Long-lasting anti-counterfeiting ink composition and preparation method thereof

Abstract

The present invention discloses a visible light-excited long-afterglow optical ink for anti-counterfeiting and a preparation method thereof. The ink is prepared from a long-afterglow luminescent nanopowder and a thermoplastic compound resin. The mass ratio of the long-afterglow luminescent nanopowder to the thermoplastic compound resin is 1:2-10. The excitation light of the long-afterglow luminescent nanopowder is ultraviolet light and / or visible light, with an emission wavelength of 500-530nm, and has a cyan, green, or yellow-green long afterglow. The thermoplastic compound resin has a solid content of 30-50% and a softening point of 80-130°C. The invention is simple to manufacture, easy to identify for anti-counterfeiting, expands the capacity of encrypted information, and is innovative and environmentally friendly. It invents a tunable multiple encryption method. By regulating the luminescent properties of the long-afterglow luminescent nanopowder, multiple information encryption anti-counterfeiting applications are achieved. This has profound research significance and broad application prospects for avoiding the interference of fluorescence on anti-counterfeiting applications and expanding the forms of anti-counterfeiting encryption.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-counterfeiting inks, and in particular relates to a long-afterglow anti-counterfeiting ink composition and a preparation method thereof. Background Art

[0002] In today's era of globalization and digitalization, the demand for product anti-counterfeiting technology is growing. However, the existing anti-counterfeiting methods have single encryption technology, limited information storage capacity, low security, and are easy to crack and copy. Therefore, the development of new, efficient, and difficult-to-copy anti-counterfeiting technologies has become an urgent problem that needs to be solved. As an advanced anti-counterfeiting method today, photoluminescent anti-counterfeiting ink has the advantages of high visibility, diverse effect selection, difficulty in forging and imitating, integrability and diversity, real-time verification and non-destructive detection, and therefore has broad application prospects in the field of anti-counterfeiting. However, most of the current photoluminescent ink materials have problems such as being environmentally unfriendly and high cost, and most of them are fluorescent anti-counterfeiting with serious substrate interference, making it difficult to carry out high-level, multi-content encryption methods, all of which limit its further application.

[0003] As a photoluminescent material that stores the energy of excitation light, long afterglow materials can continue to emit light after the excitation light stops. Among them, carbon dot materials have superior optical properties, such as light conversion and reversible dynamic optical characteristics, and have advantages such as wide source, low cost, and green environmental protection. First, the long afterglow phenomenon of carbon dots can be used for encryption; second, the stimulus-response properties of the material can be used to realize anti-counterfeiting encryption functions. It expands the capacity of encrypted information, innovates environmentally friendly methods, and invents tunable multiple encryption methods. Through the research and development of long afterglow materials and the exploration of the relationship between the luminescence properties of materials and anti-counterfeiting applications, long afterglow carbon dot anti-counterfeiting inks that can be excited by visible light are synthesized to avoid the interference of fluorescent background on anti-counterfeiting applications. Mobile phone light sources can be used for anti-counterfeiting identification, making anti-counterfeiting identification convenient and feasible. The research and development of long afterglow materials has profound research significance and broad application prospects in anti-counterfeiting applications. Summary of the Invention

[0004] The present invention aims to overcome the defects of the prior art and provide a long-lasting anti-counterfeiting ink composition.

[0005] Another object of the present invention is to provide a method for preparing the long afterglow anti-counterfeiting ink composition.

[0006] The technical solutions of the present invention are as follows:

[0007] A long-lasting anti-counterfeiting ink composition is prepared from long-lasting luminescent nanopowder and thermoplastic compound resin, wherein the ratio of the long-lasting luminescent nanopowder to the thermoplastic compound resin is 1:2-10;

[0008] The excitation light of the long afterglow luminescent nanopowder is ultraviolet light and / or visible light, the emission wavelength is 500-530nm, and it has a long afterglow of cyan, green or yellow-green;

[0009] The thermoplastic compound resin has a solid content of 30-50% and a softening point of 80-130°C, and includes at least one of ternary chloroacetic acid resin, polyester resin, aldehyde ketone resin, polystyrene, epoxy resin, petroleum resin, chlorinated polypropylene resin, polyurethane resin, rosin resin, and polyamide resin.

[0010] In some possible implementations, the long afterglow luminescent nanopowder is a carbon dot-melamine complex.

[0011] In some possible implementations, the carbon source of the carbon dot-melamine complex is at least one of m-phenylenediamine, acridine yellow, and acridine orange.

[0012] In some possible implementations, the thermoplastic compound resin is compounded from polyurethane resin, polystyrene resin and vinyl chloride resin.

[0013] In some possible implementations, the ratio of acrylic resin, polyvinyl chloride resin and polyurethane resin is 5:1.25:1.25.

[0014] In some possible implementations, the particle size of the long afterglow luminescent nanopowder is less than 800 mesh.

[0015] In some possible implementations, the method for preparing long-lasting luminescent nanopowders includes:

[0016] A. mixing a carbon source, a phosphate of the carbon source, and ethanol, performing a hydrothermal reaction at 180° C. for 12 h, centrifuging, and filtering to obtain a carbon dot filtrate, wherein the carbon source is at least one of m-phenylenediamine, acridine yellow, and acridine orange;

[0017] B. Mix the carbon dot filtrate, melamine, water and ethanol, and heat with stirring at 150-250°C for 3 hours. Filter and remove the solvent to obtain the long afterglow luminescent nanopowder.

[0018] In some possible implementations, the molar ratio of the carbon source to the phosphate of the carbon source in step A is 1:10-40.

[0019] In some possible implementations, the mass volume ratio of the carbon dot filtrate, melamine, water, and ethanol in step B is 2 mL:1.5 g:15 mL:5 mL.

[0020] The method for preparing the long afterglow anti-counterfeiting ink composition comprises: uniformly mixing long afterglow luminescent nanometer powder and thermoplastic compound resin.

[0021] The beneficial effects of the present invention are:

[0022] 1. The invention is simple to manufacture, easy to identify anti-counterfeiting, expands the capacity of encrypted information, is innovative and environmentally friendly, and invents a tunable multiple encryption method. By regulating the luminescence properties of long-afterglow luminescent nanopowders, multiple information encryption anti-counterfeiting applications are realized. It has profound research significance and broad application prospects for avoiding the interference of fluorescence on anti-counterfeiting applications and expanding anti-counterfeiting encryption forms.

[0023] 2. The long-lasting luminescent nanopowders of this invention can replace traditional luminescent materials, reducing costs, simplifying preparation, and being environmentally friendly. Combining long-lasting luminescence, multi-color luminescence, and stimulated luminescence, they are expected to develop into a new generation of environmentally friendly, multi-dynamic anti-counterfeiting optical anti-counterfeiting materials with high capacity, high resolution, and environmentally friendly properties.

[0024] 3. The long afterglow luminescent nanopowder of the present invention can be used in ink compositions to realize reusable and tunable dynamic anti-counterfeiting applications; the dual-color can enhance the visual anti-counterfeiting effect; and the use of ultraviolet light source and / or visible light source excitation can meet the requirements of concealed, portable, and easy anti-counterfeiting identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 These are digital photos of three different colors of long-lasting luminescent nanopowders prepared in Examples 1-3 under visible light and ultraviolet light, from left to right: long-lasting luminescent nanopowders A, B, and C;

[0026] Figure 2 Figures (a) and (b) are afterglow excitation spectra and emission spectra of three different colors of long afterglow luminescent nanopowders A, B, and C prepared in Examples 1-3 in the visible light band, wherein MPDCDs-MA represents long afterglow luminescent nanopowder A or long afterglow anti-counterfeiting ink composition A, AYCDs-MA represents long afterglow luminescent nanopowder B or long afterglow anti-counterfeiting ink composition B, and AOCDs-MA represents long afterglow luminescent nanopowder C or long afterglow anti-counterfeiting ink composition C, and the same applies hereinafter;

[0027] Figure 3 The long afterglow luminescent powders A, B, and C prepared in Examples 1-3 were mixed with polystyrene and coated, and afterglow was visible to the naked eye after drying;

[0028] Figure 4 The afterglow emission spectra of the long afterglow anti-counterfeiting ink compositions A, B, and C prepared in Examples 1-3 in different acidic and alkaline environments, (a) is the long afterglow luminescent nanopowder A, (b) is the long afterglow luminescent nanopowder B, and (c) is the long afterglow luminescent nanopowder C;

[0029] Figure 5These are the anti-photobleaching images of the long-lasting anti-counterfeiting ink compositions A, B, and C prepared in Examples 1-3, (a) is the long-lasting luminescent nanopowder A, (b) is the long-lasting luminescent nanopowder B, and (c) is the long-lasting luminescent nanopowder C;

[0030] Figure 6 These are the photostability diagrams of the long afterglow anti-counterfeiting ink compositions A, B, and C prepared in Examples 1-3, (a) is the long afterglow luminescent nanopowder A, (b) is the long afterglow luminescent nanopowder B, and (c) is the long afterglow luminescent nanopowder C. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further illustrated and described below through specific implementation methods in conjunction with the accompanying drawings.

[0032] In the process of preparing the long-afterglow luminescent nanopowder in Example 1-3, the powder is ground and filtered to a particle size of less than 800 mesh. This step is mainly to make the ink smoother and improve the printing quality. However, the particle size does not affect the long-afterglow characteristics of the long-afterglow luminescent nanopowder and should not be regarded as a limitation to the technical solution.

[0033] Example 1: Preparation of long-lasting anti-counterfeiting ink composition A

[0034] (1) Preparation of long-lasting luminescent nanopowder A

[0035] A. Add a mixture of m-phenylenediamine (MPD), m-phenylenediamine phosphate, and ethanol into a reaction vessel, hydrothermally react at 180°C for 12 hours, centrifuge, and filter to obtain a carbon dot filtrate; wherein the molar ratio of m-phenylenediamine to m-phenylenediamine phosphate is 1:40;

[0036] B. Add 1.5g melamine, 5mL ethanol and 15mL water to 2mL of the above carbon dot filtrate, mix, hydrothermal at 200℃ with stirring for 3h, grind to 800 mesh, filter and obtain long afterglow luminescent nanopowder A. Figure 1 As shown, the long afterglow luminescent nanopowder A is yellow powder under fluorescent light and exhibits blue-green fluorescence under ultraviolet light radiation.

[0037] (2) Preparation of thermoplastic compound resin: polyurethane resin U335, polystyrene resin PS525 and chloroacetic acid resin VA6178 in a mass ratio of 5:1.25:1.25 were softened at 80-130°C to prepare a thermoplastic compound resin with a solid content of 40% and a softening point of 90°C;

[0038] (3) Preparation of long afterglow anti-counterfeiting ink composition A: The long afterglow luminescent nanopowder A and the thermoplastic compound resin are mixed in a mass ratio of 1:1 to 1:10, and the mixture is shaken with an oscillator to obtain the long afterglow anti-counterfeiting ink composition A.

[0039] Example 2: Preparation of long afterglow anti-counterfeiting ink composition B

[0040] (1) Preparation of long afterglow luminescent nanopowder B:

[0041] A. Add a mixture of acriflavine (AY), acriflavine phosphate, and ethanol into a reaction vessel, hydrothermally react at 180°C for 12 hours, centrifuge, and filter to obtain a carbon dot filtrate; wherein the molar ratio of acriflavine to acriflavine phosphate is 1:40;

[0042] B. Add 1.5 g of melamine, 5 mL of ethanol, and 15 mL of water to 2 mL of the above carbon dot filtrate, mix, and hydrothermal at 200°C with stirring for 3 h. Grind to 800 mesh, and filter to obtain long afterglow luminescent nanopowder B (AYCDs-MA). Figure 1 As shown, the long afterglow luminescent nanopowder B is a yellow powder under a fluorescent lamp and exhibits yellow-white fluorescence under ultraviolet light radiation.

[0043] (2) Preparation of thermoplastic compound resin: polyurethane resin U335, polystyrene resin PS525 and vinyl chloride resin VA6178 in a mass ratio of 5:1.25:1.25 were softened at 80-130°C to prepare a thermoplastic compound resin with a solid content of 40% and a softening point of 90°C;

[0044] (3) Preparation of long afterglow anti-counterfeiting ink composition B: The long afterglow luminescent nanopowder B and the thermoplastic compound resin are mixed in a mass ratio of 1:5, and the mixture is shaken with an oscillator to obtain the long afterglow anti-counterfeiting ink composition B.

[0045] Example 3: Preparation of long afterglow anti-counterfeiting ink composition C

[0046] (1) Preparation of long afterglow luminescent nanopowder C:

[0047] A. Add acridine orange (AO), acridine orange phosphate, and ethanol into a reaction vessel, hydrothermally react at 180°C for 12 hours, centrifuge, and filter to obtain a carbon dot filtrate; wherein the molar ratio of acridine orange to acridine orange phosphate is 1:40;

[0048] B. Add 1.5 g of melamine, 5 mL of ethanol, and 15 mL of water to 2 mL of the above carbon dot filtrate, mix, and hydrothermal at 200°C with stirring for 3 h. Grind to 800 mesh, and filter to obtain long-lasting luminescent nanopowder C (AOCDs-MA). Figure 1 As shown, the long afterglow luminescent nanopowder C is orange powder under fluorescent light and exhibits yellow-green fluorescence under ultraviolet light radiation.

[0049] (2) Preparation of thermoplastic composite resin: polyurethane resin U335, polystyrene resin PS525 and vinyl chloride resin VA6178 in a mass ratio of 5:1.25:1.25 were softened at 80-130°C to prepare a thermoplastic composite resin with a solid content of 40 wt% and a softening point of 90°C;

[0050] (3) Preparation of long afterglow anti-counterfeiting ink composition C: The long afterglow luminescent nanopowder C and the thermoplastic compound resin are mixed at a mass ratio of 1:5, and the mixture is shaken with an oscillator to obtain the long afterglow anti-counterfeiting ink composition C.

[0051] Example 4: Optical Response of Long-Afterglow Anti-Counterfeiting Ink Composition on Different Printing Substrates

[0052] The long-afterglow anti-counterfeiting ink compositions A and B prepared in Example 1 and Example 2 were respectively printed on two common label papers (long-afterglow anti-counterfeiting ink composition A was printed on a white companion label paper, and long-afterglow anti-counterfeiting ink composition B was printed on a silver label paper). After irradiation with a fluorescent lamp and an ultraviolet lamp (365nm) and then turning off the light source, clear fluorescent patterns were visible. This shows that the long-afterglow anti-counterfeiting ink composition can be used on different printing substrates and can avoid fluorescence interference on printing substrates with fluorescent reactions, thereby achieving multiple encryption and meeting various printing needs.

[0053] Example 5: Optical properties of long-lasting luminescent nanopowders in the visible band

[0054] This example characterizes the optical properties of the long-lasting luminescent nanopowders A, B, and C prepared in Examples 1-3. The scanning speed is preferably 240 nm / min; the excitation slit ratio to the emission slit is preferably 5 nm:10 nm; the response time is preferably 2 s; the extension time is preferably 0 s; and the PMT voltage is preferably 700 V.

[0055] like Figure 2 As shown, the optimal optical response excitation wavelengths corresponding to the three long afterglow luminescent nanopowders A, B and C are 470nm, 473nm and 500nm, and the optical response emission wavelengths are 500nm, 510nm and 535nm respectively.

[0056] Example 6: Visible afterglow time of the long afterglow anti-counterfeiting ink composition

[0057] The long afterglow luminescent nanopowders A, B, and C prepared in Examples 1-3 were mixed with 40 wt% of polystyrene to obtain a long afterglow anti-counterfeiting ink. The ink was irradiated with a mobile phone flashlight (visible light) for 10 seconds, and then the light source was turned off. Figure 3As shown, A emits a cyan-green color for several seconds, B emits green for several seconds, and C emits a yellow-green color with a long afterglow. All three materials also exhibit a persistent glow for several seconds after visible light is turned off. The three long-afterglow anti-counterfeiting inks generally have an afterglow of approximately 8 seconds after UV excitation and approximately 4 seconds under visible light excitation.

[0058] Example 7: Luminescence of the long afterglow anti-counterfeiting ink composition in an acidic and alkaline environment

[0059] Long afterglow anti-counterfeiting ink compositions may encounter various solvent interferences in actual anti-counterfeiting applications. If the performance of the long afterglow anti-counterfeiting ink compositions is affected, the application will be affected. In this example, the long afterglow anti-counterfeiting ink compositions A, B, and C prepared in Examples 1-3 were transferred onto label paper, and then water, sulfuric acid (pH=2), and sodium hydroxide alkaline solution (pH=9) were added dropwise to the label paper surface to observe the afterglow luminescence after irradiation with ultraviolet light. Figure 4 As shown in Figure (a), the afterglow of long-lasting anti-counterfeiting ink composition A is significantly affected by acid and alkali conditions, but the afterglow is still observable. The long-lasting anti-counterfeiting ink compositions B and C, shown in Figures (b) and (c), exhibit stable luminescence and are not easily affected by acid and alkali conditions. This demonstrates that the long-lasting anti-counterfeiting ink compositions prepared in Examples 1-3 can be used for information anti-counterfeiting in real production and life, as well as in extreme environments.

[0060] Example 8: Long-lasting anti-counterfeiting ink composition resists light interference

[0061] The photobleaching resistance of the long afterglow luminescent nanopowders A, B, and C prepared in Examples 1-3 was tested: a certain amount of long afterglow luminescent nanopowders A, B, and C were placed in a powder sample tank, and irradiated continuously for 60 minutes under a 360nm xenon lamp light source. The afterglow spectra of the long afterglow luminescent nanopowders A, B, and C before and after irradiation were measured to explore the effect of ultraviolet light irradiation time on the afterglow intensity. The experimental results are shown in FIG. Figure 5 As shown, long-term continuous illumination does not affect the optical properties of the material, and the optical properties of the long afterglow anti-counterfeiting ink compositions A and B are stable.

[0062] The photostability of long afterglow anti-counterfeiting ink compositions A, B, and C was tested: labels were printed with long afterglow anti-counterfeiting ink compositions A, B, and C and placed in the air for 50 days. The afterglow spectra were measured every 10 days. The results are as follows: Figure 6 It can be seen that the afterglow intensity of the three changed very little within 50 days, indicating that repeated light stimulation does not affect the optical properties of the long afterglow anti-counterfeiting ink composition, and the long afterglow anti-counterfeiting ink compositions A and B can be reused.

[0063] The above description is merely a preferred embodiment of the present invention and therefore cannot be used to limit the scope of the present invention. In other words, equivalent changes and modifications made according to the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. Use of a long afterglow anti-counterfeiting ink composition in reusable tunable dynamic anti-counterfeiting, characterized in that: The long afterglow anti-counterfeiting ink composition is prepared from long afterglow luminescent nanopowder and thermoplastic compound resin, wherein the mass ratio of the long afterglow luminescent nanopowder to the thermoplastic compound resin is 1:2-10; The excitation light of the long afterglow luminescent nanopowder is visible light with an emission wavelength of 500-530nm, and has a long afterglow of cyan, green or yellow-green; The long-lasting luminescent nanopowder is a carbon dot-melamine complex, the carbon source of the carbon dot-melamine complex is at least one of m-phenylenediamine, acridine yellow, and acridine orange, the phosphate of the carbon source is at least one of m-phenylenediamine phosphate, acridine yellow phosphate, and acridine orange phosphate, and the preparation method of the carbon dot-melamine complex comprises: A. Mixing a carbon source, a phosphate of the carbon source, and ethanol, hydrothermally reacting at 180° C. for 12 h, centrifuging, and filtering to obtain a carbon dot filtrate, wherein the molar ratio of the carbon source to the phosphate of the carbon source is 1:10-40; B. Mix the carbon dot filtrate, melamine, water and ethanol, and heat them at 150-250° C. with stirring for 3 h. Filter and remove the solvent to obtain the long afterglow luminescent nanopowder. The mass volume ratio of the carbon dot filtrate, melamine, water and ethanol is 2 mL:1.5 g:15 mL:5 mL. Thermoplastic compound resin, with a solid content of 30-50% and a softening point of 80-130°C, is compounded from polyurethane resin, polystyrene resin and ternary chloroacetic acid resin.

2. The use according to claim 1, characterized in that The particle size of the long afterglow luminescent nano powder is less than 800 meshes.

3. The use according to claim 1 or 2, characterized in that The preparation method of the long afterglow anti-counterfeiting ink composition comprises: uniformly mixing the long afterglow luminescent nano powder and the thermoplastic compound resin.

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