing, gravure printing, and screen printing inks. WO 2010 / 135 354 A1 also discloses inks such as offset printing, letterpress printing, gravure printing, and screen printing inks.

[0011] In conventional printing methods for security documents, particularly banknotes, several inks are applied sequentially and independently through a multi-step printing process. The rapid drying properties of UV-Vis curable inks advantageously result in the production of security features that are not subject to low surface curing properties, thereby avoiding any delays in subsequent printing steps.

[0012] However, the prior art does not disclose formulation details, nor does it disclose UV-Vis curable security inks.

[0013] Therefore, there remains a need for UV-Vis curable security inks containing SERS labels, in which the obtained security features can be easily and clearly identified. Summary of the Invention

[0014] Therefore, the object of the present invention is to overcome the deficiencies of the prior art. This is achieved by providing a UV-Vis radiation-curable printing ink comprising:

[0015] i) one or more surface-enhanced Raman spectroscopy (SERS) tags, in total of about 0.01 wt.% to about 1 wt.%, preferably about 0.02 wt.% to about 1 wt.%, preferably the one or more SERS tags are nanoparticles, and more preferably at least one of the one or more SERS tags contains gold (Au) as a SERS reinforcing material;

[0016] ii) one or more radiation-curable compounds, in total of about 50 wt.% to about 95 wt.%, preferably about 60 wt.% to about 95 wt.%; and

[0017] iii)One or more photoinitiators, in total amounts from about 1 wt.% to about 20 wt.%, preferably from about 2 wt.% to about 15 wt.%,

[0018] wherein the UV-Vis radiation-curable printing ink is free of compounds containing vinyl ethers,

[0019] the weight percentages are based on the total weight of the UV-Vis radiation-curable printing ink.

[0020] This document also describes safety features made from the UV-Vis radiation-curable printing ink described herein, and safety articles comprising a substrate and a radiation-cured coating obtained by UV-Vis radiation curing of the UV-Vis radiation-curable printing ink described herein.

[0021] This document also describes a method for producing the safety article described herein, wherein the method comprises the following steps:

[0022] a. preferably printing the UV-Vis radiation-curable printing ink of any one of claims 1 to 10 onto a substrate by a printing method selected from the group consisting of screen printing, flexographic printing or non-contact fluid micro-dispensing technology, and

[0023] b. preferably UV-Vis radiation curing the UV-Vis radiation-curable printing ink with one or more light sources selected from the group consisting of mercury lamps, UV-LED lamps and sequences thereof to form one or more safety features.

[0024] This document also describes a method for identifying one or more security features and security articles described herein, the method comprising the following steps:

[0025] a. providing a security article described herein and containing one or more security features described herein, said security features being made of a radiation-cured layer made of UV-Vis radiation-curable printing ink described herein;

[0026] b. irradiating one or more security features with visible light and / or near-IR light and measuring the SERS spectrum; and

[0027] c. comparing the SERS spectrum obtained in step b with a pre-recorded reference Raman spectrum.

[0028] UV-Vis curable security ink containing the SERS label described herein allows for the printing and preparation of security features for security articles, said security features being advantageously and definitively identified by means of Raman spectroscopy. This definitive identification relates to the detection problems that may arise due to saturation of the SERS signal of the security feature, as described in this specification (page 2 / 34, CN 121773169 A). Advantageously, due to the reduced drying time and its good chemical and physical resistance, the present invention allows for the rapid production of flow-resistant safety features. Brief Description of the Drawings

[0029] Figures 1 to 6 show the Raman shifts of printed features consisting of cured layers independently made from UV-Vis radiation-curable printing inks (E1-E21 and C1-C22).

[0030] Figure 1 shows the Raman shifts of printed features consisting of cured layers made from UV-Vis radiation-curable inkjet printing ink (E1).Raman shift, the feature being applied by inkjet printing with different ink coverage (25%, 50%, and 75%) and by hand coating (HC).

[0031] Figures 2-1 to 2-6 and Figure 6-1 show the Raman shift of a printed feature consisting of a cured layer independently made from UV-Vis radiation-curable inkjet printing inks (E1-E6 in Figures 2-1 to 2-6 and E20 in Figure 6-1).

[0032] Figures 3-1 to 3-12 show the Raman shift of a printed feature consisting of a cured layer independently made from comparative UV-Vis radiation-curable inkjet printing inks (C1-C12).

[0033] Figures 4-1 to 4-13 and Figure 6-2 show the Raman shift of a printed feature consisting of a cured layer independently made from UV-Vis radiation-curable screen printing inks (E7-E19 in Figures 4-1 to 4-13 and E21 in Figure 6-2).

[0034] Figures 5-1 to 5-10 show the Raman shifts of printing features consisting of cured layers made independently of comparative UV-Vis radiation-curable screen printing inks (C16-C22), wherein the Raman shifts are reported in wavenumbers in units of cm⁻¹ (=[(1 / λ₀)-(1 / λ₁)], where λ₀ is the laser excitation wavelength and λ₁ is the Raman spectral wavelength). Detailed Description

[0035] Definitions

[0036] The following definitions are used to clarify the meaning of terms discussed in the specification and defined in the claims.

[0037] As used herein, the indefinite article “a / an” means one or more than one, and does not necessarily limit its designated noun to a single one.

[0038] As used herein, the term “at least one” is intended to define one or more, for example, one, two, or three.

[0039] As used herein, the term “and / or” means that all or only one of the elements of the group may be present. For example, “A and / or B” should mean “A only, or B only, or both A and B”. In the case of “A only”, the term also covers the possibility that B is not present, i.e., “A only, but not B”.

[0040] As used herein, the term “about” means that the quantity or value in discussion can be a specified particular value or some other value near it. Generally, the term “about” indicating a certain value is intended to indicate a range within ±5% of that value. As an example, the phrase “about 100” indicates a range of 100 ± 5, i.e., a range of 95 to 105. Preferably, the range indicated by the term “about” indicates a range within ±3% of that value, more preferably within ±1%. Generally, when the term “about” is used, similar results or effects according to the invention can be expected to be obtained within ±5% of the indicated value.

[0041] The term “comprising” as used herein is intended to be non-exclusive and open-ended. Thus, for example, a solution containing compound A may contain other compounds besides A. However, as in a particular embodiment thereof, the term “comprising” also covers “basic” compounds.The more restrictive meaning of "consisting of..." and "composed of..." means that, for example, "a solution containing A, B and optional C" can also be (substantially) composed of A and B, or (substantially) composed of A, B and C.

[0042] The term "safety article" refers to an article that is generally protected against counterfeiting or tampering by more than one safety feature.

[0043] The term "safety feature" is used to refer to an image, pattern or graphic element that can be used for identification purposes. Specification 3 / 34 pages 6 CN 121773169 A

[0044] Where this specification relates to "preferred" embodiments / features, combinations of these "preferred" embodiments / features should also be considered disclosed, provided that such combinations of "preferred" embodiments / features are technically meaningful.

[0045] The terms "UV-Vis curability" and "UV-Vis curing" refer to radiation curing via photopolymerization under irradiation having wavelength components in the UV or UV and visible portions of the electromagnetic spectrum (typically between 100 nm and 800 nm, preferably between 150 nm and 600 nm, more preferably between 200 nm and 470 nm).

[0046] The present invention provides UV-Vis radiation-curable printing inks, preferably selected from the group consisting of: UV-Vis radiation-curable screen printing inks, UV-Vis radiation-curable flexographic printing inks, and UV-Vis radiation-curable non-contact fluid micro-distribution inks, more preferably selected from the group consisting of: UV-Vis radiation-curable screen printing inks and UV-Vis radiation-curable non-contact fluid micro-distribution inks, and even more preferably selected from the group consisting of: UV-Vis radiation-curable screen printing inks and UV-Vis radiation-curable inkjet printing inks. More than one safety feature can be created when applying and curing the UV-Vis radiation-curable printing ink.

[0047] Typically, UV-Vis radiation-curable printing inks suitable for screen printing methods have a viscosity at 25°C ranging from about 500 mPa s to about 2500 mPa s, preferably from about 600 mPa s to about 1500 mPa s (using, for example, a Brookfield machine "RVDV-I Prime", rotor 27, at 100 rpm).

[0048] Screen printing (also known in the art as silkscreen printing) is a printing technique that typically uses a woven mesh to support an ink-blocking stencil. The connected stencil forms open areas of the mesh, transferring ink as a sharply edged image onto the substrate. A squeegee is moved across the mesh with the ink-blocking stencil, forcing the ink through the threads of the woven mesh in the open areas. A significant feature of screen printing is that, compared with other printing techniques...Compared to other printing techniques, a greater thickness of ink can be applied to the substrate. Therefore, screen printing is preferred when an ink deposit with a thickness of about 10 to 50 μm or more is required, as this cannot be easily achieved with other printing techniques. Typically, a screen is made of a porous, finely woven fabric called a mesh, stretched on a frame such as aluminum or wood. Currently, most meshes are made of man-made materials such as synthetic threads or steel wires. Preferred synthetic materials are nylon or polyester threads.

[0049] In addition to screens made based on woven meshes of synthetic or metal threads, screens have been developed in solid metal plates with perforated grids. Such screens are prepared by a method comprising electrolyzing the metal screen by forming a screen skeleton in a first electrolytic bath on a substrate provided with a separating agent, peeling the formed screen skeleton from the substrate, and subjecting the screen skeleton to electrolysis in a second electrolytic bath to deposit metal onto the skeleton.

[0050] There are three types of screen printing machines: flatbed, roller, and rotary screen printing machines. Flatbed and rotary screen printing machines are similar in that both use a flat screen and a three-step reciprocating process for printing. First, the screen is moved above the substrate, then a squeegee is pressed against the screen and pulled across the image area, and then the screen is lifted away from the substrate to complete the process. In the case of a flatbed screen printing machine, the substrate to be printed is typically positioned on a horizontal printing table parallel to the screen. In the case of a rotary screen printing machine, the substrate is mounted on a cylinder. Both flatbed and rotary screen printing methods are discontinuous, thus limiting speed, typically to a maximum of 45 m / min in web printing or a maximum of 3,000 sheets / hour in a sheet-fed process.

[0051] In contrast, rotary screen printing machines are designed for continuous, high-speed printing. The screen used on a rotary screen printing machine is, for example, a thin metal cylinder obtained using the electroforming method described above or made of braided steel wire. The cylinder, with open ends, is capped at both ends and fitted into a plate on the side of the printing machine. During printing, ink is pumped into one end of the cylinder to maintain a continuous and fresh supply. The squeegee is fixed inside the rotary screen, and the squeegee pressure is maintained and adjusted to allow for good and consistent print quality. The advantage of rotary screen printing machines is their speed, which can easily reach 150 m / min in roll paper or 10,000 sheets / hour in sheet-feed processes.

[0052] Screen printing is further described, for example, in: The Printing Ink Manual, R.H. Leach and R.J. Pierce, Springer, 5th edition, pp. 58-62; Printing Technology.Technology), JM Adams and PA Dolin, Delmar Thomson Learning, 5th edition, pp. 293-328; and Handbook of Print Media, H. Kipphan, Springer, pp. 409-422 and 498-499.

[0053] Typically, UV-Vis radiation-curable printing inks suitable for flexographic printing methods have a viscosity in the range of about 50 mPa s to about 2000 mPa s at 25°C, preferably in the range of about 600 mPa s to about 1500 mPa s at 25°C (using, for example, Brookfield machine “RVDV-I Prime”, rotor No. 27, at 100 rpm).

[0054] Flexographic printing methods preferably use a unit having a cavity squeegee, an anilox roller, and a printing plate cylinder. Anilox rollers advantageously have cells whose volume and / or density determine the application rate of ink or varnish. A cavity-type doctor blade abuts against the anilox roller, filling the cells while scraping away excess ink or varnish. The anilox roller transfers the ink to a plate cylinder, which ultimately transfers the ink to the substrate. The plate cylinder can be made of polymer or elastomeric materials. Polymers are primarily used as photopolymers in printing plates and sometimes as seamless coatings on sleeves. Photopolymer printing plates are made of photosensitive polymers that are cured by ultraviolet (UV) light. The photopolymer printing plate is cut to the desired size and placed in a UV light exposure unit. One side of the printing plate is fully exposed to UV light to harden or cure the base of the printing plate. The printing plate is then flipped over, the film for the operation is mounted on the uncured side, and the printing plate is further exposed to UV light. This hardens the printing plate in the image areas. The printing plate is then processed to remove the uncured photopolymer from the non-image areas, which reduces the surface area of ​​the printing plate in these non-image areas. After processing, the printing plate is dried and subjected to a post-exposure dose of UV light to cure the entire printing plate. The preparation of the printing plate cylinder for flexographic printing is described in: Printing Technology, JM Adams and PA Dolin, Delmar Thomson Learning, 5th edition, pp. 359-360.

[0055] Non-contact fluid microdispensing methods include methods preferably selected from the group consisting of: spraying, aerosol jet printing, electrohydrodynamic printing, slot coating, laser-induced forward transfer (LIFT) printing, and inkjet printing, more preferably by inkjet printing methods.

[0056] Spraying is a technique involving forcing a composition through a nozzle to form a fine aerosol. Carrier gas and electrostatic chargeElectricity can help guide the aerosol to the surface to be printed. Spraying allows for the printing of dots and lines. Suitable compositions for spraying typically have a viscosity between about 10 mPa·s and about 1 Pa·s (25°C, 1000 s⁻¹). The resolution of spray printing is in the millimeter range. Spraying is described, for example, in FC Krebs, Solar Energy Materials & Solar Cells (2009), 93, page 407.

[0057] Aerosol jet printing (AJP) is an emerging non-contact direct-writing method designed to produce fine features on a wide range of substrates. AJP is compatible with a broad range of materials and free-form deposition, allowing for a combination of high resolution (on the order of about 10 micrometers) and relatively large stand-off distances (e.g., 1–5 mm), in addition to orientation independence. This technology involves aerosol generation using ultrasonic or pneumatic atomizers, generating aerosols from compositions typically with viscosities between about 1 mPa·s and about 1 Pa·s (25 °C, 1000 s⁻¹). Aerosol jet printing is described, for example, in NJ Wilkinson et al., The International Journal of Advanced Manufacturing Technology, (2019), 105: 4599-4619.

[0058] Electrodynamic inkjet printing is a high-resolution inkjet printing technology. Electrodynamic inkjet printing technology utilizes an externally applied electric field to manipulate droplet size, jetting frequency, and arrangement on a substrate to achieve higher resolution than conventional inkjet printing while maintaining high production speed. The resolution of electrodynamic inkjet printing is about two orders of magnitude higher than that of conventional inkjet printing technology; therefore, it can be used for the orientation of nanoscale and microscale patterns. Electrodynamic inkjet printing can be used in both DOD or continuous mode as per the specification page 5 / 34 8 CN 121773169 A. Compositions used for electrohydrodynamic inkjet printing typically have a viscosity between about 1 mPa s and about 1000 mPa s (25°C, 1000 s⁻¹). Electrohydrodynamic inkjet printing technology is described, for example, in PV Raje and NC Murmu, International Journal of Emerging Technology and Advanced Engineering, (2014), 4(5), pp. 174–183.

[0059] Slit coating is a one-dimensional coating technique. Slit coating allows for the application of stripes of coating material, which is ideal for creating multilayer coatings with stripes of different materials stacked on top of each other. Pattern alignment is achieved by moving the coating head along a direction perpendicular to the roll of paper.This is produced by translation in the direction of the direction. The slit coating head contains a mask defining a slit through which the slit coating ink is dispersed. Examples of slit coating heads are described in F. C. Krebs, Solar Energy Materials & Solar Cells (2009), 93, pp. 405-406. Suitable compositions for slit coating typically have a viscosity between about 1 mPa s and about 20 mPa s (25°C, 1000 s⁻¹).

[0060] Laser-induced forward transfer (LIFT) printing is a direct-write technique based on the action of a laser to print small portions of material from a thin donor layer onto a receiving substrate. Solid donor films have been used since its origin, but the same operating principle is also used for liquid ink films. LIFT is a nozzleless printing technique that can be used for two-dimensional and three-dimensional printing and has virtually no limitations in terms of the particle size and viscosity of the ink to be printed. In LIFT, a laser pulse generates a pulse within a thin film of material, resulting in the formation of a liquid jet. Compositions used for LIFT printing typically have a viscosity between about 1 mPa s and about 100 Pa s (25°C, 1000 s⁻¹). Examples of LIFT applications have been described, for example, by J. Marcos Fernandez-Pradas and Perre Serra, Crystals (2020) 10(8), p. 651, and by M. Jalaal et al., J. Fluid Mech. (2019), 880, pp. 497–513.

[0061] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is printed by an inkjet printing method, preferably a continuous inkjet (CI) printing method or a drop-on-demand (DOD) inkjet printing method, more preferably a drop-on-demand (DOD) inkjet printing method. On-demand droplet (DOD) printing is a non-contact printing method in which droplets are generated only when printing is required, and are typically generated by an ejection mechanism rather than by destabilizing the jet. DOD printing is classified into piezoelectric pulse, thermal jet, valve jet (viscosity between about 1 mPa·s and about 1 Pa·s (25°C, 1000 s⁻¹)) and electrostatic methods, depending on the mechanism used to generate the droplets in the printhead.

[0062] The light source required to cure the UV-Vis radiation-curable printing ink described herein is selected from the group consisting of: mercury lamps (preferably medium-pressure mercury lamps), UV-LED lamps, and sequences thereof. A typical sequence includes the use of one or more UV-LED lamps in a first step to partially cure the UV-Vis radiation composition, and the use of one or more medium-pressure mercury lamps in a second step. Mercury lamps advantageously emit over a wide wavelength range in the UV-A, UV-B, and UV-C ranges.

[0063] The UV-Vis radiation-curable printing inks described herein do not contain compounds containing vinyl ethers. The term "does not contain" means that the UV-Vis radiation-curable printing inks described herein contain 0 wt.% of compounds containing vinyl ethers, the weight percentage being based on the total weight of the UV-Vis radiation-curable printing inks.

[0064] The UV-Vis radiation-curable printing inks described herein contain one or more surface-enhanced Raman (SERS) tags in a total amount of about 0.01 wt.% to about 1 wt.%, preferably about 0.02 wt.% to about 1 wt.%, more preferably about 0.04 wt.% to about 0.6 wt.%, the weight percentage being based on the total weight of the UV-Vis radiation-curable printing inks.

[0065] According to one embodiment, one or more surface-enhanced Raman spectroscopy (SERS) tags are incorporated in the form of a dispersion into the UV-Vis radiation-curable printing ink described herein, including, for example, a dispersion comprising an alkyd resin, wherein the dispersion comprises about 10 wt.% to about 30 wt.%, for example, 20 wt.% of the surface-enhanced Raman spectroscopy (SERS) tag.

[0066] The SERS tag is an aggregate of nanoparticles that present a plasmonic surface and have Raman-active reporter molecules adsorbed on its surface. The SERS tag presenting a plasmonic surface is responsible for generating the electric field required for Raman signal or Raman scattering amplification, while the Raman-active reporter molecules provide a unique vibrational fingerprint of the SERS tag. Typically, aggregates exist in the external coating, which a) isolate the SERS tag from the external medium, thereby preventing Raman-active reporter molecules from leaching from the SERS tag and protecting the SERS tag from contamination by the external medium that may cause vibrational noise; b) increase the stability of the SERS tag; and c) provide a convenient surface for further chemical functionalization. To date, polymers and silica have been used as external coatings. External coatings include silica and polymers such as poly(ethyleneimine) (PEI), sodium poly(styrene-alt-maleic acid) (PSMA), and poly(diallyldimethylammonium chloride) (PDADMAC).

[0067] Preferred Raman-active reporter molecules include fully conjugated molecules comprising an aryl group substituted with one or more substituents selected from -NR1R2, -SH, -≡, -≡N, and -N=, preferably selected from -NR1R2 and -SH, and / or containing an N-heteroaryl group and / or containing an S-heteroaryl group, wherein residues R1 and R2 are independently selected from -H and alkyl groups, preferably selected from -H and C1-C4 alkyl groups. As is known to those skilled in the art of organic chemistry, a fully conjugated molecule is a molecule having a conjugated electron system that extends throughout the entire molecule. A conjugated electron system is a system of connected p orbitals with delocalized electrons.

[0068] As is known to those skilled in the art, "aryl" is a group derived from a monocyclic or polycyclic aromatic hydrocarbon compound by removing a hydrogen atom from a ring carbon atom. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, anthraceneyl, phenanthrene, and pyreneyl.

[0069] N-containing heteroaromatic compounds are aromatic compounds containing at least one nitrogen heteroatom as part of a cyclic conjugated π-system. As part of the cyclic conjugated π-system, N-containing heteroaromatic compounds may further contain more than one oxygen atom. Examples of N-containing heteroaryl groups include, but are not limited to, imidazole, pyrazolyl, triazolyl, tetrazolyl, benzimidazole, indazole, benzotriazolyl, pyridinyl, pyrimidinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, diazanaphthyl, quinazolinyl, cyclolinyl, phthalazinyl, quinoxalinyl, purine, aziphenanthryl, diazaphenanthryl, azianthracene, diazaanthracene, azipyrene, diazapyrene, oxazolyl, isoxazolyl, oxadiazolyl, benzoxazolyl, benziisoxazolyl, and benzoxadiazolyl.

[0070] S-containing heteroaryl compounds are aromatic compounds containing a sulfur heteroatom as part of a cyclic conjugated π system. As part of a cyclic conjugated π system, S-containing heteroaryl compounds may further contain more than one nitrogen atom. Examples of S-containing heteroaryl groups include, but are not limited to, thienyl, thiazolyl, isothiazolyl, thiadiazolyl, benzothienyl, benzothiazolyl, benzoisothiazolyl, benzothiadiazolyl, imidazothiazolyl, and imidazothiadiazolyl.

[0071] Preferred Raman-active reporter molecules include, but are not limited to:

[0072] - Fully conjugated compounds consisting of: an aryl group substituted by one or more substituents selected from -NR1R2, -SH, -≡, -≡N and -N=, preferably selected from -NR1R2 and -SH, which is directly or via a linker -L1- connected to an aryl group, an N-containing heteroaryl group, or an S-containing heteroaryl group substituted by one or more substituents selected from the list containing amino (-NH2), N-alkylamino, N,N-dialkyl-amino, thiol, ethynyl, cyano and isocyanate groups, wherein

[0073] substituents R1 and R2 have the meanings defined herein;

[0074] group Y is selected from O, S, NH;

[0075] linker -L1- is selected from -CR8=CR9-, -N=N-, -≡-, -CR10=CR11-o-C6H4-, -CR 10=CR11-m-C6H4-、-CR10=CR11-p-C6H4-、-CR10=CR11-o-C6H4-CR12=CR13-、-CR10=CR11-m-C6H4-CR12=CR13-、-CR10=CR11-p-C6H4-CR12=CR13-、-CR14=N-N=CR15-、

[0076] 、、、、 Specification 7 / 34 pages 10 CN 121773169 A

[0077] 、、 、

[0078] 、 、 、

[0079] 、 、 、

[0080] 、 、 、

[0081] 、 、 、

[0082] 、 、 、

[0083] 、 and;

[0084] and

[0085] the substituents R8-R15 are selected from hydrogen, alkyl, alkoxy, alkylthio, formyl, cyano, nitro, halide, hydroxycarbonyl and alkoxycarbonyl;

[0086] - a fully conjugated compound consisting of: containing an N-heteroaryl group, which is directly or via a linker -L1- linked to an N-heteroaryl group or an S-heteroaryl group,

[0087] wherein,

[0088] the linker -L1- is selected from -CR8=CR9-, -N=N-, -≡-, -CR10=CR11-o-C6H4-, -CR 10=CR11-m-C6H4-、-CR10=CR11-p-C6H4-、-CR10=CR11-o-C6H4-CR12=CR13-、-CR10=CR11-m-C6H4-CR12=CR13-、-CR10=CR11-p-C6H4-CR12=CR13-、-CR14=N-N=CR15-、 Instruction manual 8 / 34 page 11 CN 121773169 A

[0089] 、、、

[0090] 、、、

[0091] 、、、

[0092] 、、、

[0093] 、、、

[0094] 、、、

[0095] 、、、

[0096] 、 and;

[0097] And

[0098] the substituents R8-R15 are selected from hydrogen, alkyl, alkoxy, alkylthio, formyl, cyano, nitro, halide, hydroxycarbonyl and alkoxycarbonyl;

[0099] - a fully conjugated compound consisting of an S-containing heteroaryl group, which is directly or via a linker -L1- linked to the S-containing heteroaryl group,

[0100] wherein,

[0101] the linker -L1- is selected from -CR8=CR9-, -N=N-, -≡-, -CR10=CR11-o-C6H4-, -CR10=CR11-m-C6H4-, -CR10=CR11-p-C6H4-, -CR10=CR11-o-C6H4-CR12=CR13-, -CR10=CR11-m-C6H4-CR 12=CR13-、-CR10=CR11- Instruction manual 9 / 34 page 12 CN 121773169 A p-C6H4-CR 12=CR13-、-CR14=N-N=CR15-、

[0102] 、、、

[0103] 、、、

[0104] 、、、

[0105] 、、、

[0106] 、、、

[0107] 、、

[0108] ,

[0109] , and;

[0110] and the substituents R8-R15 are selected from hydrogen, alkyl, alkoxy, alkylthio, formyl, cyano, nitro, halide, hydroxycarbonyl and alkoxycarbonyl;

[0111] and

[0112] - a fully conjugated compound consisting of: an aryl group substituted with one or more, preferably at least two, substituents selected from -NR1R2, -SH, -≡, -≡N and -N=, preferably selected from -NR1R2 and -SH; an N-containing heteroaryl group optionally substituted with one or more substituents selected from -NR3R4, -SH, -≡, -≡N and -N=; or optionally substituted with one or more substituents selected from -NR5R6, -SH, -≡, -≡ An S-containing heteroaryl group substituted with one or more substituents of N and -N= is directly attached to a hydrogen atom, wherein substituents R1 and R2 have the meaning as defined herein (see page 10 / 34, CN 121773169 A), and substituents R3-R6 are independently selected from -H and alkyl, preferably -H and C1-C4 alkyl. The aryl group substituted with one or more substituents selected from -NR1R2, -SH, -≡, -≡N, and -N=, preferably from -NR1R2 and -SH, may contain, preferably, one or more substituents selected from: hydroxyl, alkyl, alkoxy, alkylthio, formyl, nitro, halide, hydroxycarbonyl, alkoxycarbonyl, and O-containing heteroaryl, more preferably from: alkyl, alkoxy, alkylthio, halide, and O-containing heteroaryl.

[0113] The N-containing and S-containing heteroaryl groups may contain, preferably, substituents selected from: amino, N-alkylamino, N,N-dialkylamino, thiol, hydroxyl, alkyl, alkoxy, alkylthio, formyl, cyano, isocyanate, ethynyl, nitro, halide, hydroxycarbonyl, alkoxycarbonyl, and O-containing heteroaryl groups, preferably selected from one or more of alkyl, alkoxy, alkylthio, halide, and O-containing heteroaryl groups.

[0114] Examples of O-containing heteroaryl groups include, but are not limited to, furanyl, benzofuranyl, isobenzofuranyl, oxazolyl, isoxazolyl, benzoxazolyl, and oxadiazolyl.

[0115] Preferred Raman-active reporter compounds are compounds of general formula (I),

[0116]

[0117] (I)

[0118] wherein,

[0119] A1, B1 and C1 are independently selected from N, CR16 and CR17, provided that only one of A1, B1 and C1 is N;

[0120] A2, B2 and C2 are independently selected from N, CR18 and CR19, provided that only one of A2, B2 and C2 is N;

[0121] E1, D1, E2, D2, R16, R17, R18 and R19 are independently selected from: hydrogen, amino, N-alkylamino, N,N-dialkylamino, thiol, hydroxyl, alkyl, alkoxy, alkylthio, formyl, cyano, isocyanate, alkynyl, nitro, halide, hydroxylCarbonyl, alkoxycarbonyl, and O-containing heteroaryl, preferably selected from hydrogen, alkyl, alkoxy, alkylthio, halide, and O-containing heteroaryl; and

[0122] X is a single bond or a linker selected from the following: -L2-: -CR8=CR9-, -N=N-, -≡-, -CR10=CR11-o-C6H4-, -CR10=CR11-m-C6H4-, -CR10=CR11-p-C6H4-, -CR10=CR11-o-C6H4-CR12=CR13-, -CR10=CR11-m-C6H4-CR12=CR13-, -CR10=CR11-p-C6H4-CR12=CR13-, -CR14=N-N=CR15-,

[0123] , , , Specification 11 / 34 Page 14 CN 121773169 A

[0124] 、 、 、

[0125] 、 、 、

[0126] 、 、 、

[0127] 、 、 、

[0128] 、 、 、

[0129] 、 、 、

[0130] 、 and;

[0131] wherein R8-R15 are selected from hydrogen, alkyl, alkoxy, alkylthio, formyl, cyano, nitro, halide, hydroxycarbonyl and alkoxycarbonyl.

[0132] Preferably, in general formula (I), residues A1 and A2 are N. More preferably, in general formula (I), residues A1 and A2 are N, and substituents E1, D1, E2, D2, R16, R17, R18 and R19 are hydrogen.

[0133] Raman-active reporter molecules include, but are not limited to: 2-mercaptopyridine; thiophene; mercaptobenzoic acid; 4-nitrothiophene; 3,4-dichlorothiophene; 3-fluorothiophene; 4-fluorothiophene; 3-5-bis(trifluoromethyl)thiophene; 4-mercaptophenol; biphenyl-4-thiophenol; 7-mercapto-4-methylcoumarin; 1-(4-hydroxyphenyl)-1H-tetrazole-5-thiol; 2-fluorothiophene; 2-naphthiophene; 4-(((3-mercapto-5-(2-methoxyphenyl)-4H-1,2,4-triazol-4-yl)imino)methyl)phenol; (2-trifluoromethyl) Thiophenol, 4-aminothiophenol, 1-naphthiophenol, 1,1',4,1''-terphenyl-4-thiophenol, biphenyl-4,4'-dithiophenol, thiosalicylic acid, 4-(((3-mercapto-5-(2-pyridyl)-4H-1,2,4-triazol-4-yl)imino)methyl)-1,2-benzenediol, 4-(((3-mercapto-5-(2-pyridyl)-4H-1,2,4-triazol-4-yl)imino)methyl)benzoic acid, 2,3,4,6-tetrafluorothiophenol, (5-(4-methoxyphenyl)-1,3,4-oxazol-2-thiol), (E)-1,2-di(pyridin-4-yl)ethylene, 5-(pyridin-4-yl)... (Instructions 12 / 34 pages 15 CN)121773169 A (-1,3,4-oxadiazol-2-thiol and 1,4-bis((E)-2-(pyridin-4-yl)vinyl)benzene.

[0134] Typically, SERS tags are nanoparticles. Within the meaning of this invention, the term "nanoparticle" is defined as a single particle having a size corresponding to a maximum physical size (e.g., length, diameter, etc.) in the range of 20±5 nm to 160±5 nm, preferably 40±5 nm to 140±5 nm. The SERS tags used in this invention have a plasmonic surface, i.e., the nanoparticle has an outer surface capable of enhancing Raman scattering of Raman-active molecules. The outer surface of the nanoparticle is made of any known SERS-enhancing material. Preferably, the SERS-enhancing material is selected from: gold (Au), silver (Ag), copper (Cu), aluminum (Al), palladium (Pd), platinum (Pt) or mixtures or alloys thereof, more preferably gold (Au). The SERS tags used in this invention can be solid or hollow, preferably solid. Solid nanoparticles can be made of a single material, i.e., the SERS reinforcing material on the outer surface of the nanoparticle; or solid nanoparticles can be made of more materials, i.e., the material of the core of the nanoparticle can be different from the SERS reinforcing material on the outer surface of the nanoparticle. Hollow nanoparticles are nanoparticles whose core is a void space. Nanoparticles can have any shape that can be produced. Preferably, at least one of the more than one SERS label is a solid Au nanoparticle, wherein the nanoparticle preferably has a shape selected from the group consisting of spherical, ellipsoidal, rod-shaped, disc-shaped, prismatic and cubic, more preferably selected from spherical and ellipsoidal, and even more preferably ellipsoidal.

[0135] The UV-Vis radiation-curable printing ink described herein can be a cationic curable printing ink (i.e., containing a cationic curable compound), a free radical curable ink (i.e., containing a free radical curable compound), or a mixed curable ink (i.e., containing a cationic curable compound and a free radical curable compound). Cationic UV-Vis radiation-curable printing inks are cured via a cationic mechanism, which consists of: activating one or more cationic photoinitiators with UV-Vis light to release cationic substances such as acids, thereby initiating the polymerization of cationic curable monomers to form a cured binder, exhibiting increased adhesion and mechanical resistance compared to free radical UV-Vis radiation-curable coatings. Free radical UV-Vis radiation-curable printing inks are cured via a free radical mechanism, which consists of: activating one or more free radical photoinitiators capable of releasing free radicals under radiation, particularly UV-Vis light, thereby initiating the polymerization of free radical curable monomers and / or oligomers to form a cured layer. Hybrid UV-Vis radiation-curable printing inks contain cationic curable compounds and free radical curable compounds, cationic photoinitiators and free radical photoinitiators.

[0136] The UV-Vis radiation-curable printing ink described herein contains one or more radiation-curable compounds, the total amount of which is from about 50 wt.% to about 95 wt.%, preferably from about 60 wt.% to about 95 wt.%, the weight percentages being based on the total weight of the UV-Vis radiation-curable printing ink. The radiation-curable compound can be a cationic curable compound and a free radical curable compound.

[0137] The cationic curable compound is preferably selected from the group consisting of: propylene ethers, cyclic ethers (such as epoxides, oxetanes, glycidyl ethers and tetrahydrofurans), lactones, cyclic sulfides, propylene sulfides, silanes and mixtures thereof; more preferably selected from the group consisting of: propylene ethers, cyclic ethers (such as epoxides, oxetanes and tetrahydrofurans), lactones, silanes and mixtures thereof; even more preferably cyclic ethers, such as epoxides, oxetanes and mixtures thereof.

[0138] According to one embodiment, the cationic curable compound is selected from the group consisting of epoxides, oxetanes, and mixtures thereof, preferably alicyclic epoxides, oxetanes, and mixtures thereof.

[0139] According to one embodiment, the UV-Vis radiation-curable printing ink described herein comprises at least one alicyclic epoxide, wherein the alicyclic epoxide may be bifunctional or polyfunctional. The UV-Vis radiation-curable printing ink described herein comprising at least one alicyclic epoxide may further comprise one or more cationic curable epoxysiloxane compounds as described herein.

[0140] According to one embodiment, the UV-Vis radiation-curable printing ink described herein comprises at least one alicyclic epoxide and at least one oxetane. The UV-Vis radiation-curable printing ink described herein, comprising at least one alicyclic group A epoxide as described herein (pages 13 / 34, CN 121773169, CN 121773169) and at least one oxacyclobutane as described herein, may further comprise one or more cationic curable epoxysiloxane compounds as described herein.

[0141] As is well known to those skilled in the art, alicyclic epoxides are cationic curable monomers containing at least a substituted or unsubstituted epoxycyclohexyl residue: .

[0142] Preferably, the alicyclic epoxides described herein comprise at least one cyclohexane ring and at least two epoxy groups. Preferred alicyclic epoxides comprise more than one (i.e., at least two) cyclohexyl groups and preferably have the structural formula (II):

[0143]

[0144] (II)

[0145] wherein -X- represents a single bond or a divalent group containing more than one atom. Alicyclic epoxides of general formula (II)Optionally, the group is substituted with one or more straight-chain or branched alkyl residues containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, octyl, and decyl), preferably straight-chain or branched alkyl residues containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and isopropyl).

[0146] According to one embodiment, -X- is a divalent hydrocarbon group, which can be a straight-chain or branched alkylene group containing 1 to 18 carbon atoms, wherein examples of the straight-chain or branched alkylene group include, but are not limited to, methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene.

[0147] According to one embodiment, -X- is a divalent alicyclic hydrocarbon group or cycloalkylene group, such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylene.

[0148] According to one embodiment, -X- is a divalent group comprising one or more oxygen-containing linking groups, wherein the oxygen-containing linking group is selected from the group consisting of -C(=O)-, -OC(=O)O-, -C(=O)O-, and -O-. Preferably, the alicyclic epoxide is an alicyclic epoxide of general formula (II), wherein -X- is a divalent group containing one or more oxygen-containing linking groups, wherein the oxygen-containing linking group is selected from the group consisting of -C(=O)-, -OC(=O)O-, -C(=O)O- and -O-, and more preferably an alicyclic epoxide of general formula (II-a), (II-b) or (II-c) as defined below:

[0149]

[0150] (II-a)

[0151] wherein,

[0152] X1 may be the same or different each time it appears, and is a straight-chain or branched alkyl residue containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, octyl and decyl), Specification 14 / 34 pages 17 CN 121773169 A And preferably, it is a straight-chain or branched alkyl residue containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl and isopropyl);

[0153] X2 may be the same or different each time it appears, and is a straight-chain or branched alkyl residue containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, octyl and decyl), and preferably is a straight-chain or branched alkyl residue containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl and isopropyl); and

[0154] l1 and l2 are independently integers contained between 0 and 9, preferably between 0 and 3, more preferably 0;

[0155]

[0156] (II-b)

[0157] wherein,

[0158] X1 may be the same or different each time it appears, and is a straight-chain or branched alkyl residue containing 1 to 10 carbon atomsResidues (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, octyl, and decyl), and preferably straight-chain or branched alkyl residues containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and isopropyl);

[0159] X2 may be the same or different each time it appears, and is a straight-chain or branched alkyl residue containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, octyl, and decyl), and preferably a straight-chain or branched alkyl residue containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and isopropyl); and

[0160] l1 and l2 are independently integers contained between 0 and 9, preferably between 0 and 3, and more preferably 0;

[0161] -X3- is a single bond or a straight-chain or branched divalent hydrocarbon group containing 1 to 10 carbon atoms, preferably 3 to 8 carbon atoms, such as alkylene groups including trimethylene, tetramethylene, hexamethylene and 2-ethylhexylene, and cyclohexylene groups such as 1,2-cyclohexylene, 1,3-cyclohexylene and 1,4-cyclohexylene and cyclohexylene;

[0162]

[0163] (II-c)

[0164] wherein,

[0165] X1 may be the same or different each time it appears, and is a straight-chain or branched alkyl residue containing 1 to 3 carbon atoms, such as methyl, ethyl, n-propyl and isopropyl;

[0166] X2 may be the same or different each time it appears, and is a straight-chain or branched alkyl residue containing 1 to 3 carbon atoms, such as methyl, ethyl, n-propyl and isopropyl; and specification 15 / 34 pages 18 CN 121773169 A

[0167] l1 and l2 are independent of each other and are integers contained between 0 and 9, preferably between 0 and 3, and more preferably 0.

[0168] Preferred alicyclic epoxides of general formula (II-a) include, but are not limited to: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-6-methyl-cyclohexylmethyl-3,4-epoxy-6-methylcyclohexane carboxylate, 3,4-epoxy-2-methyl-cyclohexylmethyl-3,4-epoxy-2-methylcyclohexane carboxylate, and 3,4-epoxy-4-methyl-cyclohexylmethyl-3,4-epoxy-4-methylcyclohexane carboxylate.

[0169] Preferred alicyclic epoxides of general formula (II-b) include, but are not limited to: bis(3,4-epoxycyclohexylmethyl) adipic acid; bis(3,4-epoxy-6-methylcyclohexylmethyl) adipic acid, bis(3,4-epoxycyclohexylmethyl) oxalate, bis(3,4-epoxycyclohexylmethyl) pimecrolate, and bis(3,4-epoxycyclohexylmethyl) sebacate.

[0170] Preferred alicyclic epoxides of general formula (II-c) are 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-cyclohexyl-5 ...(III-a)cyclohexane-m-dioxane.

[0171] Other alicyclic epoxides include alicyclic epoxides of general formula (III-a) and alicyclic epoxides of general formula (III-b), which are optionally substituted with one or more straight-chain or branched alkyl groups containing 1 to 10 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, octyl and decyl), preferably straight-chain or branched alkyl groups containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl and isopropyl).

[0172]

[0173] (III-a)

[0174]

[0175] (III-b).

[0176] The alicyclic epoxides described herein may be hydroxyl-modified or (meth)acrylate-modified.

[0177] According to one embodiment, the UV-Vis radiation-curable printing ink described herein comprises at least one alicyclic epoxide class described herein, and further comprises at least one linear epoxide class. The use of linear epoxide classes other than alicyclic epoxide classes in the ink described herein helps to accelerate curing and reduce tack, as well as reduce ink viscosity, while also promoting strong copolymerization. Preferred examples of linear epoxides include, but are not limited to, cyclohexanediol diglycidyl ether, poly(ethylene glycol) diglycidyl ether, poly(propylene glycol) diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, bisphenol A diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether, butyl glycidyl ether, p-tert-butylphenyl glycidyl ether, hexadecyl glycidyl ether, 2-ethylhexyl glycidyl ether, octyl glycidyl ether, decyl glycidyl ether, dodecyl glycidyl ether, tetradecyl glycidyl ether, C12 / C14 alkyl glycidyl ether, C13 / C15 alkyl glycidyl ether, and mixtures thereof. Suitable linear epoxides are commercially available from: the trademark Grilonit® from EMS Griltech, including, for example, RV 1802, RV 1806, RV 1907.41, RV 1812, V 51-31, and V 51-63, or the trademark Araldite® DY from Huntman, including, for example, DY-C, DY-D, DY-E, DY-G, DY-F, DY-H, DY-K, DY-P, DY-31, and DY-3601.

[0178] Oxyhexacyclic butane compounds are known in the art to accelerate curing and reduce tack, thus limiting the risk of sticking and smudging when printed sheets are stacked immediately after printing and curing. They also help reduce ink viscosity while strongly copolymerizing. Preferred examples of oxacyclobutanes include trimethylene oxide and 3,3-dimethyloxacyclobutane. (See page 16 / 34 of the specification, 19 CN)121773169 A Cyclobutane, Trimethylolpropaneoxetane, 3-Ethyl-3-hydroxymethyloxetane, 3-Ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, 3,3-Dicyclomethyloxetane, 3-Ethyl-3-phenoxymethyloxetane, bis([1-ethyl(3-oxetane)]methyl) ether, 1,4-bis[3-ethyl-3-oxetanemethoxy)methyl]benzene, 3,3-dimethyl-2(p-methoxy-phenyl)oxetane, 3-ethyl-[(tri-ethoxysilylpropoxy)methyl]oxetane, 4,4-bis(3-ethyl-3-oxetane)methoxymethyl]biphenyl and 3,3-dimethyl-2(p-methoxy-phenyl)oxetane. The one or more oxetanes described herein may be hydroxyl-modified or (meth)acrylate-modified. When present, the one or more oxetanes described herein are preferably present in a total amount of about 0.1 wt.% to about 25 wt.%, the weight percentage based on the total weight of the UV-Vis radiation-curable printing ink.

[0179] As described herein for UV-Vis radiation-curable printing inks containing at least one alicyclic epoxide as described herein, or for inks containing both at least one alicyclic epoxide as described herein and at least one oxetane as described herein, the ink may further contain one or more cationic curable epoxy siloxane compounds. Preferred examples of epoxy siloxane compounds are 3-glycidyl etheroxypropyltrimethoxysilane (Dynasylan® GLYMO) and 3-glycidyl etheroxypropyltriethoxysilane (Dynasylan® GLYEO).

[0180] The cationic photoinitiator (also referred to in the art as a photoacid generator) is preferably an onium salt. The onium salts described herein are preferably selected from the group consisting of: nitrogen onium salts, oxyonium salts, iodonium salts, sulfonium salts, and mixtures thereof; more preferably selected from the group consisting of: oxyonium 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.

[0181] The one or more iodonium salts described herein have a cationic portion and an anionic portion, wherein the anionic portion is preferably BF4-, B(C6F5)4-, PF6-, (PF6-m(CnF2n-1)m)- (where m is an integer from 1 to 5 and n is an integer from 1 to 4), AsF6-, SbF6- or CF3SO3-, perfluoroalkyl sulfonate or pentafluorohydroxyantimonate, more preferably SbF6-, PF6- or B(C6F5)4-, and wherein the cationic portion is preferably an aromatic iodonium ion, more preferably an iodonium ion containing two aryl groups, wherein the two aryl groups can be independently converted 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 combinations thereof are substituted. Particularly suitable examples of iodonium salts used in this invention are commercially available under the names WPI-113, WPI-116, and WPI-124 from FUJIFILM Wako Chemicals.

[0182] The one or more sulfonium salts described herein have a cationic portion and an anionic portion, wherein the anionic portion is preferably BF4-, B(C6F5)4-, PF6-, (PF6-m(CnF2n-1)m)- (where m is an integer from 1 to 5 and n is an integer from 1 to 4), AsF6-, SbF6-, CF3SO3-, perfluoroalkyl sulfonate or pentafluorohydroxyantimonate, more preferably SbF6- or PF6-, and wherein the cationic portion is preferably an aromatic sulfonium ion, more preferably a sulfonium ion containing two or more aryl groups, wherein the two or more aryl groups can 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 aryloxy groups, one or more halogen-containing groups, one or more hydroxyl groups or combinations thereof.

[0183] The free radical curable compound is cured via a free radical mechanism, which consists of: activating one or more photoinitiators that release free radicals through energy, thereby initiating polymerization to form an adhesive. Preferably, the free radical curable compound is selected from the group consisting of (meth)acrylates, and more preferably from the group consisting of: epoxy (meth)acrylates, (meth)acrylated oils, polyesters and polyethers (meth)acrylates, aliphatic or aromatic urethane (meth)acrylates, silicone (meth)acrylates, acrylic (meth)acrylates, and mixtures thereof.

[0184] Suitable examples of (meth)acrylates include tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof.

[0185] In addition to the free radical curable compounds described herein (page 17 / 34, 20 CN 121773169 A), the UV-Vis radiation-curable printing inks described herein may further comprise one or more free radical curable diluents preferably selected from the group consisting of mono(meth)acrylates, di(meth)acrylates, and mixtures thereof.

[0186] Suitable examples of mono(meth)acrylates include, but are not limited to, alkyl (meth)acrylates, cycloalkyl (meth)acrylates, benzyl (meth)acrylates, phenyl (meth)acrylates (including phenoxyalkyl (meth)acrylates such as phenoxyethyl acrylate), cyclic trimethylolpropane acetal acrylates, tetrahydrofurfuryl acrylates, aliphatic carbamate (meth)acrylates, and their alkoxylated (particularly ethoxylated or propoxylated) compounds.

[0187] Suitable examples of di(meth)acrylates include ethylene glycol diacrylate; ethylene glycol dimethacrylate; 1,4-butanediol diacrylate; 1,4-butanediol dimethacrylate; 1,3-butanediol diacrylate; 1,3-butanediol dimethacrylate; 2-methyl-1,3-propanediol diacrylate; 3-methyl-1,5-pentanediol diacrylate; 2-butyl-2-ethyl-1,3-propanediol diacrylate; 1,6-hexanediol diacrylate; 1,6-hexanediol dimethacrylate; Neopentyl glycol diacrylate; Neopentyl glycol dimethacrylate; 1,9-nonanediol diacrylate; 1,9-nonanediol dimethacrylate; 1,10-decanediol diacrylate; 1,10-decanediol dimethacrylate; Alkoxylated (especially ethoxylated and propoxylated) 1,6-hexanediol diacrylate; Propoxylated neopentyl glycol diacrylate; Ethoxylated 2-methyl-1,3-propanediol diacrylate; Tricyclodecanediethanol diacrylate; Diethylene glycol diacrylate; Diethylene glycol dimethacrylate; Dipropylene glycol diacrylate; Triethylene glycol diacrylate; Triethylene glycol dimethacrylate; Tripropylene glycol diacrylate; Tripropylene glycol dimethacrylate; Tetraethylene glycol diacrylate; Tetraethylene glycol dimethacrylate; Polyethylene glycol 200 / 400 / 600 diacrylate; Polyethylene glycol 200 / 400 / 600 dimethacrylate; Ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A diacrylate; and Ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A dimethacrylate.

[0188] Suitable examples of tri(meth)acrylates include, but are not limited to, trimethylolpropane triacrylate, trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) glycerol triacrylate, pentaerythritol triacrylate, alkoxylated (especially ethoxylated or propoxylated) pentaerythritol triacrylate and mixtures thereof, 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.

[0189] Suitable examples of tetra(meth)acrylates include, but are not limited to, di-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkoxylated (e.g., ethoxylated and propoxylated) pentaerythritol tetra(meth)acrylate, and mixtures thereof, preferably selected from the group consisting of: di-trimethylolpropane tetra(meth)acrylateEsters, alkoxylated pentaerythritol tetra(meth)acrylates, and mixtures thereof.

[0190] The free radical photoinitiator is preferably selected from the group consisting of: hydroxy ketones (e.g., α-hydroxy ketones), alkoxy ketones (e.g., α-alkoxy ketones), acetophenones, benzophenones, ketone sulfones, benzyl ketals, benzoyl ethers, coumarins, camphorquinones, phosphine oxides, phenyl glyoxylates, and mixtures thereof, more preferably selected from the group consisting of: phosphine oxides, hydroxy ketones, and mixtures thereof.

[0191] Suitable examples of α-hydroxy ketones include, but are not limited to, (1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-prop-1-one); 1-hydroxycyclohexylphenyl ketone; 2-hydroxy-2-methyl-1-phenylprop-1-one; 2-hydroxy-2-methyl-1-(4-tert-butyl)phenylprop-1-one; 2-hydroxy-1-[4-[[4-(2-hydroxy-2-methylpropanoyl)phenyl]methyl]phenyl]-2-methylprop-1-one; 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylprop-1-one; (See specification 18 / 34 pages 21 CN 121773169 A) and oligomeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone].

[0192] Suitable examples of acetophenones include, but are not limited to, 2,2-diethoxyacetophenone and 2-methoxy-2-phenylacetophenone.

[0193] Suitable examples of benzophenones include, but are not limited to, benzophenone; polymeric benzophenone compounds; 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 mixtures of 50% benzophenone and 50% 1-hydroxycyclohexylphenyl ketone.

[0194] Suitable examples of ketone sulfones include, but are not limited to, 1-[4-(4-benzoylphenylthioalkyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)prop-1-one.

[0195] Suitable examples of benzyl ketals include, but are not limited to, 2,2-dimethoxy-2-phenylacetophenone.

[0196] Suitable examples of benzoin ethers include, but are not limited to, 2-ethoxy-1,2-diphenylacetophenone; 2-isopropoxy-1,2-diphenylacetophenone; 2-isobutoxy-1,2-diphenylacetophenone; 2-butoxy-1,2-diphenylacetophenone; 2,2-dimethoxy-1,2-diphenylacetophenone; and 2,2-diethoxyacetophenone.

[0197] Suitable examples of coumarins include, but are not limited to, 3-(4-dodecylbenzoyl)-5,7-dimethoxy-2H-1-Benzopyran-2-one and 3-(4-C10-C13-benzoyl)-5,7-dimethoxy-2H-1-benzoopyran-2-one.

[0198] Suitable examples of camphorquinones include, but are not limited to, 1,7,7-trimethyl-bicyclo[2.2.1]heptane-2,3-dione.

[0199] Suitable examples of phosphine oxides include, but are not limited to, 2,4,6-trimethylbenzoyl diphenylphosphine oxide; ethyl (2,4,6-trimethylbenzoyl)phenylphosphine ester; phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide; bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; a mixture of diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methylphenylacetone; a mixture of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methylphenylacetone; and a mixture of ethyl (2,4,6-trimethylbenzoyl)phenylphosphine ester and 2-hydroxy-2-methylphenylacetone.

[0200] Suitable examples of phenyl glyoxylates include, but are not limited to, methyl benzoylformate; 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate; and mixtures of 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester.

[0201] Other examples of available photoinitiators can be found in standard textbooks such as "Chemistry & Technology of UV & EB Formulation for Coatings, Inks & Paints", Volume III, and "Photoinitiators for Free Radical Cationic and Anionic Polymerization", 2nd ed., by JV Crivello & K. Dietliker, edited by G. Bradley, published jointly by John Wiley & Sons and SITA Technology Limited in 1998.

[0202] The UV-Vis radiation-curable printing inks described herein contain one or more photoinitiators described herein, in total amounts of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink. For UV-Vis radiation-curable printing inks described herein that are composed of cationic curable inks, theThe ink comprises one or more cationic photoinitiators described herein, in a total amount of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink. For the UV-Vis radiation-curable printing ink described herein composed of a radical-curable ink, the ink comprises one or more radical photoinitiators described herein, in a total amount of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink as described in document 19 / 34, page 22, CN 121773169 A. For the UV-Vis radiation-curable printing ink described herein composed of a mixed-curable ink, the ink comprises a combination of one or more cationic photoinitiators and one or more radical photoinitiators described herein, in a total amount of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0203] Optionally, more than one photosensitizer may also be present. The photosensitizer is activated by more than one wavelength emitted by a UV-Vis light source and reaches an excited state. The excited photosensitizer transfers energy to more than one photoinitiator (in free radical polymerization) or electrons (in cationic polymerization). Either process then initiates the polymerization process. The UV-Vis radiation-curable printing inks described herein may further contain more than one photosensitizer in combination with more than one photoinitiator described herein to achieve effective curing. Suitable examples of photosensitizers are known to those skilled in the art (e.g., in Industrial Photoinitiators, WA Green, CRC Press, 2010, Table 8.1, page 170). Preferably, one or more photosensitizers are selected from the group consisting of: thioxanthone compounds, naphthalene compounds, anthracene compounds, titanoceramic compounds, and mixtures thereof; more preferably, they are selected from the group consisting of: thioxanthone compounds (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 and their oligomer or polymeric forms), anthracene compounds (such as 9,10-diethoxyanthracene and 9,10-dibutoxyanthracene) and mixtures thereof. When present, one or more photosensitizers are preferably present in a total amount of about 0.1 wt.% to about 5 wt.%, more preferably about 0.2 wt.% to about 1 wt.%, the weight percentages being based on the total weight of the UV-Vis radiation-curable printing ink.

[0204] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is a cationic curable printing ink.(i.e., containing cationic curable compounds), and the one or more radiation-curable compounds described herein, i.e., one or more cationic curable compounds (preferably cationic curable compounds selected from the group consisting of epoxides, oxetanes and mixtures thereof, preferably alicyclic epoxides, oxetanes and mixtures thereof) and the cationic curable epoxy siloxane compound described herein, when present, are present in a total amount of about 50 wt.% to about 95 wt.%, preferably about 60 wt.% to about 95 wt.%, the weight percentages being based on the total weight of the UV-Vis radiation-curable printing ink.

[0205] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is a free radical curable printing ink (i.e., containing a free radical curable compound), and one or more radiation-curable compounds described herein, i.e., one or more tri(meth)acrylates and tetra(meth)acrylates and one or more reactive diluents described herein, when present, are present in a total amount of about 50 wt.% to about 95 wt.%, preferably about 60 wt.% to about 95 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0206] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is a mixed-curable ink (i.e., containing a cationic curable compound and a free radical curable compound), and the more than one radiation-curable compound described herein, i.e., more than one cationic curable compound (preferably the cationic curable compound is selected from the group consisting of epoxides, oxetanes and mixtures thereof, preferably alicyclic epoxides, oxetanes and mixtures thereof), and when present, one cationic curable epoxysiloxane compound described herein, more than one tri(meth)acrylate and one tetra(meth)acrylate described herein, and when present, one or more reactive diluents described herein, are present in a total amount of about 50 wt.% to about 95 wt.%, preferably about 60 wt.% to about 95 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0207] The UV-Vis radiation-curable printing ink described herein, especially the cationic or mixed UV-Vis radiation-curable screen printing ink described herein, may further contain more than one polyhydroxy compound. For embodiments in which the radiation-curable coating composition comprises one or more polyhydroxy compounds described herein, the one or more polyhydroxy compounds are preferably present in a total amount of less than or equal to about 15 wt.%, more preferably in a total amount of about 1 wt.% to about 15 wt.%, by weight percentage.The total weight of UV-Vis radiation-curable printing ink. Polyhydroxy compounds are known in the art to improve adhesion to substrates known to exhibit poor adhesion properties, such as plastic or polymer substrates that are becoming increasingly popular in the fields of secure documents, particularly banknotes.

[0208] The one or more polyhydroxy compounds described herein preferably contain more than two hydroxyl groups and may be linear, branched, or hyperbranched (also referred to in the art as dendritic). Preferably, the one or more polyhydroxy compounds described herein are trifunctional, tetrafunctional, hexafunctional, or polyfunctional compounds.

[0209] The one or more 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.

[0210] The one or more polyhydroxy compounds described herein may be at least partially alkoxylated. Therefore, the one or more polyhydroxy compounds described herein may have alkoxylation units, preferably ethoxylation and / or propoxylation units. According to a preferred embodiment, the one or more 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, wherein said compounds, preferably the trimethylolpropane, pentaerythritol, and dipentaerythritol, may be alkoxylated (ethoxylated and / or propoxylated).

[0211] The UV-Vis radiation-curable printing inks described herein, and particularly the UV-Vis radiation-curable screen printing inks described herein, may further comprise one or more fillers or extenders, preferably selected from the group consisting of: carbon fibers, talc, mica (silica), wollastonite, calcined clay, kaolin, kaolin, carbonates (e.g., calcium carbonate, sodium aluminum carbonate), silicates (e.g., magnesium silicate, aluminum silicate), sulfates (e.g., magnesium sulfate, barium sulfate), titanates (e.g., potassium titanate), alumina hydrates, silica, fumed silica, montmorillonite, graphite, anatase, rutile, bentonite, vermiculite, zinc white, zinc sulfide, wood flour, quartz powder, natural fibers, synthetic fibers, and combinations thereof. When present, one or more fillers or extenders are preferably present in a total amount of about 0.1 wt.% to about 20 wt.%, more preferably about 0.1 wt.% to about 10 wt.%, the weight percentage based on the total weight of the UV-Vis radiation-curable printing ink.

[0212] The UV-Vis radiation-curable printing ink may further contain one or more solvents to fine-tune the viscosity of the ink. Preferred solvents are polar aprotic solvents exhibiting high boiling points, such as carbonates. A preferred carbonate is carbonic acid.Alkyl esters (e.g., ethylene carbonate, propylene carbonate, and butyl carbonate). Propylene carbonate is particularly preferred due to its high boiling point and favorable ecotoxicity characteristics. When present, one or more solvents are present in a total amount of less than about 5 wt.%, more preferably less than about 2.5 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0213] The UV-Vis radiation-curable printing inks described herein may further comprise one or more coloring components selected from the group consisting of organic pigment particles, inorganic pigment particles, and organic dyes, and / or one or more additives. The latter includes, but is not limited to, compounds and materials used to adjust the physical, rheological, and chemical parameters of the coating composition, such as viscosity (e.g., thickeners and surfactants), consistency (e.g., antisettling agents and plasticizers), foaming properties (e.g., defoamers), lubricity (waxes, oils), UV stability (light stabilizers), adhesion, antistatic properties, storage stability (polymerization inhibitors), etc. The additives described herein may be present in coating compositions in amounts and forms known in the art, including so-called nanomaterials, wherein at least one size of the additive is in the range of 1 to 1000 nm.

[0214] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is the UV-Vis radiation-curable inkjet printing ink described herein, preferably a cationic UV-Vis radiation-curable inkjet printing ink, as those described herein. The cationic UV-Vis radiation-curable inkjet printing ink preferably comprises: (Instruction manual, pages 21 / 34, CN 121773169 A)

[0215] i) one or more cationic curable compounds described herein, preferably selected from the group consisting of: cyclic ethers (more preferably cyclic ethers selected from the group consisting of alicyclic epoxides described herein), oxobutanes described herein, and mixtures thereof;

[0216] ii) one or more cationic photoinitiators described herein, preferably selected from the group consisting of iodonium salts, sulfonium salts, and mixtures thereof;

[0217] iii) optionally one or more cationic curable epoxy siloxane compounds;

[0218] iii) optionally one or more photosensitizers, preferably selected from the group consisting of thioxanthone compounds, anthracene compounds, and mixtures thereof; and

[0219] iv) optionally one or more solvents;

[0220] wherein one or more cationic curable compounds (i) + optionally iii) are preferably in a concentration of about 50 wt%. The total amount is from about 0.% to about 95 wt.%, more preferably from about 60 wt.% to about 95 wt.%, and the total amount of one or more cationic photoinitiators (ii) is preferably from about 1 wt.% to about 20 wt.%, more preferably from about 2 wt.% to about 15 wt.%,

[0221] The weight percentage is based on the total weight of the cationic UV-Vis radiation-curable inkjet printing ink.

[0222] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is the UV-Vis radiation-curable inkjet printing ink described herein, preferably a mixture of UV-Vis radiation-curable inkjet printing inks, such as those described herein. The mixed UV-Vis radiation-curable inkjet printing ink preferably comprises:

[0223] i) one or more cationic curable compounds as described herein, preferably selected from the group consisting of: cyclic ethers (more preferably cyclic ethers selected from the group consisting of alicyclic epoxides as described herein), oxacyclobutanes as described herein, and mixtures thereof;

[0224] ii) one or more cationic photoinitiators as described herein, preferably selected from the group consisting of iodonium salts, sulfonium salts, and mixtures thereof;

[0225] iii) one or more free radical curable compounds as described herein, preferably selected from the group consisting of aliphatic epoxy (meth)acrylate compounds, more preferably selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof as described herein;

[0226] iv) one or more free radical photoinitiators as described herein, preferably selected from the group consisting of phosphine oxides, hydroxy ketones, and mixtures thereof;

[0227] v) optionally one or more cationic curable epoxy siloxane compounds; and

[0228] vi) optionally one or more solvents,

[0229] Wherein, one or more cationic curable compounds (i) + optional v) and one or more free radical curable compounds (iii) described herein are preferably present in a total amount of about 50 wt.% to about 95 wt.%, more preferably in a total amount of about 60 wt.% to about 95 wt.%;

[0230] The total amount of one or more cationic photoinitiators (ii) and one or more free radical photoinitiators (iv) is preferably about 1 wt.% to about 20 wt.%, more preferably about 2 wt.% to about 15 wt.%,

[0231] The weight percentages are based on the total weight of the mixed UV-Vis radiation-curable inkjet printing inks.

[0232] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is the UV-Vis radiation-curable screen printing ink described herein, preferably a cationic UV-Vis radiation-curable screen printing ink, as those described herein. The cationic UV-Vis radiation-curable screen printing ink preferably comprises:

[0233] i) one or more cationic curable compounds as described herein, preferably compounds selected from the group consisting of: cyclic ethers (more preferably cyclic ethers selected from the group consisting of alicyclic epoxides as described herein), Specification 22 / 34 pages 25 CN 121773169 AThe oxacyclobutanes and mixtures thereof described herein,

[0234] ii) one or more cationic photoinitiators described herein, preferably selected from the group consisting of iodonium salts, sulfonium salts and mixtures thereof;

[0235] iii) optionally one or more polyhydroxy compounds described herein;

[0236] iv) optionally one or more fillers or extenders described herein;

[0237] v) optionally one or more solvents described herein; and

[0238] vii) optionally one or more photosensitizers, preferably selected from the group consisting of thioxanthone compounds, anthracene compounds and mixtures thereof,

[0239] wherein one or more cationic curable compounds (i) are preferably present in a total amount of about 50 wt.% to about 95 wt.%, more preferably in a total amount of about 60 wt.% to about 95 wt.%, and the total amount of one or more cationic photoinitiators (ii) is preferably about 1 wt.% to about 20 wt.%, more preferably about 2 wt.% to about 15 wt.%,

[0240] The weight percentage is based on the total weight of the cationic UV-Vis radiation-curable inkjet printing ink.

[0241] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is the UV-Vis radiation-curable screen printing ink described herein, preferably a mixture of UV-Vis radiation-curable screen printing inks, such as those described herein. The mixed UV-Vis radiation-curable screen printing ink preferably comprises:

[0242] i) one or more cationic curable compounds described herein, preferably selected from the group consisting of: cyclic ethers (more preferably cyclic ethers selected from the group consisting of alicyclic epoxides described herein), oxobutanes described herein, and mixtures thereof;

[0243] ii) one or more cationic photoinitiators described herein, preferably selected from the group consisting of iodonium salts, sulfonium salts, and mixtures thereof;

[0244] iii) one or more free radical curable compounds described herein, preferably selected from the group consisting of aliphatic epoxy (meth)acrylate compounds, more preferably selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof;

[0245] iv) one or more free radical photoinitiators described herein, preferably selected from the group consisting of phosphine oxides, hydroxy ketones, and mixtures thereof;

[0246] v) optionally one or more polyhydroxy compounds described herein;

[0247] vi)

[0248] vii) One or more fillers or extenders optionally described herein; and

[0249] viii) One or more photosensitizers optionally selected from the group consisting of thioxanthone compounds, anthracene compounds, and mixtures thereof;

[0250] Wherein, one or more cationic curable compounds (i) + optional v) and one or more free radical curable compounds (iii) described herein are preferably present in a total amount of about 50 wt.% to about 95 wt.%, more preferably in a total amount of about 60 wt.% to about 95 wt.%,

[0251] The total amount of one or more cationic photoinitiators (ii) and one or more free radical photoinitiators (iv) is preferably about 1 wt.% to about 20 wt.%, more preferably about 2 wt.% to about 15 wt.%,

[0252] The weight percentages are based on the total weight of the cationic UV-Vis radiation-curable screen printing ink.

[0253] The UV-Vis radiation-curable printing ink described herein can be prepared by dispersing or mixing all the components described herein to form a liquid composition. Alternatively, for the UV-Vis radiation-curable screen printing ink described herein, one or more photoinitiators and optionally one or more photosensitizers may be added to the composition during the dispersion or mixing steps of all other components (pages 23 / 34, CN 121773169 A), or may be added at a later stage, i.e., after the formation of the liquid coating composition.

[0254] This document also describes the use of the UV-Vis radiation-curable printing ink described herein for manufacturing one or more safety features on safety articles and the safety articles obtained therefrom.

[0255] This document also describes a method for producing safety articles and the safety articles obtained therefrom.

[0256] The UV-Vis radiation-curable printing ink described herein can i) be applied to substrates as described herein by a printing method preferably selected from the group consisting of: screen printing, flexographic printing, or non-contact fluid microdispensing technology (preferably inkjet printing) as described herein, preferably by the screen printing method or inkjet printing method described herein, and ii) preferably UV-Vis radiation-curing the ink with one or more light sources selected from the group consisting of mercury lamps, UV-LED lamps, and sequences thereof as described herein, to form one or more security features on the substrates described herein.

[0257] As mentioned above, the one or more security features described herein can be used to protect and identify security articles or decorative elements.

[0258] The shape of the one or more security features is not limited and can be any desired marking, including any symbol, image, and pattern. According to one embodiment, the one or more security features consist of one or more markings. As used herein, the term "marking" should mean continuous and discontinuous layers consisting of distinguishing identifiers or signs or patterns. Preferably, the one or more markers (x30) described herein are selected from the group consisting of: codes, symbols,Alphanumeric symbols, graphics, geometric patterns (e.g., circles, triangles, and regular or irregular polygons), letters, words, numbers, logos, pictures, portraits, and combinations thereof. Examples of encoding include encoded identifiers such as encoded alphanumeric data, one-dimensional barcodes, two-dimensional barcodes, QR codes, data matrices, and IR readout codes.

[0259] For the purpose of further increasing the security level of security articles and their resistance to counterfeiting and illegal copying, the substrates described herein may include printed, coated, or laser-marked or laser-perforated markings, watermarks, security threads, fibers, planchettes, luminescent compounds, windows, foils, labels, primers, and combinations thereof.

[0260] For the purpose of increasing durability through stain resistance or chemical resistance and cleanliness, thereby improving the circulation life of security documents, or for the purpose of altering their aesthetic appearance (e.g., optical gloss), one or more protective layers may be applied over the security features or security documents described herein, provided that the protective layers do not negatively interfere with the Raman spectrum of interest of the security features described herein.

[0261] The one or more security features described herein can be directly applied to a substrate, and the one or more security features will be permanently retained on the substrate (e.g., for banknote applications). Alternatively, the one or more security features can also be applied to a temporary substrate for production purposes, from which the one or more security features are subsequently removed. Thereafter, after printing and curing the UV-Vis radiation-curable security ink described herein for producing the one or more security features, the temporary substrate can be removed from the one or more security features.

[0262] Alternatively, in another embodiment, an adhesive layer can be present on the one or more security features, or on the substrate containing the features, the adhesive layer being located on a side of the substrate opposite to the side where the one or more security features are applied, or on the same side as the one or more security features and above the features. Thus, an adhesive layer can be applied to one or more security features or substrates after the curing step has been completed. Such articles can be attached to all kinds of documents or other articles or articles without printing or other processes involving machinery and a considerable amount of work. Alternatively, the substrate described herein, which includes more than one security feature, may be in the form of a transfer foil, which may be applied to the document or article in a separate transfer step. For this purpose, the substrate is provided with a release coating, on which more than one security feature is produced, as described herein. More than one adhesive layer may be applied to the feature thus produced. Specification 24 / 34 pages 27 CN 121773169 A

[0263] As used herein, the term "substrate" includes any security article substrate on which one or more ink-printed security features can be applied. Security article substrates include, but are not limited to, paper or other fibrous materials such as cellulose, paper-containing materials, glass, metal, ceramics, plastics and polymers, composite materials, and mixtures or combinations thereof. Typical paper, paper-like, or other fibrous materials are made from a variety of fibers, including but not limited to, abaca, cotton, flax, wood pulp, and blends thereof. As is known to those skilled in the art, cotton and cotton / flax blends are preferred for banknotes, while wood pulp is commonly used for security documents other than banknotes. Typical examples of plastics and polymers include: polyolefins such as polyethylene (PE) and polypropylene (PP), polyamides such as polyethylene terephthalate (PET), polybutadiene terephthalate (PBT), polyethylene 2,6-naphthelate (PEN), polyesters, and polyvinyl chloride (PVC). Typical examples of composite materials include, but are not limited to, multilayer structures or laminates of paper and at least one plastic or polymeric material as described above. The substrate of the security articles described herein may be printed with any desired markings, including any symbols, images, and patterns. The substrate described herein should preferably not emit any luminescence and / or Raman signals that could interfere with the properties of one or more surface-enhanced Raman spectroscopy (SERS) tags in the inks described herein. In the event that the substrate exhibits any luminescence properties and / or Raman signals, said properties should be less than 25,000 au.

[0264] Typical examples of decorative elements or objects include, but are not limited to, luxury goods, cosmetic packaging, vehicle parts, electronic / electrical appliances, furniture, and nail articles.

[0265] As used herein, the term "security article" refers to an article of value that makes it potentially susceptible to attempted counterfeiting or illegal copying and is generally protected against counterfeiting or tampering by one or more security features. Security articles include, but are not limited to, articles of value or documents and commodities of value. Typical examples of valuable goods or documents include, but are not limited to, banknotes, contracts, bills, checks, vouchers, stamp duty stamps and tax labels, and agreements; identity documents such as passports, ID cards, visas, bank cards, credit cards, transaction cards, travel documents, academic certificates or professional titles, admission tickets, public transport tickets or titles, and agreements. The term "valuable goods" refers to packaging materials, particularly those used for cosmetics, nutritional products, pharmaceuticals, alcoholic beverages, tobacco products, beverages or food, electrical / electronic products, textiles, or jewelry—materials that should be protected against counterfeiting and / or illegal reproduction to ensure the contents of the packaging are genuine, such as products containing pharmaceuticals. Examples of such packaging materials include, but are not limited to, labels such as brand identification labels and tamper-evident labels.Evidence labels) and seals. It should be noted that the disclosed substrates, valuable documents and valuable goods are given for illustrative purposes only and do not limit the scope of the invention.

[0266] This document also describes a method for identifying one or more security features and security articles described herein. For the purpose of identifying one or more security features and security articles described herein, the Raman spectra of the one or more security features are measured and obtained before their circulation and use, and are recorded as reference Raman spectra. The method for identifying one or more security features and security articles described herein includes the following steps:

[0267] a) providing a security article described herein and containing one or more security features described herein, said one or more security features being made of a cured layer made of UV-Vis radiation-curable printing ink described herein;

[0268] b) irradiating one or more security features with visible light and / or near-IR light, and measuring the SERS spectrum; and

[0269] c) comparing the SERS spectrum obtained in step b) with the pre-recorded reference Raman spectrum.

[0270] Several modifications to the above specific embodiments may be conceived by those skilled in the art without departing from the spirit of the invention. These modifications are included in the invention.

[0271] Furthermore, all documents mentioned throughout this specification are incorporated herein by reference in their entirety, as fully set forth herein.

[0272] Embodiment Description 25 / 34 pages 28 CN 121773169 A

[0273] The invention will now be described in more detail with reference to non-limiting embodiments. The following embodiments provide further details on the production of UV-Vis radiation-curable printing inks containing surface-enhanced Raman spectroscopy (SERS) labels, particularly UV-Vis radiation-curable inkjet printing inks and UV-Vis radiation-curable screen printing inks, as well as the production and identification of security features made from said inks.

[0274] Examples and comparative examples of UV-Vis radiation-curable inkjet printing inks prepared as described herein (E1-E6 and E20 in Tables 1A-1 and 1C-1; C1-C12 in Table 1A-2) and examples and comparative examples of UV-Vis radiation-curable screen printing inks (E7-E19 and E21 in Tables 1B-1 and 1C-2; C13-C22 in Table 1B-2).

[0275] Examples E1-E21 and Comparative Examples C1-C22 were prepared by applying UV-Vis radiation-curable printing inks as 5cm×10cm rectangles (E1-E6 and E20 (Table 1A-1 and Table 1C-1) and C1-C12 (Table 1A-2)) or as 6cm×10cm rectangles (E7-E19 and E21 (Table 1B-1 and Table 1C-2) and C13-C22 (Table 1A-2)) onto a polymer substrate (Guardian® from CCL).

[0276] Examples E1-E21 and Comparative Examples C1-C22 were cured immediately after application using the following methods:

[0277] Hg lamp (TECHNIGRAPH AKTIPRINT MINI (UN50049); 80 W / cm; passing once at 12 m / min, dose: 222 mJ / cm2) (E1, E3, E5, E6-14, E17-E21; C1, C3-C8, C9-a), C10-a), C11-C16, C17-a), C18, C19-a), C21, C22) or

[0278] LED LUV20 lamp (IST, 385 nm, 40 m / min; passing twice, dose 1080 mJ / cm2) (E2, E4, E15, E16; C2, C-9b), C10-b), C17-b), C19-b), C20).

[0279] Preparation of dispersion containing SERS tag

[0280] The gold colloid used to prepare the SERS tag contained in the UV-Vis radiation-curable ink of the examples and comparative examples was prepared according to the method described in Example I.3 "Preparation of 90nm gold colloid stock solution" of WO 2021 / 009090 A1.

[0281] The gold colloid suspension (160 ml; 0.25 g / 1 lt Au) was stirred in a mixing reactor under vigorous magnetic stirring. A 1 mmol solution (0.1 ml) of (E)-1,2-bis(pyridin-4-yl)ethylene (97%; CAS Nr: 13362-78-2) in ethanol was rapidly added. After about 20 seconds, the aggregation process was stopped by adding a solution of the polymer in water. The mixture was stirred for 15 minutes, concentrated to 1 g by ultrafiltration and washed several times with NaOH solution.

[0282] The aggregates were coated with silica using the St. Bernal method, a method well known to those skilled in the art and disclosed, for example, in US 7723100 B2.

[0283] Flaxseed-based alkyd resin was added to obtain a dispersion of SERS labels in the alkyd resin, and residual solvents (water and ethanol) were removed under vacuum. The dispersion thus obtained, containing about 20 wt.% SERS, was used as is for printing inks (Tables 1A-1, 1A-2, 1B-1, 1B-2, 1C-1, and 1C-2).

[0284] Preparation of UV-Vis radiation-curable printing inks

[0285] UV-Vis radiation-curable inkjet printing inks E1-E6 and E20 and C1-C12 were prepared independently by mixing the components listed in Tables 1A-1, 1A-2, and 1C-1 for 20 minutes at room temperature and 1000 rpm using Dispermat (LC220-12).The viscosities of the inks provided in Tables 1A-1, 1A-2, and 1C-1 were independently measured at 45°C using a Paar viscometer (model QC300, rotor B-SC4-21, 250 rpm).

[0286] UV-Vis radiation-curable screen printing inks E7-E19, E21, and C13-C22 were independently prepared by mixing the components listed in Tables 1B-1, 1B-2, and 1C-2 at 2000 rpm for 10 minutes using a Dispermat CV-3. The viscosities of the inks provided in Tables 1B-1, 1B-2, and 1C-2 were independently measured at 25°C using a Brookfield viscometer (model "DV-I Prime", rotor S27, 100 rpm).

[0287] Preparation instructions for printing security features, 26 / 34 pages, 29 CN 121773169 A

[0288] Evaluation of UV-Vis radiation-curable inkjet printing inks E1-E6 and E20 and C1-C12 applied by hand coating was conducted to facilitate the screening of said inks.

[0289] Figure 1 discloses the Raman shift spectra of UV-Vis radiation-curable inkjet printing ink E1 applied by inkjet printing (2dpd, ink coverage of (a) 25%, (b) 50% and (c) 75%) using a Ricoh Gen5 inkjet printhead and by hand coating (K Hand Coater from ERICHSEN, HC 0 bar, layer thickness of about 4 μm, (HC)). After curing, the Raman shift spectra of the samples were measured as described below. Figure 1 shows that the inkjet-printed security features and the hand-coated samples produced comparable spectra, especially for inkjet printing ink coverage of about 50%.

[0290] Examples E2-E6 and E20 (Tables 1A-1 and 1C-1) and C1-C12 (Table 1A-2) were all prepared by manual coating application using HC 0 bar.

[0291] UV-Vis radiation-curable screen printing inks E7-E19, E21 and C13-C22 were applied independently by manual screen printing using 77T screens to form layers with a thickness of approximately 22 μm.

[0292] Measurement of SERS spectra

[0293] The Raman shift spectra of Examples E1-E21 and Comparative Examples C1-C22 were measured using a Raman spectrophotometer from Wasatch Photonics (laser type: 100mW single-mode; wavelength: 785nm) with an integration time of 800 ms and a laser power of 4.3mW.

[0294] The Raman shift spectra (t0; black curves in Figures 1 to 6) were measured immediately after the curing step.

[0295] The substrate bearing the coating is individually arranged between two glass plates (15cm × 20cm × 0.3cm; 220g each).The substrate was stored in an oven at 50°C (10% relative humidity) for 48 hours to simulate the conditions of the printed sheet in the substrate stack during the printing process on an industrial printing press.

[0296] The Raman shift spectrum (t48; gray curve in Figures 2 to 6) was measured and compared with the spectrum measured immediately after curing (t0; black curve in Figures 2 to 6).

[0297] As shown in Figures 2-1 to 2-6 of Examples E1-E6 and Figure 6-1 of E20 (inkjet printing inks from Tables 1A-1 and 1C-1) and Figures 4-1 to 4-13 of Examples E7-E19 and Figure 6-2 of E21 (screen printing inks from Tables 1B-1 and 1C-2), the spectrum at t48 (gray curve) is similar to the spectrum at t0 (black curve), and in particular, no saturation of the signal (intensity ≥ 65,000) was observed.

[0298] On the other hand, as shown in Figures 3-1 to 3-12 of Comparative Examples C1-C12 (inkjet printing inks from Table 1A-2) and Figures 5-1 to 5-10 of Comparative Examples C13-C22 (screen printing inks from Table 1B-2), the spectrum (gray curve) at t48 shows spectral saturation, that is, at least in part of the measurement range, the measurement intensity reaches a value of ≥65,000, thus preventing the clear identification of the SERS label.

[0299] List of compounds in Table 1A-C

[0300] CAB-381-0.5 (Eastman™): Cellulose acetate butyrate [CAS Nr 9004-36-8]

[0301] DPGDA (Dipropylene glycol diacrylate) (Cytec): 1,1'-[oxybis(methyl-2,1-ethanediyl)-2-acrylate] [CAS Nr 57472-68-1]

[0302] Dynasylan® GLYMO (EVONIK Industries): Glycidyl ether oxypropyltrimethoxysilane [CAS 2530-83-8]

[0303] GENOMER 1120 (Rahn): 3,3,5-trimethylcyclohexyl-2-acrylate [CAS Nr 86178-38-3]

[0304] MIRAMER M4004 ((Rahn): α-hydrogen-ω -[(1-oxo-2-propen-1-yl)oxy]-ether with 2,2-bis(hydroxymethyl)-1,3-propanediol poly(oxy-1,2-ethanediyl) (polyether polyol tetraacrylate) [CAS Nr 51728-26-8] Specification 27 / 34 pages 30 CN 121773169 A

[0305] MIRAMER M410 (DiTMPTA; polyether polyol tetraacrylate) ((Rahn): 1,1'-[2-[[2,2-bis)[[(1-oxo-2-propen-1-yl)oxy]methyl]butoxy]methyl]-2-ethyl-1,3-propanediyl]-2-acrylate [CAS Nr 94108-97-1]

[0306] Photomer® 3016-20G (IGM Resins): Bisphenol A epoxy acrylate [CAS 55818-57-0] and glyceryl[4PO]triacrylate (GPTA) [CAS Nr 52408-84-1]

[0307] Polyol R4631 (Perstorp): Polymer of 2,2-bis(hydroxymethyl)-1,3-propanediol, 2-methylethylene oxide and ethylene oxide [CAS Nr 30374-35-7]

[0308] UviCure S105ES (Lambson): 7-oxabicyclo[4.1.0]hept-3-ylmethyl7-oxabicyclo[4.1.0]heptane-3-carboxylic acid ester [CAS Nr 2386-87-0]

[0309] UviCure S130 (Lambson): 3-ethyl-3-hydroxymethyloxabicyclobutane [CAS Nr 3047-32-3]

[0310] ANTHRACURE® UVS 1331 (Kawasaki Kasei Chemicals Ltd): 9,10-dibutoxy-anthracene [CAS Nr 76275-14-4]

[0311] CHIVACURE® 1176 (CHITEC Technology): diphenyl(4-phenylthio)phenylsulfonium hexafluoroantimonate [CAS Nr 71449-78-0] and thiodi-4,1-phenylene)bis(diphenylsulfonium)bishexafluoroantimonate [CAS Nr 89452-37-9] in propylene carbonate [CAS Nr 108-32-7]

[0312] IRGACURE® 290 (IGM): tri-[4-[(4-acetylphenyl)thio]phenyl]sulfonium tetrapentafluorophenyl borate [CAS Nr 1203809-92-0]

[0313] GENOCURE DETX (Rahn): 2,4-diethyl-thioxanthone [CAS Nr 82799-44-8]

[0314] GENOCURE ITX (Rahn): 2-isopropyl-9H-thioxanthone-9-one [CAS Nr 5495-84-1]

[0315] Omnirad 1173(IGM): 2-Hydroxy-2-methyl-1-phenylprop-1-one [CAS Nr 7473-98-5]

[0316] SpeedCure TPO-L(Lambson): 2,4,6-Trimethylbenzoyl-ethoxyphenylphosphine oxide [CAS Nr 84434-11-7]

[0317] SpeedCure CPTX (Lambson): 1-chloro-2-propoxy-thioxanthone [CAS Nr 142770-42-1]

[0318] SpeedCure 976 (Lambson): bis[4-(diphenylsulfonyl)phenyl]sulfide bis(hexafluoroantimonate) [CAS Nr 89452-37-9] and 4-(phenylthio)phenyl diphenylsulfonyl hexafluoroantimonate [CAS Nr 71449-78-0] in propylene carbonate [CAS Nr 108-32-7]

[0319] SpeedCure 992 (Lambson): diphenyl[(phenylthio)phenyl]sulfonyl hexafluorophosphate and S,S'-(thiodi-4,1-phenylene)bis[S,S-diphenyl-sulfonyl hexafluorophosphate] in propylene carbonate [CAS Nr Mixtures in 108-32-7 [CAS 68156-13-8, 74227-35-3, 108-32-7]

[0320] WPI 113 (FUJIFILM Wako Chemicals): bis(C10-14-alkylphenyl)iodonium hexafluorophosphate [CAS Nr 868698-33-3]

[0321] WPI 116 (FUJIFILM Wako Chemicals): bis(decylphenyl)iodonium hexafluoroantimonate [CAS Nr 149759-20-6]

[0322] WPI 124 (FUJIFILM Wako Chemicals): bis(decylphenyl)iodonium tetra-pentafluorophenyl borate [CAS Nr 1791428-74-4]

[0323] AEROSIL® 200 (Evonik): Hydrophilic fumed silica [CAS Nr 7631-86-9]

[0324] BYK-UV 3510 (BYK): Polyether-modified polydimethylsiloxane

[0325] GENORAD 16 (Rahn): Stabilizer

[0326] TEGO® Airex 900 (Evonik): Defoamer, instructions 28 / 34, page 31, CN 121773169 A

[0327] TEGO® Rad 2300 (Evonik): Leveling agent

[0328] Propylene carbonate (Brenntag Scheizerhall): [CAS Nr 108-32-7]

[0329] UCAR Ester EEP (DOW): Ethyl 3-ethoxypropionate [CAS 763-69-9]

[0330] DVE-3-TEDGE (BASF): Triethylene glycol divinyl ether [CAS Nr 765-12-8]

[0331] DVE-2 (BASF): Diethylene glycol divinyl ether [CAS Nr 764-99-8]

[0332] CHDVE (BASF): 1,4-bis[(ethoxy)methyl]-cyclohexane [CAS Nr 17351-75-6]

[0333] VEEA (Nippon Shokubai): 2-[2-(ethoxy)ethoxy]-2-ethyl acrylate [CAS Nr 86273-46-3]

[0334] Table 1A-1 (Figures 2-1 to 2-6 show Raman shifts)

[0335] Specification 29 / 34 pages 32 CN 121773169 A

[0336] Table 1A-2 (Figures 3-1 to 3-12 show Raman shifts)

[0337]

[0338] Table 1B-1 (Figures 4-1 to 4-13 show Raman shifts) Specification page 30 / 34, page 33, CN 121773169 A

[0339]

[0340] Table 1B-2 (Raman displacements are shown in Figures 5-1 to 5-10) Specification page 31 / 34, page 34, CN 121773169 A

[0341]

[0342] Table 1C-1 (Raman displacements are shown in Figure 6-1) Specification page 32 / 34, page 35, CN 121773169 A

[0343]

[0344] Table 1C-2 (Raman displacements are shown in Figure 6-2)

[0345]

[0346] As shown in Figures 2-1 to 2-6 of E1-E6 and Figure 6-1 of E20 (layers made from UV-Vis radiation-curable inkjet printing inks from Tables 1A-1 and 1C-1), and Figures 4-1 to 4-13 of E7-E19 and Figure 6-2 of E21 (layers made from UV-Vis radiation-curable screen printing inks from Tables 1B-1 and 1C-2), the UV-Vis radiation-curable printing inks of the present invention, which contain SERS labels and do not contain any vinyl ether-containing compounds (as opposed to Comparative Examples C1-C22), cause the cured ink layer to exhibit a Raman shift spectrum (grey curve) at t48, i.e., the spectrum measured after 48 hours of storage on the substrate at 50°C and 10% relative humidity, which is substantially the same as or very similar to the Raman shift spectrum measured at t0, i.e., immediately after curing, and shows no signal saturation, i.e., no signal ≥65,000 units.

[0347] Comparative Examples C1-C22 (Figures 3-1 to 3-12 and Figures 5-1 to 5-10) made from UV-Vis radiation-curable printing inks containing SERS labels and one or more vinyl ether compounds resulted in the cured ink layer exhibiting Raman shift light at t48. (See page 33 / 34 of the specification, CN 121773169 A)The spectrum (gray curve) indicates signal saturation, i.e., a signal ≥ 65,000 units in at least a portion of the spectrum. This can be seen in variations in the concentration of vinyl ether compounds, for example, in C1 and C3 (Figs. 3-1 and 3-3) or C13–C14 (Figs. 5-1 to 5-2), or variations in the vinyl ether composition, for example, in C1, C4–C6 (Figs. 3-1, 3-4, 3-5, and 3-6) or C13, C15–C16 (Figs. 5-1, 5-3, and 5-4), or variations in the photoinitiator, for example, in C1, C7, C9–C10 (Figs. 3-1, 3-7, 3-9, and 3-10) or C13, C17–C22 (Figs. 5-1 and 5-5 to 5-10), or variations in the photoinitiator, for example, in C9–b), C10–b). The changes in the irradiation sources in C17-b), C19-b), and C20 (Fig. 3-9b), 3-10b), 5-5b), 5-7b, and 5-8) did not solve the problem that the signal remained saturated. Instruction Manual 34 / 34 Page 37 CN 121773169 A Figure 1 Figure 2-1 Instruction Manual Figure 1 / 21 Page 38 CN 121773169 A Figure 2-2 Figure 2-3 Figure 2-4 Instruction Manual Figure 2 / 21 Page 39 CN 121773169 A Figure 2-5 Figure 2-6 Instruction Manual Figure 3 / 21 Page 40 CN 121773169 A Figure 3-1 Figure 3-2 Figure 3-3 Instruction Manual Figure 4 / 21 Page 41 CN 121773169 A Figure 3-4 Figure 3-5 Figure 3-6 Instruction Manual Figure 5 / 21 Page 42 CN 121773169 A Figure 3-7 Figure 3-8 Instruction Manual Figure 6 / 21 Page 43 CN 121773169 A Figure 3-9 Instruction Manual Figure 7 / 21 Page 44 CN 121773169 A Figure 3-10 Figure 3-11 Appendix to the Instruction Manual, Page 8 / 21, 45 CN 121773169 A Figure 3-12 Figure 4-1 Appendix to the Instruction Manual, Page 9 / 21, 46 CN 121773169 A Figure 4-2 Figure 4-3 Appendix to the Instruction Manual, Page 10 / 21, 47 CN 121773169 A Figure 4-4 Figure 4-5 Appendix to the Instruction Manual, Page 11 / 21, 48 CN 121773169 A Figure 4-6 Figure 4-7 Appendix to the Instruction Manual, Page 12 / 21, 49 CN 121773169 A Figure 4-8 Figure 4-9 Figure 4-10 Appendix to the Instruction Manual, Page 13 / 21, 50 CN 121773169 A Figure 4-11 Figure 4-12Figure 4-13 Appendix to the Instruction Manual, Page 14 / 21, 51 CN 121773169 A Figure 5-1 Figure 5-2 Figure 5-3 Appendix to the Instruction Manual, Page 15 / 21, 52 CN 121773169 A Figure 5-4 Appendix to the Instruction Manual, Page 16 / 21, 53 CN 121773169 A Figure 5-5 Figure 5-6 Appendix to the Instruction Manual, Page 17 / 21, 54 CN 121773169 A Figure 5-7 Appendix to the Instruction Manual, Page 18 / 21, 55 CN 121773169 A Figure 5-8 Figure 5-9 Appendix to the Instruction Manual, Page 19 / 21, 56 CN 121773169 A Figure 5-10 Figure 6-1 Appendix to the Instruction Manual, Page 20 / 21, 57 CN 121773169 A Figure 6-2 Appendix to the Instruction Manual, Page 21 / 21, 58 CN 121773169 A

Claims

1. A UV-Vis radiation curable printing ink comprising: i) one or more surface enhanced Raman spectroscopy (SERS) tags in a total amount of from about 0.01 wt.% to about 1 wt.%, preferably from about 0.02 wt.% to about 1 wt.%, preferably one or more surface enhanced Raman spectroscopy (SERS) tags are nanoparticles, and more preferably at least one of the one or more SERS tags comprises gold (Au) as SERS enhancing material; ii) one or more radiation curable compounds in a total amount of from about 50 wt.% to about 95 wt.%, preferably from about 60 wt.% to about 95 wt.%; and iii) one or more photoinitiators in a total amount of from about 1 wt.% to about 20 wt.%, preferably from about 2 wt.% to about 15 wt.%, wherein the UV-Vis radiation curable printing ink is free of vinyl ether containing compounds, the weight percentages being based on the total weight of the UV-Vis radiation curable printing ink. The one or more SERS tags are present in the form of a dispersion, preferably a dispersion comprising an alkyd resin and from about 10 wt.% to about 30 wt.%, for example 20 wt.% of the surface enhanced Raman spectroscopy (SERS) tags, the weight percentages being based on the total weight of the dispersion.

3. The UV-Vis radiation curable printing ink according to claim 1 or 2, which is selected from the group consisting of a screen printing ink, a flexographic printing ink and a non- contact fluid micro-dispensing technology ink.

2. The UV-Vis radiation curable printing ink according to claim 1, wherein, The one or more radiation curable compounds are cationically curable compounds selected from the group consisting of propenyl ethers, cyclic ethers, lactones, cyclic sulfides, propenyl sulfides, silanes and mixtures thereof, preferably cyclic ethers, more preferably epoxides, oxetanes and mixtures thereof, and The one or more photoinitiators are one or more cationic photoinitiators, which are onium salts, preferably selected from the group consisting of oxonium salts, iodonium salts, sulfonium salts and mixtures thereof.

4. The UV-Vis radiation curable printing ink according to any one of claims 1 to 3, wherein, 5. The UV-Vis radiation curable printing ink according to claim 4, wherein the cationically curable compounds are selected from the group consisting of epoxides, oxetanes and mixtures thereof, preferably cycloaliphatic epoxides, oxetanes and mixtures thereof.

6. The UV-Vis radiation curable printing ink according to claim 4 or 5, further comprising one or more free radically curable compounds selected from the group consisting of tri(meth)acrylates, tetra(meth)acrylates and mixtures thereof, and one or more, one or more free radical photoinitiators selected from the group consisting of hydroxy ketones, alkoxy ketones, acetophenone, benzophenone, ketone sulfones, benzyl ketal, benzoin ethers, coumarins, camphorquinones, phosphine oxides, phenyl glyoxalates and mixtures thereof, preferably selected from the group consisting of phosphine oxides, hydroxy ketones and mixtures thereof. ​ ​ 7. The UV-Vis radiation curable printing ink according to claim 4 or 5, which is a cationic UV-Vis radiation curable screen printing ink, and further comprises one or more polyols and / or one or more fillers or extenders and / or one or more solvents and / or one or more photosensitizers.

8. The UV-Vis radiation curable printing ink according to claim 6, which is a hybrid UV-Vis radiation curable screen printing ink, and further is one or more polyols, one or more fillers or extenders and / or one or more solvents and / or one or more photosensitizers.

9. The UV-Vis radiation curable printing ink according to claim 4 or 5, which is a cationic UV-Vis radiation curable inkjet printing ink, and further comprises one or more cationically curable epoxysiloxane compounds and / or one or more photosensitizers and / or one or more solvents.

10. The UV-Vis radiation curable printing ink according to claim 6, which is a hybrid UV-Vis radiation curable inkjet printing ink, and further comprises one or more cationically curable epoxysiloxane compounds and / or one or more solvents.

11. Use of the UV-Vis radiation curable printing ink according to any one of claims 1 to 10 for manufacturing one or more security features on a substrate.

12. A security feature made from the UV-Vis radiation curable printing ink according to any one of claims 1 to 10.

13. A security article comprising a substrate and a radiation cured coating obtained by UV-Vis radiation curing of the UV-Vis radiation curable printing ink according to any one of claims 1 to 10, wherein the substrate is preferably selected from the group consisting of paper or other fibrous material, paper-containing material, glass, metal, ceramic, plastic and polymer, composite material and mixtures or combinations of two or more thereof.

14. A method for producing the security article according to claim 13, comprising the steps of: a. printing the UV-Vis radiation curable printing ink according to any one of claims 1 to 10 on a substrate, preferably by a printing method selected from the group consisting of screen printing, flexographic printing or non-contact fluid micro-dispensing technology, and b. UV-Vis radiation curing the UV-Vis radiation curable printing ink, preferably with one or more light sources selected from the group consisting of mercury lamps, UV-LED lamps and sequences thereof, to form one or more security features.

15. A method of authenticating one or more security features according to claim 12 and the security article according to claim 13, comprising the steps of: a. providing a security article according to claim 13 and comprising one or more security features according to claim 12, said one or more security features being made from a radiation cured layer made from the UV-Vis radiation curable printing ink according to any one of claims 1 to 10; b. illuminating the one or more security features with visible and / or near-IR light and measuring the SERS spectrum, and c. Comparing the SERS spectrum obtained in step b with a pre-recorded reference Raman spectrum.

Images