CN113416450A

CN113416450A - Anti-counterfeiting ink and preparation method thereof, anti-counterfeiting layer and preparation method thereof

Info

Publication number: CN113416450A
Application number: CN202110758796.7A
Authority: CN
Inventors: 刘�东; 官建国; 罗巍; 李刚; 李春芝; 马会茹; 赵红梅; 杨秀菊
Original assignee: China Banknote Printing Technology Research Institute Co ltd; China Banknote Printing and Minting Corp
Current assignee: China Banknote Printing Technology Research Institute Co ltd; China Banknote Printing and Minting Corp
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2021-09-21
Anticipated expiration: 2041-07-05
Also published as: CN113416450B

Abstract

The invention provides anti-counterfeiting ink and a preparation method thereof, and an anti-counterfeiting layer and a preparation method thereof. The anti-counterfeiting ink comprises magnetic photonic crystals and a curable composition, wherein the magnetic photonic crystals are uniformly dispersed in the curable composition, and the anti-counterfeiting ink is prepared by adopting the following method: dispersing the magnetic photonic crystals in the liquid of the curable composition to obtain a mixed liquid; and stirring the mixed solution to obtain the anti-counterfeiting ink. According to the anti-counterfeiting ink, the magnetic photonic crystals are uniformly dispersed in the curable composition, so that the anti-counterfeiting ink can show the color change and the light rolling and dynamic effects in a magnetic field through the magnetic photonic crystals, and the anti-counterfeiting effect is enhanced.

Description

Anti-counterfeiting ink and preparation method thereof, anti-counterfeiting layer and preparation method thereof

Technical Field

The application belongs to the technical field of anti-counterfeiting, and particularly relates to anti-counterfeiting ink and a preparation method thereof, and an anti-counterfeiting layer and a preparation method thereof.

Background

The public anti-counterfeiting technology generally means that materials can display patterns or colors with different characteristics under different visual angles or light sources and other states without external instruments and equipment, so that the anti-counterfeiting purpose is achieved. The color of the reflected light of the optical color-changing ink (also called photochromic ink) under the irradiation of white light shows the change of different colors along with the change of the observation angle, thereby showing the excellent anti-counterfeiting performance which is difficult to copy by a scanner and a color copier, and being the security ink with the highest anti-counterfeiting performance which is generally accepted in the world at present. However, the photochromic ink is single in photochromic system and limited to interconversion between two colors; in addition, in practical application, the difficulty coefficients of magnetic orientation arrangement and ink layer thickness control are high; meanwhile, with the long-term use of the anti-counterfeiting technology, the anti-counterfeiting technology is facing to be decoded seriously and safely.

The photonic crystal is a novel physical chromogenic functional material developed in recent years, and is an ordered micro-nano structure formed by periodically arranging media with different refractive indexes in space. The visible light with specific wavelength according with Bragg diffraction rule can generate strong diffraction to present bright structural color, is easier for human eye to identify and is more suitable for public anti-counterfeiting. At present, anti-counterfeiting ink and an anti-counterfeiting layer which are arranged by utilizing the magnetic photonic crystal directly wrap magnetic photonic crystal stock solution in a capsule, so that after the anti-counterfeiting layer is solidified, the magnetic photonic crystal stock solution in the capsule can enable the anti-counterfeiting layer to form a fixed anti-counterfeiting pattern in a magnetic field irradiation mode. However, in the ink prepared by the method, the magnetic photonic crystals are unevenly distributed in the ink, so that the overall distribution of the magnetic photonic crystals is uneven due to the patterns printed by the ink, and thus, the anti-counterfeiting layer formed by magnetic irradiation is rough, and the method cannot be applied to occasions with high requirements on anti-counterfeiting precision. For example, the ink using the magnetic variable color capsule has poor effect and is not fine enough when used for preparing the anti-counterfeiting layer on the RMB. Meanwhile, when the conventional anti-counterfeiting ink is used for preparing a layer, the layer is formed by adopting a large-color-block splicing mode, but in this mode, lines between spliced layers cannot be connected seamlessly, and the color is single. In order to solve the problem, a scheme that an ink layer is integrally formed on a printing layer and then the integrally formed ink layer is divided into color blocks through an additional anti-counterfeiting process is provided. In the practical process, the magnetic photonic crystals in the capsule ink are distributed unevenly, so that the integrally-formed anti-counterfeiting pattern layer prepared by the capsule ink has a poor effect in the later color block division. Moreover, the anti-counterfeiting layer prepared in the capsule form can be developed only by excitation with a magnetic field during anti-counterfeiting detection, so that the operation is troublesome.

Therefore, how to provide an anti-counterfeiting ink capable of making the magnetic photonic crystals distributed more uniformly so that the anti-counterfeiting ink can be used in a layer preparation method in which an ink layer is integrally formed and then color block division is performed at the later stage becomes a problem to be solved urgently at present.

Disclosure of Invention

Embodiments according to the present invention aim to solve or improve at least one of the above technical problems.

In order to achieve the above object, a first aspect of the present invention provides a forgery-preventing ink.

The second aspect of the invention aims to provide a preparation method of anti-counterfeiting ink.

The third aspect of the invention aims to provide a preparation method of an anti-counterfeiting layer.

The fourth aspect of the invention aims to provide an anti-counterfeiting layer.

In order to achieve the first object according to the embodiment of the present invention, the technical solution of the present invention provides a security ink, which includes a magnetic photonic crystal and a curable composition, the magnetic photonic crystal is uniformly dispersed in the curable composition, and the security ink is prepared by the following method: dispersing the magnetic photonic crystals in the liquid of the curable composition to obtain a mixed liquid; and stirring the mixed solution to obtain the anti-counterfeiting ink.

According to the anti-counterfeiting ink provided by the invention, the magnetic photonic crystals are uniformly dispersed in the curable composition, and the anti-counterfeiting ink based on the magnetic photonic crystals can be applied to printing, so that the anti-counterfeiting ink has bright color, good adhesive force and curing speed, and can meet the requirement of high-precision printing. The specific preparation method of the anti-counterfeiting ink comprises the steps of dispersing the magnetic photonic crystals in curable composition liquid, stirring to obtain mixed liquid which is the anti-counterfeiting ink, carrying out magnetic irradiation before the ink is cured, curing the ink after a desired anti-counterfeiting pattern is obtained, directly wrapping the original liquid of the magnetic photonic crystals in a capsule at present, curing the anti-counterfeiting pattern layer, and then forming the preset anti-counterfeiting pattern on the anti-counterfeiting pattern layer by means of magnetic field irradiation, wherein the magnetic photonic crystals wrapped in the capsule are not as uniform as the magnetic photonic crystals directly distributed in the liquid ink, so that the processed pattern is relatively coarse, the accuracy of the anti-counterfeiting pattern is not high enough, and the anti-counterfeiting ink cannot be applied to occasions with high accuracy requirements, and the magnetic photonic crystals are directly distributed in the liquid ink, the uniformity of the anti-counterfeiting ink after stirring is undoubted, so that the pattern obtained after magnetic irradiation treatment is necessarily very fine, and after the desired anti-counterfeiting pattern is obtained, the liquid ink is cured, so that the fineness of the anti-counterfeiting pattern made of the ink is greatly improved, the anti-counterfeiting effect of the anti-counterfeiting article is improved, and the anti-counterfeiting article is more difficult to forge. Meanwhile, as the magnetic photonic crystals are distributed very uniformly, the anti-counterfeiting patterns can be printed at one time in the preparation process, and an additional anti-counterfeiting treatment process is introduced during the magnetization stage, so that the anti-counterfeiting patterns formed by one-time printing can be divided into color blocks, and multi-color-block pictures and texts in seamless connection can be formed. Namely, the method for preparing the image layer by carrying out color block division in the later period after integral forming can be realized by adopting the very uniform printing ink distributed by the magnetic photonic crystals.

In addition, the anti-counterfeiting ink provided by the technical scheme of the invention also has the following additional technical characteristics:

in the above technical solution, the magnetic photonic crystal is a monodisperse magnetic colloidal nanoparticle or a magnetic photonic nanochain or a mixture of monodisperse magnetic colloidal nanoparticles and magnetic photonic nanochains that can change or develop color in the curable composition; the curable composition comprises an epoxy compound and a cationic initiator, wherein the content of the cationic initiator is 1 to 12 percent of that of the epoxy compound; the epoxy compound is any one or a mixture of any more of resins, and the resin is alicyclic epoxy resin or acrylic resin; the cation initiator is at least one of diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluoroantimonate and diaryl iodonium salt.

In the technical scheme, the magnetic photonic crystal has a structure that the magnetic material is clamped between the dielectric multilayer films, so that the magnetic photonic crystal has high transmissivity and can improve the magneto-optical effect, and the second harmonic wave caused by magnetization is generated to enable the magneto-optical field to be controlled to be possible. The epoxy compound is a cyclic ether having a structure of-C-. Due to the presence of ring tension, epoxides have high reactivity, are sensitive to both acids and nucleophilic reagents, and can react with a variety of reagents such as hydrogen halides, water, alcohols, amines, Grignard reagents, and the like to open rings. The cationic initiator is a very important photo-initiation reagent, and has the basic action characteristic that the molecules are activated by light to be in an excited state, and the molecules are subjected to serial decomposition reactions to finally generate the super-strong protonic acid. The cationic initiator serves as a living species for cationic polymerization to initiate polymerization of the epoxy compound. The content of the cationic initiator is 1%, 6%, 12% and the like of the epoxy compound, so that the polymerization curing effect of the curable composition can be ensured.

The resin is an organic polymer which has a softening or melting range after being heated, has a tendency to flow under an external force when softened, and is solid, semi-solid, or liquid at room temperature. The magnetic photonic crystal, the resin and the cationic initiator are uniformly stirred, and the anti-counterfeiting ink can be obtained.

Because the epoxy group of the alicyclic epoxy resin is directly connected to the alicyclic ring, a compact rigid molecular structure can be formed, and the crosslinking density is increased after curing, so that the heat distortion temperature is higher. The anti-counterfeiting ink adopting the alicyclic epoxy resin has the advantages of small curing shrinkage, high tensile strength, good weather resistance, ultraviolet radiation resistance, high curing bonding strength and mechanical properties. The anti-counterfeiting ink adopting the acrylic resin has good adhesive force to the surfaces of metal and woodware.

At least one of diphenyl- (4-phenylsulfide) phenylsulfonium hexafluorophosphate, diphenyl- (4-phenylsulfide) phenylsulfonium hexafluoroantimonate, and diaryliodonium salt can be used as a cationic initiator to initiate polymerization of the epoxy compound, thereby obtaining a curable composition.

The magnetic nano-particles are nano-particles and generally comprise a magnetic core consisting of metal oxides such as iron, cobalt, nickel and the like and a high polymer/silicon/hydroxyapatite shell layer wrapping the magnetic core. The most common core layer is made of Fe with superparamagnetic or ferromagnetic properties₃O₄Or gamma-Fe₂O₃The prepared product has magnetic guidance, also called targeting. Under the action of an external magnetic field, the magnetic nanoparticles can realize directional movement, and are convenient to position and separate from a medium. Therefore, the magnetic nanoparticles have the characteristics of both magnetic particles and polymer particles, and have magnetic guidance. The magnetic colloid nano particles are magnetic nano particles which are integrally in a colloid structure and are suitable for preparing printing ink. For example, monodisperse magnetic colloidal nanoparticles Fe₃O₄Has good chemical stability and magnetic responsiveness. By adopting the nano magnetic induction color-changing particle technology of color changing or developing, the arrangement, the structure and the color of the magnetic colloid nano particles are correspondingly changed under a magnetic field, and the produced product has dynamic and visual anti-counterfeiting effect and good anti-counterfeiting effect.

The magnetic photon nanometer chain is a one-dimensional chain structure consisting of a plurality of monodisperse magnetic colloid nanometer particles. The magnetic photon nanochain can be used as a filler to be dispersed in an epoxy compound, diffracts structural color with high color saturation after a magnetic field is applied, and can improve the anti-counterfeiting effect of the anti-counterfeiting ink.

In any of the above embodiments, the curable composition further comprises a photoinitiator.

In the technical scheme, the photoinitiator is also called a photosensitizer or a light curing agent, so that the anti-counterfeiting ink is converted from a liquid state to a solid state within seconds, and the anti-counterfeiting ink is more conveniently applied to anti-counterfeiting.

Further, the photoinitiator is alpha-hydroxyisobutyrophenone.

In the technical scheme, the alpha-hydroxyisobutyrophenone is used as a high-efficiency photoinitiator of an ultraviolet curing system, so that the anti-counterfeiting ink is converted from a liquid state to a solid state in a shorter time, and the efficiency of converting the liquid state to the solid state of the anti-counterfeiting ink is improved.

In order to achieve the second object according to the embodiment of the invention, the technical scheme of the invention provides a preparation method of anti-counterfeiting ink, which comprises the steps of dispersing magnetic photonic crystals in a liquid of a curable composition to obtain a mixed liquid; and stirring the mixed solution to obtain the anti-counterfeiting ink.

According to the preparation method of the anti-counterfeiting ink provided by the invention, the magnetic photonic crystals are dispersed in the curable composition liquid, the mixed liquid obtained after stirring is the anti-counterfeiting ink, the preparation method can carry out magnetic irradiation before the ink is cured, the ink is cured after the desired anti-counterfeiting pattern is obtained, the existing method of directly wrapping the magnetic photonic crystal stock solution in a capsule and forming the preset anti-counterfeiting pattern on the anti-counterfeiting layer through a magnetic field irradiation mode is adopted, the magnetic photonic crystals wrapped in the capsule cannot be as uniform as the magnetic photonic crystals directly distributed in the liquid ink, so the pattern obtained after treatment is relatively rough, the accuracy of the anti-counterfeiting pattern is not high enough and the anti-counterfeiting ink cannot be applied to occasions with higher accuracy requirements, and the magnetic photonic crystals are directly distributed in the liquid ink, the uniformity of the anti-counterfeiting ink after stirring is undoubted, so that the pattern obtained after magnetic irradiation treatment is necessarily very fine, and after the desired anti-counterfeiting pattern is obtained, the liquid ink is cured, so that the fineness of the anti-counterfeiting pattern made of the ink is greatly improved, the anti-counterfeiting effect of the anti-counterfeiting article is improved, and the anti-counterfeiting article is more difficult to forge. Meanwhile, the magnetic photonic crystals of the anti-counterfeiting ink prepared by the method are uniformly dispersed in the curable composition, and the anti-counterfeiting ink based on the magnetic photonic crystals can be applied to printing, so that the anti-counterfeiting ink has bright color, good adhesive force and curing speed, and can meet the requirement of high-precision printing. Meanwhile, the anti-counterfeiting ink prepared by the method has the advantages that the magnetic photonic crystals are distributed very uniformly, so that anti-counterfeiting patterns can be printed at one time in the preparation process, and in the magnetization stage, an additional anti-counterfeiting treatment process is introduced, so that the anti-counterfeiting patterns formed by one-time printing can be divided into color blocks, and seamless-connected multi-color-block pictures and texts can be formed. Namely, the method for preparing the image layer by carrying out color block division in the later period after integral forming can be realized by adopting the very uniform printing ink distributed by the magnetic photonic crystals.

In any of the above technical solutions, dispersing the magnetic photonic crystals in the curable composition to obtain a mixture specifically includes: dispersing the magnetic photonic crystals in an epoxy compound to obtain a first mixture; adding a cationic initiator to the first mixture in an amount of 1% to 12% of the epoxy compound to obtain a second mixture.

In this embodiment, the epoxy compound has a cyclic ether of the structure-C-. Due to the presence of ring tension, epoxides have high reactivity, are sensitive to both acids and nucleophilic reagents, and can react with a variety of reagents such as hydrogen halides, water, alcohols, amines, Grignard reagents, and the like to open rings. The cationic initiator is a very important photo-initiation reagent, and has the basic action characteristic that the molecules are activated by light to be in an excited state, and the molecules are subjected to serial decomposition reactions to finally generate the super-strong protonic acid. The cationic initiator serves as a living species for cationic polymerization to initiate polymerization of the epoxy compound. The content of the cationic initiator is 1%, 6%, 12% and the like of the epoxy compound, so that the polymerization curing effect of the curable composition can be ensured.

In any of the above technical solutions, dispersing the magnetic photonic crystal in an epoxy compound to obtain a first mixture specifically includes: dispersing monodisperse magnetic colloidal nanoparticles or magnetic photonic nanochains capable of changing or developing color in a curable composition or a mixture of monodisperse magnetic colloidal nanoparticles and magnetic photonic nanochains in a cycloaliphatic epoxy resin or an acrylic resin or a mixture of a cycloaliphatic epoxy resin and an acrylic resin in a resin to obtain a first mixture; adding a cationic initiator in an amount of 1% to 12% of the epoxy compound to the first mixture to obtain a second mixture, specifically comprising: adding at least one of diphenyl- (4-phenylthio) phenylsulfonium hexafluorophosphate, diphenyl- (4-phenylthio) phenylsulfonium hexafluoroantimonate and diaryliodonium salt to the first mixture in an amount of 1 to 12% of the epoxy compound; and stirring the second mixture to obtain the anti-counterfeiting ink.

In any of the above technical solutions, adding a cationic initiator with a content of 1% to 12% of the epoxy compound to the first mixture, and stirring to obtain a second mixture, the method further includes: a photoinitiator is added to the first mixture.

In the technical scheme, the photoinitiator and the cationic initiator are added into the first mixture, so that the anti-counterfeiting ink is converted from a liquid state into a solid state within a few seconds, and the anti-counterfeiting ink is more conveniently applied to anti-counterfeiting.

In order to achieve the third object according to the embodiment of the present invention, a technical solution of the present invention provides a method for preparing an anti-counterfeit layer, including: printing the anti-counterfeiting ink prepared by adopting any one of the technical schemes on a printing layer to obtain a printed pattern; before the printed pattern is solidified, the printed pattern is placed in a magnetic field for magnetization to obtain a magnetized pattern; and curing the magnetized pattern to obtain the photonic crystal pattern.

In the technical scheme, the anti-counterfeiting ink with the uniformly distributed magnetic photonic crystals is placed in a magnetic field for magnetization after being printed. The printed pattern is placed at the edge of the magnet or above the magnetic field so that the printed pattern is magnetized in the magnetic field. The printed pattern can show the structural color of the photonic crystal after a magnetic field is applied, the magnetic photonic crystal generates specific orientation by controlling the size and the orientation of the magnetic field, and then the magnetized pattern is solidified to obtain the photonic crystal pattern, namely the anti-counterfeiting pattern. By observing the photonic crystal pattern at different viewing angles, the continuous change of the color of the photonic crystal pattern and the effects of light rolling and dynamic sense can be observed, so that the anti-counterfeiting pattern has a good anti-counterfeiting effect. According to the scheme, before the printed pattern is solidified, the printed pattern is placed in the magnetic field for magnetization to obtain the magnetized pattern, so that the pattern is shaped before the prepared anti-counterfeiting layer is solidified, and therefore, a user can directly see the colored pattern during anti-counterfeiting identification without exciting the pattern by using an extra magnetic field, and subsequent anti-counterfeiting identification is better in operation. In addition, the preparation method adopts the anti-counterfeiting ink uniformly distributed with the magnetic photonic crystals, so that the magnetic photonic crystals are uniformly distributed, the anti-counterfeiting patterns can be printed at one time in the preparation process, and an additional anti-counterfeiting treatment process is introduced during the magnetization stage so as to divide the color blocks of the anti-counterfeiting patterns formed by one-time printing, and form seamless multi-color-block pictures and texts. Namely, the method for preparing the image layer by carrying out color block division in the later period after integral forming can be realized by adopting the very uniform printing ink distributed by the magnetic photonic crystals.

Further, the printing method is any one of letterpress printing, gravure printing, stencil printing, offset printing, inkjet printing, and flexographic printing.

According to the technical scheme, the photonic crystal anti-counterfeiting pattern can be prepared on a large scale by adopting printing modes such as relief printing, intaglio printing, porous printing, lithographic printing, ink-jet printing, flexographic printing and the like, and the method is simple, convenient, easy to operate, low in manufacturing cost and easy for large-scale manufacturing and production.

In any of the above technical solutions, curing the magnetization pattern to obtain a photonic crystal pattern specifically includes: polymerizing the magnetized pattern under ultraviolet rays; and polymerizing the magnetization pattern for 2 to 4 minutes, and then curing to obtain the photonic crystal pattern.

In the technical scheme, the ultraviolet ray is invisible light and is a section of electromagnetic radiation except visible purple light, and the wavelength range is 10nm to 400 nm. After the magnetized pattern is irradiated by ultraviolet rays with certain intensity, active free radicals or ionic radicals are generated, so that polymerization reaction is initiated, the anti-counterfeiting ink is converted from a liquid state to a solid state within 2 to 4 minutes after printing, and the photonic crystal pattern can be obtained.

In any of the above embodiments, the time for polymerizing the magnetization pattern is 3 minutes.

In the technical scheme, the magnetized pattern generates active free radicals or ion radicals after being irradiated by high-intensity ultraviolet rays, so that polymerization reaction is initiated, the anti-counterfeiting ink is solidified for 3 minutes after being printed, liquid state is converted into solid state, and the photonic crystal pattern can be quickly obtained.

In any of the above solutions, the strength of the magnetic field is greater than 50 gauss.

In the technical scheme, the intensity of the magnetic field is greater than 50 gauss, and the larger the intensity of the magnetic field is, the better the magnetization effect of the printed pattern can be ensured, and the magnetized pattern with better quality can be obtained.

In any of the above technical solutions, the printed pattern is integrally printed and formed by the anti-counterfeiting ink prepared in any of the above technical solutions, and the preparation method of the anti-counterfeiting layer further includes:

before the printed pattern is solidified, subjecting the printed pattern to a preset process treatment so that the printed pattern is divided into at least two layers with different visual characteristics, wherein the preset anti-counterfeiting process treatment comprises one or a combination of the following steps: the method comprises the following steps of illumination process treatment, heat radiation process treatment, pressurization process treatment, gravity process treatment, electric field process treatment, magnetic field process treatment and airflow process treatment.

In the technical scheme, the printing pattern is integrally formed on the printing layer, namely the whole printing pattern is printed at one time, namely different layers on the printing pattern are the same as the ink material used by the layers. That is to say, when the printing layer is printed, different layers are printed on the printing layer at the same time, for example, for two layers, only one layer may be processed, and the other layer may not be processed, or the two layers may be processed differently, as long as the layers with different color blocks are formed. That is, the preparation method does not print different color blocks at the beginning, so that the different color blocks are not formed by splicing but formed by different post-process treatments. In this way, because the layers are integrally formed and not spliced, the situation of error in the process of splicing the color blocks does not exist, error-free splicing is realized, the patterns are finer, the visual characteristics of the anti-counterfeiting structure are richer, and the counterfeiting difficulty is enhanced. In order to achieve the fourth object according to the embodiment of the present invention, the technical solution of the present invention provides an anti-counterfeit layer, which is prepared by the anti-counterfeit layer preparation method in the technical solution.

In order to achieve the fourth object according to the embodiment of the present invention, the technical solution of the present invention provides an anti-counterfeit layer, which is prepared by the anti-counterfeit layer preparation method in the technical solution.

In this technical scheme, the anti-counterfeiting layer of this technical scheme is formed by the anti-counterfeiting layer preparation method of any one of the above technical schemes, so that all the beneficial effects of any one of the above technical schemes are achieved, and further description is omitted here.

Additional aspects and advantages of embodiments in accordance with the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments in accordance with the invention.

Drawings

The above and/or additional aspects and advantages of embodiments according to the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1a is a flow diagram of an anti-counterfeiting method according to some embodiments of the invention;

FIG. 1b is a flow diagram of an anti-counterfeiting method according to some embodiments of the invention;

FIG. 1c is a flow diagram of an anti-counterfeiting method according to some embodiments of the invention;

FIG. 2a is one of several digital photographs of a security device according to some embodiments of the invention at different fields of view;

FIG. 2b is a second digital photograph of a security device according to some embodiments of the present invention at a different field of view;

FIG. 2c is a third digital photograph of a security device according to some embodiments of the present invention at a different field of view;

FIG. 2d is a fourth digital photographic view of a security device according to some embodiments of the present invention at different fields of view;

FIG. 2e is a fifth digital photo representation of a security device according to some embodiments of the present invention at different fields of view;

FIG. 2f is a sixth digital photographic view of a security device according to some embodiments of the present invention at a different field of view;

FIG. 3a is one of the digital photographs of a security device rotated to the left under different fields of view according to some embodiments of the present invention;

FIG. 3b is a second digital photograph of a security device rotated to the left under different fields of view according to some embodiments of the present invention;

FIG. 3c is a third digital photograph of a security device rotated to the left under different views in accordance with some embodiments of the present invention;

FIG. 3d is a fourth illustration of a digital photograph of a security device rotated to the left under different fields of view in accordance with some embodiments of the present invention;

FIG. 4a is one of the digital photographs of a security device rotated to the right under different fields of view according to some embodiments of the present invention;

FIG. 4b is a second digital photograph of a security device rotated to the right under different fields of view according to some embodiments of the present invention;

FIG. 4c is a third digital photograph of a security device rotated to the right for different views in accordance with some embodiments of the present invention;

FIG. 4d is a fourth illustration of a digital photograph of a security device rotated to the right under different fields of view in accordance with some embodiments of the present invention;

FIG. 5a is one of the digital photographs taken at different views of a security device rotated back and forth according to some embodiments of the present invention;

FIG. 5b is a second digital photograph of a security device rotated back and forth to different views according to some embodiments of the present invention;

FIG. 5c is a third digital photographic image of a security device rotated back and forth to different views in accordance with some embodiments of the present invention;

FIG. 5d is a fourth illustration of digital photographs taken from different views of a security device rotated back and forth in accordance with some embodiments of the present invention;

FIG. 5e is a fifth illustration of a digital photograph of a security device rotated back and forth to different views in accordance with some embodiments of the present invention;

FIG. 6a is a seventh illustration of a digital photograph of a security device according to some embodiments of the present invention at different fields of view;

FIG. 6b is an eighth digital photographic view of a security device according to some embodiments of the present invention at a different field of view;

FIG. 6c is a ninth illustration of a digital photograph of a security device at different views according to some embodiments of the invention;

FIG. 6d is a ten-fold digital photographic view of a security device under different fields of view according to some embodiments of the present invention;

FIG. 7a is a digital photograph of a security device according to some embodiments of the present invention before a "finger rub" test;

FIG. 7b is a digital photograph of a security device after a "finger rub" test according to some embodiments of the present invention;

FIG. 8a is a digital photograph of a security device prior to a Water flush experiment according to some embodiments of the present invention;

FIG. 8b is a digital photograph of a security device after a "water rinse" experiment according to some embodiments of the present invention;

fig. 9 is a spectrum of a security device before and after immersion in different solvents according to some embodiments of the invention.

Detailed Description

In order that the above objects, features and advantages of embodiments in accordance with the present invention can be more clearly understood, embodiments in accordance with the present invention are described in further detail below with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments according to the invention, however, embodiments according to the invention may be practiced in other ways than those described herein, and therefore the scope of embodiments according to the invention is not limited by the specific embodiments disclosed below.

Anti-counterfeiting inks and methods of making the same, anti-counterfeiting image layers and methods of making the same according to some embodiments of the present invention are described below with reference to fig. 1-9.

Example 1

The embodiment provides anti-counterfeiting ink which comprises magnetic photonic crystals and a curable composition, wherein the magnetic photonic crystals are uniformly dispersed in the curable composition. Wherein the magnetic photonic crystal is a monodisperse magnetic colloidal nanoparticle or a magnetic photonic nanochain or a mixture of monodisperse magnetic colloidal nanoparticles and magnetic photonic nanochains capable of changing or developing color in the curable composition; the curable composition comprises an epoxy compound and a cationic initiator, wherein the content of the cationic initiator is 1 to 12 percent of that of the epoxy compound; the epoxy compound is any one or a mixture of any more of resins, and the resin is alicyclic epoxy resin or acrylic resin; the cation initiator is at least one of diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluoroantimonate and diaryl iodonium salt.

In the present embodiment, a structure in which two or more materials having different refractive indices are periodically arranged on the wavelength scale of light is referred to as a photonic crystal. The magnetic photonic crystal has a structure in which a magnetic material is sandwiched between dielectric multilayer films, and a local mode occurs in a photonic band gap due to the defect layer. Due to this phenomenon, the magnetic photonic crystal can improve the magneto-optical effect while having high transmittance, so that the occurrence of second harmonics caused by magnetization makes it possible to control the magneto-optical field.

Common colloidal particles, such as Polystyrene (PS), silicon dioxide (SiO2), Polymethyl methacrylate (PMMA) and the like, can use an inkjet printing technology to construct patterned photonic crystals, but inkjet printing has a high requirement on a substrate, and cannot achieve the effects of optical rolling and motion sense. The magnetic photonic crystals are uniformly dispersed in the curable composition, and the anti-counterfeiting ink based on the magnetic photonic crystals can be applied to printing, so that the anti-counterfeiting ink has bright color, good adhesive force and curing speed, and can meet the requirement of high-precision printing.

The epoxy compound is a cyclic ether having a structure of-C-. Due to the presence of ring tension, epoxides have high reactivity, are sensitive to both acids and nucleophilic reagents, and can react with a variety of reagents such as hydrogen halides, water, alcohols, amines, Grignard reagents, and the like to open rings. The cationic initiator is a very important photo-initiation reagent, and has the basic action characteristic that the molecules are activated by light to be in an excited state, and the molecules are subjected to serial decomposition reactions to finally generate the super-strong protonic acid. The cationic initiator serves as a living species for cationic polymerization to initiate polymerization of the epoxy compound. The content of the cationic initiator is 1%, 6%, 12% and the like of the epoxy compound, so that the polymerization curing effect of the curable composition can be ensured.

Because the epoxy group of the alicyclic epoxy resin is directly connected to the alicyclic ring, a compact rigid molecular structure can be formed, the crosslinking density is increased after curing, the thermal deformation temperature is higher, the martensite can resist heat above 190 ℃, and the thermal decomposition temperature is higher than 360 ℃. Small curing shrinkage and high tensile strength. The alicyclic epoxy resin also has good weather resistance, ultraviolet radiation resistance, high curing bonding strength and mechanical properties. Therefore, the anti-counterfeiting ink adopting the alicyclic epoxy resin also has the characteristic of the performance of the alicyclic epoxy resin. The acrylic resin is a polar material and has good adhesion to the surfaces of metal and woodware, so the anti-counterfeiting ink adopting the acrylic resin also has the characteristics.

The magnetic nano-particles are nano-particles and generally comprise a magnetic core consisting of metal oxides such as iron, cobalt, nickel and the like and a high polymer/silicon/hydroxyapatite shell layer wrapping the magnetic core. The most common core layer is made of Fe with superparamagnetic or ferromagnetic properties₃O₄Or gamma-Fe₂O₃The prepared product has magnetic guidance, also called targeting. Under the action of an external magnetic field, the magnetic nanoparticles can realize directional movement, and are convenient to position and separate from a medium. The most common shell layer is composed of high molecular polymers, and active groups coupled on the shell layer can be combined with various biomolecules, such as proteins, enzymes, antigens, antibodies, nucleic acids and the like, so as to realize the functionalization of the shell layer. Therefore, the magnetic nanoparticles have the characteristics of both magnetic particles and polymer particles, and have magnetic guidance. The magnetic colloid nano particles are magnetic nano particles which are integrally in a colloid structure and are suitable for preparing printing ink. For example, monodisperse magnetic colloidal nanoparticles Fe₃O₄Has good chemical stability and magnetic responsiveness. By adopting the nano magnetic induction color-changing particle technology of color changing or developing, the arrangement, the structure and the color of the magnetic colloid nano particles are correspondingly changed under a magnetic field, and the produced product has dynamic and visual anti-counterfeiting effect and good anti-counterfeiting effect.

Example 2

The embodiment provides anti-counterfeiting ink. In addition to the technical features of the above embodiment, the present embodiment further includes the following technical features:

the curable composition also includes a photoinitiator.

In this embodiment, the photoinitiator is also called a photosensitizer or a photocuring agent, and is a compound that can absorb energy with a certain wavelength in an ultraviolet region (250 nm to 420 nm) or a visible light region (400 nm to 800 nm) to generate a radical and a cation, thereby initiating polymerization, crosslinking and curing of the monomer. Ultraviolet light is invisible light, is a section of electromagnetic radiation other than visible violet light, and has a wavelength ranging from 10nm to 400 nm. The photoinitiator is added into the anti-counterfeiting ink, and after absorbing high-intensity ultraviolet light in ultraviolet light curing equipment, active free radicals or ionic groups are generated, so that polymerization, crosslinking and grafting reactions are initiated, the anti-counterfeiting ink is converted from a liquid state to a solid state within seconds, and the anti-counterfeiting ink is more conveniently applied to anti-counterfeiting.

Example 3

the photoinitiator is alpha-hydroxyisobutyrophenone.

In this example, the alpha-hydroxyisobutyryl benzene is commonly referred to as photoinitiator 1173, photoinitiator UV1173, molecular formula C₁0H₁₂O₄The efficient photoinitiator for the ultraviolet curing system enables the anti-counterfeiting ink to be converted from a liquid state to a solid state in a shorter time, and provides the efficiency of converting the anti-counterfeiting ink from the liquid state to the solid state.

Example 4

As shown in fig. 1a, this embodiment provides a method for preparing a security ink, which is used to prepare the security ink in any of the above embodiments, and the method for preparing the security ink includes:

s102: the magnetic photonic crystals are dispersed in a liquid of the curable composition to obtain a mixed liquid.

S104: and stirring the mixed solution to obtain the anti-counterfeiting ink.

Further, as shown in fig. 1b, the magnetic photonic crystals are dispersed in the curable composition to be mixed, i.e., S102 specifically includes:

s202: the magnetic photonic crystals are dispersed in an epoxy compound to obtain a first mixture.

S204: adding a cationic initiator to the first mixture in an amount of 1% to 12% of the epoxy compound to obtain a second mixture.

Dispersing the magnetic photonic crystals in an epoxy compound to obtain a first mixture, specifically comprising:

monodisperse magnetic colloidal nanoparticles or magnetic photonic nanochains or a mixture of monodisperse magnetic colloidal nanoparticles and magnetic photonic nanochains capable of changing or developing color in a curable composition are dispersed in a cycloaliphatic epoxy resin or an acrylic resin or a mixture of a cycloaliphatic epoxy resin and an acrylic resin in a resin to obtain a first mixture.

Adding a cationic initiator in an amount of 1% to 12% of the epoxy compound to the first mixture to obtain a second mixture, specifically comprising:

at least one of diphenyl- (4-phenylthio) phenylsulfonium hexafluorophosphate, diphenyl- (4-phenylthio) phenylsulfonium hexafluoroantimonate and diaryliodonium salt is added to the first mixture in an amount of 1 to 12% of the epoxy compound.

S206: and stirring the second mixture to obtain the anti-counterfeiting ink.

In this embodiment, the mixture is stirred and uniformly stirred to obtain the anti-counterfeiting ink, so that the magnetic photonic crystals in the prepared anti-counterfeiting ink are uniformly dispersed in the curable composition. Specifically, the discolored or colored monodisperse magnetic colloidal nanoparticles or magnetic photonic nanochains or the mixture of the monodisperse magnetic colloidal nanoparticles and the magnetic photonic nanochains are dispersed in the alicyclic epoxy resin or acrylic resin or the mixture of the alicyclic epoxy resin and the acrylic resin in the resin of the epoxy compound as the magnetic photonic crystals, so that a uniform first mixture is favorably formed, the subsequent stirring time is saved, and the manufacturing efficiency of the anti-counterfeiting ink is improved. And stirring and uniformly stirring the second mixture to obtain the anti-counterfeiting ink, namely stirring and uniformly stirring the cationic initiator, the magnetic photonic crystals and the epoxy compound to ensure that the magnetic photonic crystals in the prepared anti-counterfeiting ink can be uniformly dispersed in the curable composition containing the cationic initiator and the epoxy compound, so that the stable performance of the anti-counterfeiting ink can be ensured.

Example 5

The embodiment provides a preparation method of anti-counterfeiting ink. In addition to the technical features of the above embodiment, the present embodiment further includes the following technical features:

adding a cationic initiator to the first mixture in an amount of 1% to 12% of the epoxy compound to obtain a second mixture, previously comprising:

a photoinitiator is added to the first mixture.

In this embodiment, a photoinitiator and a cationic initiator are added to the first mixture, and the photoinitiator generates active free radicals or ionic groups after absorbing high-intensity ultraviolet light in ultraviolet light curing equipment, so as to initiate polymerization, crosslinking and grafting reactions, so that the anti-counterfeiting ink is converted from a liquid state to a solid state within several seconds, and thus the anti-counterfeiting ink is more conveniently applied to anti-counterfeiting.

Example 6

As shown in fig. 1c, this embodiment provides a method for printing the anti-counterfeit ink in any embodiment, including:

s302: printing the prepared anti-counterfeiting ink on a printing layer to obtain a printed pattern; wherein, the preparation method of the anti-counterfeiting ink in any embodiment is adopted when the anti-counterfeiting ink is prepared.

S304: and (4) magnetizing the printed pattern in a magnetic field to obtain a magnetized pattern.

S306: and curing the magnetized pattern to obtain the photonic crystal pattern.

In the embodiment, the magnetic photonic crystal in the anti-counterfeiting ink has high transmissivity and can improve the magneto-optical effect, so that the second harmonic caused by magnetization can be generated to control the magneto-optical field to be possible. After printing, the anti-counterfeiting ink containing the magnetic photonic crystals is placed in a magnetic field for magnetization. Wherein, can form the magnetic field through the magnet, place the printing pattern at the edge of magnet or place the printing pattern in the top of magnetic field, make the printing pattern magnetize in the magnetic field. The printed pattern can show the structural color of the photonic crystal after a magnetic field is applied, the magnetic photonic crystal generates specific orientation by controlling the size and the orientation of the magnetic field, and then the magnetized pattern is solidified to obtain the photonic crystal pattern, namely the anti-counterfeiting pattern. By observing the photonic crystal pattern at different viewing angles, the continuous change of the color of the photonic crystal pattern and the effects of light rolling and dynamic sense can be observed, so that the anti-counterfeiting pattern has a good anti-counterfeiting effect.

Example 7

The embodiment provides a printing method of anti-counterfeiting ink. In addition to the technical features of the above embodiment, the present embodiment further includes the following technical features:

the printing method is any one of relief printing, gravure printing, stencil printing, offset printing, inkjet printing and flexographic printing.

In this embodiment, letterpress printing is a printing process, and specifically, the ink is uniformly distributed by the ink supply device of the printing press, and then the ink is transferred to the printing plate by the ink roller, and because the image-text part on the letterpress is far higher than the non-image-text part on the printing plate, the ink on the ink roller can only be transferred to the image-text part of the printing plate, and the non-image-text part is free of the ink. Intaglio printing is one kind of printing process, and is one direct printing process, and the intaglio pits contain ink and is directly printed on the printing stock, the shade level of the printed picture is determined by the size and depth of the pits, if the pits are deeper, the contained ink is more, and the ink layer left on the printed matter after printing is thicker; conversely, if the pit is shallow, the amount of ink contained is small, and the ink layer left on the substrate after the imprint is thin. The printed product printed by the gravure has the advantages of thick ink layer, bright color, high saturation, high printing plate printing resistance, stable quality of the printed product, high printing speed and the like. The stencil printing is also called screen printing, namely a printing mode which adopts a screen as a printing plate material, and has the advantages of thick printing ink, bright color and capability of being printed by any material. The image-text part and the non-image-text part on the lithographic printing plate are almost on the same plane, the plate making work is simple and convenient, and the cost is low. The ink-jet printing needs to be carried out by an ink-jet printer, and the ink-jet printer can print simple block color patterns, full-color patterns or patterns with excessive colors at one time, has beautiful colors, vivid effect, waterproof and sun-proof images, strong wear-resistant adhesive force, no color fading, simple and easy machine operation and stable performance. The flexography belongs to the type of letterpress, is suitable for printing various printing materials such as various papers, plastic films, metal films, adhesive stickers and the like, and has the advantages of wide application range, good quality and environmental protection. The photonic crystal anti-counterfeiting pattern can be prepared on a large scale by adopting printing modes such as relief printing, intaglio printing, porous printing, lithographic printing, ink-jet printing, flexographic printing and the like, and the method is simple and convenient, easy to operate, low in manufacturing cost and easy for large-scale manufacturing and production.

Example 8

solidifying the magnetization pattern to obtain a photonic crystal pattern, which specifically comprises:

polymerizing the magnetized pattern under ultraviolet rays;

and polymerizing the magnetization pattern for 2 to 4 minutes, and then curing to obtain the photonic crystal pattern.

In this embodiment, the ultraviolet light is invisible light, is a segment of electromagnetic radiation other than visible violet light, and has a wavelength range of 10nm to 400 nm. The ultraviolet rays may be generated by an ultraviolet lamp. After the magnetized pattern is irradiated by ultraviolet rays with certain intensity, active free radicals or ionic radicals are generated, so that polymerization reaction is initiated, the anti-counterfeiting ink is converted from a liquid state to a solid state within 2 to 4 minutes after printing, and the photonic crystal pattern can be obtained.

Example 9

the time for polymerization of the magnetization pattern was 3 minutes.

In this embodiment, the magnetized pattern generates active radicals or ionic groups after being irradiated by high-intensity ultraviolet rays, so as to initiate a polymerization reaction, so that the anti-counterfeiting ink is cured for 3 minutes after being printed, and is converted from a liquid state to a solid state, and a photonic crystal pattern can be rapidly obtained.

Example 10

the strength of the magnetic field is greater than 50 gauss.

The embodiment finds that the strength of the magnetic field is a characteristic quantity of ampere-turns of the coil and can reflect the strength of the source of the magnetic field. The intensity of the magnetic field is larger than 50 gauss, and the larger the intensity of the magnetic field is, the better the magnetization effect of the printed pattern can be ensured, and the magnetized pattern with better quality can be obtained.

Example 11

The embodiment provides anti-counterfeiting ink based on magnetic photonic crystals, a preparation method of the anti-counterfeiting ink and a printing method of the anti-counterfeiting ink. The magnetic photonic crystal-based security ink comprises a curable composition and magnetic photonic crystals uniformly dispersed therein. The anti-counterfeiting ink can print a pattern on a printing stock, displays the structural color of the photonic crystal after a magnetic field is applied, can obtain the photonic crystal anti-counterfeiting pattern after curing, can observe the continuous change of the color and the effects of optical rolling and dynamic sense under different viewing angles due to the specific orientation of the magnetic photonic crystal after curing by controlling the size and the orientation of the magnetic field, and has good anti-counterfeiting effect.

In this embodiment, the curable composition includes an epoxy compound, a cationic initiator. The epoxy compound is at least one of 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexyl formate and di (3, 4-epoxycyclohexylmethyl) adipate. The cationic initiator is at least one of diphenyl- (4-phenylthio) phenyl sulfonium hexafluorophosphate, diphenyl- (4-phenylthio) phenyl sulfonium hexafluoroantimonate and diaryl iodonium salt, and the content of the cationic initiator is 1-12% of that of the epoxy compound. The magnetic photonic crystals may be monodisperse magnetic colloidal particles, magnetic photonic nanochains, or a mixture of both that can change or develop color in the curable composition.

In the embodiment, the pattern is printed on the printing stock by using the anti-counterfeiting ink, the photonic crystal structural color is displayed after the magnetic field is applied, the photonic crystal anti-counterfeiting pattern can be obtained after curing, the continuous change of the color and the light rolling and dynamic effects can be observed at different viewing angles due to the specific orientation of the magnetic photonic crystal after curing by controlling the size and the orientation of the magnetic field, and the anti-counterfeiting effect is good.

The printing pattern is printed by any one of relief printing, gravure printing, stencil printing, offset printing, inkjet printing, and flexographic printing. The printed pattern has good resistance, and the printed matter containing the printed pattern is not affected after being soaked in acid, alkali, water and organic solvent for more than 1 hour.

The applied magnetic field is uniform magnetic field or non-uniform magnetic field, and the strength is more than 50 Gauss (GS).

Example 12

The embodiment provides an anti-counterfeiting layer and a preparation method thereof, wherein a printing pattern is integrally printed and formed by the anti-counterfeiting ink prepared in any one of the above embodiments, and the preparation method of the anti-counterfeiting layer further comprises the following steps: before the printed pattern is solidified, subjecting the printed pattern to a preset process treatment so that the printed pattern is divided into at least two layers with different visual characteristics, wherein the preset anti-counterfeiting process treatment comprises one or a combination of the following steps: the method comprises the following steps of illumination process treatment, heat radiation process treatment, pressurization process treatment, gravity process treatment, electric field process treatment, magnetic field process treatment and airflow process treatment.

In this embodiment, the printing pattern is integrally formed on the printing layer, that is, the whole printing pattern is printed at one time, that is, different layers on the printing pattern are the same as the ink material used for the layers. That is to say, when the printing layer is printed, different layers are printed on the printing layer at the same time, for example, for two layers, only one layer may be processed, and the other layer may not be processed, or the two layers may be processed differently, as long as the layers with different color blocks are formed. That is, the preparation method does not print different color blocks at the beginning, so that the different color blocks are not formed by splicing but formed by different post-process treatments. In this way, because the layers are integrally formed and not spliced, the situation of error in the process of splicing the color blocks does not exist, error-free splicing is realized, the patterns are finer, the visual characteristics of the anti-counterfeiting structure are richer, and the counterfeiting difficulty is enhanced. In order to achieve the fourth object according to the embodiment of the present invention, the technical solution of the present invention provides an anti-counterfeit layer, which is prepared by the anti-counterfeit layer preparation method in the technical solution.

Example 13

Magnetic photon nanochain Fe₃O₄@ PVP @ PGDMA is dispersed in 3, 4-epoxy cyclohexyl methyl-3, 4-epoxy cyclohexyl formate, 8% of cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate is added, and the mixture is stirred to form uniform magnetic photonic crystal ink, so that the anti-counterfeiting ink is obtained. Printing a 100-shaped pattern on a Polyvinyl chloride (PVC) printing layer by adopting a screen printing mode, then placing the pattern above a magnet, applying a uniform magnetic field of 100Gs, and polymerizing for 3 minutes (min) under an Ultraviolet light emitting diode (UV-LED) to obtain a photonic crystal pattern with excellent anti-counterfeiting performance, namely an anti-counterfeiting pattern. The continuous change of the color of the anti-counterfeiting pattern can be seen under different vision.

FIGS. 2a to 2f are digital photographs of the "100" photonic crystal pattern obtained in example 12 at different fields of view. Fig. 2a is a digital photograph at an observation angle of 10 °, fig. 2b is a digital photograph at an observation angle of 15 °, fig. 2c is a digital photograph at an observation angle of 30 °, fig. 2d is a digital photograph at an observation angle of 40 °, fig. 2e is a digital photograph at an observation angle of 60 °, and fig. 2f is a digital photograph at an observation angle of 75 °. The continuous color change of the anti-counterfeiting pattern can be seen through continuous observation of the anti-counterfeiting pattern at different viewing angles.

Example 14

Magnetic lightSub-nanochain Fe₃O₄The method comprises the steps of dispersing @ PVP @ PGDMA in 3, 4-epoxy cyclohexyl methyl-3, 4-epoxy cyclohexyl formate, adding 8% of a cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, stirring to form uniform magnetic photonic crystal ink, printing a 100-shaped pattern on a PVC printing layer in a screen printing mode, then placing the pattern on the edge of a magnet, and polymerizing for 3min under a UV-LED ultraviolet lamp to obtain the photonic crystal pattern with excellent anti-counterfeiting performance, wherein the color can be seen to be continuously changed by rotating a sample left and right, and the color change mode is different.

FIGS. 3a to 3d are digital photographs of the "100" photonic crystal pattern obtained in example 13, rotated continuously to the left, at different fields of view. Fig. 3a is a digital photograph view rotated to the left by 5 °, fig. 3b is a digital photograph view rotated to the left by 20 °, fig. 3c is a digital photograph view rotated to the left by 50 °, and fig. 3d is a digital photograph view rotated to the left by 60 °. The continuous color change of the anti-counterfeiting pattern can be seen through the continuous observation of the anti-counterfeiting pattern by turning left at different angles. FIGS. 4a to 4d are digital photographs of the "100" photonic crystal pattern obtained in example 13, rotated successively to the right, at different fields of view. Fig. 4a is a digital photograph view rotated to the right by 15 °, fig. 4b is a digital photograph view rotated to the right by 20 °, fig. 4c is a digital photograph view rotated to the right by 40 °, and fig. 4d is a digital photograph view rotated to the right by 50 °. The continuous color change of the anti-counterfeiting pattern can be seen through the continuous observation of the anti-counterfeiting pattern by turning the anti-counterfeiting pattern to the right at different angles.

Example 15

Magnetic photon nanochain Fe₃O₄@ PVP @ PGDMA is dispersed in 3, 4-epoxy cyclohexyl methyl-3, 4-epoxy cyclohexyl formate, 8% of cation initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate is added, stirring is carried out to form uniform magnetic photonic crystal ink, a 100-shaped pattern is printed on a PVC printing layer in a screen printing mode, then the pattern is placed on the edge of a magnet to enable the pattern to appear a metal color, polymerization is carried out for 3min under a UV-LED ultraviolet lamp, a photonic crystal pattern with excellent anti-counterfeiting performance is obtained, and a sample is rotated back and forthThe color change can be seen, as well as the effect of the light scrolling.

FIGS. 5a to 5e are digital photographs of the "100" photonic crystal pattern obtained in example 14 at different fields of view. Fig. 5a is a digital photograph view rotated backward by 30 °, fig. 5b is a digital photograph view rotated forward by 5 °, fig. 5c is a digital photograph view rotated forward by 15 °, fig. 5d is a digital photograph view rotated forward by 30 °, and fig. 5e is a digital photograph view rotated forward by 45 °. The continuous observation of the anti-counterfeiting pattern at different angles before and after can see the continuous change of the color of the anti-counterfeiting pattern.

Example 16

Magnetic photon nanochain Fe₃O₄The method comprises the steps of dispersing @ PVP @ PGDMA in 3, 4-epoxy cyclohexyl methyl-3, 4-epoxy cyclohexyl formate, adding 8% of a cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, stirring to form uniform magnetic photonic crystal ink, printing a circular pattern on a PVC printing layer in a screen printing mode, then placing the pattern above an annular magnet, and polymerizing for 3min under a UV-LED ultraviolet lamp to obtain the photonic crystal pattern with excellent anti-counterfeiting performance, wherein the color change can be seen by rotating a sample, and the anti-counterfeiting film has good tolerance.

Fig. 6a to 6d are digital photograph images of the photonic crystal pattern obtained in example 15 at different fields of view. Fig. 6a shows a digital photograph with 10 ° rotation, fig. 6b shows a digital photograph with 20 ° rotation, fig. 6c shows a digital photograph with 40 ° rotation, and fig. 6d shows a digital photograph with 50 ° rotation. The continuous observation of the anti-counterfeiting pattern by rotating different angles can see the continuous change of the color of the anti-counterfeiting pattern.

FIGS. 7a and 7b are photographs of the photonic crystal pattern obtained in example 15, taken 5min before and after the "finger rubbing" test. Wherein, fig. 7a is a picture of an original sample, and fig. 7b is a picture of 5min after the "finger rubbing" experiment. As can be seen from a comparison of fig. 7a and 7b, the color of the pattern does not change.

Fig. 8a and 8b are photographs of the photonic crystal pattern obtained in example 15, before and after 15min of the "water rinse" experiment. Where fig. 8a is a picture of the original sample and fig. 8b is a picture of 15min after the "water rinse" experiment. As can be seen from a comparison of fig. 8a and 8b, the color of the pattern does not change.

Example 17

Magnetic photon nanochain Fe₃O₄The preparation method comprises the steps of dispersing @ PVP @ PGDMA in 3, 4-epoxy cyclohexyl methyl-3, 4-epoxy cyclohexyl formate, adding 8% of a cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, stirring to form uniform magnetic photonic crystal ink, coating the ink on a glass printing layer, then placing the ink above a magnet, applying a magnetic field of 100Gs, polymerizing for 3min under a UV-LED ultraviolet lamp to obtain a photonic crystal film with excellent anti-counterfeiting performance, soaking the photonic crystal film in different solvents for 1h, and testing the spectrum of the photonic crystal film.

FIG. 9 is a spectrum of the photonic crystal film obtained in example 17 before and after immersion in different solvents.

Wherein A represents the original spectrum; b represents a spectrogram of the photonic crystal film after being soaked in sodium hydroxide (2 percent m/v). C represents the spectrogram of the photonic crystal film after being soaked in sulfuric acid (2% v/v). D represents a spectrogram of the photonic crystal film after being soaked in ethanol. And E represents a spectrogram of the photonic crystal film after being soaked in acetone. F represents a spectrogram of the photonic crystal film after being soaked in the toluene. G represents a spectrogram of the photonic crystal film after being soaked in ethyl acetate.

Example 18

Magnetic photon nanochain Fe₃O₄The method comprises the steps of dispersing @ PVP @ PEGDMA in di (3, 4-epoxy cyclohexyl methyl) adipate, adding 1% of a cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluoroantimonate, stirring to form uniform magnetic photonic crystal ink, printing a pattern on a poly (ethylene terephthalate, short for PET) printing layer in a relief printing mode, then placing the pattern above a magnet, and polymerizing for 3min under a UV-LED ultraviolet lamp to obtain the photonic crystal pattern with excellent anti-counterfeiting performance.

Example 19

Magnetic photon nanochain Fe₃O₄@PVP@PEGDMADispersing in bis (3, 4-epoxy cyclohexyl methyl) adipate, adding 12% of cationic initiator diaryl iodonium salt, stirring to form uniform magnetic photonic crystal ink, printing a pattern on a PVC printing layer by adopting a gravure printing mode, then placing the pattern above a magnet, and polymerizing for 3min under a UV-LED ultraviolet lamp to obtain the photonic crystal pattern with excellent anti-counterfeiting performance.

Example 20

Magnetic particles Fe₃O₄The method comprises the following steps of dispersing @ PVP @ PEGDMA in a mixture of di (3, 4-epoxycyclohexylmethyl) adipate and acrylic resin, adding a photoinitiator alpha-hydroxyisobutyrophenone (2-hydroxy-2-methylprophenone, HMPP for short) and a cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, stirring to form uniform magnetic photonic crystal ink, printing a pattern in a flexible board printing mode, placing the pattern above a magnet, applying a magnetic field with the strength of 400Gs, and polymerizing for 2min under an UV-LED ultraviolet lamp to obtain the photonic crystal pattern with excellent anti-counterfeiting performance.

Example 21

Magnetic particles Fe₃O₄The method comprises the following steps of dispersing @ PVP @ PEGDMA in a mixture of di (3, 4-epoxycyclohexylmethyl) adipate and acrylic resin, adding a photoinitiator HMPP and a cationic initiator diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, stirring to form uniform magnetic photonic crystal ink, printing a pattern in an ink jet printing mode, then placing the pattern above a magnet, applying a magnetic field with the strength of 400Gs, and polymerizing for 4min under a UV-LED ultraviolet lamp to obtain the photonic crystal pattern with excellent anti-counterfeiting performance.

Fe₃O₄The material is ferroferric oxide, PEGDMA is short for polyethylene glycol dimethacrylate, and PVP is short for Polyvinyl pyrrolidone. PGEMA is the abbreviation of propylene glycol dimethacrylate.

In summary, the beneficial effects according to the embodiments of the present invention are:

by controlling the size and the direction of the magnetic field and adopting an ultraviolet curing mode, the photonic crystal pattern is cured in the resin printing layer, and the continuous color change and the light rolling and dynamic effects of the photonic crystal pattern can be seen only by changing the visual angle. According to the anti-counterfeiting method provided by the embodiment of the invention, the raw materials are easy to obtain, the printing mode is mature, the large-scale production and manufacturing are easy, the anti-counterfeiting effect of the photonic crystal pattern is excellent, the tolerance is good, and the public anti-counterfeiting of paper money, securities, certificates and the like can be realized.

In embodiments according to the present invention, the terms "first", "second", "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. Specific meanings of the above terms in the embodiments according to the present invention can be understood by those of ordinary skill in the art according to specific situations.

In the description of the embodiments according to the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, only for convenience of description and simplification of description of the embodiments according to the present invention, and do not indicate or imply that the referred devices or units must have a specific direction, be configured and operated in a specific orientation, and thus, should not be construed as limiting the embodiments according to the present invention.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an embodiment according to the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment according to the present invention, and is not intended to limit the embodiment according to the present invention, and various modifications and variations may be made to the embodiment according to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiment according to the present invention should be included in the protection scope of the embodiment according to the present invention.

Claims

1. The anti-counterfeiting ink is characterized by comprising magnetic photonic crystals and a curable composition, wherein the magnetic photonic crystals are uniformly dispersed in the curable composition, and the anti-counterfeiting ink is prepared by adopting the following method:

dispersing the magnetic photonic crystals in the liquid of the curable composition to obtain a mixed liquid;

and stirring the mixed solution to obtain the anti-counterfeiting ink.

2. A security ink as claimed in claim 1,

the magnetic photonic crystals are monodisperse magnetic colloidal nanoparticles or magnetic photonic nanochains or a mixture of the monodisperse magnetic colloidal nanoparticles and the magnetic photonic nanochains capable of changing or developing color in the curable composition;

the curable composition comprises an epoxy compound and a cationic initiator, the cationic initiator being present in an amount of 1% to 12% of the epoxy compound; the epoxy compound is any one or a mixture of any more of resins, and the resin is alicyclic epoxy resin or acrylic resin; the cationic initiator is at least one of diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluoroantimonate and diaryl iodonium salt.

3. A security ink as claimed in claim 1,

the curable composition further comprises a photoinitiator.

4. A preparation method of anti-counterfeiting ink is characterized by comprising the following steps:

and stirring the mixed solution to obtain the anti-counterfeiting ink.

5. A method of preparing a security ink as claimed in claim 4 wherein the magnetic photonic crystals are dispersed in a curable composition to provide a mixture comprising:

dispersing the magnetic photonic crystals in an epoxy compound to obtain a first mixture;

adding a cationic initiator to the first mixture in an amount of 1% to 12% of the epoxy compound to obtain a second mixture.

6. The method for preparing a security ink according to claim 5, wherein the step of dispersing the magnetic photonic crystals in the epoxy compound to obtain a first mixture specifically comprises:

dispersing monodisperse magnetic colloidal nanoparticles or magnetic photonic nanochains or a mixture of said monodisperse magnetic colloidal nanoparticles and said magnetic photonic nanochains capable of changing or developing color in said curable composition in a cycloaliphatic epoxy resin or an acrylic resin in a resin or a mixture of said cycloaliphatic epoxy resin and said acrylic resin to obtain said first mixture;

adding a cationic initiator with the content of 1-12% of the epoxy compound into the first mixture to obtain a second mixture, wherein the second mixture specifically comprises:

adding at least one of diphenyl- (4-phenylsulfide) phenylsulfonium hexafluorophosphate, diphenyl- (4-phenylsulfide) phenylsulfonium hexafluoroantimonate and diaryliodonium salt to the first mixture in an amount of 1 to 12% of the epoxy compound;

and stirring the second mixture to obtain the anti-counterfeiting ink.

7. The method for preparing a security ink according to claim 6, wherein the first mixture is stirred by adding a cationic initiator in an amount of 1% to 12% of the epoxy compound to obtain a second mixture, and the method further comprises:

a photoinitiator is added to the first mixture.

8. A preparation method of an anti-counterfeiting layer is characterized by comprising the following steps:

printing the anti-counterfeiting ink prepared by the preparation method of the anti-counterfeiting ink according to any one of claims 4 to 7 on a printing layer to obtain a printed pattern;

before the printed pattern is solidified, the printed pattern is placed in a magnetic field for magnetization to obtain a magnetized pattern;

and curing the magnetization pattern to obtain a photonic crystal pattern.

9. The method according to claim 8, wherein the curing of the magnetized pattern to obtain a photonic crystal pattern comprises:

polymerizing the magnetized pattern under ultraviolet rays;

10. A security layer produced by the method of production of a security layer according to claim 8 or 9.