KR20200050579A - Security article having security serial color code using magnetically photonic color changable ink - Google Patents

Abstract

The present invention relates to a security medium of which the surface is printed with a color code for security information by using magnetically color turnable photonic crystal ink (MTX). The color code is a color, a pattern, an image and/or data printed by the MTX. For the color code, the security information is decoded by means of a reflected light image or a transmitted light image generated from the security medium. The decoding of the security information is performed by using decoding information in which the color, the pattern, the image and/or the data appearing at at least one specific viewing angle is set as the color code from the color, the pattern, the image and/or the data appearing while being changed according to a viewing angle for the reflected light image or the transmitted light image. When a color code is matched with the set decoding information, the decoding is performed. Therefore, the security medium can display the security information without a separate means such as the application of an external magnetic field.

Description

SECURITY ARTICLE HAVING SECURITY SERIAL COLOR CODE USING MAGNETICALLY PHOTONIC COLOR CHANGABLE INK}

The present invention relates to a security medium on which a security information color code is printed using a magnetic color variable ink and a method for manufacturing the same, and more specifically, a magnetic color in which a photonic color is changed according to an applied external magnetic field. The variable ink is placed under a device in which the magnetic field is changed differently according to external information to generate a series of color codes for different types of security information according to the external information, and each color code is colored or at least one viewing angle. By observing the pattern, it relates to a security medium capable of recognizing initial security information and a method for manufacturing the same.

The security medium printed with a self-color variable pigment is used as a product suitable for security, authenticity, and other purposes by various means and combinations.

In the Republic of Korea Patent Publication No. 10-2018-0018612, the magnetic material and the general pigment contained in the color variable layer interposed between the substrates are configured to be unilaterally distributed by the specific gravity and external force of the solvent, and the color is caused by factors such as external magnetic field and gravity. It is intended to generate a variable effect. By using this effect, various types of security information can be displayed, but this can only be used for special purposes because an external magnetic field is required and the user needs to recognize prior information about the color variable effect.

In addition, in the Republic of Korea Patent Publication No. 10-2017-0124763, the information transfer layer constituting the forgery and alteration prevention print is an optically variable ink (optically variable pigment, OVP), a heat-sensitive ink, UV ink, fluorescent ink, or any one of these or holograms Consists of a first variable layer formed by a combination of and a second variable layer formed by a magnetically color turnable photonic crystal ink (MTX), in addition to the color variable effect on the magnetic field by the magnetic color variable ink, various inks It is possible to realize a color variable effect by a combination of. However, such a means also requires the application of an external magnetic field, and since the user must be aware of the prior information on the color variable effect, it can be used only for special purposes, and thus it is difficult to use it universally.

Republic of Korea Patent Publication No. 10-2018-0018612 Republic of Korea Patent Publication No. 10-2017-0124763

The present invention has been devised in view of the prior art as described above, and the security information formed by the color code printed on the surface of the medium changes according to the viewing angle and is decoded at a specific viewing angle, so that security information can be displayed. The purpose is to provide a medium.

The security medium of the present invention for solving the above problems relates to a security medium in which a color code for security information is printed on the surface of the medium using a magnetically color turnable photonic crystal ink (MTX). The color code is color, pattern, image and / or data printed by the magnetic color variable ink, and the color code is decoded of security information by a reflected light image or transmitted light image generated from the security medium, and the security Decoding of the information is the color, pattern, image and / or data appearing at least one specific viewing angle from the color, pattern, image and / or data appearing changed according to the viewing angle of the reflected light image or transmitted light image. When the code is set as the decoding information and matches the set decoding information It is characterized by being performed.

In this case, the color code may be used to decode security information by changing the printed color, pattern, image, and / or data by changing the structure of the security medium that flexes, contracts, or expands due to external pressure applied to the security medium. Can be performed.

Also, some areas of the color code may be changed in color and pattern by application of a magnetic field.

Further, the magnetic color variable ink may include magnetic particles and light absorbing particles, wherein the magnetization value of the light absorbing particles is greater than the magnetization value of the magnetic particles. In this case, the medium on which the color code for security information is printed does not include a light absorbing layer, and may be made of a transparent or opaque material.

The method of manufacturing a security medium according to the present invention includes a step of forming a print layer to apply security color variable ink on the surface of the medium to print security information; Arranging particles reacting with the electromagnetic field constituting the magnetic color variable ink by applying an external electromagnetic field to the printed layer; And irreversible curing of the printed layer to form a color code.

In this case, the irreversible curing may be performed by applying at least one of light energy, thermal energy, and chemical energy.

The security medium according to the present invention enables security information to be displayed by allowing security information formed from a color code printed on the surface of the medium to be changed according to the viewing angle and decoded at a specific viewing angle, such as the application of an external magnetic field. Since it is possible to display security information without the means of, and to store dataized security information as well as visual effects, it represents an effect applicable to various security media.

1 is a conceptual diagram illustrating an operating method for implementing a secure medium according to the present invention.
2 is an exemplary view of a security medium according to the present invention implemented in a banknote.
3 is a flowchart illustrating a method (a) for forming a color code and a method (b) for identifying information by decoding according to an embodiment of the present invention.
4 is a schematic diagram illustrating a process of identifying information and outputting a result of a color code according to one embodiment.
5 is a photograph showing a process in which the pixels printed on the surface of the security medium are varied according to the viewing angle, and the patterns at 90 (a), 60 (b), and 30 ° (c) are varied (top) and one It shows the state (bottom) in which the pixels of the variable.
6 is a flowchart illustrating a method (a) for forming a color code and a method (b) for identifying information by decoding according to another embodiment.
7 is a schematic diagram showing a process of identifying information and outputting a result of a color code according to the embodiment.
8 is an exemplary view illustrating a process in which a color code is changed when it is bent by an external pressure applied to a security medium in another embodiment.
9 is a schematic diagram showing a method for identifying information on a security medium on which a color code is printed on a transparent substrate, an information identification method for observing a reflected image (a) and a transmitted image (b) and a color printed on the transparent substrate This is a photograph showing the state when the code (c) is placed on a white background (d), a black background (e), and a complementary background (f).
FIG. 10 is an exemplary view showing a method for identifying information of a security medium in which a part of a color code is changed in color and pattern by application of a magnetic field, wherein the color code printed on the surface of the bill is changed according to the viewing angle (a) And a process (b) in which the color and pattern are changed when the magnetic material is approached.
11 is a schematic diagram showing the structure and operation principle of a secure medium according to another embodiment.

Hereinafter, the present invention will be described in detail.

The security medium according to the present invention is a security medium in which a color code for security information is printed on the surface of the medium using a magnetic color variable ink. In such a security medium, colors, patterns, images and / or data for displaying security information are visually changed according to the viewing angle, and the colors, patterns, images and / or data appearing at a particular viewing angle are set as decoding information. By doing so, it is possible to activate the product by checking whether the decoding information matches the set decoding information.

In the present invention, the color code refers to all forms in which security information is hidden with colors, patterns, images and / or data that vary depending on the viewing angle, and coding refers to a process of producing the color code, and decoding refers to the color. It means to display recognizable security information by visually checking whether a user who appears when a code displays a specific color, pattern, image, and / or data at a specific viewing angle matches predetermined decoding information.

In addition, in the present invention, the viewing angle is an angle of observing the surface of the security medium by the user's vision, a scanning device, or an imaging device, which means observing the surface of the security medium at an angle of 0 to 180 ° relative to the surface. do. The security medium may represent a reflected light image or a transmitted light image, and if necessary, both a reflected light image and a transmitted light image.

The process of displaying the information by decoding the color codes and the color codes can be understood through FIG. 1.

1 illustrates an operation method for implementing a security medium according to the present invention. First, as shown in FIG. 1 (a), the security information is set as the decoding information by setting a light wavelength that a specific user can recognize at a specific viewing angle, and based on this, color, pattern, image to be printed on the medium, Determine any one or combination of data. That is, the display information in the decoding state is determined in advance, and then it is implemented in a manner that it is hidden by changing it according to a change in the viewing angle. In addition, these color codes not only change the color, pattern, or image that can be confirmed by human observation angle, but also scan or photograph pixelated data according to the observation angle and output it through a program or application to decode the decoded information. It can also be marked and confirmed.

2 illustrates an embodiment in which the security medium of the present invention is applied to a banknote. Referring to FIG. 2, since the color code printed on the surface of the bill corresponding to the surface of the medium is changed and displayed according to the user's viewing angle, it is possible to visually check whether the bill is authentic. In addition, it is also possible to check the authenticity of the bill by using a smartphone. When the color code printed on the surface of the bill is scanned with the smartphone according to the observation angle, the authenticity of the bill can be determined through an application installed on the smartphone. There will be.

The color code is printed on the surface of the medium, and the ink used is magnetically color turnable photonic crystal ink (MTX).

The magnetic color variable ink causes a color variable effect by using a photonic crystal technology, and particles that react to an electromagnetic field, such as nanoparticles, color nanoparticles, color nanocomposites, or microcapsules containing the nanoparticles Can be used to implement this effect.

The color nanocomposite may be implemented through the intrinsic color of the particles due to the colorant particles contained in the nanocomposite, and at the same time, the nanocomposite is rearranged or the charge state changes by application from the outside of the electric or magnetic field. Color may be realized by transmitting or reflecting light of a wavelength. That is, the color nanocomposite must have a very uniform particle size for realizing color through rearrangement of particles or change of charge state, and must have characteristics of easy rearrangement due to high mobility in a medium.

The magnetic color variable ink may be dispersed in a medium or may exist dispersed in a medium in the form of particles having charge, and may be composed of a core-cell structure or a multi-core structure. For such dispersion, the self-color variable pigment preferably has a particle size of 50 to 1,000 nm, preferably 100 to 500 nm, more preferably 100 to 300 nm. However, when the particles contain a colorant, the uniformity of the particles may be a more important factor than the particle size, and thus may fall outside the range of the particle size.

In addition, the nanoparticles may be conductive particles, metal particles, organic metal particles, metal oxide particles, magnetic particles, or hydrophobic organic polymer particles, and photonic crystals having regularity in the arrangement and spacing of particles by application of external energy It may be a particle exhibiting properties. For example, silicon (Si), titanium (Ti), barium (Ba), strontium (Sr), iron (Fe), nickel (Ni), cobalt (Co), lead (Pb), aluminum (Al), copper (Cu), silver (Ag), gold (Au), tungsten (W), molybdenum (Mo), zinc (Zn), zirconium (Zr), any one or more metal or a nitride or oxide thereof .

In addition, as nanoparticles of organic materials, polystyrene, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, etc. may also be used as polymer materials, and particles whose surface is modified by organic compounds having hydrocarbon groups, carboxyl groups, ester groups, ah Particles whose surface is modified by an organic compound having any one or more of actual groups, particles whose surface is modified by a complex compound containing a halogen element, and whose surface is modified by a coordination compound containing amine, thiol, phosphine. And particles having charges by forming radicals on the particles and surfaces.

In addition, the nanoparticles may be particles that have electrical polarization properties. That is, as an external magnetic field or electric field is applied for polarization with the medium, polarization of ions or atoms is additionally induced, so that the polarization amount is greatly increased, and even when an external magnetic or electric field is not applied, the residual polarization amount exists and the magnetic or electric field is applied. It may include a ferroelectric material that remains hysteresis depending on the direction, and an ionic or atomic polarization is additionally induced as an external magnetic field or electric field is applied, but the polarization amount is greatly increased, but an external magnetic field or electric field is not applied. In this case, it may include a paraelectric material and a superparaelectric material in which residual polarization amount and hysteresis are not left.

Such a material may include a material having a perovskite structure. That is, as a material having an ABO ₃ structure, PbZrO ₃ , PbTiO ₃ , Pb (Zr, Ti) O ₃ , SrTiO ₃ , BaTiO ₃ , (Ba, Sr) TiO ₃ , CaTiO ₃ , LiNbO _3, etc. You can.

In addition, the nanoparticles may be composed of particles containing single or different metals, oxide particles or photocrystalline particles.

In the case of metals, metal nitrate compounds, metal sulfate compounds, metal fluoracetoacetate compounds, metal halide compounds, metal perchlorate compounds, metal sulfamate compounds, metal stearate compounds and organic metal compounds A magnetic precursor selected from the group consisting of a neutral ligand such as an alkyltrimethylammonium halide-based cationic ligand, alkyl acid, trialkylphosphine, trialkylphosphine oxide, alkylamine, or alkylthiol, sodium alkyl sulfate, and sodium alkyl carboxylate. , It can be prepared by preparing an amorphous metal gel by dissolving a ligand selected from the group consisting of anionic ligands such as sodium alkyl phosphate and sodium acetate by adding it to a solvent, and heating it to phase-transfer to crystalline particles.

At this time, the magnetic properties of the particles finally obtained by containing different kinds of precursors are enhanced, or various magnetic materials such as superparamagnetism, paramagnetism, ferromagnetism, antiferromagnetism, ferrimagnetism, and magnetism can be obtained.

The magnetic color variable ink is dispersed in a medium and rearranged by application of an electric field or a magnetic field. As the medium, a polar or non-polar medium may be used. For example, water, methanol, ethanol, propanol, butanol, propylene carbonate, toluene, benzene, hexane, chloroform, halocarbon oil, perchloroethylene, trichloroethylene, isoparffin oil, isopar-G, isopar-M , isopar-H, or more.

In addition, since the magnetic color variable ink may have an intrinsic color and is decoded at a specific viewing angle by displaying color by rearrangement of particles, information of a color code may be changed when a dye or pigment is added for a combination of colors . Therefore, unlike conventional display devices for security media, additional dyes or pigments should not be used.

In addition, the magnetic color variable ink may include a material that is magnetic, that is, magnetized as a magnetic field is applied. In addition, magnetization occurs when an external magnetic field is applied to prevent agglomeration between particles having magnetic properties when a magnetic field is not applied from the outside, but residual magnetization occurs when an external magnetic field is not applied. Superparamagnetic materials that do not occur can also be used.

In addition, in order to prevent the nanoparticles from being well dispersed and agglomerated in the solvent, the particle surface can be coated with a charge of the same code, and the particle surface is made of a material having a specific gravity different from that of the particle in order to prevent the particle from sedimenting in the solvent. You can also coat or mix the particles with substances of different specific gravity.

In addition, the nanoparticles may be configured to reflect light of a specific wavelength, that is, to have a specific color. More specifically, the particles according to the present invention may have a specific color through the control of oxidation number or coating of inorganic pigments, pigments, and the like. For example, as the inorganic pigment coated on the particles according to the present invention, Zn, Pb, Ti, Cd, Fe, As, Co, Mg, Al, etc. containing chromophores can be used in the form of oxides, emulsions, and sulfates. , As a dye coated on the particles according to the present invention, fluorescent dyes, acid dyes, basic dyes, mordant dyes, sulfide dyes, bat dyes, disperse dyes, reactive dyes and the like can be used.

In addition, the nanoparticles may be coated with a material having a charge so that they have the same charge.

Further, the magnetic color variable ink may include a microcapsule, in which case the microcapsule contains a solvent in which a photonic crystal or a photonic crystal having an intrinsic color is dispersed. In this case, the microcapsules are aginate, gelatin, ethyl cellulose, polyamide, melamine formaldehyde resin, polyvinyl pyridine By forming a capsule wall with at least one transparent polymer of polystyrene, a resin containing a urethane bond, and polymethyl methacrylate, the photonic crystals are rearranged by applying a magnetic field to realize color. It becomes possible.

Such microcapsules are microcapsules disclosed in Korean Patent Application Publication No. 10-2017-0124028 developed by the applicant, or in Korean Patent Publication Nos. 10-2015-0031197, 10-2015-0017796, 10-2015-0020491 All of the disclosed microcapsules can be used, and can be applied to both electrophoresis and magnetic field application methods, so that they can react to electromagnetic fields applied from the outside.

When printing on the surface of the medium, the magnetic color variable ink is applied to the surface of the medium by using a printer as shown in FIG. 1 (b). Unlike the general ink, the magnetic color variable ink is applied to the medium. And immediately becomes uncured. This is to prevent the self-color variable ink from curing without ultraviolet irradiation or heating by including a photopolymerization initiator or a thermal polymerization initiator.

To this end, the magnetic color variable ink is benzophenone, benzophenone derivative, acetophenone, acetophenone derivative, benzyl ketone, α-alkoxy benzyl ketone, monomeric hydroxy ketone, polymer hydroxy ketone, α-amino ketone, alkoxy ketone, Acyl phosphine oxide, metallocene, benzoin ether, benzyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone, may include photopolymerization initiators such as acylphosphine, azo-based compounds, organic peroxides, hydrogen peroxide And a thermal polymerization initiator.

In addition, after applying the magnetic color variable ink to the surface of the medium using a printer as shown in Figure 1 (b), as shown in Figure 1 (c) by applying an electromagnetic field from the outside included in the magnetic color variable ink Particles that react to the electromagnetic field are arranged at an angle.

In general, the magnetic color variable ink is arranged by the application of an external electromagnetic field, and then scattered in a random form when the factors of the external electromagnetic field disappear. Therefore, when the arrangement of the particles is completed by the application of the electromagnetic field, heat or ultraviolet rays are applied to cure the particles in the arranged state.

Through this process, the magnetic color variable ink is applied to the surface of the medium and then cured after forming the color code.

As described above, the color code changes the color, pattern, and / or image as the viewing angle changes, which is the same as changing the color or image according to the viewing angle as illustrated in FIG. 1 (d).

At this time, when security information by a specific color, pattern, image and / or data, that is, color, pattern, image or data, or a combination of two or more of them is set as a color code, it is decoded only at a specific viewing angle to display security information to the user To make it possible.

In one embodiment, the security medium according to the present invention may be decoded at one viewing angle, but may be configured to display different decoding information at a plurality of viewing angles and combine them to recognize security information.

For this, the color code may be formed as data. This is formed through the process as in FIG. 2 (a), and is identified through the process as in FIG. 2 (b).

Referring to FIG. 2 (a), data to be inserted (color code) is determined in advance, information to be inserted is generated by binary code and pixelation, and information is generated, and then data is coded through conversion and output of an electromagnetic field signal according to the binary code This allows color codes to be generated on the surface of the medium.

Also, in the process of decoding the color code, as shown in FIG. 2 (b), a plurality of pixel areas are selected by scanning or photographing a security medium according to an observation angle, and the color codes of the pixel areas are converted into binary codes. Then, the security information can be identified by identifying the binary code and displaying the corresponding data. At this time, the scan or photographing may be performed through a camera, and the process of converting the pixel region into a binary code and displaying data again may be performed by a program or an application.

In addition, in this case, if different pixels for a plurality of viewing angles and corresponding binary codes are hidden, security information may be identified by combining the binary codes obtained by scanning or shooting. It is also possible to display more detailed security information than to recognize changes in color or pattern.

Most simply, a decoding process as described above may be performed using a smartphone, as shown in FIG. 3, by scanning or photographing image information of a color code formed on the surface of a secure medium, the obtained smartphone Or input to a computer or the like, identify the acquired information through a program or application installed on the smartphone or computer, convert pixel information into a binary code, and identify the binary code again and display the result as data. You can print it. Through this process, it is possible to display various types of information indicating genuine and fake according to the type of the data.

In addition, the process of changing the behavior of the pixels constituting the color code according to the change in the viewing angle can be seen through FIG. 4. In the upper view of FIG. 4, it can be seen that the observation angle of scanning the color code formed as a pattern changes the shape of the pattern at 90 ° (a), 60 ° (b), and 30 ° (c). In addition, in the lower figure, it can be seen that the process of changing the shape of one pixel from circular to elliptical as the observation angles are changed to 90 ° (a), 60 ° (b), and 30 ° (c). That is, even in the case of a color code patterned with the same pixel, the shape information of each pixel and the shape information of the entire pattern are changed according to the viewing angle, so that it can be set to be decoded at a specific viewing angle.

In connection with the above embodiment, it is also possible to configure the identification according to the viewing angle in a complex manner. This is performed through the same process as in FIG. 5, and data can be decoded by determining data at the first viewing angle and checking and converting information at the second viewing angle.

Referring to FIG. 5 (a), data to be inserted (color code) is determined in advance, information to be inserted is binary coded and pixelated to generate information, and data is coded through conversion and output of an electromagnetic field signal according to the binary code This allows color codes to be generated on the surface of the medium. At this time, color code information at the second viewing angle is determined, and binary color coded and pixelated to generate additional color codes.

The secure medium that has generated the color code through this process can be decoded as in FIG. 5 (b). That is, when a plurality of pixel areas are selected by scanning or photographing an image at a first viewing angle, the color codes of the pixel areas are converted to binary codes, and then an image is scanned or photographed at a second viewing angle for another plurality of pixels. When the pixel area is selected, the color code of the pixel area is converted into a binary code, and the binary codes obtained at the first observation angle and the second observation angle are compared to determine whether or not the security information matches the security information.

6, the security information is displayed by synthesizing the first color code obtained at the first observation angle and the second color code obtained at the second observation angle while changing the viewing angle, as shown in FIG. 6. Scanning or photographing the image information of the color code formed on the screen while changing the viewing angle, input the acquired information to a smartphone or computer, and identify the acquired information through a program or application installed on the smartphone or computer to identify pixels It is possible to output information through a process of converting information into a binary code, re-identifying the binary code, and matching binary codes corresponding to the first color code and the second color code to display the data. Through this process, it is possible to display various security information indicating genuine and fake according to the type of the data.

Since the security medium of the present invention can form an image by reflected light and / or transmitted light, a flexible medium can also be used for this. In the case of a security medium made of such a flexible medium, the printed color, pattern, image and / or data may be changed by a change in the structure of the security medium that flexes, contracts, or expands by an external pressure applied, in this case The decoded information can be output in a specific modified structure.

FIG. 8 shows this as an example, and when a flexible security medium is bent to form a bend, the color distribution of the pattern changes, so that various security information indicating genuine and fake can be displayed.

In addition, by using the medium of the secure medium as a transparent substrate, it can be applied to various information identification methods. When this is explained through FIG. 9, when a color code is printed on a transparent substrate, light is divided into reflected light and transmitted light, and the user may observe the reflected light as shown in FIG. 9 (a), and FIG. 9 ( It is also possible to observe the transmitted light as in b). At this time, it is possible to further enhance the security factor by displaying the decoded information at a specific angle or a specific background color of reflected light or transmitted light.

Specifically, as illustrated in FIG. 9 (c), the color codes printed on the transparent substrate are white (d), black (e), or complementary colors (f) because reflected light is affected by the background color. The difference in the pattern becomes clear. Therefore, the decoded information can be confirmed by observing reflected light or observing reflected light or transmitted light at a specific angle by changing the background color.

In addition, the color, pattern, image, and / or data may be changed according to the viewing angle, so that a part of the color code that appears changes color and pattern by application of a magnetic field, thereby further enhancing the security factor.

When this is described in detail with reference to FIG. 10, when a color and pattern of a region of the color code changes due to the application of a magnetic field, the color code printed on the surface of the bill as shown in FIG. By changing, it is possible to display the decoded information, and at the same time, when the magnetic material is approached to the surface of the bill from the outside, the color and pattern are changed as shown in FIG. 10 (b) so that the decoded information can be displayed. It is also possible to add a combination of security elements.

In addition, by changing the configuration of the magnetic color variable ink, it is also possible to implement a method of operating different types of color codes. 11 shows the structure and operating principle of such a security medium.

The color code for security information of the security medium may be implemented by a magnetic color variable ink containing magnetic particles and light absorbing particles, wherein the magnetization value of the light absorbing particles is greater than the magnetization value of the magnetic particles. It is possible to implement the working structure of various color codes.

The magnetic particles and light absorbing particles contained in the magnetic color variable ink have different magnetization values. Therefore, the distance between each other is changed by moving according to the change of the external magnetic field.

As illustrated in FIG. 11, a capsule encapsulating a solvent in which a plurality of magnetic particles and light-absorbing particles are dispersed as a light-transmitting material is applied as an ink composition or ink containing the plurality of magnetic particles and light-absorbing particles on a substrate having a partition wall formed thereon. When the color code is printed by filling the composition, light is absorbed by the light absorbing particles having a relatively large magnetization value in the region where the color code is visually observed when an external magnetic field is applied by approaching a magnetic material to the lower portion of the medium. The blocking effect can be obtained. In addition, since the distance of the light absorbing particles changes according to the intensity of the external magnetic field, the wavelength of the reflected light is changed, and accordingly, various color variable effects of the color code are realized by implementing a state in which the color is partially changed while completely blocked. You can implement

It is preferable that the light absorbing particles have a black color so as to easily absorb light, but some other color may be employed within a range that serves to absorb light.

Since the light absorbing particles must have a magnetization value greater than that of the magnetic particles, black particles such as carbon black, aniline black, iron oxide black, titanium oxide, chromium, etc. are mixed with the particles having a larger magnetization value than the magnetic particles to be blackened. Particles coated or adsorbed of a mixed organic pigment composition can be used. At this time, as a polymer composition composed of a mixture of black dye, C.I. Food Black 1, C.I. Food black-based dyes such as Food Black 2, C.I. Direct Black 9, C.I. Direct Black 17, C.I. Direct Black 38, C.I. Direct Black 51, C.I. Direct Black 60, C.I. Direct Black 102, C.I. Direct Black 107, C.I. Direct Black 122, C.I. Direct Black 142, C.I. Direct Black 154, C.I. Naphthol black direct azo dyes such as Direct Black 168, C.I. Acid Black 2, C.I. Acid Black 31, C.I. Acid Black 52, C.I. Acid Black 140, C.I. Acid azo dyes such as Acid Black 187 can also be used. In addition, the composition may comprise light absorbing particles in combination with a polymer material such as polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), or polyethylen terephthalate (PET).

In the conventional security medium, a light absorbing layer (black sheet) is additionally laminated on the surface of the medium in order to realize such a color variable effect, but the security medium according to the embodiment can implement a color variable effect without the light absorbing layer. As it may, the light absorbing layer may not be included. In addition, by manufacturing the medium with a transparent or opaque material, a color variable effect through reflection or transmission of light can be appropriately selected and implemented.

In addition, since the light absorbing particles in the color code can directly absorb the light incident compared to the conventional technique including the light absorbing layer, there is an advantage that it is possible to fundamentally prevent interference and distortion caused by cross-sectional reflection. Interplanar reflection should be understood as including Fresnel reflection, which is a reflection that occurs when light passes through an interface between materials having different refractive indices of light.

Unlike a conventional display device using a magnetic color variable ink, such a security medium is more versatile because the external electromagnetic field is applied only when forming a color code, and when using it, information can be confirmed by simply changing the viewing angle. It is excellent and can be used for various security products.

Although the present invention has been described with the preferred embodiments as described above, it is not limited to the above embodiments and various modifications and changes can be made by those skilled in the art without departing from the spirit of the present invention. Examples are to be regarded as falling within the scope of the present invention and the appended claims.

Claims (7)

As a security medium in which a color code for security information is printed on the surface of a medium using magnetically color turnable photonic crystal ink (MTX),
The color code is color, pattern, image and / or data printed by the magnetic color variable ink,
The color code is decoded by the security information by the reflected light image or transmitted light image generated from the security medium,
The decoding of the security information is performed by changing the color, pattern, image and / or data appearing in at least one specific viewing angle from the color, pattern, image and / or data that is changed according to the viewing angle of the reflected light image or transmitted light image. A security medium characterized in that it is performed when the color code is set as the decoding information and matches the set decoding information.
The method according to claim 1,
In the color code, decoding of security information is performed by changing the printed color, pattern, image, and / or data by changing the structure of the security medium that is bent, contracted, or expanded by external pressure applied to the security medium. Security medium characterized in that.
The method according to claim 1,
A security medium, characterized in that the color and pattern are changed by the application of a magnetic field in some areas of the color code.
The method according to claim 1,
The magnetic color variable ink includes magnetic particles and light absorbing particles, wherein the magnetization value of the light absorbing particles is greater than the magnetization value of the magnetic particles. The method according to claim 4,
The medium on which the color code for security information is printed does not include a light absorbing layer, and is made of a transparent or opaque material.
A method for manufacturing a security medium according to claim 1,
A printing layer forming step of applying security color variable ink to the surface of the medium to print security information;
Arranging particles reacting with the electromagnetic field constituting the magnetic color variable ink by applying an external electromagnetic field to the printed layer;
Irreversible curing of the printed layer to form a color code;
Method of manufacturing a secure medium comprising a.
The method according to claim 1,
The irreversible curing is performed by applying at least one energy of light energy, heat energy, and chemical energy.

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