Optical anti-forgery ink as well as preparation method and application thereof

Abstract

The invention relates to the technical field of optical anti-forgery, in particular to optical anti-forgery ink and a preparation method and application thereof.The optical anti-forgery ink comprises pigment and a curable gloss oil mixture, the pigment comprises magnetic photonic crystal optically variable pigment and flaky magnetic optically variable pigment, the pigment is uniformly dispersed in the curable gloss oil mixture. According to the optical anti-counterfeiting ink disclosed by the invention, by mixing the magnetic photonic crystal optically variable pigment and the flaky magnetic optically variable pigment, the overall brightness of an anti-counterfeiting pattern is ensured, and the structural color of the photonic crystal can be well presented, so that the overall pattern also has relatively high resolution and finer color, and has a higher anti-counterfeiting effect. An optical anti-counterfeiting pattern printed by adopting the optical anti-counterfeiting ink disclosed by the invention has a relatively high resolution, a finer color and a higher-grade anti-counterfeiting effect, and in addition, the anti-counterfeiting pattern has different colors and shapes under different visual angles, so that the optical anti-counterfeiting ink has a higher-grade anti-counterfeiting effect.

Description

Technical Field

[0001] The present invention relates to the field of optical anti-counterfeiting technology, and particularly to an optical anti-counterfeiting ink, a preparation method thereof, and an application thereof. Background Art

[0002] Optical anti-counterfeiting inks are widely used in daily life due to their unique advantages. Currently, the optical anti-counterfeiting ink recognized as the safest is composed of flaky magnetic photovariable pigments and curable varnishes. However, there are drawbacks to this current technology: for example, the flaky pigments are relatively large in size, resulting in a stronger graininess and lower resolution in printed products. Moreover, the optical variation is limited to between a pair of color systems, and there is a risk of being deciphered after long-term use.

[0003] Patent CN119019885A discloses a preparation method for achieving a multi-effect pattern. However, the transparent photovariable pigments used do not have magnetism and cannot form a pattern through magnetic induction. Additionally, the multi-effect pattern disclosed in this invention has a strong graininess and has defects in practical applications. Patent CN113416450A discloses an anti-counterfeiting ink, a preparation method thereof, an anti-counterfeiting coating layer, and a preparation method thereof. However, the overall brightness of the anti-counterfeiting coating layer is relatively low, which is not conducive to practical applications.

[0004] Therefore, how to propose an optical anti-counterfeiting ink and an anti-counterfeiting pattern obtained based on this optical anti-counterfeiting ink, such that the anti-counterfeiting pattern has a high resolution, finer colors while maintaining high brightness, and achieves a better anti-counterfeiting effect, has become an urgent problem to be solved currently. Summary of the Invention

[0005] One of the purposes of the present invention is to provide an optical anti-counterfeiting ink. By mixing magnetic photonic crystal photovariable pigments and flaky magnetic photovariable pigments, it not only ensures the overall brightness of the anti-counterfeiting pattern but also can well present the structural color of the photonic crystal, enabling the overall pattern to also have a relatively high resolution and finer colors, and having a more advanced anti-counterfeiting effect.

[0006] Another purpose of the present invention is to provide a preparation method for an optical anti-counterfeiting ink, and the preparation method is simple and easy to operate.

[0007] A third purpose of the present invention is to provide a preparation method for an optical anti-counterfeiting pattern. The preparation method is simple, the anti-counterfeiting pattern has a relatively high brightness, has a high resolution and finer colors, and can achieve a better anti-counterfeiting effect.

[0008] The solution adopted by the present invention to achieve the first purpose is: an optical anti-counterfeiting ink, wherein the optical anti-counterfeiting ink includes a mixture of pigments and curable varnishes, the pigments include magnetic photonic crystal photovariable pigments and flaky magnetic photovariable pigments, and the pigments are uniformly dispersed in the curable varnish mixture.

[0009] Preferably, the magnetic photonic crystal photochromic pigment comprises monodisperse magnetic colloidal nanoparticles capable of assembling and discoloring and / or magnetic photonic nanochains capable of orientation color display.

[0010] Preferably, the flaky magnetic photochromic pigment comprises at least one of optical interference magnetic discoloring pigments and magnetic nacre pigments having a multilayer film structure.

[0011] Preferably, after the optical anti-counterfeiting ink is printed and placed in an external magnetic field, in the direction parallel to the magnetic induction line (i.e., along the magnetic induction line), the magnetic photonic crystal photochromic pigments are periodically arranged, showing the structural color of the photonic crystal, and the flaky magnetic photochromic pigments tend to arrange their longest dimensions, resulting in dark areas and no color display; in the direction perpendicular to the magnetic induction line, the flaky magnetic photochromic pigments are tiled and oriented, showing the color of the flaky magnetic photochromic pigments, and the magnetic photonic crystal photochromic pigments do not show color.

[0012] Preferably, the curable varnish mixture comprises a matrix resin, an initiator, and an auxiliary agent.

[0013] Preferably, the matrix resin comprises at least one of epoxy resins, acrylic resins, and polyurethane resins; the initiator comprises at least one of cationic initiators, photoinitiators, and thermal initiators, and the content of the initiator is 1%-12% of the mass of the optical anti-counterfeiting ink; the auxiliary agent comprises an antifoaming agent and a wetting agent, the content of the antifoaming agent is 0.1%-1.0% of the mass of the optical anti-counterfeiting ink, and the content of the wetting agent is 0.1%-1.0% of the mass of the optical anti-counterfeiting ink.

[0014] Preferably, the content of the pigment is 2%-40% of the mass of the optical anti-counterfeiting ink.

[0015] Preferably, the mass percentage of the magnetic photonic crystal photochromic pigment to the flaky magnetic photochromic pigment in the pigment is 1:99 to 99:1.

[0016] The technical solution adopted by the present invention to achieve the second object is: a preparation method of the optical anti-counterfeiting ink as described above, comprising the following steps: (1) Dispersing the magnetic photonic crystal photochromic pigment in the curable varnish mixture and stirring evenly to obtain a mixed solution; (2) Adding the flaky magnetic photochromic pigment to the mixed solution obtained in step (1) and stirring evenly to obtain the optical anti-counterfeiting ink.

[0017] The technical solution adopted by the present invention to achieve the third object is: a preparation method of an optical anti-counterfeiting pattern, comprising the following steps: (1) Printing the optical anti-counterfeiting ink according to any one of claims 1-8 onto a substrate; (2)Place the printing substrate printed with the optical anti-counterfeiting ink in a magnetic field. Fix the magnetism to present an effect pattern, and cure the formed pattern to obtain a pattern with optical anti-counterfeiting function.

[0018] The beneficial effects of the present invention are as follows: The optical anti-counterfeiting ink of the present invention, by mixing magnetic photonic crystal photovariable pigments and flaky magnetic photovariable pigments, not only ensures the overall brightness of the anti-counterfeiting pattern, but also can well present the structural color of the photonic crystal, making the overall pattern have higher resolution and more delicate colors, and having a more advanced anti-counterfeiting effect.

[0019] When the optical anti-counterfeiting ink of the present invention is placed in an external magnetic field, in the direction parallel to the magnetic induction line, the magnetic photonic crystal photovariable pigments are periodically arranged, showing the structural color of the photonic crystal. The flaky magnetic photovariable pigments tend to arrange their longest dimensions, resulting in dark areas and no color display; in the direction perpendicular to the magnetic induction line, the flaky magnetic photovariable pigments are laid flat and oriented, showing the color of the flaky magnetic photovariable pigments, and the magnetic photonic crystal photovariable pigments do not show color.

[0020] The optical anti-counterfeiting pattern printed with the optical anti-counterfeiting ink of the present invention has higher resolution and more delicate colors, and has a more advanced anti-counterfeiting effect. In addition, from different perspectives, the color and shape of the anti-counterfeiting pattern are different, having an advanced anti-counterfeiting effect. Description of the Drawings

[0021] Figure 1 It is a digital photo of the optical anti-counterfeiting ink in Example 1; Figure 2 It is a digital photo of the optical anti-counterfeiting ink in Example 3; Figure 3 It is a digital photo of the optical anti-counterfeiting ink in Example 4; Figure 4 It is a digital photo of the optical anti-counterfeiting pattern in Example 5; Figure 5 It is a digital photo of the optical anti-counterfeiting pattern in different perspectives in Example 6; Figure 6 It is a digital photo of the optical anti-counterfeiting pattern in Example 7. Detailed Embodiments

[0022] In order to more clearly understand the purpose, features and advantages of the present invention. The following embodiments are further descriptions of the present invention. Many specific details are set forth in the following description in order to fully understand the embodiments of the present invention. However, the embodiments of the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the embodiments of the present invention is not limited by the specific embodiments disclosed below.

[0023] Example 1 This example provides an optical anti-counterfeiting ink. The optical anti-counterfeiting ink contains 2% by mass of pigments, and the mass percentage ratio of magnetic photonic crystal photochromic pigments to flaky magnetic photochromic pigments is 99:1; in addition, it also contains 1% of cationic initiator, 0.1% of defoamer, 0.1% of wetting agent, and 96.8% of epoxy resin.

[0024] The preparation method of the optical anti-counterfeiting ink includes: (1) Disperse the magnetic photonic crystal photochromic pigments in the curable varnish mixture, stir evenly to obtain a mixed solution; (2) Add the flaky magnetic photochromic pigments to the mixed solution in step (1), stir evenly to obtain the optical anti-counterfeiting ink.

[0025] Figure 1 The digital photo of the optical anti-counterfeiting ink in Example 1 is shown. It can be seen from the figure that the optical anti-counterfeiting ink presents a good state, the pigments are evenly distributed. Without applying a magnetic field, the optical anti-counterfeiting ink as a whole presents a yellow-brown color, which is because the magnetic photonic crystal photochromic pigments occupy the main part at this time.

[0026] Example 2 This example provides an optical anti-counterfeiting ink. The optical anti-counterfeiting ink contains 40% by mass of pigments, and the mass percentage ratio of magnetic photonic crystal photochromic pigments to flaky magnetic photochromic pigments is 1:99; in addition, it also contains 12.0% of cationic initiator, 1.0% of defoamer, 1.0% of wetting agent, and a mixture of 46% of acrylic resin and polyurethane resin.

[0027] The preparation method of the optical anti-counterfeiting ink includes: (1) Disperse the magnetic photonic crystal photochromic pigments in the curable varnish mixture, stir evenly to obtain a mixed solution; (2) Add the flaky magnetic photochromic pigments to the mixed solution in step (1), stir evenly to obtain the optical anti-counterfeiting ink.

[0028] The optical anti-counterfeiting ink presents a good state, the pigments are evenly distributed. Without applying a magnetic field, the optical anti-counterfeiting ink as a whole presents a pink color, which is because the flaky magnetic photochromic pigments occupy the main part at this time.

[0029] Example 3 This example provides an optical anti-counterfeiting ink. The optical anti-counterfeiting ink contains 10% by mass of pigments, and the mass percentage ratio of magnetic photonic crystal photochromic pigments to flaky magnetic photochromic pigments is 25:75; in addition, it also contains 10% of cationic initiator, 0.5% of defoamer, 0.5% of wetting agent, 40% of epoxy resin, and 39% of acrylic resin.

[0030] The preparation method of the optical anti-counterfeiting ink includes: (1) Dispersing the magnetic photonic crystal photovariable pigment in a curable varnish mixture, and stirring evenly to obtain a mixed solution; (2) Adding a flaky magnetic photovariable pigment to the mixed solution in step (1), and stirring evenly to obtain the optical anti-counterfeiting ink.

[0031] Figure 2 The digital photo of the optical anti-counterfeiting ink in Example 3 is shown. It can be seen from the figure that the optical anti-counterfeiting ink presents a good state, the pigment is evenly distributed, and the whole optical anti-counterfeiting ink presents a pink color without applying a magnetic field.

[0032] Example 4 This example provides an optical anti-counterfeiting ink, which contains 10% by mass of pigment, and the mass percentage ratio of the magnetic photonic crystal photovariable pigment to the flaky magnetic photovariable pigment is 50:50; in addition, it also contains 8% of a cationic initiator, 0.5% of an antifoaming agent, 0.5% of a wetting agent, 40% of an epoxy resin, and 41% of an acrylic resin.

[0033] The preparation method of the optical anti-counterfeiting ink includes: (1) Dispersing the magnetic photonic crystal photovariable pigment in a curable varnish mixture, and stirring evenly to obtain a mixed solution; (2) Adding a flaky magnetic photovariable pigment to the mixed solution in step (1), and stirring evenly to obtain the optical anti-counterfeiting ink.

[0034] Figure 3 The digital photo of the optical anti-counterfeiting ink in Example 4 is shown. It can be seen from the figure that the optical anti-counterfeiting ink presents a good state, the pigment is evenly distributed, and the whole optical anti-counterfeiting ink presents a yellowish-pink color without applying a magnetic field.

[0035] Example 5 This example provides a preparation method of an optical anti-counterfeiting pattern, including the following steps: (1) Screen-printing the optical anti-counterfeiting ink in Example 4 on a substrate.

[0036] (2) Placing the substrate printed with the optical anti-counterfeiting ink on a letter magnet, fixing the magnetism to obtain an effect pattern, and curing the formed pattern to obtain a pattern with optical anti-counterfeiting function. Figure 4 The optical anti-counterfeiting pattern obtained by using a letter magnet ("OH") in Example 5 is shown. It can be seen from the figure that the letter presents a green color, and its color mainly comes from the structural color of the photonic crystal, the color is uniform and delicate, the resolution is high, and the edge of the letter presents black and metallic colors from the inside to the outside in turn.

[0037] Example 6 This embodiment provides a method for preparing an optical anti-counterfeiting pattern, comprising the following steps: (1) Screen-print the optical anti-counterfeiting ink of the above-mentioned Embodiment 4 on a printing substrate.

[0038] (2) Place the printing substrate printed with the optical anti-counterfeiting ink in a circular magnetic field, fix the magnetism to obtain an effect pattern, and cure the formed pattern to obtain a pattern with optical anti-counterfeiting. In Embodiment 6, the printing substrate is placed on a circular magnet, then the magnetism is fixed to obtain an effect pattern, and the formed pattern is cured to obtain a pattern with optical anti-counterfeiting. Figure 5 Digital photos of the obtained optical anti-counterfeiting pattern at different viewing angles are shown. Among them, Figure a is the digital photo when rotated 5° to the left, b is the digital photo when rotated 20° to the left, c is the digital photo when rotated 40° to the left, d is the digital photo when rotated 20° to the right, and f is the digital photo when rotated 40° to the right. At different viewing angles, the color and shape of the ring are different, having a high-level anti-counterfeiting effect.

[0039] Embodiment 7 This embodiment provides a method for preparing an optical anti-counterfeiting pattern, comprising the following steps: (1) Screen-print the optical anti-counterfeiting ink in Embodiment 4 on a printing substrate to obtain a pattern.

[0040] (2) Place the obtained pattern in a magnetic field composed of three circular magnets, magnetically position to obtain a pattern, and then cure it to obtain an optical anti-counterfeiting pattern.

[0041] Figure 6 The optical anti-counterfeiting pattern obtained by using three circular magnets in Embodiment 7 is shown. It can be seen from the figure that the ring appears green, mainly from the structural color of the photonic crystal, with a uniform and delicate color. Both the outside and inside of the ring appear black; other parts are magenta, which is due to the effect of the flaky magnetic photochromic pigment.

[0042] The above is the preferred embodiment of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and changes can still be made, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. An optical anti-counterfeiting ink, characterized in that, The optical anti-counterfeiting ink described above comprises a pigment and a curable varnish mixture, and the pigment contains a magnetic photonic crystal photochromic pigment and a flaky magnetic photochromic pigment, and the pigment is uniformly dispersed in the curable varnish mixture.

2. The optical anti-counterfeiting ink according to claim 1, characterized in that: The magnetic photonic crystal photochromic pigment contains monodisperse magnetic colloidal nanoparticles capable of assembling and changing color and / or magnetic photonic nanochains capable of orientation color display.

3. The optical anti-counterfeiting ink according to claim 1, wherein: The flaky magnetic photochromic pigment contains at least one of an optical interference magnetic discoloration pigment and a magnetic pearlescent pigment having a multilayer film structure.

4. The optical anti-counterfeiting ink according to claim 1, characterized in that: After the optical anti-counterfeiting ink is printed and placed in an external magnetic field, in the direction parallel to the magnetic induction line, the magnetic photonic crystal photochromic pigment is periodically arranged, showing the structural color of the photonic crystal, and the flaky magnetic photochromic pigment tends to arrange their longest dimension, resulting in a dark area and no color display; in the direction perpendicular to the magnetic induction line, the flaky magnetic photochromic pigment is tiled and oriented, showing the color of the flaky magnetic photochromic pigment, and the magnetic photonic crystal photochromic pigment does not show color.

5. The optical anti-counterfeiting ink according to claim 1, wherein: The curable varnish mixture contains a matrix resin, an initiator and an auxiliary agent.

6. The optical anti-counterfeiting ink according to claim 5, characterized in that: The matrix resin contains at least one of an epoxy resin, an acrylic resin and a polyurethane resin; the initiator contains at least one of a cationic initiator, a photoinitiator and a thermal initiator, and the content of the initiator is 1%-12% of the mass of the optical anti-counterfeiting ink; the auxiliary agent contains an antifoaming agent and a wetting agent, the content of the antifoaming agent is 0.1%-1.0% of the mass of the optical anti-counterfeiting ink, and the content of the wetting agent is 0.1%-1.0% of the mass of the optical anti-counterfeiting ink.

7. The optical anti-counterfeiting ink according to claim 1, characterized in that: The content of the pigment is 2%-40% of the mass of the optical anti-counterfeiting ink.

8. The optical anti-counterfeiting ink according to claim 1, characterized in that: The mass percentage of the magnetic photonic crystal photochromic pigment to the flaky magnetic photochromic pigment in the pigment is 1:99 to 99:

1.

9. A method for preparing the optical anti-counterfeiting ink according to any one of claims 1-8, characterized in that, It includes the following steps: (1) Dispersing the magnetic photonic crystal photochromic pigment in the curable varnish mixture and stirring evenly to obtain a mixed solution; (2) Adding the flaky magnetic photochromic pigment to the mixed solution obtained in step (1) and stirring evenly to obtain the optical anti-counterfeiting ink.

10. A method for preparing an optical anti-counterfeiting pattern, characterized in that, It includes the following steps: (1) Printing the optical anti-counterfeiting ink described in any one of claims 1-8 onto a substrate; (2) Placing the substrate printed with the optical anti-counterfeiting ink in a magnetic field, magnetizing to produce an effect pattern, and curing the formed pattern to obtain a pattern with optical anti-counterfeiting performance.

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