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, said inks being used for printing security features on substrates, in particular security documents or articles, wherein the ink comprises i) one or more surface enhanced Raman spectroscopy (SERS) tags, ii) one or more vinyl ether-containing compounds, iii) one or more cationic radiation-curable compounds different from the one or more vinyl ether-containing compounds of ii), and iv) one or more cationic photoinitiators that are hexafluorophosphates.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480056514.0 (22) Application Date 2024.09.02 (30) Priority Data 23195677.2 2023.09.06 EP (85) PCT International Application Entering National Phase Date 2026.03.04 (86) PCT International Application Application Data PCT / EP2024 / 074412 2024.09.02 (87) PCT International Application Publication Data WO2025 / 051659 EN 2025.03.13 (71) Applicant: Sikbay Holding Ltd. Address: Switzerland (72) Inventors: D. Espinosa, T. Martini, R. Lagrohn, A. Molina (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 / 38 (2006.01) C09D 11 / 037 (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 being used to print safety features on substrates, particularly on security documents or articles, said inks comprising i) one or more surface-enhanced Raman spectroscopy (SERS) labels, ii) one or more vinyl ether-containing compounds, iii) one or more cationic radiation-curable compounds different from the vinyl ether-containing compounds in ii) and iv) one or more cationic photoinitiators as hexafluorophosphate. Claims 2 pages, Description 37 pages, Drawings 27 pages, CN 121773168 A 2026.03.31 CN 1 21 77 31 68 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 vinyl ether-containing compounds, in total of about 0.1 wt.% to about 25 wt.%, preferably about 1 wt.% to about 25 wt.%; iii) one or more cationic radiation-curable compounds, different from the one or more vinyl ether-containing compounds in ii), in total of about 30 wt.% to about 90 wt.%, preferably about 30 wt.% to about 85 wt.%; and iv) one or more cationic photoinitiators, independently hexafluorophosphate, in total of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%, weight percentages 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, the dispersion preferably comprising an alkyd resin and about 10 wt.% to about 30 wt.%, for example 20 wt.%, of the surface-enhanced Raman spectroscopy (SERS) label, weight percentages based on the total weight of the dispersion. 3. The UV-Vis radiation-curable printing ink according to claim 1 or 2, wherein the one or more vinyl ether-containing compounds are selected from the group consisting of: diethylene glycol divinyl ether, triethylene glycol divinyl ether, cyclohexanediethanol divinyl ether, 2-(2-ethyleneoxyethoxy)ethyl acrylate, and 2-(2-ethyleneoxyethoxy)ethyl methacrylate, preferably diethylene glycol divinyl ether, triethylene glycol divinyl ether, and 2-(2-ethyleneoxyethoxy)ethyl acrylate. 4. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 3, wherein it is selected from the group consisting of: screen printing ink, flexographic printing ink, and non-contact fluid micro-distribution technology ink. 5. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 4, wherein the one or more cationic radiation-curable compounds (iii) are selected from the group consisting of: propylene ethers, silanes, cyclic ethers, lactones, cyclic sulfides, propylene sulfides, and mixtures thereof, preferably cyclic ethers, more preferably epoxides, oxetanes, and mixtures thereof, preferably alicyclic epoxides, oxetanes, and mixtures thereof, and the one or more cationic photoinitiators are ononium salts, preferably selected from the group consisting of: iodonium salts, sulfonium salts, and mixtures thereof. 6. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 5, further comprising one or more free radical curable compounds, preferably 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.7. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 5, wherein it is a cationic UV-Vis radiation-curable screen printing ink, and further comprises one or more polyhydroxy compounds 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, wherein it is a mixed UV-Vis radiation-curable screen printing ink, and further comprises one or more polyhydroxy compounds and / or one or more fillers or extenders and / or one or more solvents and / or one or more photosensitizers. Claims 1 / 2 Page 2 CN 121773168 A 9. The UV-Vis radiation-curable printing ink according to claim 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. 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. 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 safety features according to claim 12 and the safety article of claim 14, comprising the steps of: a.A security article is provided as described in claim 14 and comprising one or more security features as described in claim 12, wherein the one or more security features are made of a radiation-cured layer made of UV-Vis radiation-curable printing ink as described 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. comparing the SERS spectrum obtained in step b with a pre-recorded reference Raman spectrum. Claims 2 / 2 Page 3 CN 121773168 A UV-Vis Curable Security Ink Containing Labels and Security Features Obtained Therefrom Technical Field

[0001] The present invention relates to the technical field of security features comprising markers by surface-enhanced Raman spectroscopy (SERS) and their detection. Furthermore, the present 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 in an effort to protect security articles and documents that are not reproducible, such as banknotes, valuable documents or cards, transportation tickets or cards, tax banders, and merchandise labels, from counterfeiting, alteration, or illegal copying, the conventional practice is to introduce various security features into or onto these documents.

[0003] For example, security features used for secure documents and articles can be classified as "overt" and "covert" security features. Overt security features are easily detectable using independent human senses; for example, such features may be visible and / or detectable via tactile senses, while still being difficult to produce and / or copy. Covert 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 secure documents, particularly for banknote printing, to produce covert security features.

[0005] Machine-readable inks containing SERS-type or SERRS-type markers (hereinafter referred to as SERS tags and SERRS tags) have been developed for protecting security articles and documents. Surface-enhanced Raman scattering is called SERS, and surface-enhanced resonance 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 resonance Raman scattering features, respectively), which allow for their detection and identification using standard Raman spectrometers.

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

[0007] SERS tags contain a metal or other reinforcing surface that is electromagnetically coupled to incident electromagnetic radiation and generates a locally amplified electromagnetic field that causes a 10² to 10⁹-fold or greater increase in Raman scattering by SERS-active molecules located on or near the reinforcing surface. The output in a SERS experiment is the 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 integrated intensity of its characteristic Raman band.

[0010] As described 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 security features that are not subject to slow 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 safety inks.

[0013] Therefore, there is still a need for UV-Vis curable safety inks containing SERS labels, wherein the safety features acquired 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) 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 SERS labels contains gold (Au) as a SERS reinforcing material;

[0016] ii) one or more vinyl ether-containing compounds, in total of about 0.1 wt.% to about 25 wt.%, preferably about 1 wt.% to about 25 wt.%;

[0017] iii) one or more cationic radiation-curable compounds, which are different from the one or more vinyl ether-containing compounds in ii), in total of about 30 wt.% to about 90 wt.%, preferably about 30 wt.% to about 85 wt.%; and

[0018] iv) one or more cationic photoinitiators, which are independently hexafluorophosphates, in total of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%;

[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 articles described herein, wherein the method comprises the following steps:

[0022] a. printing the UV-Vis radiation-curable printing ink of 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

[0023] b. 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 safety features and safety articles described herein, the method comprising the following steps:

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

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

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

[0028] UV-Vis curable safety ink containing the SERS label described herein allows for the printing and preparation of safety features for use in the safety article specification 2 / 37 page 5 CN 121773168 A, said safety features being advantageously and definitively identified by means of Raman spectroscopy. The definitive identification involves notThere are detection problems that may occur due to saturation of the SERS signal of the safety feature. Advantageously, the present invention allows for the rapid production of flow-resistant safety features due to reduced drying time and its good chemical and physical resistance. Brief Description of the Drawings

[0029] Figures 1-6 show the Raman shifts of printed features consisting of cured layers made independently of UV-Vis radiation-curable printing inks (E1-E21 and C1-C31).

[0030] Figure 1 shows the Raman shifts of printed features consisting of cured layers made of UV-Vis radiation-curable inkjet printing ink (E1), which are applied by inkjet printing methods at different ink coverages (25%, 50%, and 75%) and by hand coating (HC).

[0031] Figures 2-1 and 2-2 show the Raman shifts of printed features consisting of cured layers made independently of UV-Vis radiation-curable inkjet printing inks.

[0032] Figures 3-1 to 3-7 show the Raman shifts of printing features consisting of cured layers independently made from UV-Vis radiation-curable inkjet printing inks (E1-E7).

[0033] Figures 4-1 to 4-15 show the Raman shifts of printing features consisting of cured layers independently made from comparative UV-Vis radiation-curable inkjet printing inks (C1-C15).

[0034] Figures 5-1 to 5-14 show the Raman shifts of printing features consisting of cured layers independently made from UV-Vis radiation-curable screen printing inks (E8-E21).

[0035] Figures 6-1 to 6-16 show the Raman shifts of printing features consisting of cured layers made independently of comparative UV-Vis radiation-curable screen printing inks (C16-C31),

[0036] where the Raman shift is 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

[0037] Definitions

[0038] The following definitions are used to clarify the meaning of terms discussed in the specification and defined in the claims.

[0039] 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.

[0040] As used herein, the term “at least one” is intended to define one or more, for example, one, two, or three.

[0041] 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”.

[0042] As used herein, the term “about” means that the quantity or value in discussion may be a specified particular value or one near it.Other values. Generally, the term "about" to indicate a certain value is intended to indicate a range within ±5% of that value. As an example, the phrase "about 100" indicates a range of 100 ± 5, that is, a range of 95 to 105. 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.

[0043] The term "comprising" as used herein is intended to be non-exclusive and open-ended. Thus, for example, a solution comprising compound A may comprise other compounds besides A. However, as in particular embodiments thereof, the term "comprising" also covers the more restrictive meaning of "basically composed of..." and "composed of...", such that, for example, "a solution comprising A, B and optionally C" may also be composed (basically) of A and B, or (basically) of A, B and C.

[0044] The term "security article" refers to an article that is typically protected against counterfeiting or tampering by one or more security features.

[0045] The term "security feature" is used to refer to an image, pattern, or graphic element that can be used for identification purposes.

[0046] Where this specification refers to "preferred" embodiments / features, combinations of these "preferred" embodiments / features should also be considered disclosed, provided that such combinations of "preferred" embodiments / features are technically meaningful.

[0047] The terms "UV-Vis curability" and "UV-Vis curing" refer to radiation curing by photopolymerization under the influence of irradiation having wavelength components in the UV or UV and visible portions of the electromagnetic spectrum (typically 100 nm to 800 nm, preferably between 150 nm and 600 nm, more preferably between 200 nm and 470 nm).

[0048] The present invention provides UV-Vis radiation-curable printing ink, preferably selected from the group consisting of: UV-Vis radiation-curable screen printing ink, UV-Vis radiation-curable flexographic printing ink, and UV-Vis radiation-curable non-contact fluid micro-distribution ink, more preferably selected from the group consisting of: UV-Vis radiation-curable screen printing ink and UV-Vis radiation-curable non-contact fluid micro-distribution ink, and even more preferably selected from the group consisting of: UV-Vis radiation-curable screen printing ink and UV-Vis radiation-curable inkjet printing ink. More than one safety feature can be created when applying and curing the UV-Vis radiation-curable printing ink.

[0049] Generally, UV-Vis radiation-curable printing inks suitable for screen printing methods have a viscosity at 25°C in the range of about 300 mPa s to about 2500 mPa s, preferably in the range of about 400 mPa s to about 1000 mPa s (using, for example...).Brookfield machine “RVDV-I Prime”, rotor 27, at 100 rpm).

[0050] Screen printing (also known in the art as silkscreen printing) is a printing technique that typically uses a screen made of woven mesh to support an ink-blocking stencil. The connected stencils form open areas of the mesh, transferring ink as a sharply edged image onto the substrate. A squeegee is moved across the screen 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 it can apply a greater thickness of ink to the substrate compared to other printing techniques. Therefore, screen printing is preferred when an ink deposit with a thickness of about 10 to 50 μm or more is required, which cannot be easily achieved with other printing techniques. Typically, the screen is made of a piece of 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 wire. Preferred synthetic materials are nylon or polyester threads.

[0051] In addition to screens based on woven meshes made of synthetic or metal wires, screens have been developed in solid metal plates with perforated meshes. Such screens are prepared by a method comprising electrolyzing the metal screen by: forming a screen skeleton on a matrix provided with a separating agent in a first electrolytic bath; peeling the formed screen skeleton from the matrix; and subjecting the screen skeleton to electrolysis in a second electrolytic bath to deposit metal onto the skeleton.

[0052] There are three types of screen printing machines: flatbed, rotary, 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 to a position 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 roller. 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 sheet-fed processes.

[0053] 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 end openings is capped at both ends and fitted into a plate on the side of the printing press. During printing, ink is pumped into the cylinder...One end is fixed to maintain a continuous fresh supply. The squeegee is fixed inside the rotary screen, and the squeegee pressure is maintained and adjusted to allow for good and constant print quality. The advantage of rotary screen printing machines is the speed, which can easily reach 150 m / min in roll paper or 10,000 sheets / hour in single-sheet feeding.

[0054] 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, 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.

[0055] 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, a Brookfield machine "RVDV-I Prime", rotor No. 27, at 100 rpm).

[0056] Flexographic printing methods preferably use a unit having a cavity squeegee, an anilox roller, and a plate cylinder. The anilox roller advantageously has cells whose volume and / or density determine the ink or varnish application rate. The cavity squeegee abuts against the anilox roller, filling the cells while scraping off excess ink or varnish. The anilox roller transfers the ink to the plate cylinder, which ultimately transfers the ink to the substrate. The plate cylinder can be made of a polymer or elastomer material. 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 job is mounted on the uncured side, and the printing plate is further exposed to UV light. This hardens the printing plate in the image area. The printing plate is then processed to remove the uncured photopolymer from the non-image areas, which lowers the surface of the printing plate in these non-image areas. After processing, the printing plate is dried and given 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 below: Printing TechnologyTechnology), JM Adams and PA Dolin, Delmar Thomson Learning, 5th edition, pp. 359-360.

[0057] 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. Spraying is a technique involving forcing a composition through a nozzle to form a fine aerosol. A carrier gas and electrostatic charging may participate in helping to 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, p. 407.

[0058] Aerosol jet printing (AJP) is an emerging non-contact direct-write 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 approximately 10 micrometers) and relatively large stand-off distances (e.g., 1–5 mm) in addition to orientation independence. The technique involves aerosol generation using ultrasonic or pneumatic atomizers, producing aerosols from compositions typically with viscosities between approximately 1 mPa·s and approximately 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.

[0059] Electrohydrodynamic inkjet printing is a high-resolution inkjet printing technology. Electrodynamic inkjet printing technology patent specification, page 5 / 37, CN 121773168 A. It uses an externally applied electric field to manipulate droplet size, jetting frequency, and arrangement on the substrate to achieve higher resolution than conventional inkjet printing while maintaining high production speed. Electrodynamic inkjet printing offers approximately two orders of magnitude higher resolution than conventional inkjet printing; therefore, it can be used for the orientation of nanometer and micrometer-scale patterns. Electrodynamic inkjet printing can be used in either DOD or continuous mode. Compositions used for electrodynamic inkjet printing typically have a range of approximately 1 mPa·s and approximately 1000 mPa·s.Viscosities between 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.

[0060] Slit coating is a one-dimensional coating technique. Slit coating allows for the application of stripes of coating material, which is well-suited for creating multilayer coatings with stripes of different materials stacked on top of each other. The alignment of the pattern is achieved by translating the coating head along a direction perpendicular to the direction of roll paper movement. The slit coating head contains a mask defining a slit through which the slit coating ink is dispersed. An example of a slit coating head is described in F. C. Krebs, Solar Energy Materials & Solar Cells (2009), 93, pp. 405–406. Suitable compositions for slot coating typically have a viscosity between about 1 mPa s and about 20 mPa s (25°C, 1000 s⁻¹).

[0061] 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 pulses within a thin film of material, resulting in the formation of a liquid jet. Compositions 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.

[0062] 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. Drop-on-demand (DOD) printing is a non-contact printing method in which droplets are generated only when printing is required, and are typically generated by a jetting mechanism rather than by destabilizing the jet. According to the mechanism used in the printhead to generate droplets...The manufacturing process, DOD printing, includes 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.

[0063] The light source required for curing 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 using one or more UV-LED lamps in a first step to partially cure the UV-Vis radiation composition, and using 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.

[0064] The UV-Vis radiation-curable printing ink described herein contains one or more surface-enhanced Raman spectroscopy (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.%, preferably about 0.02 wt.% to about 1 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

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

[0066] SERS tags are aggregates of nanoparticles exhibiting a plasmonic surface and having Raman-active reporter molecules adsorbed on their surface. The SERS tag, presenting a plasmonic surface, is responsible for generating the electric field required for Raman signal generation or Raman scattering amplification (see page 6 / 37 of CN 121773168 A). The Raman-active reporter molecule provides the unique vibrational fingerprint of the SERS tag. Typically, aggregates exist in an external coating that a) isolates the SERS tag from the external medium, preventing the Raman-active reporter molecule from leaching out and protecting the SERS tag from contamination by external media that may cause vibrational noise; b) increases the stability of the SERS tag; and c) provides 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 containing 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 N-heteroaryl and / or S-heteroaryl.Aryl groups, wherein residues R1 and R2 are independently selected from -H and alkyl groups, preferably from -H and C1-C4 alkyl groups. As known to those skilled in the art of organic chemistry, a fully conjugated molecule is a molecule having a system of conjugated electrons that extends throughout the entire molecule. A system of conjugated electrons is a system of connected p orbitals with delocalized electrons.

[0068] As 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 a 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‑,‑CR 10=CR11‑o‑C6H4‑CR12=CR13-、-CR10=CR11-m-C6H4-CR 12=CR13-、-CR10=CR11- p-C6H4-CR 12=CR13-、-CR14=N-N=CR15-、

[0076] 、 、 、 Specification 7 / 37 Page 10 CN 121773168 A

[0077] 、 、 、

[0078] 、 、 、

[0079] 、 、 、

[0080] 、 、 、

[0081] 、 、 、

[0082] 、 、 、

[0083] 、 and;

[0084] and

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

[0086] - A fully conjugated compound consisting of 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-, -CR10=CR11-m-C6H4-, -CR10=CR11-p-C6H4-, -CR10=CR11-o-C6H4-, -CR12=CR13-, -CR10=CR11-m-C6H4-CR 12=CR13-、-CR10=CR11- p-C6H4-CR 12=CR13-、-CR14=N-N=CR15-、 Specification 8 / 37 Page 11 CN 121773168 A

[0089] 、、、

[0090] 、、、

[0091] 、、、

[0092] 、、、

[0093] 、、、

[0094] 、、、

[0095] 、、、

[0096] 、and;

[0097] and

[0098] 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-CR12=CR13-, -CR10=CR11- DescriptionBook 9 / 37, page 12, CN 121773168, 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 substituents selected from -NR1R2, -SH, -≡, -≡N and -N=, preferably selected from -NR1R2 and -SH, preferably at least two; an N-containing heteroaryl group substituted with one or more substituents selected from -NR3R4, -SH, -≡, -≡N and -N=; or an S-containing heteroaryl group substituted with one or more substituents selected from -NR5R6, -SH, -≡, -≡N and -N=, directly attached to a hydrogen atom, wherein substituents R1 and R2 have the meaning as defined herein, and substituents R3-R6 are independently selected from -H and alkyl groups, preferably -H and C1-C4 alkyl groups. The aryl group substituted by one or more substituents selected from -NR1R2, -SH, -≡, -≡N and -N=, preferably selected from -NR1R2 and -SH, may contain a substituent preferably selected from: hydroxyl, alkyl, alkoxy, alkylthio, formyl, nitro, halide, hydroxycarbonyl, alkoxycarbonyl and O-containing heteroaryl, more preferably selected from: alkyl, alkoxy, alkoxy, halide and O-containing heteroaryl, and other substituents ...

[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, hydroxycarbonyl, 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-, -CR 10=CR11-p-C6H4-、-CR 10=CR11-o-C6H4-CR 12=CR13-、-CR10=CR11-m-C6H4- CR12=CR13-、-CR10=CR11-p-C6H4-CR 12=CR13-、-CR14=N-N=CR15-、

[0123] 、 、 、 Specification 11 / 37 Page 14 CN 121773168 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-tetrafluorobenzenethiophenol, (5-(4-methoxyphenyl)-1,3,4-oxazol-2-thiol), (E)-1,2-di(pyridin-4-yl)ethylene, 5-(pyridin-4-yl)-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 maximum physical size (e.g., length, diameter, etc.) corresponding to a 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 nanoparticles have an outer surface capable of enhancing Raman scattering of Raman-active molecules. The outer surface of the nanoparticles 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-enhancing material of 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-enhancing material of 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) or a mixed curable ink (i.e., containing a cationic curable compound and a free radical curable compound). The cationic UV-Vis radiation-curable printing ink is cured by a cationic mechanism, which consists of: activating one or more cationic photoinitiators by 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 compared to a free radical UV-Vis radiation-curable coating.Properties and mechanical resistance. 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 comprise cationic curable compounds and free radical curable compounds, cationic photoinitiators and free radical photoinitiators.

[0136] The UV-Vis radiation-curable printing inks described herein comprise one or more vinyl ether-containing compounds in total of about 0.1 wt.% to about 25 wt.%, preferably about 1 wt.% to about 25 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0137] It is known in the art that vinyl ether-containing compounds 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 improve the physical and chemical resistance of the safety features of the print and enhance the flexibility of the printed and cured ink layers, which can be advantageous when printing the UV-Vis radiation-curable screen printing inks described herein onto plastic or polymer substrates. Vinyl ethers also help reduce the viscosity of the ink while strongly copolymerizing with it.

[0138] Examples of preferred vinyl ether-containing compounds include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, ethylhexyl vinyl ether, octadecyl vinyl ether, dodecyl vinyl ether, isopropyl vinyl ether, tert-butyl vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether, cyclohexanediol monovinyl ether, cyclohexanediol divinyl ether, 4-(ethoxymethyl)cyclohexylmethylbenzoate, phenyl vinyl ether, methyl phenyl vinyl ether Methoxyphenyl vinyl ether, 2-chloroethyl vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 1,6-hexanediol monovinyl ether, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, 4-(ethyleneoxy)butyl benzoate, bis[4-(ethyleneoxy)butyl] adipic acid, bis[4-(ethyleneoxy)butyl] succinate, bis[4-(ethyleneoxy)methyl)cyclohexyl (Instructions 13 / 37) Page 16 CN 121773168 A Methyl glutarate, 4-(ethoxy)butyl stearate, trimethylolpropane trivinyl ether, propylene carbonate ether, diethylene glycol monovinyl ether, diethylene glycol divinyl ether, ethylene glycol butyl vinyl ether, dipropylene glycol divinyl ether, triethylene glycol divinyl ether, triethylene glycol methyl vinyl ether, triethylene glycol monobutyl vinyl ether, tetraethylene glycolDivinyl ether, poly(tetrahydrofuran) divinyl ether, polyethylene glycol-520 methyl vinyl ether, pluriol-E200 divinyl ether, trimellitic acid tri[4-(ethyleneoxy)butyl] ester, 1,4-bis(2-ethyleneoxyethoxy)benzene, 2,2-bis(4-ethyleneoxyethoxyphenyl)propane, bis[4-(ethyleneoxy)methyl]cyclohexyl]methyl]terephthalate, bis[4-(ethyleneoxy)methyl]cyclohexyl]methyl]isophthalate. More preferably, vinyl ether-containing compounds include diethylene glycol divinyl ether, triethylene glycol divinyl ether, cyclohexanediol divinyl ether, 2-(2-ethyleneoxyethoxy)ethyl acrylate and 2-(2-ethyleneoxyethoxy)ethyl methacrylate, and even more preferably, diethylene glycol divinyl ether, triethylene glycol divinyl ether and 2-(2-ethyleneoxyethoxy)ethyl acrylate.

[0139] Suitable vinyl ether-containing compounds are, for example, the following commercially available compounds: EVE, IBVE, DDVE, ODVE, BDDVE, DVE-2, DVE-3, CHVE, CHDM-di, HBVE from BASF; and Rapi-Cure™ DVE2, Rapi-Cure™ DVE3, Rapi-Cure™ DVB1D, Rapi-Cure™ HBVE, Rapi-Cure™ PEPC, Rapi-Cure™ DDVE, Rapi-Cure™ CHMVE, Rapi-Cure™ CVE, Rapi-Cure™ EHVE, Rapi-Cure™ ODVE, and Rapi-Cure™ DVF from DOW. The vinyl ethers described herein may be hydroxyl-modified or (meth)acrylate-modified (e.g., HBVE 4-hydroxybutyl vinyl ether from BASF, VEEA® 2-(2-ethyleneoxyethoxy)ethyl acrylate and VEEM® methacrylate (2-(2-ethyleneoxyethoxy)ethyl acrylate) from Nippon Shokubai). A portion of the vinyl ether-containing compound in the UV-Vis radiation-curable printing inks described herein may be replaced by one or more allyl ethers; suitable examples of allyl ethers are AOMA® from Nippon Shokubai.

[0140] The UV-Vis radiation-curable printing inks described herein contain one or more cationic radiation-curable compounds (hereinafter referred to as "cationic radiation-curable compounds") that are different from the vinyl ether-containing compounds, in a total amount of about 30 wt.% to about 90 wt.%, preferably about 30 wt.% to about 85 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0141] 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, silanes, propylene sulfides, 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.

[0142] 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.

[0143] 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 multifunctional. The UV-Vis radiation-curable printing ink described herein, comprising at least one alicyclic epoxide class, may further comprise one or more cationic curable epoxy siloxane compounds as described herein.

[0144] According to one embodiment, the UV-Vis radiation-curable printing ink described herein comprises at least one alicyclic epoxide class and at least one oxetane class described herein, wherein the at least one alicyclic epoxide class and the at least one oxetane class are present in a total amount of about 30 wt.% to about 90 wt.%, preferably about 30 wt.% to about 85 wt.%, based on the total weight of the UV-Vis radiation-curable printing. The UV-Vis radiation-curable printing ink described herein, comprising at least one alicyclic epoxide and at least one oxetane as described herein (page 14 / 37, CN 121773168 A), may further comprise one or more cationic curable epoxy siloxane compounds as described herein, wherein the at least one alicyclic epoxide, the at least one oxetane, and the one or more cationic curable epoxy siloxane compounds are present in a total amount of about 30 wt.% to about 90 wt.%, preferably about 30 wt.% to about 85 wt.%, based on the total weight of the UV-Vis radiation-curable printing.

[0145] As is well known to those skilled in the art, alicyclic epoxides are cationic curable monomers containing at least a substituted or unsubstituted epoxy cyclohexyl residue: .

[0146] Preferably, the alicyclic epoxides described herein comprise at least one cyclohexane ring and at least two epoxy groups. Preferred alicyclic epoxides contain more than one (i.e., at least two) cyclohexyl groups and preferably have the structural formula (II):

[0147]

[0148] (II)

[0149] Wherein -X- represents a single bond or a divalent group containing one or more atoms. Alicyclic epoxides of general formula (II) are optionally 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).

[0150] According to one embodiment, -X- is a divalent hydrocarbon group, which may be a straight-chain or branched alkylene group containing 1 to 18 carbon atoms, examples of which include, but are not limited to, methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene.

[0151] 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.

[0152] 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 is an alicyclic epoxide of general formula (II-a), (II-b) or (II-c) as defined below:

[0153]

[0154] (II-a)

[0155] wherein, Specification 15 / 37 pages 18 CN 121773168 A

[0156] 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), 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);

[0157] 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

[0158] l1 and l2 are independently integers contained between 0 and 9, preferably between 0 and 3, and more preferably 0;

[0159]

[0160] (II-b)

[0161] Wherein,

[0162] 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), and preferably a straight-chain or branched alkyl residue containing 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, and isopropyl);

[0163] 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

[0164] 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;

[0165] -X3- is a single bond or a straight-chain or branched divalent hydrocarbon group containing 1 to 10 carbon atoms, preferably containing 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;

[0166]

[0167] (II-c)

[0168] wherein,

[0169] 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; Specification 16 / 37 pages 19 CN 121773168 A

[0170] 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

[0171] l1 and l2 are independent of each other and are integers contained between 0 and 9, preferably between 0 and 3, more preferably 0.

[0172] 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.

[0173] 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.

[0174] Preferred alicyclic epoxides of general formula (II-c) are 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-m-dioxane.

[0175] 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).

[0176]

[0177] (III-a)

[0178]

[0179] (III-b).

[0180] The alicyclic epoxides described herein may be hydroxyl-modified or (meth)acrylate-modified.

[0181] According to one embodiment, the UV-Vis radiation-curable printing inks described herein comprise at least one alicyclic epoxide described herein, and further comprise at least one linear epoxide. The use of linear epoxides other than alicyclic epoxides in the inks 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, DY-3601.

[0182] It is known in the art that oxobutane compounds accelerate curing and reduce tack, thus limiting the use of printed sheets on pages 17 / 37 of the specification (20 CN 121773168 A).They reduce the risk of sticking and smudging when stacked immediately after printing and curing. They also help reduce ink viscosity while promoting strong copolymerization. Preferred examples of oxetanes include trimethylene oxide, 3,3-dimethyloxetane, trimethylolpropaneoxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, 3,3-dicyclic methyloxetane, 3-ethyl-3-phenoxymethyloxetane, bis([1-ethyl(3-oxetane)]methyl) ether, 1,4-bis[3-ethyl-3-oxetane methoxy)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.

[0183] 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).

[0184] The cationic photoinitiator (also referred to in the art as a photoacid generator) is preferably an onium salt. The ononium salts described herein are preferably selected from the group consisting of: nitrogen ononium 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.

[0185] The one or more iodonium salts described herein have a cationic portion and an anionic portion, wherein the anionic portion is hexafluorophosphate (PF6-, CAS 16919-18-9), 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 replaced 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, or one or more alkyl groups.The hydroxyl groups or combinations thereof are substituted. Preferred cationic iodonium moieties include bis(4-dodecylphenyl)iodonium (CAS 71786-69-1; PF6 salt CAS 477602-76-9); bis[4-(1,1-dimethylethyl)phenyl]iodonium (CAS 61267-44-5; PF6 salt CAS 61358-25-6); (4-isopropylphenyl)(4-methylphenyl)iodonium (CAS 178233-71-1; PF6 salt CAS 184477-29-0); bis(4-methylphenyl)iodonium (CAS 46449-56-3; PF6 salt CAS 60565-88-0); (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium (CAS 46449-56-3; PF6 salt CAS 60565-88-0); (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium (CAS 46449-56-3; PF6 salt CAS 60565-88-0); (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium (CAS 46449-56-1 ... 344562-79-4; PF6 salt CAS 344562-80-7); bis(2,4-dimethylphenyl)]iodonium (CAS 78337-07-2; PF6 salt CAS 1446786-05-5); bis(3,4-dimethylphenyl)]iodonium (CAS 66482-57-3; PF6 salt CAS 67578-25-0); (4-methylphenyl)(2,4,6-trimethylphenyl)iodonium (CAS 758629-51-5; PF6 salt CAS 1640277-11-7); bis[(4-(2-methylpropyl)phenyl]iodonium (CAS 157552-66-4); PF6 salt CAS 249300-47-8; bis(4-butylphenyl)iodonium (CAS 76310-29-7; PF6 salt CAS 2379547-92-7); bis(2,4,6-trimethylphenyl)iodonium (CAS 94564-97-3; PF6 salt CAS 94564-98-4); bis(4-hexylphenyl)iodonium (CAS 249300-48-9; PF6 salt CAS 249300-49-0); bis(4-decylphenyl)iodonium (CAS 137141-44-7; PF6 salt CAS 858973-47-4); (4-decylphenyl)(4-undecylphenyl)iodonium (CAS 167997-83-3); bis(4-undecylphenyl)iodonium (CAS 167997-61-7); bis(4-tridecylphenyl)iodonium (CAS 124053-08-3); bis(4-tetradecylphenyl)iodonium (CAS 167997-63-9); bis(4-hexadecylphenyl)iodonium (CAS 137141-41-4; PF6-salt CAS 137141-42-5); bis(4-heptadecylphenyl)iodonium (CAS 144095-91-0); Bis(4-octadecylphenyl)iodonium (CAS 202068-75-5); (4-decylphenyl)(4-dodecylphenyl)iodonium (CAS 167997-67-3); (4-decylphenyl)(4-tridecylphenyl)iodonium (CAS 167997-77-5); (4-decylphenyl)(4-tetradecylphenyl)iodonium (CAS 167997-81-1); (4-dodecylphenyl)(4-undecylphenyl)iodonium (CAS 167997-71-9); 4-(dodecylphenyl)(4-tridecylphenyl)iodonium (CAS 167997-69-5); (4-dodecylphenyl)(4-tetradecylphenyl)iodonium (CAS 167997-69-5); (4-dodecylphenyl)(4-tetradecylphenyl)iodonium (CAS 167997-67-3); (4-decylphenyl)(4-tetradecylphenyl)iodonium (CAS 167997-67-3); (4-decylphenyl)(4-tetradecylphenyl)iodonium (CAS 167997-77-5); (4-dodecylphenyl)(4-tetradecylphenyl)iodonium (CAS 167997-6 ... 167997-65-1); (4-tetraylphenyl)(4-undecylphenyl)iodonium (CAS 167997-73-1); (4-tetradecylphenyl)(4-undecylphenyl)iodonium (CAS 167997-79-7); (4-tetradecylphenyl)(4-tetraylphenyl)iodonium (CAS 167997-75-3); p-(octoxyphenyl)phenyliodonium (CAS 121239-74-5; PF6 salt CAS 125604-89-9); [4-[(2-hydroxytetradecyl)oxy]phenyl]phenyliodonium (CAS 139301-14-7; PF6 salt CAS 408332-53-6); phenyl[3-(trifluoromethyl)phenyl]iodonium (CAS 167997-79-7); 789443-26-1); bis(4-fluorophenyl)iodonium (CAS 91290-88-9; PF6 salt CAS 91290-89-0); (4-nitrophenyl)phenyliodonium (CAS 46734-23-0; PF6 salt CAS 2127904-41-8); (4-nitrophenyl)(2,4,6-trimethylphenyl)iodonium (CAS 1146127-10-7); [iodonium ylidene bis([1,1'-biphenyl]-4',4-diyl)]bis[diphenyl-sulfonium (CAS 524678-28-2; PF6 salt CAS 524678-29-3); bis[4-[1,1-dimethyl-2- [[[[2-[(1-oxo-2-propen-1-yl)oxy]ethyl]amino]carbonyl]oxy]ethyl]-3,5-dimethylphenyl]-iodonium (CAS 2863964-71-9; PF6 salt CAS 2893964-72-0); [iodonium ylidenebis(4,1-phenylenethio-4,1-phenylene)]bis[diphenyl-sulfonium (CAS 524678-23-7; PF6 salt CAS 2893964-72-0)524678-24-8); bis[3-(1,1-dimethylethyl)phenyl]iodonium (CAS 159349-74-3; PF6 salt CAS 159349-76-5); bis(2-methylphenyl)iodonium (CAS 46423-98-7; PF6 salt CAS 91290-91-4); bis(3-methylphenyl)iodonium (CAS 84383-80-2; PF6 salt CAS 159349-70-9); bis(4-ethylphenyl)iodonium (CAS 66482-59-5; PF6 salt CAS 2760165-32-8); and bis[4-(1-methylethyl)phenyl]iodonium (CAS 62051-10-9; PF6 - Salt CAS 69842-76-8). A particularly suitable example of an iodonium salt used in the present invention is commercially available under the name WPI-113 from FUJIFILM Wako Chemicals.

[0186] The one or more sulfonium salts described herein have a cationic moiety and anionic moiety, wherein the anionic moiety is a hexafluorophosphate (PF6-), and wherein the cationic moiety is preferably an aromatic sulfonium ion, more preferably a sulfonium ion containing two or more aryl groups, wherein the two or more aryl groups may be independently substituted by one or more alkyl groups (such as methyl, ethyl, isobutyl, tert-butyl, etc.), one or more alkoxy groups, one or more aryloxy groups, one or more halogen-containing groups, one or more hydroxyl groups, or combinations thereof.

[0187] Preferred cationic sulfonium moieties include tris[4-(4-acetylphenylthioalkyl(sulfanyl))phenyl]-sulfonium (CAS 953084-12-3; PF6-salt CAS 953084-13-4); 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthium (CAS 591773-91-0; PF6-salt CAS 591773-92-1); (9-oxo-9H-thioxanthium-2-yl)diphenyl-sulfonium (CAS 1140908-08-2; PF6-salt CAS 2758693-70-6); 4-(phenylthio)phenyldiphenyl-sulfonium (CAS 47480-44-4; PF6- PF6 salt (CAS 75482-18-7); bis[4-(diphenylsulfonium)phenyl]sulfide (CAS 74227-34-2; PF6 salt CAS 74227-35-3); (4-methylphenyl)diphenyl-sulfonium (CAS 47045-31-8; PF6 salt CAS 66482-51-7); (3-methylphenyl)diphenyl-sulfonium (CAS 347841-49-0); bis(4-methylphenyl)phenyl-sulfonium (CAS 70082-58-5); PF6 salt CAS70082-59-6); [(4-(1,1-dimethylethyl)phenyl]diphenyl-sulfonium (CAS 66482-54-0); bis[4-(1-methylethyl)phenyl]phenyl-sulfonium (CAS 70084-21-8); [(4-(2-methylpropyl)phenyl]diphenyl-sulfonium (CAS 255056-41-8; PF6-salt CAS 255056-41-8); (4-methoxyphenyl)diphenyl-sulfonium (CAS 70084-23-0; PF6-salt CAS 119280-67-0); 1-naphthyldiphenyl-sulfonium (CAS 116808-68-5); tris(4-methylphenyl)-sulfonium (CAS 47197-43-3; PF6-salt CAS 119280-67-0); 1-naphthyldiphenyl-sulfonium (CAS 116808-68-5); tris(4-methylphenyl)-sulfonium (CAS 47197-43-3; PF6-salt CAS 119280-67-0). 146062-15-9); (4-bromophenyl)diphenylsulfonium (CAS 70244-60-9); (4-iodophenyl)diphenylsulfonium (CAS 255056-45-2); (4-fluorophenyl)diphenyl-sulfonium (CAS 70084-25-2; PF6-salt CAS 106888-36-2); (4-chlorophenyl)diphenyl-sulfonium (CAS 47045-32-9; PF6-salt CAS 337378-34-4); (4-phenyloxyphenyl)diphenyl-sulfonium (CAS 82617-07-0; PF6-salt CAS 121773168) (Instruction manual page 19 / 37, 22 CN 121773168 A) 127279-84-9); (4'-methyl[1,1'-biphenyl]-4-yl)diphenyl-sulfonium (CAS 868610-38-2); tris(4-propylphenyl)-sulfonium (CAS 935399-09-0); bis(4-butylphenyl)phenyl-sulfonium (CAS 518991-23-6); tris[4(1-methylethyl)phenyl]-sulfonium (CAS 592518-39-3); S,S'-1,3-phenylenebis[S,S'-diphenyl]-sulfonium (CAS 641638-18-8); (4-dodecylphenyl)diphenyl-sulfonium (CAS 108493-55-6); (4-benzoylphenyl)diphenyl-sulfonium (CAS 868610-38-2); tris(4-propylphenyl)-sulfonium (CAS 935399-09-0); bis(4-butylphenyl)-sulfonium (CAS 935399-09-0); tris ... 127855-23-6); bis([1,1'-biphenyl]-4-yl)(4-methylphenyl)-sulfonium (CAS 91815-48-4); tris[4-[1,1-dimethylethyl)phenyl]-sulfonium (CAS 91815-56-4; PF6-salt CAS 91815-56-4); triphenyl-sulfonium (CAS 18393-55-0; PF6-salt CAS 57835-99-1); 5-(4-methylphenyl)-dibenzothiophenonium (CAS 49867-39-2); PF6-salt CAS337378-38-8); 5-[4-(2-hydroxyethoxy)phenyl]-thiaanthrannium (CAS 492466-55-4; PF6 salt CAS 492466-56-5); 10-(4-methylphenyl)-9H-thiatonium (CAS 66482-77-7); diphenyl[4-[[(4-phenylthiophene]thio]phenyl]-sulfonium (CAS 101200-54-8; PF6 salt CAS 101200-55-9); phenylbisphenyl-bis[4-phenylthio)phenyl]-sulfonium (CAS 101200-59-3; PF6 salt CAS 101200-62-8); 5-[4-(phenylthio)phenyl]-thiaanthrannium (CAS 492466-55-4; PF6 salt CAS 492466-56-5); 10-(4-methylphenyl)-9H-thiatonium (CAS 66482-77-7); diphenyl[4-[[(4-phenylthio]thio]phenyl]-sulfonium (CAS 101200-59-3; PF6 salt CAS 101200-62-8); 5-[4-(phenylthio)phenyl]-thiaanthrannium (CAS 101200-54-8 ...PF6 salt CAS 101200-54-8; PF6 salt CAS 101200-54-8; PF6 salt CAS 10 101200-56-0; PF6-salt CAS 101200-63-9); 5-[4-(phenylthio)phenyl]-dibenzothiophenonium (CAS 492466-67-8; PF6-salt CAS 492466-68-9); 10-[4-(diphenylthio)phenyl]-9H-thiatonium (CAS 903907-41-5); 5-phenylthiathracene (CAS 47041-10-1; PF6-salt CAS 82049-30-7); 10-phenyl-9H-thiatonium (CAS 53512-22-4; PF6-salt CAS 132684-14-1); 5-(4-methylphenyl)-thiathracene (CAS 101200-63-9); 47124-94-7; PF6 salt (CAS 337378-41-3); 5-[1,1'-biphenyl]-4-yl-thiaanthranzium (CAS 478774-67-; PF6 salt CAS 591774-04-8); and S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium (CAS 106220-69-3; PF6 salt CAS 106220-70-6). Particularly suitable examples of sulfonium salts used in this invention are commercially available under the names OMNICAT 270 and OMNICAT 432 from IGM, and under the name SpeedCure 992 from Lambson.

[0188] The one or more oxonium salts described herein are preferably pyranium salts, wherein the cationic pyranium moiety includes 2,4,6-triphenylpyranium (CAS 15959-35-0); 2,4,6-tris(4-methylphenyl)-pyranium (CAS 47551-87-1; PF6-salt CAS 1135860-65-9); 2,4,6-tris(4-methoxyphenyl)-pyranium (CAS 47659-08-5; PF6-salt CAS 1135860-65-9); 2,4,6-tris(4-methoxyphenyl)-pyranium (CAS 47659-08-5; PF6-salt CAS 1135860-65-9).1135860-68-2); 2,6-bis(4-fluorophenyl)-4-(4-methoxyphenyl)-pyranium (CAS 1621587-27-6; PF6-salt CAS 2197979-06-7); 3-methyl-2,4,6-triphenyl-pyranium (CAS 33225-59-1; PF6-salt CAS 698360-12-2); 2,4,6-tris([1,1'-biphenyl]-4-yl)-pyranium (CAS 114987-61-0; PF6-salt CAS 477318-03-9); 4-[4-(dimethylamino)phenyl]-2,6-diphenyl-pyranium (CAS 47551-72-4; PF6-salt CAS 2197979-06-7); 118969-07-6); and 2,4-bis(4-methoxyphenyl)-6-phenyl-pyranium (CAS 47589-11-7; PF6-salt CAS 113798-76-8).

[0189] For embodiments in which the UV-Vis radiation-curable printing ink is a mixed UV-Vis radiation-curable printing ink, in addition to one or more vinyl ether-containing compounds, cationic radiation-curable compounds and cationic photoinitiators described herein, the ink also contains one or more radical radiation-curable compounds and one or more radical photoinitiators, wherein the one or more radical radiation-curable compounds are preferably present in a total amount of about 0.5 wt.% to about 30 wt.%, preferably about 1 wt.% to about 25 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0190] The free radical curable compound is cured via a free radical mechanism, which consists of: one or more free radical photoinitiators that release free radicals through energy activation, 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 carbamates (meth)acrylates, silicone (meth)acrylates, acrylic (meth)acrylates, and mixtures thereof.

[0191] Suitable examples of (meth)acrylates include tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof.

[0192] In addition to free radical curable compounds that are tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof, the UV-Vis radiation curable printing inks described herein may further comprise, preferably, mono(meth)acrylates.One or more free radical curable diluents from the group consisting of acrylates, di(meth)acrylates, and mixtures thereof.

[0193] 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 urethane (meth)acrylates, and their alkoxylated (especially ethoxylated or propoxylated) compounds.

[0194] 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.

[0195] Suitable examples of tri(meth)acrylates include, but are not limited to, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane 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...Alkyl triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) glycerol triacrylate, pentaerythritol triacrylate, and mixtures thereof.

[0196] 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)acrylate, alkoxylated pentaerythritol tetra(meth)acrylate, and mixtures thereof.

[0197] 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, benzoin ethers, phosphine oxides, phenyl glyoxylates, coumarins, camphorquinones, and mixtures thereof, more preferably selected from the group consisting of: phosphine oxides, hydroxy ketones, and mixtures thereof, and even more preferably hydroxy ketones. Specification page 21 / 37 24 CN 121773168 A

[0198] 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-methylpropionyl)phenyl]methyl]phenyl]-2-methylprop-1-one; 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)phenoxy]phenyl]-2-methylprop-1-one; and oligomeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone].

[0199] Suitable examples of acetophenones include, but are not limited to, 2,2-diethoxyacetophenone and 2-methoxy-2-phenylacetophenone.

[0200] 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.

[0201] Suitable examples of ketone sulfones include, but are not limited to, 1-[4-(4-benzoylphenylthioalkyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)prop-1-one.

[0202] Suitable examples of benzyl ketals include, but are not limited to, 2,2-dimethoxy-2-phenylacetophenone.

[0203] 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.

[0204] 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-benzopyran-2-one.

[0205] Suitable examples of camphorquinones include, but are not limited to, 1,7,7-trimethyl-bicyclo[2.2.1]heptane-2,3-dione.

[0206] 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.

[0207] Suitable examples of phenylacetoxyesters 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.

[0208] 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 J.V. Crivello & K. Dietliker, edited by G. Bradley, and by JohnPublished jointly by Wiley & Sons and SITA Technology Limited in 1998.

[0209] The UV-Vis radiation-curable printing ink described herein contains one or more 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 and composed of cationic curable ink, page 22 / 37 of CN 121773168 A, the ink contains 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 and composed of a mixed curable ink, the ink comprises a combination of one or more cationic photoinitiators and one or more free 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.

[0210] Optionally, one or more photosensitizers may also be present. The photosensitizers are activated by one or more wavelengths emitted by a UV-Vis light source and reach an excited state. The excited photosensitizers transfer energy to one or more photoinitiators (in free radical polymerization) or electrons (in cationic polymerization). Either process then initiates the polymerization process. The UV-Vis radiation-curable printing ink described herein may further comprise one or more photosensitizers in combination with one or more photoinitiators 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, anthracene compounds, naphthalene compounds, titanoceramsite 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), naphthalene compounds (such as 1,4-diethoxynaphthalene), and mixtures thereof. When present, one or more...The photosensitizer is 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.

[0211] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is a cationic curable printing ink (i.e., comprising a cationic curable compound and one or more cationic photoinitiators), wherein the one or more cationic curable compounds described herein (preferably the cationic curable compounds selected from the group consisting of epoxides, oxetanes and mixtures thereof, more preferably alicyclic epoxides, oxetanes and mixtures thereof) and, when present, the one or more cationic curable epoxy siloxane compounds described herein, are present in a total amount of about 40 wt.% to about 90 wt.%, preferably about 50 wt.% to about 85 wt.%, the weight percentages being based on the total weight of the UV-Vis radiation-curable printing ink.

[0212] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is a mixed-curable ink (i.e., comprising a cationic curable compound, a free radical curable compound, one or more cationic photoinitiators and one or more free radical photoinitiators), wherein the one or more cationic curable compounds described herein (preferably selected from the group consisting of epoxides, oxetanes and mixtures thereof, more preferably alicyclic epoxides, oxetanes and mixtures thereof) and, when present, the one or more cationic curable epoxysiloxane compounds described herein, one or more free radical curable compounds (preferably one or more tri(meth)acrylates and tetra(meth)acrylates described herein) and, when present, the one or more reactive diluents described herein are present in a total amount of about 40 wt.% to about 90 wt.%, preferably about 50 wt.% to about 85 wt.%, based on the total weight of the UV-Vis radiation-curable printing ink.

[0213] The UV-Vis radiation-curable printing inks described herein, particularly the cationic or hybrid UV-Vis radiation-curable screen printing inks described herein, may further contain one or more polyhydroxy compounds. For embodiments in which the UV-Vis radiation-curable printing ink contains 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 from about 1 wt.% to about 15 wt.%, the weight percentage based on the total weight of the 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, which are becoming increasingly popular in the fields of secure documents, particularly banknotes).

[0214] 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 multifunctional compounds.

[0215] 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.

[0216] 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 the compounds, preferably the trimethylolpropane, pentaerythritol, and dipentaerythritol, may be alkoxylated (ethoxylated and / or propoxylated).

[0217] 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 percentages being based on the total weight of the UV-Vis radiation-curable printing ink.

[0218] 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. Preferred carbonates are alkylene carbonates (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 amounts less than about 5 wt.%, more preferably less than about 5 wt.%.A total of 2.5 wt.% is present, the weight percentage being based on the total weight of the UV-Vis radiation-curable printing ink.

[0219] The UV-Vis radiation-curable printing ink 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 the coating composition 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.

[0220] 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:

[0221] i) one or more vinyl ether-containing compounds as described herein, preferably triethylene glycol divinyl ether;

[0222] ii) one or more cationic curable compounds, which are different from the one or more vinyl ether-containing compounds described herein, preferably compounds selected from the group consisting of: cyclic ethers (more preferably cyclic ethers selected from the group consisting of cyclic epoxides as described herein), oxobutanes as described herein, and mixtures thereof;

[0223] iii) one or more cationic photoinitiators, which are hexafluorophosphates as described herein, preferably selected from the group consisting of iodonium hexafluorophosphate compounds, sulfonium hexafluorophosphate compounds, and mixtures thereof;

[0224] iv) optionally one or more cationic curable epoxysiloxane compounds;

[0225] v) optionally one or more solvents; and

[0226] vi) One or more photosensitizers may be selected, preferably from the group consisting of thioxanthone compounds, anthracene compounds, and mixtures thereof,

[0227] wherein,

[0228] one or more vinyl ether-containing compounds (i) are preferably present in a total amount of about 0.1 wt.% to about 25 wt.%, more preferably in a total amount of about 1 wt.% to about 25 wt.%,

[0229] one or more cationic curable compounds (ii) + optional iv) are preferably present in a total amount of about 40 wt.% to about 90 wt.%.The total amount, more preferably, is present in a total amount of about 50 wt.% to about 80 wt.%,

[0230] 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.%,

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

[0232] 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 hybrid UV-Vis radiation-curable inkjet printing ink preferably comprises:

[0233] i) one or more vinyl ether-containing compounds as described herein, preferably triethylene glycol divinyl ether;

[0234] ii) one or more cationic curable compounds, which are different from the one or more vinyl ether-containing compounds described herein, preferably compounds 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;

[0235] iii) one or more cationic photoinitiators, which are hexafluorophosphates described herein, preferably selected from the group consisting of iodonium hexafluorophosphate compounds, sulfonium hexafluorophosphate compounds, and mixtures thereof;

[0236] iv) optionally one or more cationic curable epoxy siloxane compounds;

[0237] v) one or more free radical curable compounds as described herein, preferably free aliphatic epoxy (methyl) compounds. The group consisting of acrylate compounds, more preferably the group consisting of tri(meth)acrylate, tetra(meth)acrylate and mixtures thereof as described herein;

[0238] vi) one or more free radical photoinitiators as described herein, preferably the group consisting of phosphine oxides, hydroxy ketones and mixtures thereof; and

[0239] vii) optionally one or more solvents as described herein,

[0240] wherein,

[0241] one or more vinyl ether-containing compounds (i) are preferably present in a total amount of about 0.1 wt.% to about 25 wt.%, more preferably in a total amount of about 1 wt.% to about 25 wt.%,

[0242] one or more cationic curable compounds (ii) + optionally iv) are preferably present in a total amount of about 40 wt.% to about 90 wt.%, more preferably in a total amount of about 50 wt.% to about 75 wt.%,

[0243] one or more free radical curable compounds (v) are preferably present in a total amount of about 0.5 wt.% to about 30 wt.%. .%, preferably present in a total amount of about 1 wt.% to about 25 wt.%, and

[0244] The total amount of one or more cationic photoinitiators (iii) and one or more free radical photoinitiators (vi) is preferably about 1 wt.% to about 20 wt.%, more preferably about 2 wt.% to about 15 wt.%, as specified in the specification (page 25 / 37, CN 121773168 A).

[0245] The weight percentages are based on the total weight of the mixed UV-Vis radiation-curable inkjet printing inks.

[0246] According to one embodiment, the UV-Vis radiation-curable printing inks described herein are UV-Vis radiation-curable screen printing inks described herein, preferably cationic UV-Vis radiation-curable printing inks, such as those described herein. The cationic UV-Vis radiation-curable screen printing ink preferably comprises:

[0247] i) one or more vinyl ether-containing compounds as described herein, preferably triethylene glycol divinyl ether;

[0248] ii) one or more cationic curable compounds, which are different from the one or more vinyl ether-containing compounds described herein, preferably compounds 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;

[0249] iii) one or more cationic photoinitiators, which are hexafluorophosphates described herein, preferably selected from the group consisting of iodonium hexafluorophosphate compounds, sulfonium hexafluorophosphate compounds, and mixtures thereof;

[0250] iv) optionally one or more polyhydroxy compounds as described herein;

[0251] v) optionally one or more fillers or extenders as described herein;

[0252] vi) optionally one or more solvents as described herein; and

[0253] vii) The photoinitiator may be selected from one or more of the following, preferably from the group consisting of thioxanthone compounds, anthracene compounds and mixtures thereof.

[0254] One or more vinyl ether-containing compounds (i) are preferably present in a total amount of about 0.1 wt.% to about 25 wt.%, more preferably in a total amount of about 1 wt.% to about 25 wt.%.

[0255] One or more cationic curable compounds (ii) are preferably present in a total amount of about 40 wt.% to about 90 wt.%, more preferably in a total amount of about 50 wt.% to about 70 wt.%.

[0256] 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.%.

[0257] The weight percentages are based on the total weight of the cationic UV-Vis radiation-curable screen printing ink.

[0258] According to one embodiment, the UV-Vis radiation-curable printing ink described herein is the UV-Vis radiation-curable ink described herein.Radiation-curable screen printing inks, preferably blends of UV-Vis radiation-curable printing inks, such as those described herein. The mixed UV-Vis radiation-curable screen printing ink preferably comprises:

[0259] i) one or more vinyl ether-containing compounds as described herein, preferably triethylene glycol divinyl ether;

[0260] ii) one or more cationic curable compounds, which are different from the one or more vinyl ether-containing compounds described herein, preferably compounds 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;

[0261] iii) one or more cationic photoinitiators, which are hexafluorophosphates described herein, preferably selected from the group consisting of iodonium hexafluorophosphate compounds, sulfonium hexafluorophosphate compounds, and mixtures thereof;

[0262] iv) 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 described herein;

[0263] v) One or more free radical photoinitiators described herein, preferably selected from the group consisting of free phosphine oxides, hydroxy ketones, and mixtures thereof;

[0264] vi) optionally one or more polyhydroxy compounds described herein;

[0265] vii) optionally one or more fillers or extenders described herein; Specification 26 / 37 pages 29 CN 121773168 A

[0266] viii) optionally one or more solvents described herein; and

[0267] ix) optionally one or more photosensitizers, preferably selected from the group consisting of free thioxanthone compounds, anthracene compounds, and mixtures thereof,

[0268] wherein,

[0269] one or more vinyl ether-containing compounds (i) are preferably present in a total amount of about 0.1 wt.% to about 25 wt.%, more preferably in a total amount of about 1 wt.% to about 25 wt.%,

[0270] One or more cationic curable compounds (ii) are preferably present in a total amount of about 30 wt.% to about 90 wt.%, more preferably in a total amount of about 30 wt.% to about 50 wt.%,

[0271] One or more free radical curable compounds (iv) are preferably present in a total amount of about 0.5 wt.% to about 30 wt.%, more preferably in a total amount of about 1 wt.% to about 25 wt.%, and

[0272] The total amount of one or more cationic photoinitiators (iii) and one or more free radical photoinitiators (v) is preferably about 1 wt.% to about 20 wt.%, more preferably about 2 wt.% to about 15 wt.%,

[0273] The weight percentages are based on the total weight of the mixed UV-Vis radiation-curable screen printing inks.

[0274] The UV-Vis radiation-curable printing inks 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 inks 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, or may be added at a later stage, i.e., after the formation of the liquid coating composition.

[0275] This document also describes the use of the UV-Vis radiation-curable printing inks described herein for manufacturing one or more safety features on safety articles and the safety articles obtained therefrom.

[0276] This document also describes methods for producing safety articles and the safety articles obtained therefrom.

[0277] 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.

[0278] As mentioned above, the one or more security features described herein can be used to protect and identify security articles or decorative elements.

[0279] 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 markings (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 codes include coded identifiers such as coded alphanumeric data, one-dimensional barcodes, two-dimensional barcodes, QR codes, data matrices, and IR read codes.

[0280] 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.

[0281] 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 (pages 27 / 37, 30 CN 121773168 A), provided that the protective layers do not negatively interfere with the Raman spectra of interest of the security features described herein.

[0282] The one or more security features described herein may 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 may 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 may be removed from the one or more security features.

[0283] Alternatively, in another embodiment, an adhesive layer may be present on more than one security feature, or on a substrate containing said feature, the adhesive layer being located on a side of the substrate opposite to the side where more than one security feature is disposed, or on the same side as more than one security feature and above said feature. Thus, an adhesive layer may be applied to more than one security feature or substrate, the adhesive layer being applied 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 containing 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, as described herein, on which more than one security feature is produced. More than one adhesive layer may be applied to the feature thus produced.

[0284] As used herein, the term "substrate" includes any security article substrate on which more than one ink-printed security feature may be applied. The substrates of security products include, but are not limited to, paper or other fibrous materials such as cellulose, paper-containing materials, glass, metals, 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, for example, polyethylene.Polyolefins such as 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 safety 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 may interfere with the properties of more than one surface-enhanced Raman spectroscopy (SERS) tag in the ink described herein. In the event that the substrate exhibits any luminescence property and / or Raman signal, said property should be less than 25,000 au.

[0285] 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.

[0286] 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 typically protected against counterfeiting or alteration by more than one security feature. Security articles include, but are not limited to, articles or documents of value and goods of value. Typical examples of articles or documents of value 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, passes, academic certificates or professional titles, admission tickets, public transport tickets or titles, and agreements. The term "goods of value" 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, which should be protected against counterfeiting and / or illegal copying to ensure the contents of the packaging, such as the instructions for genuine medicines (pages 28 / 37, 31 CN 121773168 A). Examples of these packaging materials include, but are not limited to, labels such as brand identification labels, tamper-evident 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.

[0287] This document also describes a method for identifying one or more safety features and safety articles described herein. For the purpose of identifying one or more safety features and safety articles described herein, Raman spectra of the one or more safety features are measured and obtained prior to their circulation and use, and are recorded as reference Raman spectra. The method for identifying one or more safety features and safety articles described herein includes the following steps:

[0288] a) Providing a security article containing one or more security features described herein, said security features being made of a cured layer made of UV-Vis radiation-curable printing ink described herein;

[0289] b) Irradiating the one or more security features with visible light and / or near-IR light and measuring the SERS spectrum; and

[0290] c) Comparing the SERS spectrum obtained in step b) with a pre-recorded reference Raman spectrum.

[0291] Several modifications to the above-described 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.

[0292] Furthermore, all documents mentioned throughout this specification are incorporated herein by reference in their entirety, as fully set forth herein.

[0293] Examples

[0294] The invention will now be described in more detail with reference to non-limiting examples. The following examples 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.

[0295] Two radical-curable inks are prepared as described herein, wherein said inks are cured with an Hg lamp as described below to produce security features as described herein.

[0296] A safety feature was prepared using a UV-Vis radiation-curable inkjet printing ink, wherein the ink comprises: 20 wt.% DVE-3-TEDGE, 41.8 wt.% DPGDA (Cytec, 1,1'-[oxybis(methyl-2,1-ethanediyl)-2-acrylate, CAS Nr 57472-68-1), 11.0 wt.% Genomer 1120 (Rahn, 3,3,5-trimethylcyclohexyl-2-acrylate, CAS Nr 86178-38-3), and 20.0 wt.% Miramer M410 (Rahn, DiTMPTA, 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 86178-38-3). Nr 94108-97-1), 1.0 wt.% GENORAD 16 (Rahn, a stabilizer for free radical curing inks), 0.1 wt.% TEGO® Rad 2300 (Evonik, a leveling agent), 1.0 wt.% dispersion containing the SERS label, 1.0 wt.% Omnirad 1173 (IGM, 2-hydroxy-2-methyl-1-phenylprop-1-one, CAS 7473-98-5), 5.0 wt.% SpeedCureTPO-L (Lambson, 2,4,6-trimethylbenzoyl-ethoxyphenylphosphine oxide, CAS 84434-11-7) and 0.1 wt.% GENOCURE DETX (Rahn, 2,4-diethyl-thioxanthone, CAS 82799-44-8), with a viscosity of 5.7 mPa·s, were used. The SERS displacement was measured as described below and is shown in Figure 2-1.

[0297] A safety feature was prepared using a UV-Vis radiation-curable radical-curable screen printing ink, wherein the ink comprises: 20 wt.% DVE-3-TEDGE, 16.4 wt.% DPGDA (Cytec, 1,1'-[oxybis(methyl-2,1-ethanediyl)-2-acrylate, CAS Nr 57472-68-1), 20.0 wt.% Miramer M410 (Rahn, DiTMPTA, 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), and 27.0 wt.% Genomer 1120 (Rahn, 3,3,5-trimethylcyclohexyl-2-acrylate, CAS Nr 86178-38-3), 1.0 wt.% GENORAD 16 (Rahn, stabilizer for free radical curing inks, page 29 / 37, CN 121773168 A), 0.1 wt.% TEGO® Rad 2300 (Evonik, leveling agent), 3.6 wt.% CAB-381-0.5 (Eastman™, cellulose acetate butyrate, CAS Nr 9004-36-8), 6.4 wt.% UCAR Ester EEP (Dow, ethyl 3-ethoxypropionate, CAS Nr 763-69-9), 0.5 wt.% dispersion containing the SERS label, 5.0 wt.% Omnirad 1173 (IGM, 2-hydroxy-2-methyl-1-phenyl-1-propanone, CAS Nr 7473-98-5), and has a viscosity of 290 mPa·s. The SERS displacement was measured as described below and is shown in Figure 2-2.

[0298] Examples and comparative examples of UV-Vis radiation-curable inkjet printing inks prepared herein (E1-E7 in Table 1A-1; C1-C15 in Table 1A-2) and examples and comparative examples of UV-Vis radiation-curable screen printing inks (E8-E21 in Table 1B-1; C16-C31 in Table 1B-2) are also described herein.

[0299] Examples E1-E21 and Comparative Examples C1-C31 were prepared by applying UV-Vis radiation-curable printing ink as 5cm×10cm rectangles (E1-E7 (Table 1A-1) and C1-C15 (Table 1A-2)) or as 6cm×10cm rectangles (E8-E21 (Table 1B-1) and C16-C31 (Table 1A-2)) onto a polymer substrate (Guardian® from CCL).

[0300] Examples E1-E21 and Comparative Examples C1-C31 were cured immediately after application using the following methods:

[0301] Hg lamp (TECHNIGRAPH AKTIPRINT MINI (UN50049); 80 W / cm; passing once at 12 m / min, dose: 222 mJ / cm2) (E1, E3-E5, E6-a), E7-E14, E15-a), E17-21; C1-C4, C6-C11, C12-a), C13-a), C14-C24, C25-a), C26-a), C28-C31) or

[0302] LED LUV20 lamp (IST, 385 nm, 40 m / min; passing twice, dose 1080 mJ / cm2) (E2, E6-b), E15- b), E16, C5, C12-b), C13-b), C25-b), C26-b), C27).

[0303] Preparation of dispersion containing SERS tag

[0304] 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.

[0305] 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.

[0306] The resulting 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.

[0307] Flaxseed-based alkyd resin was added to obtain a dispersion of SERS labels in 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.

[0308] Preparation of UV-Vis radiation-curable printing ink

[0309] By using Dispermat(LC220-12) UV-Vis radiation-curable inkjet printing inks E1-E7 and C1-C15 were prepared independently by mixing the components listed above and in Tables 1A-1 and 1A-2 for 20 minutes at room temperature and 1000 rpm. The viscosities of the inks provided in Tables 1A-1 and 1A-2 were measured independently at 45°C using an Anton Paar viscometer (model QC300, rotor B-SC4-21, 250 rpm).

[0310] UV-Vis radiation-curable screen printing inks E8-E21 and C16-C31 were prepared independently by mixing the components listed in Tables 1B-1 and 1B-2 for 10 minutes at 2000 rpm using a Dispermat CV-3. The viscosity of the inks described above and those provided in Tables 1B-1 and 1B-2 was independently measured at 25°C using a Brookfield viscometer (model "DV-I Prime", S27 rotor, 100 rpm).

[0311] Preparation of Printing Safety Features

[0312] The ink layers applied by hand coating were evaluated according to the specification of UV-Vis radiation-curable inkjet printing inks E1-E7 and C1-C15, pages 30 / 37, CN 121773168 A, to facilitate the screening of the inks.

[0313] Figure 1 discloses the Raman shift spectra of UV-Vis radiation-curable inkjet printing ink E1 applied by inkjet printing (2 dpd, 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 approximately 4 μm, (HC)). After curing, the Raman shift spectra of the samples were measured as described below. Figure 1 shows the comparable spectra of the inkjet-printed and hand-coated samples, particularly for inkjet-printed ink coverage of approximately 50%.

[0314] Examples E1-E7 (Table 1A-1) and C1-C15 (Table 1A-2) were all prepared by hand coating using HC 0 bar.

[0315] UV-Vis radiation-curable screen-printing inks E8-E21 and C16-C31 were applied independently by hand screen printing using 77T screens to form layers with a thickness of approximately 22 μm.

[0316] Measurement of SERS Spectra

[0317] The Raman shift spectra of Examples E1-E21 and Comparative Examples C1-C31 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.

[0318] The Raman shift spectra (t0; black curves in Figures 2 to 6) were measured immediately after the curing step.

[0319] The substrate bearing the coating was individually arranged between two glass plates (15cm × 20cm × 0.3cm; 220g each) and stored in an oven at 50°C (10% relative humidity) for 48 hours to simulate the conditions of printed sheets in a substrate stack during the printing process on an industrial printing press.

[0320] 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).

[0321] As shown in Figures 3-1 to 3-7 of Examples E1-E7 (inkjet printing inks from Table 1A-1) and Figures 5-1 to 5-14 of Examples E8-E21 (screen printing inks from Table 1B-1), the spectrum at t48 (gray curve) is similar to the spectrum at t0 (black curve), and in particular, no signal saturation (intensity ≥ 65,000) was observed.

[0322] On the other hand, as shown in Figures 4-1 to 4-15 of Comparative Examples C1-C15 (inkjet printing inks from Table 1A-2) and Figures 6-1 to 6-16 of Comparative Examples C16-C31 (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.

[0323] Ingredients

[0324] DVE-3-TEDGE (BASF): Triethylene glycol divinyl ether [CAS 765-12-8]

[0325] DVE-2 (BASF): Diethylene glycol divinyl ether [CAS 764-99-8]

[0326] CHDVE (BASF): 1,4-bis[(ethoxy)methyl]-cyclohexane [CAS 17351-75-6]

[0327] VEEA (Nippon Shokubai): 2-(2-ethoxyethoxy)ethyl acrylate [CAS 86273-46-3]

[0328] Dynasylan® GLYMO (EVONIK Industries): Glycidyl etheroxypropyltrimethoxysilane [CAS 2530-83-8]

[0329] 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 51728-26-8]

[0330] Photomer® 3016-20G (IGM Resins): Bisphenol A epoxy acrylate [CAS 55818-57-0] and glyceryl[4PO]triacrylate (GPTA) [CAS 52408-84-1]

[0331] PolyolR4631 (Perstorp): 2,2-bis(hydroxymethyl)-1,3-propanediol, 2-methylethylene oxide and cyclooxyethylene polymers [CAS 30374-35-7]

[0332] UviCure S105ES (Lambson): 7-oxabicyclo[4.1.0]hept-3-ylmethyl7-oxabicyclo[4.1.0]heptane-3-carboxylic acid ester [CAS 2386-87-0]

[0333] UviCure S130 (Lambson): 3-ethyl-3-hydroxymethyloxabicyclobutane [CAS 3047-32-3]

[0334] ANTHRACURE® UVS 1331 (Kawasaki Kasei Chemicals Ltd): 9,10-dibutoxy-anthracene [CAS 76275-14-4]

[0335] CHIVACURE® 1176 (CHITEC Technology): Diphenyl(4-phenylthio)phenylsulfonium hexafluoroantimonate [CAS 71449-78-0] and thiodi-4,1-phenylene)bis(diphenylsulfonium)bishexafluoroantimonate [CAS 89452-37-9] in propylene carbonate [CAS 108-32-7]

[0336] IRGACURE® 290 (IGM): Tri-[4-[(4-acetylphenyl)thio]phenyl]sulfonium tetrapentafluorophenyl borate [CAS 1203809-92-0]

[0337] GENOCURE DETX (Rahn): 2,4-diethyl-thioxanthone [CAS 82799-44-8]

[0338] GENOCURE ITX (Rahn): 2-Isopropyl-9H-thioxanth-9-one [CAS 5495-84-1]

[0339] Omnicat 270 (IGM): Tris[4-(4-acetylphenylthioalkyl)phenyl]sulfonium hexafluorophosphate [CAS 953084-13-4] in propylene carbonate [CAS 108-32-7]

[0340] Omnicat 432 (IGM): Diphenyl(4-phenylthio)phenylsulfonium hexafluorophosphate [CAS 68156-13-8] and (thiodi-4,1-phenylene)bis(diphenylsulfonium di-hexafluorophosphate [CAS 747227-35-3] in propylene carbonate [CAS 108-32-7]

[0341] Omnirad 1173(IGM): 2-Hydroxy-2-methyl-1-phenylprop-1-one [CAS 7473-98-5]

[0342] SpeedCure TPO-L (Lambson): 2,4,6-Trimethylbenzoyl-ethoxyphenylphosphine oxide [CAS 84434-11-7]

[0343] SpeedCure CPTX (Lambson): 1-chloro-2-propoxy-thioxanthone [CAS 142770-42-1]

[0344] SpeedCure 976 (Lambson): bis[4-(diphenylsulfonyl)phenyl]sulfide bis(hexafluoroantimonate) [CAS 89452-37-9] and 4-(phenylthio)phenyl diphenylsulfonyl hexafluoroantimonate [CAS 71449-78-0] in propylene carbonate [CAS 108-32-7]

[0345] SpeedCure 992 (Lambson): diphenyl[(phenylthio)phenyl]sulfonyl hexafluorophosphate and S,S'-(thiodi-4- Mixture of 1-(C10-14-alkylphenyl)iodonium hexafluorophosphate in propylene carbonate [CAS 68156-13-8, 74227-35-3, 108-32-7]

[0346] WPI 113 (FUJIFILM Wako Chemicals): bis(C10-14-alkylphenyl)iodonium hexafluorophosphate [CAS 868698-33-3]

[0347] WPI 116 (FUJIFILM Wako Chemicals): bis(decylphenyl)iodonium hexafluoroantimonate [CAS 149759-20-6]

[0348] WPI 124 (FUJIFILM Wako Chemicals): bis(decylphenyl)iodonium tetra-pentafluorophenyl borate [CAS 1791428-74-4]

[0349] AEROSIL® 200 (Evonik): Hydrophilic fumed silica [CAS 7631-86-9]

[0350] BYK-UV 3510 (BYK): Polyether-modified polydimethylsiloxane

[0351] CAB 381-0.5 (Eastmann): Cellulose acetate butyrate [CAS 9004-36-8]

[0352] Propylene carbonate (Brenntag Schweizerhall): [CAS 108-32-7]

[0353] TEGO® Airex 900 (Evonik): Defoamer, instructions for use, pages 32 / 37, CN 121773168 A

[0354] UCAR Ester EEP (DOW): Ethyl 3-ethoxypropionate [CAS 763-69-9]

[0355] Table 1A-1 (Raman shifts are shown in Figures 3-1 to 3-7)

[0356] Specification page 33 / 37, 36 CN 121773168 A

[0357] Table 1A-2 (Raman shifts shown in Figures 4-1 to 4-15)

[0358]

[0359] Table 1B-1 (Raman shifts shown in Figures 5-1 to 5-14) Specification 34 / 37 pages 37 CN 121773168 A

[0360]

[0361] Table 1B-2 (Raman shifts shown in Figures 6-1 to 6-16) Specification 35 / 37 pages 38 CN 121773168 A

[0362]

[0363] Figures 3-1 to 3-7 of E1-E7 (layers made from UV-Vis radiation-curable inkjet printing inks from Table 1A-1) and Figures 5-1 to 5-14 of E8-E21 (layers made from UV-Vis radiation-curable screen printing inks from Table 1B-1) Specification 36 / 37 pages 39 CN As shown in 121773168 A, a cationic and mixed UV-Vis radiation-curable printing ink containing SERS labels, one or more vinyl ether-containing compounds, and one or more cationic photoinitiators as hexafluorophosphates causes 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.

[0364] On the other hand, as shown in Figures 4-1 to 4-15 of C1-C15 (layers made from comparative UV-Vis radiation-curable inkjet printing inks from Table 1B-1) and Figures 6-1 to 6-16 of C16-C31 (layers made from comparative UV-Vis radiation-curable screen printing inks from Table 1B-12), they contain SERS labels, one or more vinyl ether-containing compounds, and hexafluoroantimonate as a derivative of hexafluorophosphates (C1-C10, C12, C14-C15 (Table 1A-2), C16-C23, C25, C27-C28, C30). The presence of one or more cationic photoinitiators (such as tetra(pentafluorophenyl)borate salts) of different anions in C11, C13, C24, C26, C29, and C31, along with mixed UV-Vis radiation-curable printing inks, results in a cured ink layer exhibiting an emission spectrum (grey curve) at t48, indicating signal saturation, i.e., a signal ≥ 65,000 units in at least a portion of the spectrum. (See also: Specification 37 / 37 pages 40 CN 121773168 A Figure 1 Figure 2-1 Specification Figure 1 / 27 pages 41 CN 121773168 A Figure 2-2 Figure 3-1 Specification Figure 2 / 27 pages 42 CN 121773168 A Figure 3-2 Figure 3-3 Specification Figure 3 / 27 pages 43 CN)121773168 A Figure 3-4 Figure 3-5 Instruction Manual Drawings 4 / 27 Page 44 CN 121773168 A Figure 3-6 Figure 3-7 Instruction Manual Drawings 5 / 27 Page 45 CN 121773168 A Figure 4-1 Figure 4-2 Instruction Manual Drawings 6 / 27 Page 46 CN 121773168 A Figure 4-3 Figure 4-4 Instruction Manual Drawings 7 / 27 Page 47 CN 121773168 A Figure 4-5 Figure 4-6 Figure 4-7 Instruction Manual Drawings 8 / 27 Page 48 CN 121773168 A Figure 4-8 Figure 4-9 Instruction Manual Drawings 9 / 27 Page 49 CN 121773168 A Figure 4-10 Figure 4-11 Instruction Manual Drawings 10 / 27 Page 50 CN 121773168 A Figure 4-12 Instruction Manual Drawings 11 / 27 Page 51 CN 121773168 A Figure 4-13 Figure 4-14 Appendix to the Instruction Manual Page 12 / 27 52 CN 121773168 A Figure 4-15 Figure 5-1 Figure 5-2 Appendix to the Instruction Manual Page 13 / 27 53 CN 121773168 A Figure 5-3 Figure 5-4 Appendix to the Instruction Manual Page 14 / 27 54 CN 121773168 A Figure 5-5 Figure 5-6 Appendix to the Instruction Manual Page 15 / 27 55 CN 121773168 A Figure 5-7 Figure 5-8 Appendix to the Instruction Manual Page 16 / 27 56 CN 121773168 A Figure 5-9 Figure 5-10 Appendix to the Instruction Manual Page 17 / 27 57 CN 121773168 A Figure 5-11 Figure 5-12 Appendix to the Instruction Manual Page 18 / 27 58 CN 121773168 A Figure 5-13 Figure 5-14 Instruction Manual Drawings, Page 19 / 27, 59 CN 121773168 A Figure 6-1 Figure 6-2 Instruction Manual Drawings, Page 20 / 27, 60 CN 121773168 A Figure 6-3 Figure 6-4 Instruction Manual Drawings, Page 21 / 27, 61 CN 121773168 A Figure 6-5 Figure 6-6 Instruction Manual Drawings, Page 22 / 27, 62 CN 121773168 A Figure 6-7 Figure 6-8 Instruction Manual Drawings, Page 23 / 27, 63 CN 121773168 A Figure 6-9 Figure 6-10 Instruction Manual Drawings, Page 24 / 27, 64 CN 121773168 A Figure 6-11 Instruction ManualFigure 25 / 27, page 65, CN 121773168 A; Figure 6-12, Figure 6-13, Figure 6-14; Figure 26 / 27, page 66, CN 121773168 A; Figure 6-15, Figure 6-16; Figure 27 / 27, page 67, CN 121773168 A

Claims

1. A UV-Vis radiation-curable printing ink, comprising: i) One or more surface-enhanced Raman spectroscopy (SERS) tags, 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) tags are nanoparticles, and more preferably at least one of the one or more SERS tags contains gold (Au) as a SERS reinforcing material; ii) One or more vinyl ether-containing compounds, in total amounts from about 0.1 wt.% to about 25 wt.%, preferably from about 1 wt.% to about 25 wt.%; iii) one or more cationic radiation-curable compounds, which differ from one or more vinyl ether-containing compounds in ii), wherein the total amount is from about 30 wt.% to about 90 wt.%, preferably from about 30 wt.% to about 85 wt.%; and iv) One or more cationic photoinitiators, independently of hexafluorophosphate, in a total amount of about 1 wt.% to about 20 wt.%, preferably about 2 wt.% to about 15 wt.%. The weight percentage is 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 tags are present in the form of a dispersion, which preferably comprises an alkyd resin and about 10 wt.% to about 30 wt.%, for example 20 wt.%, of the surface-enhanced Raman spectroscopy (SERS) tag, 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, wherein, The one or more vinyl ether-containing compounds are selected from the group consisting of: diethylene glycol divinyl ether, triethylene glycol divinyl ether, cyclohexanediethanol divinyl ether, 2-(2-ethyleneoxyethoxy)ethyl acrylate and 2-(2-ethyleneoxyethoxy)ethyl methacrylate, preferably diethylene glycol divinyl ether, triethylene glycol divinyl ether and 2-(2-ethyleneoxyethoxy)ethyl acrylate.

4. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 3, wherein the ink is selected from the group consisting of: screen printing ink, flexographic printing ink, and non-contact fluid micro-distribution technology ink.

5. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 4, wherein, The one or more cationic radiation-curable compounds iii) are selected from the group consisting of: allyl ethers, silanes, cyclic ethers, lactones, cyclic sulfides, allyl sulfides, and mixtures thereof, preferably cyclic ethers, more preferably epoxides, oxetanes, and mixtures thereof, preferably alicyclic epoxides, oxetanes, and mixtures thereof, and... The one or more cationic photoinitiators are onium salts, preferably selected from the group consisting of iodonium salts, matte salts, and mixtures thereof.

6. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 5, further comprising one or more free radical curable compounds, preferably selected from the group consisting of: tri(meth)acrylate, tetra(meth)acrylate, 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, phosphine oxides, phenyl glyoxylates, coumarins, camphorquinones, and mixtures thereof, preferably hydroxy ketones.

7. The UV-Vis radiation-curable printing ink according to any one of claims 1 to 5, wherein it is a cationic UV-Vis radiation-curable screen printing ink, and further comprises one or more polyhydroxy compounds 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, wherein it is a mixed UV-Vis radiation-curable screen printing ink, and further comprises one or more polyhydroxy compounds and / or 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 5, wherein it 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.

10. The UV-Vis radiation-curable printing ink according to claim 6, wherein it is a mixed UV-Vis radiation-curable inkjet printing ink, and further comprises one or more cationic curable epoxy siloxane compounds.

11. The use of any one of claims 1 to 10 of a UV-Vis radiation-curable printing ink for creating one or more security features on a substrate.

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

13. A safety article comprising a substrate and a radiation-cured coating obtained by UV-Vis radiation curing of a 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 following steps: a. Preferably, the UV-Vis radiation-curable printing ink of any one of claims 1 to 10 is printed on a substrate using a printing method selected from the group consisting of screen printing, flexographic printing, or non-contact fluid micro-dispensing technology, and b. Preferably, the UV-Vis radiation-curable printing ink is UV-Vis radiation-cured using 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 safety features as described in claim 12 and a safety article as described in claim 14, comprising the following steps: a. A safety article as described in claim 14 and comprising one or more safety features as described in claim 12, wherein the one or more safety features are made of a radiation-cured layer made of UV-Vis radiation-curable printing ink as described in any one of claims 1 to 10; b. Illuminate one or more security features with visible light and / or near-IR light, and measure the SERS spectrum. c. Compare the SERS spectrum obtained in step b with the pre-recorded reference Raman spectrum.

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