A 3D printable triply-bonded raman ink, and a preparation method and application thereof

Abstract

The application discloses a 3D printable triply-bonded Raman ink, a preparation method and application thereof. The triply-bonded Raman ink comprises a colorant, a connecting material, a crosslinking agent and a photoinitiator, the colorant is a polymer microsphere, and the branched chain of the polymer comprises a carbon-carbon triple bond or a carbon-nitrogen triple bond. The triply-bonded Raman ink has a strong Raman scattering signal, is invisible to the naked eye, has good stealth effect, and has good stability and is not easy to be imitated. The application realizes controllable arrangement of the Raman active polymer in a limited space by means of the 3D printing technology, and forms a series of super Raman codes.

Description

Technical Field

[0001] This invention belongs to the field of anti-counterfeiting and information security technology, specifically relating to the preparation of a 3D printable, three-bonded Raman ink and its application in anti-counterfeiting and information security. Background Technology

[0002] In recent decades, counterfeit goods and information security issues have become increasingly serious, posing a significant threat to multiple sectors and potentially causing economic instability, public health hazards, and damage to government credibility. Undetectable, unforgeable, and durable anti-counterfeiting measures are crucial for maintaining the integrity and reputation of products, companies, and governments. Materials combining anti-counterfeiting with information storage and traceability capabilities can effectively achieve anti-counterfeiting, traceability, and quality monitoring of goods, ensuring product quality and safety control throughout the entire chain. This provides a strong technical guarantee for establishing a new era of integrity supervision mechanisms. Anti-counterfeiting and traceability systems fall into two categories: one is the traditional type, primarily relying on laser-printed barcodes or QR codes for anti-counterfeiting or encryption; the other is based on rapidly developing optical materials (especially fluorescence), using screen printing or inkjet printing as the manufacturing process to achieve the creation and re-encryption of holographic images for anti-counterfeiting. Analysis of the advantages and disadvantages of the above anti-counterfeiting technologies: Traditional anti-counterfeiting technologies are simple to operate, have low design thresholds, and are extremely easy to read and imitate. They are no longer able to meet the requirements of diversified and personalized effective anti-counterfeiting. To adapt to the needs of the information age, it is urgent to develop new optical material anti-counterfeiting and information storage technologies that are sophisticated in process, responsive to diverse situations, contain massive amounts of information, and are difficult to imitate. Information storage provides a basis for the classification and traceability of diversified commodities. While vigorously developing anti-counterfeiting technologies, research on information storage is also essential, and anti-counterfeiting technologies and information storage using optical materials are complementary. New optical materials can be used for information storage while also serving as emerging anti-counterfeiting materials. Optical information storage mainly relies on optically active materials as a medium to modulate light signals, including intensity (stepped grayscale values), wavelength (wavelength division multiplexing), and time domain (time division multiplexing). Various anti-counterfeiting technologies have been developed in the existing field, significantly improving data security by utilizing advanced encryption algorithms and more complex exposing ink materials. These visible codes are typically made of fluorescent and other luminescent materials, making them invisible under normal conditions. They become visible to the naked eye only after specific treatments, such as exposure to ultraviolet light or high temperatures, thus adding extra security. However, the visibility of these treated codes can be studied and replicated by skilled counterfeiters, reducing their long-term effectiveness. Summary of the Invention

[0003] This invention provides a 3D-printable Raman ink containing triple bonds, its preparation method, and its applications, aiming to solve the problem of counterfeit anti-counterfeiting labels in existing technologies. The anti-counterfeiting labels 3D-printed with the Raman ink containing triple bonds provided by this invention are invisible to the naked eye after any reading process, requiring specialized equipment for detection and reading. Due to their extreme difficulty in counterfeiting or tampering, security is ensured.

[0004] The first aspect of this invention provides a 3D-printable Raman ink containing triple bonds, comprising:

[0005] Colorant, wherein the colorant is a polymer microsphere, and the side chains of the polymer contain carbon-carbon triple bonds or carbon-nitrogen triple bonds;

[0006] The binder is a water-based acrylic resin;

[0007] Crosslinking agent, wherein the crosslinking agent is diethylene glycol ethyl ether acrylate;

[0008] Photoinitiators are used to initiate free radical polymerization reactions of crosslinking agents, binders, and colorants.

[0009] In some embodiments of the present invention, the polymer microspheres have a particle size of 100-200 nm; and / or, the polymer has a number-average molecular weight of 20,000-40,000; and / or, the aqueous acrylic resin has a weight-average molecular weight of 2,000-4,000.

[0010] In some embodiments of the present invention, the mass ratio of colorant, binder and crosslinking agent is 1:1 to 2:0.3 to 0.5.

[0011] In some embodiments of the present invention, the aqueous acrylic resin is polyacrylate and / or polyethylene glycol diacrylate; and / or, the photoinitiator is 2,4,6-phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0012] In some embodiments of the present invention, the viscosity of the triple-bonded Raman ink is ≥6×10⁻⁶. 5 mP·s, surface tension ≤50mN / m.

[0013] A second aspect of the present invention provides a method for preparing the above-mentioned 3D-printable Raman ink containing triple bonds, comprising:

[0014] Provide polymer microspheres, wherein the side chains of the polymer contain carbon-carbon triple bonds or carbon-nitrogen triple bonds;

[0015] The polymer microspheres, binder, crosslinking agent, and photoinitiator are dispersed in a solvent, and the viscosity is adjusted to exceed 6 × 10⁻⁶. 5 With mP·s and a surface tension of less than 50 mN / m, a Raman ink containing triple bonds that can be 3D printed can be obtained.

[0016] The third aspect of this invention provides the application of the above-mentioned 3D printable Raman ink containing three bonds in the field of anti-counterfeiting.

[0017] A fourth aspect of the present invention provides a method for manufacturing a product containing anti-counterfeiting marks, comprising:

[0018] Different parts of the anti-counterfeiting mark are printed using different Raman inks to form multiple anti-counterfeiting mark fragments; after printing, the multiple anti-counterfeiting mark fragments are combined to form a complete anti-counterfeiting mark;

[0019] The Raman ink is the aforementioned 3D printable Raman ink containing triple bonds, and the Raman displacement of polymer microspheres differs between different Raman inks.

[0020] In some embodiments of the present invention, different Raman inks are used to print marking points on different anti-counterfeiting layers, and the marking points on each anti-counterfeiting layer are part of the anti-counterfeiting mark; after printing layer by layer, all marking points form a complete anti-counterfeiting mark. During the printing process, the anti-counterfeiting layers are cured with ultraviolet light.

[0021] This invention is based on the pixel-by-pixel / layer-by-layer printing function of a 3D printer to solidify and form various Raman inks in two-dimensional and three-dimensional space, and its three-dimensional structural pattern is used for anti-counterfeiting codes.

[0022] The fifth aspect of the present invention provides a product containing an anti-counterfeiting mark, comprising multiple anti-counterfeiting layers, each anti-counterfeiting layer having marking dots printed with different Raman inks, the marking dots on each anti-counterfeiting layer being part of the anti-counterfeiting mark, and all marking dots forming a complete anti-counterfeiting mark.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Existing technologies cannot achieve the mass production and high capacity of differentiated anti-counterfeiting labels. However, 3D printing technology can automatically encrypt and prevent counterfeiting information in three-dimensional space, which will greatly expand the coding capacity.

[0025] (2) The three-bonded Raman ink provided by the present invention has no interference with the Raman signal of packaging materials, which facilitates spectral differentiation and rapid decryption.

[0026] (3) The Raman anti-counterfeiting and information encryption strategy provided by the present invention has good spectral stability, can be stored for a long time, and is also convenient to be used as an anti-counterfeiting label for circulation and repeated verification of goods. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention.

[0028] Figure 1A schematic diagram illustrating the preparation of 3D-printable Raman ink containing three bonds and its encryption and decryption for anti-counterfeiting and information security.

[0029] Figure 2 This is a field emission scanning electron microscope image of the polymer used in this invention, wherein the polymer microspheres are uniform spheres with a size of 100-200 nm. Figure 2 (a) to Figure 2 (f) The triple bond Raman signal is 2160 cm⁻¹. -1 2186cm -1 2203cm -1 2227cm -1 2241cm -1 2260cm -1 Polymer microspheres.

[0030] Figure 3 To investigate the optimization of the mixing ratio of each component in a Raman ink containing triple bonds and to obtain the spectral performance diagram of the ink. Figure 3 (a); Surface tension diagrams of mixtures after reaction at different ratios; Figure 3 (b); Viscosity diagrams of mixtures after reaction at different proportions; Figure 3 (c) Comparison of Raman spectra of the prepared triple-bonded Raman ink and triple-bonded polymer; Figure 3 (d) The Raman spectrum stability diagram of the prepared triple-bonded Raman ink.

[0031] Figure 4 These are test diagrams for the stability and reliability of the printed pattern. Among them, Figure 4 (a): A real-life image of a 3D printed multifunctional pattern; Figure 4 (b): Real images of 3D printed QR codes on different substrates; Figure 4 (c): Investigation into the damage resistance of 3D printed patterns, including resistance to high temperature, ultraviolet radiation, water, and erasure. Figure 4 (d): Printed QR code continuous Raman imaging, repeated information verification and comparison images; Figure 4 (e): 3D printed patterns based on reflection, fluorescence, and Raman spectroscopy and their optical verification images; Figure 4 (f): 3D printed fluorescent patterns and their spectra; Figure 4 (g): 3D printed Raman patterns and their spectra; Figure 4 (h): Two Raman inks were used for printing three-dimensional structures;

[0032] Figure 4 (i): Scanning electron microscope images of planar and three-dimensional structural regions; Figure 4 (j): Raman spectra of two Raman inks used in a three-layer structure.

[0033] Figure 5A schematic diagram illustrating the use of spectral, spatial, and logical properties for encryption of Raman inks. Figure 5 (a); Diagram of three authentication keys: Raman code, spatial code, and 6-bit code; Figure 5 (b) The Raman spectra of petal patterns printed with one or six Raman inks containing triple bonds and the different points of the patterns; Figure 5 (c) Schematic diagram of 6-bit code information encoding and decoding based on Raman spectroscopy.

[0034] Figure 6 This is a schematic diagram of the construction of an anti-counterfeiting label based on a three-dimensional embedded invisible Raman code. Figure 6 (a) Schematic diagram of printing the three selected Raman inks layer by layer; Figure 6 (b) Creating a 3D anti-counterfeiting label illustration; Figure 6 (c) A physical image of the prepared three-dimensional anti-counterfeiting label; Figure 6 (b); Schematic diagram of the three-dimensional Raman decryption strategy for three-dimensional anti-counterfeiting labels; Figure 6 (e) Three-dimensional Raman image used for decryption; Figure 6 (f) Diagram of the decryption process of invisible Raman code embedded in the three-dimensional anti-counterfeiting label. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] For simplicity, this document only explicitly discloses certain numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range. Similarly, any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit, combined with any other point or individual value, or combined with other lower or upper limits to form an unspecified range.

[0037] It should be noted that, in the description herein, unless otherwise stated, "above" and "below" include the number itself, and "multiple" in "one or more" means two or more. Relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] In the description of this specification, the references to terms such as "any embodiment / mode," "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0039] The above description of the invention is not intended to describe every disclosed embodiment or implementation. Instead, exemplary embodiments are described in more detail below. These embodiments can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0040] This invention prepares various polymer Raman tags containing triple bonds, which possess the characteristics of a narrow-band (1-2 nm) single peak with high sensitivity, high spectral resolution, and no light interference of Raman signal molecules. Furthermore, the prepared triple-bonded polymers are used as colorants in water-based inks and blended with photocurable prepolymers and other additives to formulate triple-bonded Raman inks suitable for 3D printing. 3D printing technology enables the controllable arrangement of Raman-active polymers in a confined space, forming a series of super Raman codes. Simultaneously, based on the diverse designs of the Raman inks, 3D printing can easily achieve diverse graphics and text printing on various packaging substrates, thereby realizing spectral controllable splicing and encryption encoding in multi-dimensional space. Using Raman spectrometers and imaging technology, the graphic and textual information can be easily decoded. Utilizing the differences in spectral information within the graphics and text, a new and high-capacity anti-counterfeiting and traceability code is provided for various types and types of diversified products. This also provides a strong technical guarantee for the establishment of a new era of integrity supervision mechanisms.

[0041] Including triple-bond Raman ink:

[0042] The 3D-printable Raman ink containing triple bonds provided by this invention includes:

[0043] Colorant, wherein the colorant is a polymer microsphere, and the side chains of the polymer contain carbon-carbon triple bonds or carbon-nitrogen triple bonds;

[0044] The binder is a water-based acrylic resin;

[0045] Crosslinking agent, wherein the crosslinking agent is diethylene glycol ethyl ether acrylate;

[0046] Photoinitiators are used to initiate free radical polymerization reactions of crosslinking agents, binders, and colorants.

[0047] The colorant of the triple-bonded Raman ink provided by this invention is a polymer microsphere formed from a polymer whose side chains contain carbon-carbon triple bonds or carbon-nitrogen triple bonds. The carbon-carbon triple bonds or carbon-nitrogen triple bonds exhibit significant Raman scattering signals, and the Raman intensity of the polymer microspheres is 50 times greater than that of its monomer and 40-60 times greater than that of EdU. Figure 2 b) Therefore, the triple-bonded Raman ink provided by the present invention has a strong Raman scattering signal.

[0048] Raman scattering represents the vibrational characteristics of molecules. Its low cross-section ensures that the Raman scattering signal is invisible to the naked eye, making it particularly suitable for use in stealth coding. The unique Raman spectrum of each molecule allows for highly specific and personalized coding, while the stability of the Raman signal ensures resistance to photobleaching, environmental changes, and other forms of degradation. Therefore, the triple-bond Raman ink provided by this invention ensures high security and durability.

[0049] In some embodiments of the present invention, the polymer microspheres have a particle size of 100–200 nm; and / or, the polymer has a number-average molecular weight of 20,000–40,000; and / or, the aqueous acrylic resin has a number-average molecular weight of 2,000–4,000. Preferably, the polymer has a number-average molecular weight of 25,000–35,000, and the polymer microspheres have a particle size of 150–200 nm.

[0050] In some embodiments of the present invention, the mass ratio of colorant, binder and crosslinking agent is 1:1 to 2:0.3 to 0.5.

[0051] In some embodiments of the present invention, the amount of polyethylene glycol diacrylate added is 20wt% to 30wt% of the triple-bonded Raman ink, and the amount of acrylic resin added is 25wt% to 35wt% of the triple-bonded Raman ink. The viscosity of the triple-bonded Raman ink is ≥6×10⁻⁶. 5 With a surface tension ≤50 mN / m, it exhibits good printing performance. The purpose of adding polyethylene glycol diacrylate 700 (PEGD) to the triple-bonded Raman ink of this invention is to adjust the surface tension of the triple-bonded Raman ink, and the purpose of adding polyacrylate (PAA) is to increase the viscosity of the triple-bonded Raman ink. The amount of polyethylene glycol diacrylate added to the triple-bonded Raman ink of this invention is controlled between 20 wt% and 30 wt%, and the amount of polyacrylate added is controlled between 25 wt% and 35 wt%. The amount of polyethylene glycol diacrylate added is 20 wt%, and the amount of acrylic resin added is 30 wt%.

[0052] In some embodiments of the present invention, the photoinitiator is 2,4,6-phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. This photoinitiator can initiate a polymerization reaction under ultraviolet light irradiation, thereby curing and molding the triple-bonded Raman ink.

[0053] This invention utilizes Raman displacement within the Raman quiescent region (1800–2800 cm). -1 Polymer microspheres, when subjected to various Raman shifts within the Raman quiescent region (1800–2800 cm⁻¹), -1 When polymer microspheres are used, their spectral line combinations can be used to encode information in a complex way, resulting in higher security and codes that are extremely difficult to counterfeit or tamper with. Therefore, the triple-bond Raman ink of this invention can be made into an ideal candidate for high-capacity stealth anti-counterfeiting materials by adding more color options as an additional level of security.

[0054] Preparation method of Raman ink containing triple bonds:

[0055] The present invention provides a method for preparing a 3D-printable Raman ink containing triple bonds, comprising:

[0056] Provide polymer microspheres, wherein the side chains of the polymer contain carbon-carbon triple bonds or carbon-nitrogen triple bonds;

[0057] The polymer microspheres, binder, crosslinking agent, and photoinitiator are dispersed in a solvent, and the viscosity is adjusted to exceed 6 × 10⁻⁶. 5 With mP·s and a surface tension of less than 50 mN / m, a Raman ink containing triple bonds that can be 3D printed can be obtained.

[0058] In some embodiments of the present invention, providing polymer microspheres includes: polymerizing monomers containing both carbon-carbon double bonds and carbon-carbon triple bonds or carbon-nitrogen triple bonds using emulsion polymerization. Polymer microspheres prepared by emulsion polymerization have uniform and controllable size, and the Raman signal intensity of the triple bonds is higher than that of monomers containing both carbon-carbon double bonds and carbon-carbon triple bonds or carbon-nitrogen triple bonds. Specifically, providing polymer microspheres includes: polymerizing monomers containing both carbon-carbon double bonds and carbon-carbon triple bonds or carbon-nitrogen triple bonds in an emulsion containing an emulsifier and an initiator in an oxygen-free atmosphere to obtain polymer microspheres. The polymerization temperature is 60–80°C, and the polymerization time is 1–3 hours. Preferably, the oxygen-free atmosphere is an inert gas atmosphere or a nitrogen atmosphere. The emulsifier is an amphiphilic surfactant, specifically sodium dodecylbenzenesulfonate and / or sodium dodecyl sulfate, and the initiator is potassium persulfate and / or azobisisobutyronitrile.

[0059] This invention utilizes monomers containing both carbon-carbon double and triple bonds, or carbon-nitrogen triple bonds, with the triple bonds comprising an alkynyl group (i.e., a carbon-carbon triple bond) and a cyano group (i.e., a carbon-nitrogen triple bond). The alkynyl group is end-capped and protected by other groups. The triple bonds provide an encrypted Raman signal source, while the double bonds provide the potential for polymerization into polymers. In the presence of an initiator, the double bonds on the monomer participate in the reaction, rapidly polymerizing into polymer microspheres. In some embodiments of this invention, the monomers containing both carbon-carbon double and triple bonds, or carbon-nitrogen triple bonds, are 4-vinylbenzonitrile or acrylonitrile.

[0060] In some embodiments of the present invention, the polymer microspheres, binder, crosslinking agent, and photoinitiator are dispersed in a solvent in the following manner: the polymer microspheres, crosslinking agent, and photoinitiator are dispersed in an aqueous solution of the binder.

[0061] application:

[0062] The colorant in the 3D-printable triple-bond Raman ink provided by this invention is an invisible substance, undetectable to the naked eye. Each molecule possesses a unique Raman spectrum, enabling the creation of highly specific and personalized codes. Therefore, anti-counterfeiting labels made with it are difficult to counterfeit and offer high security. Furthermore, the Raman signal exhibits excellent stability and high resistance to photobleaching, environmental changes, and other forms of degradation. Anti-counterfeiting labels made with the triple-bond Raman ink of this invention can remain stable for a long period.

[0063] like Figure 1As shown, this invention prepares polymer microspheres from monomeric small molecules containing triple bonds, and then uses the polymer microspheres as colorants, adding crosslinking agents, binders, photoinitiators, etc. to formulate 3D printable Raman ink containing triple bonds. The three-dimensional structure code is then automatically prepared using a 3D printer for information encryption and anti-counterfeiting purposes.

[0064] For example, a multi-layered invisible anti-counterfeiting scheme can be achieved by embedding three-bonded Raman ink in layers through 3D printing. The 3D printing system prints two-dimensional planar / three-dimensional spatial patterns (mainly involving QR codes and three-dimensional structural codes representing information). A multi-ink alternating printing strategy is employed, and Raman ink is extruded from a nozzle (60mm) at a speed of 6 seconds per drop by controlling air pressure, printing according to the designed pattern. During the 3D printing process, the printed structure is cured with ultraviolet light at room temperature (wavelength 405nm, power 40mW).

[0065] Manufacturing method of products containing anti-counterfeiting marks:

[0066] The present invention provides a method for manufacturing a product containing anti-counterfeiting marks, comprising: printing different parts of the anti-counterfeiting mark using different Raman inks to form multiple anti-counterfeiting mark fragments; after printing, combining the multiple anti-counterfeiting mark fragments into a complete anti-counterfeiting mark; wherein the Raman ink is the aforementioned 3D printable Raman ink containing triple bonds, and the Raman displacement of the polymer microspheres is different among different Raman inks.

[0067] The anti-counterfeiting mark is a two-dimensional anti-counterfeiting pattern or a three-dimensional anti-counterfeiting pattern.

[0068] In some embodiments of the present invention, different Raman inks are used to print marking points on different anti-counterfeiting layers, and the marking points on each anti-counterfeiting layer are part of the anti-counterfeiting mark; after printing layer by layer, all marking points form a complete anti-counterfeiting mark. During the printing process, the anti-counterfeiting layers are cured with ultraviolet light. Specifically, the anti-counterfeiting layers are cured with ultraviolet light (405nm light, 40mW) at room temperature, and each layer is cured after printing.

[0069] This method embeds multiple layers of invisible anti-counterfeiting codes into Raman ink. These 3D invisible labels possess superior visual transparency, high coding capacity, and exceptional stability. By employing a multi-layer strategy in 3D printing, Raman ink forms multiple layers of visually imperceptible QR codes that cannot be deciphered when examined individually. Their encrypted information is only revealed when all layers are combined, meeting the development requirements for designing highly complex anti-counterfeiting labels and high-capacity coding.

[0070] The technical solution of the present invention will be described in detail below through specific embodiments:

[0071] The 4-vinylbenzonitrile, acrylonitrile, diethylene glycol ethyl ether acrylate, polyacrylate (PAA, Mw = 3000, 50% aqueous solution), and 2,4,6-phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide used in the following examples were purchased from Aladdin Reagents Ltd. (Shanghai, China). Polyethylene glycol diacrylate (PEGD), sodium dodecyl sulfate, and potassium persulfate (KPS) were purchased from Sinopharm Chemical Reagent Co., Ltd. (China). All other chemical reagents used in this invention were analytical grade, obtained from commercial suppliers, and were ready for use without further purification unless otherwise specified.

[0072] Example 1: Synthesis of a polymer with Raman activity

[0073] 50 mg of 4-vinylbenzonitrile (2227 cm) -1 ) or acrylonitrile (2241cm) -1 Dissolve the 4-vinylbenzonitrile in 10 mL of H₂O and place the solutions in separate 50 mL round-bottom flasks. Then, add 1 mL of sodium dodecyl sulfate (2 mg / mL H₂O solution) to the round-bottom flasks and homogenize by stirring (600 rpm) for 30 minutes at room temperature. When the system is heated to 70 °C, add 250 μL of KPS solution (10 mg / mL H₂O solution) to initiate the reaction, and polymerize at 70 °C for 2 hours. Note that the reaction system is always protected with nitrogen to avoid oxygen consumption of the initiator during this process. After the reaction, allow the reaction system to cool naturally to room temperature. The synthesized polymer emulsion is purified with distilled water for three days using a dialysis bag (molecular weight cutoff 3500 Da), with fresh distilled water replaced every 6 hours to remove excess surfactants and other residues. Finally, store the purified latex at 4 °C for further use and characterization. The polymer of 4-vinylbenzonitrile is designated P1, and the polymer of acrylonitrile is designated P2.

[0074] The morphology of polymers P1 and P2 was studied using field emission scanning electron microscopy (FE-SEM, Zeiss Sigma, Germany) at an accelerating voltage of 10.0 kV. The hydrodynamic diameter was measured using a dynamic light scattering instrument (DLS, Zetasizer Nano ZSP, UK). Figure 2 (d) and Figure 2 (e) shows that polymers P1 and P2 have sizes of approximately 150–200 nm, similar particle morphologies, and monodisperse diameters. These measured values ​​are consistent with the hydrodynamic diameter results.

[0075] The molecular weights of polymers P1 and P2 were characterized by gel permeation chromatography (GPC). The number-average molecular weights (Mn) of polymers P1 and P2 were 26,190 and 33,357, respectively; the weight-average molecular weights (Mw) were 73,332 and 71,183, respectively; and the peak molecular weights (Mp) were 68,935 and 81,365, respectively. The polydispersity indices (PDI) were 2.800 and 2.394, respectively, indicating that this invention obtained high-quality polymers with molecular aggregation properties through this free radical polymerization strategy. (The last sentence appears to be incomplete and possibly refers to a specific measurement or measurement.) -1 and 2241cm -1 A significant Raman shift can be observed at this location. Furthermore, the polymer exhibits a sharp Raman peak with a narrow linewidth (<2 nm) and no spectral crosstalk. Positively, the polymer displays stronger triple-bond Raman scattering than its monomers (50 times larger) and EdU (40–60 times larger), indicating that molecular aggregation can effectively enhance the Raman signal.

[0076] Example 2: Synthesis of Raman Ink Containing Triple Bonds

[0077] Under ultrasonic dispersion, 2.0 g of aqueous polyacrylate (Mw = 3000, mass fraction 50%) was added to a 50 mL flask. Then, 3.0 g of polymer P1 or P2, 2 g of polyethylene glycol diacrylate 700, 1 g of diethylene glycol ethyl ether acrylate and 10 mg of 2,4,6-phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were mixed with the aqueous polyacrylate solution to obtain a triple-bond Raman ink.

[0078] The purpose of adding polyethylene glycol diacrylate 700 (PEGD) to triple-bonded Raman inks is to adjust the surface tension of the inks, such as... Figure 3 As shown in (a), this invention adjusted the amount of PEGD added to 10wt%, 20wt%, and 30wt% of the triple-bonded Raman ink. It was found that when the amount of PEGD added was 20wt%, the triple-bonded Raman ink could stably form droplets, meeting the requirements of 3D printing. However, when the amount of PEGD added was 10wt%, although the triple-bonded Raman ink could form droplets, its stability was poor.

[0079] The purpose of adding polyacrylate (PAA) to triple-bonded Raman inks is to increase the viscosity of the ink, prevent nozzle clogging, and ensure continuous filament extrusion, such as... Figure 3 As shown in (b), the present invention adjusts the amount of PAA added to 10wt%, 20wt%, and 30wt% of the triple bond Raman ink. When the amount of PAA added is 30wt%, the triple bond Raman ink has the best 3D printing performance.

[0080] The triple-bonded Raman ink with 20wt% PEGD and 30wt% PAA was placed in the dark for later use. This triple-bonded Raman ink was used in all subsequent experiments.

[0081] Example 3: 3D Printing Experiment

[0082] 3D printing using triple-bonded Raman ink was performed using a pneumatic 3D printer. Multidimensional code was then printed using a microelectromechanical printer (MEMS). Prior to printing, the upper surface of the 3D printing substrate was treated with a vacuum plasma cleaner (cleaning for 300 seconds at 70 Pa and 200 mW) to impart hydrophilicity and facilitate water diffusion. To leverage the advantages of these triple-bonded Raman inks for 3D printing, various patterns were pre-prepared using AutoCAD drawing software and then imported into the 3D printing system to generate printing paths. The triple-bonded Raman ink was extruded from a nozzle (60 mm) at a rate of 6 seconds / drop, controlled by an air compressor of appropriate pressure, and the design pattern was automatically written along a user-defined path, using 60 mm per pixel. During the 3D printing process, UV curing (405 nm light, 40 mW power) was performed on the printed structure at room temperature. To improve curing performance, a post-UV curing process was further performed, treating the printed structure with 405 nm light at 40 mW for 10 minutes. Finally, the 3D-printed structure was ultrasonically cleaned in a 10 wt% NaCl solution for 2 minutes to remove uncured raw materials. Real-time images were acquired by using a digital camera to study the pneumatic / optical control of the continuous 3D printing process.

[0083] To demonstrate the automation of 3D printing, this invention pre-designed and successfully printed various patterns, including circles, squares, complex shapes, and QR codes. Figure 4 a). These inks demonstrate broad printing applicability on traditional packaging materials such as paper, metal, glass, and flexible films. Figure 4 (b) This enhances their potential applications in anti-counterfeiting labels and information storage. The cured pattern exhibits strong high-temperature resistance (100°C), immersion in water for one hour without damage, and easy erasure. Figure 4 c). Furthermore, this invention verifies imaging stability and information traceability. The high precision achieved in a printing process completed within minutes using the machine and ink of this invention is evidenced by the traceability performance when scanning a prepared QR code with a mobile phone. Triple-bonded Raman scattering is the hidden key to information authentication; the QR bright image utilizes the perfect superposition of characteristic triple-bonded peaks with Raman colors (…). Figure 4 d). Raman imaging regions and bright images acquired from Easy Map video show that after five repeated Raman imaging sessions with long-duration laser irradiation, more than 90% of similar Raman images were detected, demonstrating the ultra-stable potential of these Raman inks in terms of reliable information traceability.

[0084] To demonstrate the potential of 3D encryption and decryption, this invention verifies the 3D printing and 3D Raman detection capabilities of anti-counterfeiting labels. Figure 4 e- Figure 4 j). In Figure 4 e- Figure 4 In this study, comparative tests were conducted using a 3D printer equipped with colorimetric, fluorescent, and Raman pigments. The colorimetric and fluorescent pigments exhibited poor penetration and peak recognition in overlapping regions, while the Raman markers displayed distinct peaks, highlighting their superior performance. Furthermore, two Raman inks were alternately pneumatically printed using micro-nozzles. Figure 4 h). The printed pattern exhibits excellent light transmittance, and front and cross-sectional FE-SEM images reveal clearly visible polymer nanoparticles, ensuring 3D Raman detection (h). Figure 4 i). As expected, different triple bond Raman signals were detected in different layers, with Raman signals alternately observed over a thickness range of nearly 1 mm. Figure 4 j). This confirms the potential of 3D writing technology in controlled modulation of triple bond Raman scattering and demonstrates that 3D detection capabilities can provide effective decryption.

[0085] Example 4: Automated Multicolor Raman Pattern Printing and Code Building

[0086] Patterns, as information carriers, can store and hide important information. This invention designs patterns based on various physical stimuli, including spectral, spatial, and logical properties, which can be used for effective verification and to generate multiple unpredictable keys from the same pattern. Figure 5 a). Using the Raman ink of the present invention, centimeter-sized flower patterns can be easily printed on 2D surfaces using one or six Raman inks. Figure 5 (b) The colored flower pattern indicates that the encoding capacity increases with the number of pixels. The Raman image of the flower pattern shows a typical triple-bonded Raman signal at 2227 cm⁻¹.

[0087] To explore the application of Raman ink in information storage, this invention designs a complex encryption system using binary encoding. Six Raman inks, representing binary "1" and "0", are used to encode, store, and decode information. For example, "111111" originates from the simultaneous presence of Raman signals at positions 2160, 2186, 2203, 2227, 2241, and 2260 cm1, while "000000" indicates their absence. This binary encoding is converted into a 6-bit code for information encryption, such as "I love WTU" stored in an invisible mode. Figure 5 c). By matching the spectral output with the corresponding 6-bit code to decrypt the information, identity security and imitation difficulty are enhanced. This is the first time that three-key Raman ink has been used for secure encryption of 6-bit codes.

[0088] Example 5: 3D Stealth Embedded Raman Code Generated by Layer-by-Layer Printing

[0089] The invisible cross-layer code consists of three types of single-layer Raman QR codes, which are printed separately and verified by Raman imaging based on the characteristic peaks at 2160, 2186, and 2227 cm⁻¹. Figure 6 As shown in f, these Raman micrographs can be scanned with a mobile application to read the encoded information displayed on the mobile phone webpages for "Wuhan University", "Wuhan University Center for Graphic Communication, Printing and Packaging Research" and "Shenlab".

[0090] The 3D invisible embedded code was created by alternating layers printed with three different Raman inks (2160, 2186 and 2160, 2227 cm). Each ink layer was printed after photocuring and stacked on top of the previous layer. A total of six rounds of printing were performed to generate the final code. Within each layer, the encoding logic for each pixel was defined as follows: ink ejection equals "1", no ejection equals "0" (layer 1). This process was then repeated with another Raman ink for the next layer (layer 2). Although the code for each layer was printed simultaneously, the information was distributed across different layers due to the inconsistent thickness of the preceding encoded layers. Therefore, the correct code was "hidden" in different layers and could only be traced when layers were combined. Figure 6 e). Scanning each layer of code individually will not produce the correct information. Figure 6 f). Notably, each Raman image in the 3D pattern captured from different layers and Raman channels exhibits unique characteristics. Image similarity analysis shows that the similarity between different Raman images is only around 50%. This low image similarity will greatly deter counterfeiters. This 3D Raman integrated encryption system is not only invisible to the naked eye after reading and processing, but also renders single-layer decoding ineffective, requiring multiple layers to unlock the encryption. Due to the exceptional difficulty of counterfeiting, it ensures the highest level of security.

[0091] Example 6: Generation of Physically Unclonable Function (PUF) for Anti-counterfeiting

[0092] This invention discovers that red images gradually darken with depth, green images gradually brighten, and blue images are initially bright and then darken, which closely matches the 3D printing sequence in 3D codes. Inspired by the different Raman images within different layers of this 3D pattern, the PFU system can further generate ID cards from red, green, and blue codes with different Raman channels and unknown spatial locations. Figure 6 d) This represents the highest level of anti-counterfeiting technology currently available.

[0093] The application of this 3D label in the supply chain begins with manufacturing by manufacturers and distributors, followed by packaging for end users. Products are labeled as unique ID codes after leaving the manufacturer. This process is initially monitored by a public database of manufacturers and labels. Subsequently, the correct Raman code can be authenticated throughout the product's circulation, digitized via software, and stored in the public database. In the future, with upgrades to mobile Raman systems, end users of this invention will also be able to easily verify each product in a personal database closely linked to the public database. If the digital information does not match any information in the database, it will be considered counterfeit.

[0094] Example 7:

[0095] Although spectral overlap may occur in the 400–1800 cm⁻¹ region due to various ink compositions and substrates (such as paper, glass, and flexible films), triple-bonded Raman inks effectively write and express Raman information on common substrates in the 1800–2800 cm⁻¹ region without interference. The present invention then characterized the environmental stability of the Raman inks. After multiple light treatments over more than a month, the Raman spectra of all Raman inks remained stable, exhibiting excellent photostability compared to other optical materials. These Raman-active polymers exhibit greater spectral stability than SERS tags and common fluorescent dyes.

[0096] The above are merely specific embodiments of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for manufacturing a product containing anti-counterfeiting marks, characterized in that, include: Different Raman inks are used to print marking points on different anti-counterfeiting layers. The marking points on each anti-counterfeiting layer are part of the anti-counterfeiting mark. After printing layer by layer, all the marking points form a complete anti-counterfeiting mark. The Raman ink is a 3D printable Raman ink containing triple bonds, which comprises: Colorant, wherein the colorant is a polymer microsphere, and the side chains of the polymer contain carbon-carbon triple bonds or carbon-nitrogen triple bonds; The binder is a water-based acrylic resin; the water-based acrylic resin is polyacrylate and polyethylene glycol diacrylate, the amount of polyethylene glycol diacrylate added is 20wt% to 30wt% of the triple bond Raman ink, and the amount of polyacrylate added is 25wt% to 35wt% of the triple bond Raman ink. Crosslinking agent, wherein the crosslinking agent is diethylene glycol ethyl ether acrylate; Photoinitiators are used to initiate free radical polymerization reactions of crosslinking agents, binders, and colorants. The viscosity of the triple-bonded Raman ink is ≥6×10⁻⁶. 5 mPa·s, surface tension ≤50 mN / m; The Raman shifts of polymer microspheres differ between different Raman inks.

2. The method for manufacturing a product containing anti-counterfeiting marks according to claim 1, characterized in that: The polymer microspheres have a particle size of 100–200 nm.

3. The method for manufacturing a product containing anti-counterfeiting marks according to claim 1, characterized in that: The number-average molecular weight of the polymer is 20,000 to 40,000.

4. The method for manufacturing a product containing anti-counterfeiting marks according to claim 1, characterized in that: The weight-average molecular weight of the waterborne acrylic resin is 2000-4000.

5. The method for manufacturing a product containing anti-counterfeiting marks according to claim 1, characterized in that: The mass ratio of colorant, binder, and crosslinking agent is 1:1 to 2:0.3 to 0.

5.

6. The method for manufacturing a product containing anti-counterfeiting marks according to claim 1, characterized in that: The photoinitiator is 2,4,6-phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

7. A product containing anti-counterfeiting markings, characterized in that: It contains multiple anti-counterfeiting layers, each with different Raman ink-printed markings. The markings on each layer are part of the anti-counterfeiting mark, and all the markings together form a complete anti-counterfeiting mark. The Raman ink is a 3D printable Raman ink containing triple bonds, which comprises: Colorant, wherein the colorant is a polymer microsphere, and the side chains of the polymer contain carbon-carbon triple bonds or carbon-nitrogen triple bonds; The binder is an aqueous acrylic resin; the aqueous acrylic resin is polyacrylate and polyethylene glycol diacrylate, wherein the amount of polyethylene glycol diacrylate added is 20wt% to 30wt% of the triple bond Raman ink and the amount of polyacrylate added is 25wt% to 35wt% of the triple bond Raman ink. Crosslinking agent, wherein the crosslinking agent is diethylene glycol ethyl ether acrylate; Photoinitiators are used to initiate free radical polymerization reactions of crosslinking agents, binders, and colorants. The viscosity of the triple-bonded Raman ink is ≥6×10⁻⁶. 5 mPa·s, surface tension ≤50 mN / m; The Raman shifts of polymer microspheres differ between different Raman inks.

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