JP5707909B2 - Method for producing fine particles - Google Patents

Description

  The present invention relates to a technique for preventing forgery by fine particles.

  Known anti-counterfeiting techniques include holograms, watermarks, latent image patterns, pearl inks, luminescent inks, intaglio printing, and micro characters. In particular, anti-counterfeiting technology that uses information that cannot be confirmed visually (with the naked eye) is attracting attention because the possibility of imitation is reduced when it cannot be easily confirmed that anti-counterfeiting technology is applied. However, in recent years, since printing technology has been developed and high-definition printing is possible, even if it is information that cannot be visually confirmed, there is a high possibility that it will be imitated if the position of the information is specified. There was a problem.

  Therefore, forgery prevention technology using fine particles has been proposed. These fine particles are also called taggants (additives for tracking), and when applied to anti-counterfeiting media, the position of the fine particles varies from individual to individual, making it difficult to confirm the fine particles themselves, and replication It is difficult to achieve a high level of anti-counterfeiting. In addition, the individual can be identified.

  The fine particles are known to have information that can be identified by magnifying and observing, for example, fine particles having symbols such as letters, numbers, codes, marks, and special shapes, and colored thin films. Have been proposed (see, for example, Patent Documents 1 to 4). For fine particles having a symbol or special shape, authenticity can be determined by enlarging and identifying the symbol or special shape. Further, in the fine particles in which a plurality of colored thin films are laminated, it is possible to determine the authenticity by identifying the enlarged and laminated color pattern.

Japanese Patent No. 3665282 JP 2008-230228 A JP 2009-193069 A JP 2001-288698 A

The fine particles having the above symbols and special shapes are generally flat particles and easy to manufacture. Therefore, there is a possibility of imitation.
The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide novel fine particles in the forgery prevention technology using fine particles.

  In order to achieve the above object, the present invention provides a fine particle having a three-dimensional shape that can be identified by magnifying and observing, and the three-dimensional shape has at least a curved surface.

  According to the present invention, since the information that can be identified by magnifying and observing is a three-dimensional shape having at least a curved surface, it is difficult to manufacture fine particles as compared with a conventional flat surface. It is possible to improve the anti-counterfeit effect. Further, according to the present invention, since the choice of identifiable information that can be expressed is widened by using a solid shape having at least a curved surface, a variety of designs are possible and the self-other identification function can be exhibited. .

  In the said invention, it is preferable that the said microparticle contains photosensitive resin. This is because the use of the photosensitive resin makes it possible to produce fine particles with good productivity and low cost by direct drawing, a gradation mask or the like.

  In the present invention, it is preferable that 50% or more of the surface of the fine particles is composed of a curved surface. This is because the greater the proportion of the curved surface on the surface of the fine particles, the easier it is to visually recognize the three-dimensional shape due to the reflection of light and the easier it is to identify.

  Furthermore, in the present invention, it is preferable that the particle size (L) of the fine particles and the thickness (H) of the fine particles satisfy H / L ≧ 1/30. This is because, if the ratio of the fine particle thickness (H) to the fine particle diameter (L) is in the above range, the three-dimensional shape can be easily recognized by light reflection and can be easily identified.

  The fine particles of the present invention preferably contain at least one selected from the group consisting of an ultraviolet light emitting material, an infrared light emitting material, an infrared reflecting material, an infrared absorbing material, a quantum dot material, and a magnetic material. This is because the fine particles can be easily seen, authenticity determination is facilitated, and the effect of preventing forgery can be improved.

  Furthermore, the fine particles of the present invention preferably have a resin layer and a metal layer formed on the surface of the fine particles. This is because the formation of the metal layer on the surface of the fine particles having a three-dimensional shape makes it easy to visually recognize the three-dimensional shape by light reflection, facilitates authenticity determination, and improves the forgery prevention effect.

The present invention also provides an anti-counterfeit ink and an anti-counterfeit toner characterized by containing the above-mentioned fine particles.
In the present invention, since the fine particles described above are contained, it is possible to obtain an anti-counterfeit medium excellent in the anti-counterfeit effect by using the anti-counterfeit ink and anti-counterfeit toner of the present invention. In addition, when the anti-counterfeit ink and the anti-counterfeit toner of the present invention are used as an anti-counterfeit medium, the anti-counterfeit ink of the present invention is applied on a support, or the anti-counterfeit of the present invention is applied on a support. By transferring the toner or the like, the fine particles can be easily fixed on the support, so that it can be used for various supports and has a wide range of options such as the shape of the support. Have

Furthermore, the present invention provides an anti-counterfeit sheet characterized by having a fine particle-containing layer in which the fine particles described above are dispersed in a transparent resin.
In the present invention, the anti-counterfeit medium having an anti-counterfeiting effect can be obtained by using the anti-counterfeit sheet according to the present invention because it has the fine particle-containing layer containing the above-described fine particles. In addition, since the number and positions of the fine particles in the anti-counterfeit sheet of the present invention can be applied to the anti-counterfeit medium, it is possible to realize advanced anti-counterfeiting.

The present invention also provides a forgery prevention medium characterized in that the above-mentioned fine particles are fixed on a support.
In the anti-counterfeit medium of the present invention, the above-mentioned fine particles are used, which is very useful for preventing forgery. Further, in the present invention, it is possible to easily determine the authenticity using only a simple instrument such as a loupe.

  The present invention also relates to a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and having at least a curved surface, and a sacrificial layer having a solvent solubility and a photosensitive layer on a substrate. A layered body preparation step for preparing a layered body in which photosensitive resin layers are sequentially stacked, an exposure development step for performing gradation treatment on the photosensitive resin layer, performing a development process, and forming the three-dimensional shape, and the sacrificial layer And a sacrificial layer dissolving step for dissolving the particles.

  In the present invention, since the photosensitive resin layer is subjected to gradation exposure to produce fine particles having a predetermined three-dimensional shape, it is possible to produce fine particles with high productivity and low cost. In the present invention, since the photosensitive resin layer is subjected to gradation exposure, a complicated three-dimensional shape can be formed, and fine particles having an excellent anti-counterfeit effect can be obtained.

  Furthermore, the present invention is a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and observing, wherein the three-dimensional shape has at least a curved surface, and a laminate in which a photosensitive resin layer is formed on a substrate A layered body preparation step, and a gradation exposure to the photosensitive resin layer, a development process, and an exposure and development step of forming a three-dimensional shape opposite to the three-dimensional shape or the three-dimensional shape, There is provided a method for producing fine particles, comprising: an original plate forming step for forming an original plate; and a fine particle forming step for forming the fine particles using the original plate.

  In the present invention, since fine particles having a predetermined three-dimensional shape are produced using an original plate, various materials such as resin components and metals can be used for the formation of fine particles, and the advantage that the choice of fine particle materials is widened. Have Further, according to the present invention, the photosensitive resin layer is subjected to gradation exposure to produce an original plate, so that it is possible to produce fine particles with good productivity and low cost. Furthermore, in the present invention, since the photosensitive resin layer is subjected to gradation exposure, a complicated three-dimensional shape can be formed, and fine particles having an excellent anti-counterfeit effect can be obtained.

  In the said invention, it is preferable to perform drawing directly on the said photosensitive resin layer with a drawing apparatus in the gradation exposure of the said exposure and development process. In the above invention, it is also preferable to use a gradation mask in gradation exposure in the exposure and development process. This is because a complicated three-dimensional shape can be formed.

  In the present invention, the information that can be identified by magnifying and observing is a three-dimensional shape having at least a curved surface, so that it is difficult to produce fine particles as compared with a conventional flat surface, The anti-counterfeiting effect can be improved and various designs can be achieved.

It is the top view and sectional drawing which show an example of the microparticles | fine-particles of this invention. It is the perspective view and side view which show the other example of the microparticles | fine-particles of this invention. It is the top view and sectional drawing which show the other example of the microparticles | fine-particles of this invention. It is a schematic sectional drawing which shows the other example of the microparticles | fine-particles of this invention. It is a schematic sectional drawing which shows an example of the sheet for forgery prevention of this invention. It is a schematic sectional drawing which shows the other example of the sheet for forgery prevention of this invention. It is a schematic sectional drawing which shows the other example of the sheet for forgery prevention of this invention. It is a schematic sectional drawing which shows the other example of the sheet for forgery prevention of this invention. It is a schematic sectional drawing which shows the other example of the sheet for forgery prevention of this invention. It is a schematic sectional drawing which shows the other example of the sheet for forgery prevention of this invention. It is a schematic diagram which shows an example of the inspection method of the forgery prevention sheet of this invention. It is the top view and sectional view showing an example of the forgery prevention medium of the present invention. It is the top view, sectional view, and perspective view showing other examples of the forgery prevention medium of the present invention. It is process drawing which shows an example of the manufacturing method of the microparticles | fine-particles of this invention. It is process drawing which shows the other example of the manufacturing method of the microparticles | fine-particles of this invention. It is process drawing which shows the other example of the manufacturing method of the microparticles | fine-particles of this invention. It is process drawing which shows the other example of the manufacturing method of the microparticles | fine-particles of this invention. It is the top view and sectional drawing which show an example of the conventional microparticles | fine-particles.

  Hereinafter, the fine particle, the anti-counterfeit ink, the anti-counterfeit toner, the anti-counterfeit sheet, the anti-counterfeit medium, and the fine particle production method of the present invention will be described in detail.

A. Fine particles The fine particles of the present invention have a three-dimensional shape that can be identified by magnifying and observing, and the three-dimensional shape has at least a curved surface.

The fine particles of the present invention will be described with reference to the drawings.
1A and 1B are schematic views showing an example of the fine particles of the present invention. FIG. 1A is a top view, and FIG. 1B is a cross-sectional view taken along line AA in FIG. It is. The fine particles 1 shown in FIGS. 1 (a) and 1 (b) have a front surface 5 and a back surface 6, and have a three-dimensional shape 2 (teapot) that can be identified by magnifying and observing on the front surface 5. The solid shape 2 is a curved surface.

  FIGS. 2A to 2C are schematic views showing other examples of the fine particles of the present invention, FIGS. 2A and 2B are perspective views, and FIG. 2C is a side view. The fine particles 1A to 1C shown in FIGS. 2 (a) to 2 (c) each have a front surface 5 and a back surface 6, and can be identified by observing the surface 5 in an enlarged manner (D • N • P). The three-dimensional shape 2 is a curved surface.

  18 (a) and 18 (b) are schematic views showing an example of conventional fine particles, FIG. 18 (a) is a top view, and FIG. 18 (b) is a sectional view taken along the line XX of FIG. 18 (a). is there. The fine particles 101 shown in FIGS. 18A and 18B have, for example, concave portions formed in a pattern on the surface of the metal multilayer film 103, and can be identified by magnifying and observing portions 102 (stars). The identifiable portion 102 is a flat surface.

  According to the present invention, since the information that can be identified by magnifying and observing is a three-dimensional shape having at least a curved surface, it is difficult to produce fine particles as compared with the conventional one configured by a plane. It is possible to improve the anti-counterfeit effect. Further, according to the present invention, since the choice of identifiable information that can be expressed is widened by using a three-dimensional shape having at least a curved surface, a variety of designs are possible, and the self-other identification function can be exhibited. .

  Hereinafter, each structure in the fine particles of the present invention will be described.

1. Three-dimensional shape The three-dimensional shape in the present invention is identifiable by magnifying and observing, and has at least a curved surface.

  In addition, “identifiable by magnifying and observing” is difficult to identify by visual observation, and can be identified by magnifying and observing using a simple magnifier such as a magnifying glass or a microscope. It means that.

Whether the three-dimensional shape has at least a curved surface can be confirmed by measuring reflection characteristics. A plane has a single normal direction, whereas a curved surface has a normal direction that varies depending on the location. Therefore, the brightness of reflected light differs between a flat surface and a curved surface. Further, the change in brightness of reflected light when the incident angle of light is changed is different between the flat surface and the curved surface.
Specifically, it can be confirmed that the three-dimensional shape has a curved surface by a destructive or non-destructive inspection method.
Examples of the destructive inspection method include a method of confirming by cutting fine particles with a cutter, a razor, a microtome, etc., and magnifying and observing with a loupe or a microscope.
Non-destructive inspection methods include a method of confirming by performing contact-type or non-contact-type shape measurement. The contact-type shape measurement includes, for example, a technique using a stylus-type shape measuring machine that measures a shape by bringing a needle into contact with a fine particle and moving it. Non-contact type shape measurement uses, for example, white light with low coherence as a light source and uses an optical path interferometer such as a Mirau type or a Michelson type, and the optical path position (interference) of each CCD pixel corresponding to the measurement surface. There is a method using a scanning white interferometer that measures the shape by a method of finding the position where the intensity is maximum by scanning the interferometer objective lens vertically.

  The three-dimensional shape only needs to have at least a curved surface, for example, may have only a curved surface, or may have a curved surface and a flat surface.

  The size of the three-dimensional shape is not particularly limited as long as it can be identified by magnifying and observing, but specifically, it is preferably 300 μm or less, and more preferably 250 μm or less. This is because if the three-dimensional shape is too large, it can be visually observed and the forgery prevention effect may be reduced. In addition, the size of the three-dimensional shape is preferably observable using a simple magnifier such as a loupe, specifically 50 μm or more. This is because if it is possible to observe with a simple instrument such as a simple magnifier, the authenticity can be easily determined.

Such a three-dimensional shape may be any three-dimensional shape such as a person, animal, plant, food, tool, vehicle, building, landscape, or a symbol such as a letter, number, code, or mark. These three-dimensional shapes can be shapes that match the application of the fine particles of the present invention, and can also be shapes that express a predetermined meaning.
The fine particles of the present invention may be one kind of fine particles having the same three-dimensional shape as illustrated in FIG. 1 (a), and two or more kinds having different three-dimensional shapes as illustrated in FIG. 2 (a). An aggregate of fine particles may be used.

2. Fine Particle Structure The fine particles of the present invention have the above three-dimensional shape.
The fine particles of the present invention need only have the three-dimensional shape as information that can be identified by magnifying and observing, for example, FIGS. 1 (a), (b) and FIGS. 2 (a) to (c). ) May have only the three-dimensional shape 2, and may have the three-dimensional shape 2 and the mark 3 as shown in FIGS. 3A and 3B.
3 (a) and 3 (b) are schematic views showing other examples of the fine particles of the present invention, FIG. 3 (a) is a top view, and FIG. 3 (b) is a cross-sectional view of FIG. FIG.

  The size of the mark is not particularly limited as long as it can be identified by magnifying and observing, but specifically, it is preferably 300 μm or less, and more preferably 250 μm or less. This is because if the mark is too large, it can be visually observed and the forgery prevention effect may be reduced. The size of the mark is preferably observable using a simple magnifier such as a magnifying glass, specifically 50 μm or more. This is because if it is possible to observe with a simple instrument such as a simple magnifier, the authenticity can be easily determined. Note that the size of the mark may be 50 μm or less. In this case, authentication with a simple instrument is difficult, but observation with a microscope or the like is possible. If the mark becomes smaller, the manufacturing becomes difficult and the forgery prevention effect becomes higher.

Examples of the mark include symbols such as letters, numbers, codes, marks, and the like. These marks can be marks according to the application of the fine particles of the present invention, and can be marks expressing a predetermined meaning.
The fine particles of the present invention may be one kind of fine particles having the same three-dimensional shape and having the same mark, or an aggregate of two or more kinds of fine particles having the same three-dimensional shape and having different marks. There may be.

The fine particles of the present invention usually have a surface 5 having a three-dimensional shape 2 and a back surface 6 facing the surface 5 as illustrated in FIGS. 1B, 2C, and 3B. Have. Although not shown, the fine particles of the present invention may have a front surface, a back surface, and a side surface.
In the present invention, since the fine particles have a three-dimensional shape on the surface, and the three-dimensional shape has at least a curved surface, the fine particles have at least a curved surface on the surface. Thus, the fine particles only need to have at least a curved surface on the surface. For example, the fine particles may have only a curved surface, or may have a curved surface and a flat surface.
Among these, it is preferable that 50% or more of the surface of the fine particles is constituted by a curved surface, and more preferably 75% or more is constituted by a curved surface. This is because the greater the proportion of the curved surface on the surface of the fine particles, the easier it is to visually recognize the three-dimensional shape due to the reflection of light and the easier it is to identify.
The ratio of the curved surface can be measured by the destructive or non-destructive inspection method described above.

  The particle size of the fine particles of the present invention is not particularly limited as long as it can be observed by enlarging, but specifically, it is preferably 300 μm or less, and more preferably 250 μm or less. If the particle size of the fine particles is too large, the particles can be visually observed, and the position of the fine particles is specified when used in the anti-counterfeit medium, which may reduce the anti-counterfeit effect. The particle diameter of the fine particles is preferably observable with a simple magnifier such as a magnifying glass, specifically 50 μm or more. This is because if it is possible to observe with a simple instrument such as a simple magnifier, the authenticity can be easily determined. Further, if the particle size of the fine particles is too small, it may be difficult to form a three-dimensional shape on the surface of the fine particles.

  The particle size is generally used to indicate the particle size of the particle, and is a value measured by a laser method in the present invention. The laser method is a method of measuring an average particle size, a particle size distribution, and the like by dispersing particles in a solvent and thinning and calculating scattered light obtained by applying a laser beam to the dispersion solvent. The particle size is a value measured using a particle size analyzer Microtrac UPA Model-9230 manufactured by Leeds & Northrup as a particle size measuring device by a laser method.

The thickness of the fine particle of the present invention is not particularly limited as long as it can form a three-dimensional shape on the surface of the fine particle, but is preferably in the range of 1 μm to 100 μm, and is preferably in the range of 5 μm to 25 μm. More preferably, it is within. If the thickness of the fine particles is within the above range, the three-dimensional shape can be easily visually recognized by the reflection of light, and can be easily identified. On the other hand, if the fine particles are too thick, it may be difficult to produce the fine particles. If the fine particles are too thin, it is difficult to form a three-dimensional shape on the surface of the fine particles, or the strength of the fine particles is weak. It may become.
The thickness of the fine particles mentioned above refers to the thickness of the fine particles in a cross section substantially perpendicular to the back surface of the fine particles. For example, the thickness H of the fine particles as shown in FIG.

In the present invention, the particle size (L) of the fine particles and the thickness (H) of the fine particles preferably satisfy H / L ≧ 1/30, and more preferably satisfy H / L ≧ 1/20. More preferably, H / L ≧ 1/10 is satisfied. This is because, if the ratio of the fine particle thickness (H) to the fine particle diameter (L) is in the above range, the three-dimensional shape can be easily recognized by light reflection and can be easily identified. On the other hand, if the ratio is too large, it may be difficult to produce fine particles, and if the ratio is too small, it may be difficult to form a three-dimensional shape on the surface of the fine particles. If the above ratio is small, the thickness (H) of the fine particles is also relatively small, and the strength of the fine particles may be weakened.
The particle size (L) of the fine particles refers to the particle size of the fine particles in plan view from the surface side of the fine particles. For example, as shown in FIG. 3A, when the fine particles 1 have a major axis L1 and a minor axis L2, the major axis L1 of the microparticles is set as the particle size of the microparticles. Further, the thickness (H) of the fine particles is the thickness of the fine particles in a cross section substantially perpendicular to the back surface of the fine particles, as described above. For example, the thickness H of the fine particles as shown in FIG.
The particle diameter (L) and thickness (H) of the fine particles can be measured by the destructive or non-destructive inspection method described above.

  The fine particles of the present invention may be colorless or colored, and are appropriately selected according to the material of the fine particles described later. When the fine particles are colored, the fine particles are easily visible and can be easily identified.

  The fine particles of the present invention may or may not have light permeability, and are appropriately selected according to the material of the fine particles described later. When the fine particles do not have optical transparency, the fine particles can be easily seen and identified.

3. Fine Particle Material The fine particle material of the present invention is not particularly limited as long as it is a material that can produce fine particles having the above three-dimensional shape. For example, a resin, a metal, a metal compound, or the like can be used. Examples of the resin include a curable resin such as a photocurable resin and a thermosetting resin, a thermoplastic resin, and a photosensitive resin. In addition, the metal and the metal compound are not particularly limited as long as they can be formed by vapor deposition, plating, or sputtering. As the metal compound, metal oxide, metal sulfide, or the like is used. Examples of metals and metal compounds include Al, ZnS, TiO ₂ , Cu, Au, and Pt.

  Of these, the fine particle material is preferably a resin. Functional materials such as ultraviolet light emitting materials, infrared light emitting materials, infrared reflecting materials, infrared absorbing materials, quantum dot materials, magnetic materials, and coloring materials, which will be described later, can be added to the resin. This is because it is easy to determine the authenticity and the forgery prevention effect can be improved. In addition, the resin can not only be finely processed, but also can improve production efficiency.

  The resin preferably has solvent resistance, and in particular, the resin may be insoluble in a solvent used in forming a fine particle-containing layer in which fine particles are dispersed in a transparent resin using the fine particles of the present invention. preferable.

Among the resins, a photosensitive resin is particularly preferable. This is because, as described in the section “E. Method for Producing Fine Particles”, which will be described later, the fine particles can be produced with good productivity and low cost by direct drawing, a gradation mask, or the like.
As the photosensitive resin, either a positive photosensitive resin or a negative photosensitive resin can be used.

  The fine particles of the present invention preferably have a resin layer 7 and a metal layer 8 formed on the surface 5 of the fine particles 1 and formed on the resin layer 7 as illustrated in FIG. This is because the formation of the metal layer on the surface of the fine particles having a three-dimensional shape makes it easy to visually recognize the three-dimensional shape by light reflection, facilitates authenticity determination, and improves the forgery prevention effect. In particular, when a fine particle-containing layer in which fine particles are dispersed in a transparent resin is formed using the fine particles of the present invention, when the fine particles are made of a resin, the difference in refractive index between the fine particles and the transparent resin is small. There is concern that the interface between the fine particles and the transparent resin will be difficult to see and it will be difficult to see the three-dimensional shape of the fine particles. However, the metal layer is formed on the surface of the fine particles, so that the three-dimensional shape is visible. Can be increased.

As the material for the resin layer, the above-mentioned resins can be used. Moreover, said metal and metal compound can be used as a material of a metal layer.
An example of a method for forming the metal layer is a vapor deposition method.
The thickness of the metal layer is not particularly limited as long as it can improve the visibility of a three-dimensional shape when a fine particle-containing layer in which fine particles are dispersed in a transparent resin is formed using the fine particles of the present invention. For example, it can be about 1 nm to 250 nm, and is preferably in the range of 10 nm to 100 nm. If the metal layer is too thick, the three-dimensional shape may be damaged. If the metal layer is too thin, it may be difficult to form the metal layer, or the effect of increasing the visibility of the three-dimensional shape may not be obtained. Because there is a possibility of doing.

When the fine particles of the present invention contain a resin, the fine particles are functional materials such as ultraviolet light emitting materials, infrared light emitting materials, infrared reflecting materials, infrared absorbing materials, quantum dot materials, magnetic materials, and coloring materials such as pigments and dyes. It is preferable to contain. This is because, as described above, it is easy to visually recognize the fine particles and it is easy to determine the authenticity. Among these, the fine particles of the present invention preferably contain at least one selected from the group consisting of an ultraviolet light emitting material, an infrared light emitting material, an infrared reflecting material, an infrared absorbing material, a quantum dot material, and a magnetic material. This is because these materials can be identified by the characteristics of the material and can improve the anti-counterfeit effect. In particular, the fine particles of the present invention preferably contain at least one selected from the group consisting of an ultraviolet light emitting material, an infrared light emitting material, and a quantum dot material. This is because identification is possible by light emission, and authenticity determination can be performed more easily.
Hereinafter, the functional materials will be described separately.

(1) Ultraviolet Light-Emitting Material As the ultraviolet light-emitting material used in the present invention, a material that emits fluorescence by absorbing ultraviolet light can be used. As the ultraviolet light-emitting material, either a material that emits light by absorption in a short wavelength region (about 200 nm to 300 nm) or a material that emits light by absorption in a long wavelength region (about 300 nm to 400 nm) can be used. This ultraviolet light emitting material is excited by ultraviolet light and has a spectrum peak emitted when returning to a lower energy level in the wavelength range such as blue, green, red, etc., and should be selected appropriately according to the purpose. Can do. Specific examples include Ca ₂ B ₅ O ₉ Cl: Eu ²⁺ , CaWO ₄ , ZnO: Zn, Zn ₂ SiO ₄ : Mn, Y ₂ O ₂ S: Eu, ZnS: Ag, YVO ₄ : Eu, Y _2. O ₃ : Eu, Gd ₂ O ₂ S: Tb, La ₂ O ₂ S: Tb, Y ₃ Al ₅ O ₁₂ : Ce, Sr ₅ (PO ₄ ) ₃ Cl: Eu, 3 (Ba, Mg) O · 8Al ₂ O ₃ : Eu, Zn ₂ GeO ₄ : Mn, Y (P, V) O ₄ : Eu, 0.5MgF ₂ · 3.5MgO · GeO ₂ : Mn, ZnS: Cu, ZnS: Mn and the like. These may be used alone or in combination of two or more. Note that the composition of the ultraviolet light-emitting material is expressed by connecting the main component and the activator or the light emission center with “:”.

  The content of the ultraviolet light emitting material in the fine particles is not particularly limited as long as it can be distinguished by light emission, and can be about 1% by mass to 50% by mass.

(2) Infrared light emitting material As the infrared light emitting material used in the present invention, a material that emits fluorescence by absorbing infrared light can be used. The infrared light emitting material is excited by infrared light (about 800 nm to 1200 nm) and emits visible light (about 400 nm to 800 nm), and can be appropriately selected depending on the purpose. Specific examples include YF ₃ : Yb + Er, YF ₃ : Yb + Tm, BaFCl: Yb + Er, and the like. In addition, the said infrared luminescent material has described the composition by connecting a main component, an activator, or a luminescent center by ":".

  The content of the infrared light emitting material in the fine particles is not particularly limited as long as it can be identified by light emission, and can be about 1% by mass to 50% by mass.

(3) Infrared reflective material As the infrared reflective material used in the present invention, a material having wavelength selective reflectivity with respect to infrared can be used. For example, a multilayer structure material, an infrared reflective pigment, a liquid crystal material having a cholesteric structure Etc. The wavelength of infrared rays reflected by the infrared reflecting material is not particularly limited, but is usually 800 nm to 2500 nm.

Examples of the multilayer structure material include a multilayer structure material composed of a layer having an infrared reflection surface (infrared reflection layer) formed at intervals that reflect infrared rays. The multilayer structure material reflects infrared light having a specific wavelength by Bragg reflection of each layer (infrared reflective layer).
Specifically, the infrared reflective layer can be formed using a multilayer liquid crystal material having a fixed cholesteric structure such as a crosslinked cholesteric liquid crystal.

As the infrared reflective pigment, powder and particles of an infrared reflective material are used, and any of inorganic pigments and organic pigments can be used. Examples of inorganic pigments include composite metal oxides such as titanium oxide (TiO ₂ ), zinc oxide, zinc sulfide, lead white, antimony oxide, zirconium oxide, indium tin oxide (ITO), and antimony-doped tin oxide (ATO). , Metals such as aluminum, gold, and copper. Further, as an inorganic pigment, a transparent support material such as natural or synthetic mica, another foliar silicate, glass flake, flaky silicon dioxide or aluminum oxide described in JP-A-2004-4840, and a metal oxide An interference pigment made of a coating can also be used. On the other hand, examples of the organic pigment include pigments described in JP-A-2005-330466 and JP-A-2002-249676, and examples thereof include azo, anthraquinone, phthalocyanine, perinone / perylene, Indigo / thioindigo, dioxazine, quinacridone, isoindolinone, isoindoline, diketopyrrolopyrrole, azomethine, and azomethine azo organic dyes can be used.

  Examples of the liquid crystal material having a cholesteric structure (so-called cholesteric liquid crystal material) include a chiral nematic liquid crystal material obtained by mixing a nematic liquid crystal with a chiral agent, or a polymer cholesteric liquid crystal material.

  The content of the infrared reflecting material in the fine particles is not particularly limited as long as identification by infrared reflection is possible, and can be about 0.1% by mass to 50% by mass.

(4) Infrared absorbing material The infrared absorbing material used in the present invention is not particularly limited as long as the material can absorb infrared rays (800 nm to 1100 nm). Among them, an infrared absorbing material that absorbs a wavelength range of 800 nm to 1100 nm and has a sufficient light transmittance in the visible light range, that is, in a wavelength range of 380 nm to 780 nm is preferable.

  Examples of infrared absorbing materials include polymethine compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, naphthoquinone compounds, anthraquinone compounds, dithiol compounds, immonium compounds, diimonium compounds, aminium compounds, Pyryllium compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes, benzenedithiol metal complex anions disclosed in JP 2007-163644 and cyanine dye cations Organic infrared absorbing materials such as counterion conjugates, and composite tungsten oxide, tin oxide, indium oxide, magnesium oxide, titanium oxide, chromium oxide, dioxide oxide disclosed in JP-A-2006-154516 Koniumu, nickel oxide, aluminum oxide, zinc oxide, iron oxide, ammonium, lead oxide, bismuth oxide, lanthanum oxide, tungsten oxide, and inorganic infrared absorbing material such as indium tin oxide (ITO). An infrared absorption material can be used individually or in combination of 2 or more types. The “system compound” refers to an anthraquinone derivative in the case of an anthraquinone compound, for example.

  The infrared absorbing material is preferably selected as appropriate depending on the type of resin used. For example, when a photocurable resin or a photosensitive resin is used, an inorganic near-infrared absorbing material such as composite tungsten oxide can be suitably used as the infrared absorbing material.

  The content of the infrared absorbing material in the fine particles is not particularly limited as long as it can be identified by absorption of infrared rays, but is preferably in the range of 0.1% by mass to 10% by mass. This is because if the content of the infrared absorbing material is within the above range, a sufficient infrared absorbing function can be exhibited and a sufficient amount of visible light can be transmitted.

(5) Quantum dot materials Quantum dot materials are semiconductor nanometer-size microparticles that are unique due to the quantum confinement effect (quantum size effect) in which electrons and excitons are confined in small nanometer-size crystals. It shows typical optical and electrical properties and is also called a semiconductor nanoparticle or a semiconductor nanocrystal.
The quantum dot material used in the present invention is not particularly limited as long as it is a nanometer-sized fine particle of a semiconductor and produces a quantum confinement effect (quantum size effect). For example, there are semiconductor fine particles whose emission color is regulated by their own particle size and semiconductor fine particles having a dopant.

  The quantum dot material may be composed of one type of semiconductor compound or may be composed of two or more types of semiconductor compounds. For example, the quantum dot material is composed of a core composed of a semiconductor compound and a semiconductor compound different from the core. You may have a core shell type structure which has a shell. As a typical example, a core made of CdSe, a ZnS shell provided around the core, and a protective material (also referred to as a capping material) provided around the core can be exemplified. This quantum dot material has a different emission color depending on its particle size. For example, in the case of a quantum dot composed only of a core made of CdSe, the particle size is 2.3 nm, 3.0 nm, 3.8 nm. The peak wavelengths of the fluorescence spectrum at 4.6 nm are 528 nm, 570 nm, 592 nm, and 637 nm.

  Specifically, the core material of the quantum dot material is MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, II-VI semiconductor compounds such as HgS, HgSe and HgTe, III such as AlN, AlP, AlAs, AlSb, GaAs, GaP, GaN, GaSb, InN, InAs, InP, InSb, TiN, TiP, TiAs and TiSb A semiconductor crystal containing a semiconductor compound or semiconductor such as a group V semiconductor compound, a group IV semiconductor such as Si, Ge, and Pb can be exemplified. Alternatively, a semiconductor crystal including a semiconductor compound containing three or more elements such as InGaP can be used.

Further, as a quantum dot material composed of semiconductor fine particles having a dopant, a semiconductor crystal obtained by doping the semiconductor compound with a rare earth metal cation or a transition metal cation such as Eu ³⁺ , Tb ³⁺ , Ag ⁺ , or Cu ⁺ is used. Can also be used.

  Among these, semiconductor crystals such as CdS, CdSe, CdTe, InP, and InGaP are preferable from the viewpoints of ease of fabrication, controllability of the particle size for obtaining light emission in the visible range, and fluorescence quantum yield.

When a core-shell type quantum dot material is used, the semiconductor constituting the shell is a material having a higher band gap than the semiconductor compound forming the core so that excitons are confined in the core. Luminous efficiency can be increased.
Examples of the core-shell structure (core / shell) having such a bandgap relationship include CdSe / ZnS, CdSe / ZnSe, CdSe / CdS, CdTe / CdS, InP / ZnS, Gap / ZnS, Si / ZnS, Examples include InN / GaN, InP / CdSSe, InP / ZnSeTe, InGaP / ZnSe, InGaP / ZnS, Si / AlP, InP / ZnSTe, InGaP / ZnSTe, and InGaP / ZnSSe.

  The size of the quantum dot may be appropriately controlled depending on the material constituting the quantum dot so that light having a desired wavelength can be obtained. As the particle size of the quantum dot decreases, the energy band gap increases. That is, as the crystal size decreases, the light emission of the quantum dots shifts to the blue side, that is, to the high energy side. Therefore, by changing the size of the quantum dot, the emission wavelength can be adjusted over the entire wavelength range of the ultraviolet region, the visible region, and the infrared region.

  In general, the particle size (diameter) of the quantum dots is preferably in the range of 0.5 nm to 20 nm, and particularly preferably in the range of 1 nm to 10 nm. The narrower the quantum dot size distribution, the clearer the emission color.

  Further, the shape of the quantum dot is not particularly limited, and may be, for example, a spherical shape, a rod shape, a disk shape, or other shapes. When the particle dot is not spherical, the particle size of the quantum dot can be a true spherical value having the same volume.

  Information such as the particle size, shape, and dispersion state of the quantum dots can be obtained by a transmission electron microscope (TEM). The crystal structure and particle size of the quantum dots can be known by X-ray crystal diffraction (XRD). Furthermore, the information regarding the particle size and surface of a quantum dot can also be obtained by an ultraviolet-visible (UV-Vis) absorption spectrum.

  The content of the quantum dot material in the fine particles is not particularly limited as long as it can be identified by light emission, and can be about 0.1% by mass to 50% by mass.

(6) Magnetic material Magnetic materials used in the present invention include nuclear magnetic resonance (NMR), nuclear quadrupole resonance (NQR), electron spin resonance (ESR), ferromagnetic resonance, antiferromagnetic resonance, ferrimagnetic resonance, Those exhibiting magnetic resonance such as domain wall resonance, spin wave resonance, and spin echo resonance can be used.

Since the resonance frequency is determined by the magnetic rotation ratio γ, which is a parameter unique to the nucleus, and the magnetic field strength of the external magnetic field, the presence of the fine particles of the present invention can be determined by selecting the resonance frequency at which the magnetic material exhibits magnetic resonance. Can be recognized, and authenticity determination can be performed.
For example, when fine particles containing a magnetic material and fine particles not containing a magnetic material are irradiated with electromagnetic waves having a frequency at which the magnetic material exhibits nuclear magnetic resonance, the fine particles containing the magnetic material undergo resonance absorption and contain the magnetic material. Since the resonance absorption does not occur in the fine particles that do not, the presence of the fine particles can be recognized by observing the resonance absorption, and the authenticity determination can be performed. Further, in the obtained NMR spectrum, the position, intensity, half-value width, shape, etc. of the signal differ depending on the structure and energy state of the substance, so that it can be identified by the type of magnetic material used.

  As the magnetic material, powder or particles of magnetic material are used. Examples of the magnetic material include fine particles exhibiting magnetic resonance described in JP-A-2005-309418.

  The content of the magnetic material in the fine particles is not particularly limited as long as it can be identified by magnetic resonance, but is preferably in the range of 1% by mass to 30% by mass, and 5% by mass to 20% by mass. % Is more preferable. This is because if the content of the magnetic material is too small, identification becomes difficult, and if the content of the magnetic material is too large, it may be difficult to form a three-dimensional shape on the surface of the fine particles.

(7) Coloring material Examples of the coloring material used in the present invention include pigments and dyes.
The coloring material is not particularly limited as long as it can be contained in fine particles, and general pigments and dyes can be used.

  As content of the coloring material in microparticles | fine-particles, it can be set as about 0.1 mass%-50 mass%.

4). Method for Producing Fine Particles The method for producing fine particles of the present invention is described in the section “F. Method for Producing Fine Particles”, which will be described later.

5. Applications The fine particles of the present invention are suitable for anti-counterfeiting applications, such as gold vouchers, gift cards, credit cards, ID cards, passports, driver's licenses, branded products, automobile parts, precision equipment parts, home appliances, cosmetics, pharmaceuticals, It can be used for foods, OA supplies, sports equipment, CDs, DVDs, software, tobacco, liquor, etc.

B. Anti-counterfeit Ink The anti-counterfeit ink of the present invention is characterized by containing the above-mentioned fine particles.
In the present invention, since the fine particles described above are contained, it is possible to obtain an anti-counterfeit medium having an excellent anti-counterfeit effect by using the anti-counterfeit ink of the present invention. Further, when applying the anti-counterfeit ink of the present invention to an anti-counterfeit medium, the fine particles can be easily fixed on the support by applying the anti-counterfeit ink of the present invention on the support. Therefore, it can be used for various supports and has an advantage that the range of selection of the shape of the support is wide.
Hereinafter, each configuration in the anti-counterfeit ink of the present invention will be described.

1. Fine Particles The fine particles used in the present invention are described in detail in the section “A. Fine Particles”, and the description thereof is omitted here.

  As the fine particles, one kind of fine particles may be used, or two or more kinds of fine particles may be used. For example, one type of fine particles having the same three-dimensional shape may be used, or two or more types of fine particles having different three-dimensional shapes may be used. One kind of fine particles having the same three-dimensional shape and the same mark may be used, or two or more kinds of fine particles having the same three-dimensional shape and having different marks may be used. When two or more kinds of fine particles are used, the fine particles can be used in combination so as to express a predetermined meaning.

  The content of the fine particles in the anti-counterfeit ink is not particularly limited as long as the anti-counterfeit ink of the present invention is used as an anti-counterfeit medium, and authenticity can be determined by the fine particles. 0.01 It can be set to about mass% to 50 mass%.

2. Transparent resin component The anti-counterfeit ink of the present invention is usually obtained by dispersing the above-mentioned fine particles in a transparent resin component.

The light transmittance of the transparent resin component used in the present invention is such that the fine particles can be observed when the fine particle-containing layer in which the fine particles are dispersed in the transparent resin is formed using the anti-counterfeit ink of the present invention. Although not particularly limited, it is preferable that the total light transmittance in the visible region is 10% or more when the transparent resin component is formed with a predetermined thickness.
In addition, the said total light transmittance is the value measured based on JISK7105.

  The transparent resin component is not particularly limited as long as it satisfies the above light transmittance, and for example, any of a photocurable resin component, a thermosetting resin component, and a thermoplastic resin component can be used. Among these, curable resin components such as a photocurable resin component and a thermosetting resin component are preferable, and a photocurable resin component is particularly preferable. By using a photocurable resin component, it becomes possible to apply the anti-counterfeit ink of the present invention to a support having low heat resistance, and the options for use are widened. In addition, when the anti-counterfeit ink of the present invention is used to form a fine particle-containing layer in which fine particles are dispersed in a transparent resin, production efficiency can be improved.

3. Functional material The anti-counterfeit ink of the present invention contains functional materials such as an ultraviolet light emitting material, an infrared light emitting material, an infrared reflecting material, an infrared absorbing material, and a quantum dot material in addition to the fine particles and the transparent resin component. It may be.

  For example, when the anti-counterfeiting ink contains an ultraviolet light emitting material or an infrared light emitting material and the fine particles do not contain an ultraviolet light emitting material or an infrared light emitting material, the position of the fine particles is specified by the presence or absence of light emission. This makes it possible to easily determine the authenticity and improve the forgery prevention effect. In addition, when the anti-counterfeit ink contains an ultraviolet light emitting material or an infrared light emitting material, and the fine particles also contain an ultraviolet light emitting material or an infrared light emitting material, the position of the fine particles should be specified by the wavelength of light emission. This makes it possible to easily determine the authenticity and improve the forgery prevention effect.

  When the anti-counterfeiting ink contains an infrared reflecting material or infrared absorbing material, and the fine particles do not contain an infrared reflecting material or infrared absorbing material, the position of the fine particles is specified by the presence or absence of infrared absorption or reflection. This makes it possible to easily determine the authenticity and improve the anti-counterfeit effect. Further, when the anti-counterfeit ink contains an infrared reflecting material or an infrared absorbing material, and the fine particles also contain an infrared reflecting material or an infrared absorbing material, the position of the fine particles depends on the wavelength of the absorbed infrared rays. This makes it possible to determine the authenticity and to improve the effect of preventing forgery.

  When the anti-counterfeit ink contains a quantum dot material, and the fine particles do not contain a quantum dot material, the position of the fine particles can be specified by the presence or absence of light emission, and the authenticity determination becomes easy. It becomes possible to improve the anti-counterfeit effect. In addition, when the anti-counterfeit ink contains a quantum dot material, and the fine particles also contain a quantum dot material, the position of the fine particles can be specified by the wavelength of light emission, and authenticity determination is easy. In addition, it is possible to improve the forgery prevention effect.

  The functional material is the same as that described in the above section “A. Fine particles”, and the description thereof is omitted here.

  The content of the ultraviolet light emitting material in the anti-counterfeit ink is not particularly limited as long as it can be identified by light emission, and can be about 1% by mass to 50% by mass.

  The content of the infrared light emitting material in the anti-counterfeit ink is not particularly limited as long as it can be identified by light emission, and can be about 1% by mass to 50% by mass.

  The content of the infrared reflective material in the anti-counterfeit ink is not particularly limited as long as identification by infrared reflection is possible, and can be about 0.1% by mass to 50% by mass.

  The content of the infrared absorbing material in the anti-counterfeit ink is not particularly limited as long as it can be identified by absorbing infrared rays, but is preferably in the range of 0.1% by mass to 10% by mass. . This is because if the content of the infrared absorbing material is within the above range, a sufficient infrared absorbing function can be exhibited and a sufficient amount of visible light can be transmitted.

  The content of the quantum dot material in the anti-counterfeit ink is not particularly limited as long as it can be identified by light emission, and can be about 0.1% by mass to 50% by mass.

4). Solvent The anti-counterfeit ink of the present invention may contain a solvent. The solvent is not particularly limited as long as the fine particles and the transparent resin component are dispersed, and is appropriately selected according to the application method of the anti-counterfeit ink. Moreover, a solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
For example, when used as an ink for gravure printing, toluene, ethyl acetate, methyl ethyl ketone, isopropyl alcohol and the like can be mentioned. When used as offset printing ink or silk screen printing ink, high-boiling petroleum solvents (hydrocarbons having 15 or more carbon atoms (C15 or more)) can be used.

  The solid content concentration of the anti-counterfeit ink of the present invention is not particularly limited as long as the anti-counterfeit ink can be applied to the anti-counterfeit medium, and can be about 20% by mass to 85% by mass.

C. Anti-Counterfeit Toner The anti-counterfeit toner of the present invention is characterized by containing the above-mentioned fine particles.
In the present invention, since the fine particles described above are contained, it is possible to obtain an anti-counterfeit medium having an excellent anti-counterfeit effect by using the anti-counterfeit toner of the present invention. Further, when applying the anti-counterfeit toner of the present invention to an anti-counterfeit medium, the fine particles can be easily fixed on the support by transferring the anti-counterfeit toner of the present invention onto the support. Therefore, it can be used for various supports and has an advantage that the range of selection of the shape of the support is wide.

The anti-counterfeit toner of the present invention may be any toner as long as it contains the above fine particles, and may be either a dry toner or a wet toner, and can be a general composition. The anti-counterfeit toner of the present invention can contain, for example, a main resin, a secondary resin, a colorant, a charge control agent, a fluidity control agent and the like.
The main resin is not particularly limited as long as it has light transmittance and the above fine particles are dispersed. The light transmittance of the main resin can be the same as the light transmittance of the transparent resin component in the forgery prevention ink described above. Styrene-acrylic and polyester are mainly used as the main resin. Polypropylene, polyethylene, and WAXs are used as the secondary resin. The main resin and auxiliary resin may be used alone or in combination of two or more.
Carbon, cyan pigment, magenta pigment, yellow pigment, etc. are used as the colorant. Charge control agents include positive and negative systems, and include those containing metals, resin systems, and quaternary ammonium salts. Silica or the like is used as the flow control agent.

  Since the fine particles can be the same as the fine particles in the above-described anti-counterfeit ink, description thereof is omitted here.

  The anti-counterfeit toner of the present invention may further contain a functional material such as an ultraviolet light emitting material, an infrared light emitting material, an infrared reflecting material, an infrared absorbing material, or a quantum dot material. The functional material can be the same as the functional material in the forgery prevention ink described above.

D. Anti-Counterfeit Sheet The anti-counterfeit sheet of the present invention is characterized by having a fine particle-containing layer in which the fine particles described above are dispersed in a transparent resin.

The anti-counterfeit sheet of the present invention will be described with reference to the drawings.
FIG. 5 is a schematic sectional view showing an example of the anti-counterfeit sheet according to the present invention. The anti-counterfeit sheet 20 shown in FIG. 5 includes a fine particle-containing layer 22 in which predetermined fine particles 1 are dispersed in a transparent resin 21.

  In the present invention, the anti-counterfeit medium having an anti-counterfeiting effect can be obtained by using the anti-counterfeit sheet according to the present invention because it has the fine particle-containing layer containing the above-described fine particles. In addition, when applying ink containing fine particles on a support when applying the fine particles to an anti-counterfeit medium, there is a possibility that the fine particles are not present on the support if the amount of ink applied is small. However, in the present invention, since the number of fine particles in the anti-counterfeit sheet can be applied to the anti-counterfeit medium, the anti-counterfeit effect is surely obtained. Can be achieved. Furthermore, in the present invention, it is possible to map the positions of the fine particles in the anti-counterfeit sheet, and it is possible to realize advanced anti-counterfeiting. The anti-counterfeit sheet of the present invention also has an advantage that it can be easily applied to an anti-counterfeit medium. Furthermore, the anti-counterfeit sheet of the present invention can be easily laminated with other sheets, and the added value can be increased.

  FIG. 6 is a schematic cross-sectional view showing an example of the anti-counterfeit sheet according to the present invention. In the anti-counterfeit sheet 20 shown in FIG. 6, a release layer 23, an adhesive layer 24, and a fine particle-containing layer 22 in which predetermined fine particles 1 are dispersed in a transparent resin 21 are sequentially laminated.

  FIG. 7 is a schematic sectional view showing another example of the anti-counterfeit sheet of the present invention. The anti-counterfeit sheet 20 shown in FIG. 7 has a base material 25 and a fine particle-containing layer 22 formed on the base material 25 in which predetermined fine particles 1 are dispersed in a transparent resin 21. An adhesive layer 24 and a release layer 23 are sequentially laminated on the side.

  FIG. 8 is a schematic sectional view showing another example of the anti-counterfeit sheet of the present invention. The anti-counterfeit sheet 20 shown in FIG. 8 is formed on a base material 25, a fine particle-containing layer 22 formed on the base material 25, in which predetermined fine particles 1 are dispersed in a transparent resin 21, and the fine particle-containing layer 22. The adhesive layer 24 and the release layer 23 are sequentially laminated on the substrate 25 side.

  FIG. 9 is a schematic sectional view showing another example of the anti-counterfeit sheet of the present invention. In the anti-counterfeit sheet 20 shown in FIG. 9, a release layer 23, an adhesive layer 24, a hologram layer 27, and a fine particle-containing layer 22 in which predetermined fine particles 1 are dispersed in a transparent resin 21 are sequentially laminated. Yes.

  FIG. 10 is a schematic sectional view showing another example of the anti-counterfeit sheet of the present invention. The anti-counterfeit sheet 20 shown in FIG. 10 is formed on a substrate 25, a particle-containing layer 22 formed on the substrate 25, in which predetermined particles 1 are dispersed in a transparent resin 21, and the particle-containing layer 22. The hologram layer 27, the adhesive layer 24, and the release layer 23 are laminated in this order on the substrate 25 side.

Thus, the anti-counterfeit sheet of the present invention may have other configurations besides the fine particle-containing layer.
Hereinafter, each structure in the forgery prevention sheet of the present invention will be described.

1. Fine particle-containing layer The fine particle-containing layer in the present invention is obtained by dispersing the above-mentioned fine particles in a transparent resin.
Since the fine particles are described in the above section “A. Fine particles”, description thereof is omitted here.

  As the fine particles, one kind of fine particles may be used, or two or more kinds of fine particles may be used. For example, one type of fine particles having the same three-dimensional shape may be used, or two or more types of fine particles having different three-dimensional shapes may be used. One kind of fine particles having the same three-dimensional shape and the same mark may be used, or two or more kinds of fine particles having the same three-dimensional shape and having different marks may be used. When two or more kinds of fine particles are used, the fine particles can be used in combination so as to express a predetermined meaning.

The light transmittance of the transparent resin used in the present invention is not particularly limited as long as the fine particles in the fine particle-containing layer are observable. However, when the transparent resin layer is formed with the same thickness as the fine particle-containing layer, it is not visible. The total light transmittance in the region is preferably 10% or more.
In addition, the said total light transmittance is the value measured based on JISK7105.

The transparent resin is not particularly limited as long as it satisfies the above-described light transmittance. For example, any of a photocurable resin, a thermosetting resin, and a thermoplastic resin can be used. Among them, a curable resin such as a photocurable resin or a thermosetting resin is preferable, and a photocurable resin is particularly preferable. For example, as shown in FIGS. 7, 8, and 10, when the fine particle-containing layer 22 is formed on the substrate 25, a substrate having low heat resistance is also used by using a photocurable resin. This makes it possible to expand the options for use. Moreover, it is because the production efficiency of the anti-counterfeit sheet can be improved.
The transparent resin can be obtained by solidifying the transparent resin component described in the section “B. Anti-Counterfeit Ink”.

The content of the fine particles in the fine particle-containing layer is not particularly limited as long as the anti-counterfeit sheet of the present invention is used as an anti-counterfeit medium, and authenticity can be determined by the fine particles. It is preferable that at least one fine particle is contained per 1 cm ² .

  Moreover, when the fine particle-containing layer is formed on the substrate, the fine particle-containing layer may be formed on the entire surface of the substrate or may be formed in a pattern. When the pattern shape of the fine particle-containing layer is a shape that represents a predetermined meaning, the fine particles can be used as hidden information, and the effect of preventing forgery can be enhanced.

The film thickness of the fine particle-containing layer is not particularly limited as long as the anti-counterfeit sheet of the present invention is used as an anti-counterfeit medium, and the authenticity can be determined by the fine particles. The anti-counterfeit sheet of the present invention The layer structure and the type of transparent resin contained in the fine particle-containing layer are appropriately selected. For example, as shown in FIGS. 7, 8, and 10, when the fine particle-containing layer 22 is formed on the substrate 25, the film thickness of the fine particle-containing layer may be relatively thin. On the other hand, as illustrated in FIG. 5, when the fine particle-containing layer 22 is formed singly, the fine particle-containing layer is preferably relatively thick from the viewpoint of self-supporting property. Moreover, when the transparent resin contained in the fine particle-containing layer is a curable resin, it is preferable that the film thickness of the fine particle-containing layer is relatively thin from the viewpoint of suppressing cracking.
Specifically, the film thickness of the fine particle-containing layer can be about 0.1 μm to 500 μm, and is preferably in the range of 1 μm to 100 μm.

  Examples of the method for forming the fine particle-containing layer include a method in which the above-described anti-counterfeit ink is applied and solidified. For example, as shown in FIGS. 7, 8, and 10, when the fine particle-containing layer 22 is formed on the base material 25, the anti-counterfeiting ink is applied on the base material and solidified to form the fine particles. A containing layer can be formed. Further, as illustrated in FIG. 5, when the fine particle-containing layer 22 is formed alone, the anti-counterfeit ink is applied on the substrate and solidified, and then the fine particle-containing layer is peeled off from the substrate. Thus, the fine particle-containing layer can be obtained alone. The substrate used at this time may or may not have light transparency, and for example, a glass substrate, a resin substrate, or the like can be used.

Any method can be used as a method of applying the anti-counterfeit ink.
Further, the solidification method of the anti-counterfeit ink is appropriately selected according to the type of the transparent resin. In the case of a curable resin, a curing method using light or heat is used. In the case of a thermoplastic resin, a cooling method is used.

2. Base Material In the present invention, the fine particle-containing layer 22 may be formed on the base material 25 as illustrated in FIGS. 7, 8 and 10. This is because the strength of the anti-counterfeit sheet of the present invention can be increased and the handleability is improved. In particular, when the transparent resin contained in the fine particle-containing layer is a curable resin, the fine particle-containing layer is preferably relatively thin from the viewpoint of suppressing cracking of the fine particle-containing layer. Is preferably formed. In addition, when the anti-counterfeit sheet of the present invention is applied to an anti-counterfeit medium, as illustrated in FIG. 7, when the base material 25 is disposed on the surface side of the fine particle-containing layer 22, The fine particle-containing layer can be protected by the substrate. In the case of the layer configuration illustrated in FIGS. 7 and 10, a transparent substrate is used, and in the case of the layer configuration illustrated in FIG. 8, an opaque substrate can be used.

  The base material used in the present invention may or may not have optical transparency, and is appropriately selected depending on the formation position of the base material. When the anti-counterfeit sheet of the present invention is applied to an anti-counterfeit medium, as illustrated in FIG. 7, the base material 25 is disposed on the surface side of the fine particle-containing layer 22, or FIG. In the case where the base material 25 is disposed so as to be on the surface side of the hologram layer 27, the base material preferably has optical transparency. On the other hand, when the anti-counterfeit sheet of the present invention is applied to an anti-counterfeit medium, as illustrated in FIG. 8, when the base material 25 is disposed so as to be on the back side with respect to the fine particle-containing layer 22. The base material may or may not have optical transparency.

  When the substrate has light transmittance, the light transmittance is not particularly limited as long as the fine particles in the fine particle-containing layer can be observed, but the total light transmittance in the visible region is preferably 10% or more. .

  Moreover, it is preferable that a base material has flexibility. This is because the anti-counterfeit sheet of the present invention can be applied to various forms of anti-counterfeit media.

  As such a base material, a general resin base material can be used. Examples thereof include resin base materials such as polyethylene terephthalate, polyvinyl chloride, polycarbonate, polypropylene, polyethylene, polystyrene, polyarylate, triacetyl cellulose, diacetyl cellulose, polymethyl methacrylate, polyimide, and polyamide.

The surface of the substrate is preferably subjected to an easy adhesion treatment in order to improve the adhesion with the fine particle-containing layer. The easy adhesion treatment is not particularly limited as long as the fine particle-containing layer and the substrate can be adhered to each other. For example, physical treatment such as plasma treatment, corona discharge treatment, glow discharge treatment, flame treatment, or chromium treatment A chemical treatment using an acid, a silane coupling agent, a primer agent, or the like can be given.
Among these, chemical treatment using a primer agent is preferable. In any case, the primer agent is suitable for treatment at the time of production of the substrate and for treatment of the surface of the substrate after production. A commercially available substrate can be used as the substrate treated with the primer agent. In addition, the primer agent for treating the surface of the substrate after production may be any one that can be in close contact with the anti-counterfeit ink.

  The thickness of the base material is appropriately selected according to the use and type of the anti-counterfeit sheet of the present invention, and can be set to about 1 μm to 800 μm, preferably in the range of 10 μm to 50 μm. .

3. Adhesive Layer In the present invention, as illustrated in FIGS. 6 to 10, the adhesive layer 24 may be laminated on the fine particle-containing layer 22. This is because the anti-counterfeit sheet of the present invention can be pasted through the adhesive layer.

  When the fine particle-containing layer is formed on the substrate, the adhesive layer may be laminated on the substrate side, or may be laminated on the fine particle-containing layer side. When a hard coat layer described later is formed on the fine particle-containing layer, the adhesive layer is disposed on the surface opposite to the hard coat layer. When the fine particle-containing layer and the hologram layer are laminated, an adhesive layer is disposed on the hologram layer side.

  The material of the pressure-sensitive adhesive layer is not particularly limited as long as the anti-counterfeit sheet of the present invention can be attached via the pressure-sensitive adhesive layer. For example, thermoplastic, thermosetting, photo-curing, and elastomeric materials can be used. Any of them can be used, and is appropriately selected according to the use and type of the anti-counterfeit sheet. When the anti-counterfeit sheet is used as a transfer foil, an adhesive layer having heat sealability is used.

The film thickness of the pressure-sensitive adhesive layer is not particularly limited as long as the anti-counterfeit sheet of the present invention can be attached via the pressure-sensitive adhesive layer, and can be, for example, about 1 μm to 100 μm.
A known method can be used as a method for forming the adhesive layer.

4). Release Layer In the present invention, as illustrated in FIGS. 6 to 10, the adhesive layer 24 and the release layer 23 may be sequentially laminated on the fine particle-containing layer 22. This is because the anti-counterfeit sheet of the present invention can be easily handled by laminating the adhesive layer and the release layer.
When the anti-counterfeit sheet of the present invention is applied to an anti-counterfeit medium, the release layer is peeled off and used.

  The release layer is not particularly limited as long as it has releasability. For example, a general resin substrate can be used.

5. Hard Coat Layer In the present invention, a hard coat layer 26 may be formed on the fine particle-containing layer 22 as illustrated in FIGS. 8 and 10. This is because the fine particle-containing layer can be protected by the hard coat layer.
When the anti-counterfeit sheet of the present invention is applied to an anti-counterfeit medium, the hard coat layer is arranged such that the hard coat layer 26 is on the surface side of the fine particle-containing layer 22 as illustrated in FIGS. Be placed.

  The hard coat layer is light transmissive. The light transmittance of the hard coat layer is not particularly limited as long as the fine particles in the fine particle-containing layer can be observed, but the total light transmittance in the visible region is preferably 10% or more, and more preferably 50% or more. It is preferable that it is 80% or more especially.

  The material of the hard coat layer is not particularly limited as long as it satisfies the above light transmittance and can protect the fine particle-containing layer. For example, a photocurable resin can be used.

The film thickness of the hard coat layer is not particularly limited as long as the fine particle-containing layer can be protected, and can be, for example, about 1 μm to 100 μm.
As a method for forming the hard coat layer, a known method can be used.

6). Hologram Layer In the present invention, as exemplified in FIGS. 9 and 10, a hologram layer 27 may be laminated on the fine particle-containing layer 22. This is because the hologram layer can enhance the forgery prevention effect.

The type of the hologram layer is not particularly limited, and may be a relief hologram layer or a volume hologram layer. The relief hologram layer is excellent in productivity, while the volume hologram layer is excellent in the forgery prevention effect.
A known hologram layer can be used.

  The hologram layer is disposed so that the hologram layer 27 is on the back side of the fine particle-containing layer 22 as illustrated in FIGS. 9 and 10 when the anti-counterfeit sheet of the present invention is applied to an anti-counterfeit medium. The Thereby, the fine particle-containing layer can be used as a protective layer of the hologram layer.

7). Anti-Counterfeit Sheet The anti-counterfeit sheet of the present invention may be a single sheet or a long sheet.

  Further, the shape of the anti-counterfeit sheet of the present invention is not particularly limited, and may be a rectangle, a polygon, a circle, an ellipse, or any other shape. When the shape of the anti-counterfeit sheet of the present invention is a shape that represents a predetermined meaning, the fine particles can be used as hidden information.

As the method for inspecting the anti-counterfeit sheet of the present invention, for example, as shown in FIG. 11, there is a method of irradiating the anti-counterfeit sheet 20 with LED illumination 51 and acquiring an image with a camera (line sensor) 52. be able to. In FIG. 11, the LED illumination 51 is disposed on the opposite side of the fine particle-containing sheet 20 from the camera 52 and the transmitted light is observed. LED illumination may be arranged to observe the reflected light.
In the anti-counterfeit sheet inspection device, the positions of the fine particles can be mapped, stored in a database, and collated.
In the inspection, if there is a region that does not contain the fine particles in the fine particle-containing layer, a laser marking device is used to mark the region that does not contain the fine particles, and the anti-counterfeit sheet has a predetermined shape. It may be eliminated.

The anti-counterfeit sheet of the present invention can be used as it is as a label or as a transfer foil. In addition, when the anti-counterfeit sheet has a hologram layer, it can also be used as a hologram label or a hologram transfer foil. Furthermore, the anti-counterfeit sheet can also be used as a laminate film on the anti-counterfeit medium.
Since the anti-counterfeit sheet itself can be light transmissive, it can be applied to various anti-counterfeit media.

Furthermore, when applying the anti-counterfeit sheet of the present invention to an anti-counterfeit medium, the anti-counterfeit sheet may be fixed to the surface of the anti-counterfeit medium, and the anti-counterfeit medium is composed of a plurality of layers. The anti-counterfeit sheet may be embedded in the anti-counterfeit medium, and when the anti-counterfeit medium is made of paper, the anti-counterfeit sheet may be cut into a thin strip and embedded in paper. When the anti-counterfeit sheet is fixed to the surface of the anti-counterfeit medium, the anti-counterfeit sheet may be attached as it is, or may be transferred by performing a transfer foil process. An example of the transfer method is a thermal transfer method.
The anti-counterfeit medium is described in the section “E. Anti-counterfeit medium”, which will be described later, and will not be described here.

E. Anti-Counterfeit Medium The anti-counterfeit medium of the present invention is characterized in that the above-mentioned fine particles are fixed on a support.

  12A and 12B are schematic views showing an example of the forgery prevention medium of the present invention. FIG. 12A is a top view, and FIG. 12B is a DD line in FIG. It is sectional drawing. In the anti-counterfeit medium 30 shown in FIGS. 12A and 12B, the fine particle-containing layer 22 in which the fine particles 1 are dispersed in the transparent resin 21 is fixed to the surface of the support 31.

  13A to 13C are schematic views showing other examples of the anti-counterfeit medium of the present invention. FIG. 13A is a top view, and FIG. 13B is an E-line in FIG. FIG. 13C is a perspective view showing a laminated structure of the anti-counterfeit medium. In the anti-counterfeit medium 30 shown in FIGS. 13A to 13C, a forgery comprising a first resin layer 32 and a fine particle-containing layer 22 in which the fine particles 1 are dispersed in a transparent resin 21 on a support 31. The anti-counterfeit sheet 20 and the second resin layer 33 are laminated, and the anti-counterfeit sheet 20 is embedded inside the anti-counterfeit medium 30. When the anti-counterfeit sheet is embedded in the anti-counterfeit medium, the anti-counterfeit sheet can be prevented from being peeled off and misused.

  In the anti-counterfeit medium of the present invention, the above-mentioned fine particles are used, which is very useful for preventing forgery. Further, in the present invention, it is possible to easily determine the authenticity using only a simple instrument such as a loupe.

Hereinafter, each structure in the forgery prevention medium of this invention is demonstrated.
Since the fine particles are described in detail in the section “A. Fine particles”, the description thereof is omitted here.

  As the fine particles, one kind of fine particles may be used, or two or more kinds of fine particles may be used. For example, one type of fine particles having the same three-dimensional shape may be used, or two or more types of fine particles having different three-dimensional shapes may be used. One kind of fine particles having the same three-dimensional shape and the same mark may be used, or two or more kinds of fine particles having the same three-dimensional shape and having different marks may be used. When two or more kinds of fine particles are used, the fine particles can be used in combination so as to express a predetermined meaning.

  Examples of the method for fixing the fine particles on the support include a method using the above-described anti-counterfeit ink, anti-counterfeit toner, and anti-counterfeit sheet. In the case of using the anti-counterfeit ink, there is a method in which the anti-counterfeit ink is applied on a support and solidified. When the anti-counterfeit toner is used, a method of transferring the anti-counterfeit toner onto the support can be used. When using the anti-counterfeit sheet, a method of fixing the anti-counterfeit sheet to the surface of the support, a method of laminating the support, the first resin layer, the anti-counterfeit sheet and the second resin layer, and the support is paper. In some cases, a method of cutting the anti-counterfeit sheet into strips and making it into paper can be mentioned. When fixing the anti-counterfeit sheet to the surface of the support, it may be applied as it is or transferred. Examples of the method of laminating the support, the first resin layer, the anti-counterfeit sheet, and the second resin layer include, for example, a method of laminating each layer through an adhesive layer, a method of laminating each layer by thermocompression bonding, and the like. be able to.

  The support used in the present invention is appropriately selected according to the use of the anti-counterfeit medium of the present invention. The support may or may not have optical transparency. Examples of the material for the support include glass, resin, metal, paper, and the like.

Moreover, when the support body, the 1st resin layer, the forgery prevention sheet, and the 2nd resin layer are laminated | stacked, the 1st resin layer does not need to have a light transmittance. In particular, when a functional layer (for example, an image receiving layer or a hologram layer) capable of recording or having arbitrary information is formed between the support and the first resin layer, the first resin layer transmits light. It is preferable to have properties. When the first resin layer has light transmittance, the light transmittance can be the same as the light transmittance of the base material constituting the anti-counterfeit sheet. As the first resin layer, for example, a general resin substrate can be used.
On the other hand, the second resin layer is light transmissive. The light transmittance of the second resin layer can be the same as the light transmittance of the base material constituting the anti-counterfeit sheet. As the second base material, for example, a general resin base material can be used.

  Applications of the anti-counterfeit medium of the present invention include, for example, cash vouchers, gift cards, credit cards, ID cards, passports, driver's licenses, brand products, automobile parts, precision equipment parts, home appliances, cosmetics, pharmaceuticals, foods, OA supplies. Goods, sporting goods, CD, DVD, software, tobacco, liquor, etc.

F. Method for Producing Fine Particles The method for producing fine particles of the present invention is a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and having at least a curved surface, and has two embodiments. .

A first embodiment is a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and having at least a curved surface, and a sacrificial layer having solvent solubility on a substrate, A laminate preparation step for preparing a laminate in which photosensitive resin layers are sequentially laminated, an exposure development step for performing gradation processing on the photosensitive resin layer, performing a development process, and forming the three-dimensional shape, and the sacrifice And a sacrifice layer dissolving step for dissolving the layer.
The second embodiment is a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and observing, wherein the three-dimensional shape has at least a curved surface, wherein the photosensitive resin layer is formed on the substrate. A layered body preparation step for preparing a body, and an exposure development step for performing gradation processing on the photosensitive resin layer, performing a development process, and forming a three-dimensional shape opposite to the three-dimensional shape or the three-dimensional shape. A method for producing fine particles, comprising: an original plate forming step for forming an original plate; and a fine particle forming step for forming the fine particles using the original plate.
In the following, each embodiment will be described separately.

1. First Embodiment A method for producing fine particles of the present embodiment is a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and observing, wherein the three-dimensional shape has at least a curved surface. A layered body preparation step of preparing a layered body in which a sacrificial layer having solvent solubility and a photosensitive resin layer are sequentially stacked, and gradation exposure is performed on the photosensitive resin layer, development processing is performed, and the three-dimensional shape is formed. An exposure development step and a sacrificial layer dissolving step for dissolving the sacrificial layer.

  14A to 14E are process diagrams showing an example of the method for producing fine particles of the present embodiment. First, as shown in FIG. 14A, a laminated body 10 in which a sacrificial layer 13 having solvent solubility and a photosensitive resin layer 14a are sequentially laminated on a substrate 12 is prepared (laminated body preparing step). Next, as shown in FIG. 14B, the photosensitive resin layer 14a is directly drawn by irradiating the photosensitive device layer 14a with a laser beam 17 and subjected to gradation exposure, followed by development processing. As shown in 14 (c), a particle layer 14 b in which a predetermined three-dimensional shape 2 is formed is obtained (exposure development step). Next, as shown in FIG. 14D, the substrate 12 on which the particle layer 14b and the sacrificial layer 13 are formed is immersed in the solvent S, the sacrificial layer 13 is dissolved, and the particle layer 14b is separated from the substrate 12 (sacrificial). Layer dissolution step). In this way, fine particles 1 having a predetermined three-dimensional shape 2 can be obtained as shown in FIG.

  15A to 15E are process diagrams showing another example of the method for producing fine particles of the present embodiment. First, as shown in FIG. 15A, a laminate 10 in which a sacrificial layer 13 having a solvent solubility and a photosensitive resin layer 14a are sequentially laminated on a substrate 12 is prepared (laminate preparation step). Next, as shown in FIG. 15B, the photosensitive resin layer 14a is irradiated with light 19 through the gradation mask 18 to perform gradation exposure, and then development processing is performed. ), A particle layer 14b on which a predetermined three-dimensional shape 2 is formed is obtained (exposure development step). Next, as shown in FIG. 15D, the substrate 12 on which the particle layer 14b and the sacrificial layer 13 are formed is immersed in the solvent S, the sacrificial layer 13 is dissolved, and the particle layer 14b is separated from the substrate 12 (sacrificial). Layer dissolution step). In this way, fine particles 1 having a predetermined three-dimensional shape 2 can be obtained as shown in FIG.

In this embodiment, fine particles containing a photosensitive resin can be obtained. According to this embodiment, since the photosensitive resin layer is subjected to gradation exposure to produce fine particles having a predetermined three-dimensional shape, it is possible to produce fine particles with high productivity and low cost. Further, since gradation exposure is performed on the photosensitive resin layer, a complicated three-dimensional shape can be formed, and fine particles having an excellent anti-counterfeit effect can be obtained.
Hereafter, each process in the manufacturing method of the microparticles | fine-particles of this embodiment is demonstrated.

(1) Laminate Preparation Step The laminate preparation step in this embodiment is a step of preparing a laminate in which a sacrificial layer having solvent solubility and a photosensitive resin layer are sequentially laminated on a substrate.
Hereinafter, each structure in a laminated body is demonstrated.

(A) Sacrificial layer The sacrificial layer used in this embodiment is formed on a substrate and has solvent solubility.

  The solvent solubility of the sacrificial layer is not particularly limited, and may be solubility in a polar solvent or solubility in a nonpolar solvent. Especially, it is preferable that a sacrificial layer has the solubility with respect to a polar solvent, especially water. It is because it can be set as the process with a little load with respect to an environment rather than using another solvent.

  The material for the sacrificial layer is not particularly limited as long as it has solvent solubility, and the sacrificial layer is appropriately selected according to the type of solvent having solvent solubility. Specifically, a resin having solvent solubility is used. Especially, it is preferable that it is a water-soluble polymer compound, and it is more preferable to use polyvinyl alcohol. This is because polyvinyl alcohol is a water-soluble polymer compound that dissolves in water, and by using water, it can be treated with less burden on the environment than when other solvents are used.

The thickness of the sacrificial layer is not particularly limited as long as the sacrificial layer can be dissolved.
As a method for forming the sacrificial layer, a known method can be used.

(B) Photosensitive resin layer The photosensitive resin layer used in this embodiment is formed on the sacrificial layer.
As the photosensitive resin component contained in the photosensitive resin layer, either a positive photosensitive resin component or a negative photosensitive resin component can be used.

The film thickness of the photosensitive resin layer is not particularly limited as long as it is a film thickness capable of forming a predetermined three-dimensional shape, but is approximately the same as the thickness of the fine particles described in the section “A. Fine particles” above. Preferably there is.
As a method for forming the photosensitive resin layer, a known method can be used.

(C) Substrate The substrate used in this embodiment is not particularly limited as long as the sacrificial layer and the photosensitive resin layer can be formed on the substrate. For example, a glass substrate, a resin substrate, or the like is used. be able to.

(2) Exposure and development process The exposure and development process in the present embodiment is a process in which gradation exposure is performed on the photosensitive resin layer, development processing is performed, and the three-dimensional shape is formed.

  A method for performing gradation exposure on the photosensitive resin layer is not particularly limited as long as a predetermined three-dimensional shape can be formed by performing gradation exposure on the photosensitive resin layer and performing development processing. A method of drawing directly on the photosensitive resin layer with a drawing apparatus and a method of using a gradation mask are preferable. This is because a complicated three-dimensional shape can be formed.

In the case of a method of directly drawing on the photosensitive resin layer by a drawing device, for example, a laser drawing device or an electron beam drawing device can be used as the drawing device.
In the present embodiment, even when a fine particle having a predetermined mark in addition to the predetermined three-dimensional shape is manufactured, the three-dimensional shape and the mark can be formed by performing direct drawing once.

In the case of a method using a gradation mask, as the gradation mask, for example, a photomask that controls the transmission light amount (exposure amount) distribution during exposure according to the distribution state of fine dot patterns that are not resolved at the exposure wavelength. Alternatively, a photomask (gray mask) in which a light shielding agent is dispersed in a predetermined density pattern on a transparent substrate can be used.
JP, 2004-296590, A can be referred to for a photomask of a dot pattern. For gray masks, reference can be made to JP-A-2002-6473.
In the present embodiment, when producing fine particles having a predetermined mark in addition to a predetermined three-dimensional shape, two types of gradation masks are prepared, and the gradation mask is changed and exposed twice, so that the three-dimensional shape is obtained. And marks can be formed.

  A method for performing the development treatment is not particularly limited, and examples thereof include a method using a developer. As the developer, a general developer can be used, and is appropriately selected according to the type of the photosensitive resin layer.

(3) Sacrificial layer dissolving step The sacrificial layer dissolving step in this embodiment is a step of dissolving the sacrificial layer.
Examples of the method for dissolving the sacrificial layer include a method of immersing in a solvent. At this time, ultrasonic waves may be used in combination.
The solvent is appropriately selected according to the solvent solubility of the sacrificial layer. Among them, it is preferable to use a polar solvent, particularly water. This is because the waste liquid treatment generated in the sacrificial layer dissolving step can be a treatment with less burden on the environment than using other solvents.

(4) Fine Particle Recovery Step In this embodiment, a fine particle recovery step for recovering fine particles is usually performed after the sacrifice layer dissolving step.
Examples of the method for collecting the fine particles include a method of precipitating the fine particles in a solution containing a solvent in which the sacrificial layer is dissolved. At this time, centrifugation may be performed in order to settle the fine particles.
Moreover, after collecting the fine particles, classification may be performed. This is because very small particles that make it difficult to identify the three-dimensional shape can be removed.
Since the other points of the fine particles are the same as those described in the above section “A. Fine particles”, description thereof is omitted here.

2. Second Embodiment A method for producing fine particles according to this embodiment is a method for producing fine particles having a three-dimensional shape that can be identified by magnifying and having at least a curved surface. A layered body preparation step for preparing a layered body in which a photosensitive resin layer is formed, and gradation exposure is performed on the photosensitive resin layer, development processing is performed, and the three-dimensional shape or the three-dimensional shape opposite to the three-dimensional shape is formed. It has an exposure development process to form, and has an original plate forming process for forming an original plate, and a fine particle forming step for forming the fine particles using the original plate.

  FIGS. 16A to 16E are process diagrams showing an example of the method for producing fine particles of the present embodiment. First, as shown in FIG. 16A, a laminate 40 in which a photosensitive resin layer 44a is formed on a substrate 42 is prepared (laminate preparation step). Next, as shown in FIG. 16B, the photosensitive resin layer 44a is directly drawn by irradiating laser light 17 from the drawing device 16, and after gradation exposure, development processing is performed. As shown in FIG. 16C, a template layer 44b having a three-dimensional shape 45a opposite to a predetermined three-dimensional shape is obtained (exposure development step). Thereby, the original plate 41 is obtained (original plate forming step). Next, as shown in FIG. 16D, the fine particle material 46 is filled in the concave portion in which the three-dimensional shape 45 a of the template layer 44 b of the original plate 41 is formed, and the fine particle material 46 is solidified, and then from the original plate 41. As shown in FIG. 16E, fine particles 1 having a predetermined three-dimensional shape 2 can be obtained (fine particle forming step).

  17A to 17G are process diagrams showing another example of the method for producing fine particles of the present embodiment. First, as shown in FIG. 17A, a laminate 40 in which a photosensitive resin layer 44a is formed on a substrate 42 is prepared (laminate preparation step). Next, as shown in FIG. 17B, the photosensitive resin layer 44a is irradiated with light 19 through the gradation mask 18 to perform gradation exposure, and then development processing is performed. ), A template layer 44b having a three-dimensional shape 45b identical to a predetermined three-dimensional shape is obtained (exposure development step). Next, as shown in FIG. 17D, metal is vapor-deposited or plated on the mold layer 44b to form a second mold layer 47 having a three-dimensional shape 45b, that is, a three-dimensional shape 45a opposite to the predetermined three-dimensional shape. Then, as shown in FIG. 17 (e), the mold layer 44 b is peeled from the second mold layer 47. Thereby, the original plate 41 is obtained (original plate forming step). Next, as shown in FIG. 17 (f), after filling the fine particle material 46 into the concave portion in which the three-dimensional shape 45 a of the original plate 41 (second template layer 47) is formed and solidifying the fine particle material 46, As shown in FIG. 17G, fine particles 1 having a predetermined three-dimensional shape 2 can be obtained by removing from the original plate 41 (fine particle forming step).

In the present embodiment, since the fine particles are formed using the original plate, various materials such as a resin component and a metal can be used as the fine particle material. In addition, according to this embodiment, the photosensitive resin layer is subjected to gradation exposure to produce an original, so that it is possible to produce fine particles with high productivity and at low cost. Further, since gradation exposure is performed on the photosensitive resin layer, a complicated three-dimensional shape can be formed, and fine particles having an excellent anti-counterfeit effect can be obtained.
Hereafter, each process in the manufacturing method of the microparticles | fine-particles of this embodiment is demonstrated.

(1) Master Forming Process A master forming process in the present embodiment includes a laminate preparation process for preparing a laminate in which a photosensitive resin layer is formed on a substrate, gradation exposure on the photosensitive resin layer, and development. It is a step of forming an original plate by performing an exposure and developing step of forming a three-dimensional shape opposite to the three-dimensional shape or the three-dimensional shape.
Hereinafter, each process in the original plate forming process will be described.

(A) Laminated body preparation process The laminated body preparation process in this embodiment is a process of preparing the laminated body in which the photosensitive resin layer was formed on the board | substrate.
In addition, about a board | substrate and the photosensitive resin layer, since it can be made to be the same as that of what was described in the said 1st embodiment, description here is abbreviate | omitted.

(B) Exposure development process The exposure development process in this embodiment is a process in which gradation exposure is performed on the photosensitive resin layer, development processing is performed, and the three-dimensional shape or the three-dimensional shape opposite to the three-dimensional shape is formed. is there.

  Note that gradation exposure and development processing can be the same as those described in the first embodiment, and a description thereof will be omitted here.

  In this step, whether to form the same three-dimensional shape as the three-dimensional shape of the fine particles or the three-dimensional shape opposite to the three-dimensional shape of the fine particles is appropriately selected according to the original plate forming method. In addition, a well-known method can be used about the duplication method at the time of forming an original plate.

(C) Original plate The original plate in the present embodiment is not particularly limited as long as the solid shape of the fine particles has the opposite three-dimensional shape, and is appropriately selected according to the forming method of the original plate. The material of the layer having the opposite three-dimensional shape in the original plate may be a resin or a metal. In the case of a metal, it has an advantage of high durability.
The original plate may be subjected to a release treatment.

(2) Fine particle forming step The fine particle forming step in this embodiment is a step of forming fine particles using the original plate.

  Examples of the method for forming fine particles using the original plate include a method in which a material for fine particles is filled in a recess in which a three-dimensional shape opposite to that of the original plate is formed and solidified, and a method in which the original plate is embossed on a resin layer. .

The material for fine particles is not particularly limited as long as it is a material that can produce fine particles having a predetermined three-dimensional shape using an original plate. For example, a resin component, a metal, a metal compound, or the like can be used. Since these materials can be the same as those described in the above section “A. Fine particles”, description thereof is omitted here.
The method for filling the fine particle material is appropriately selected according to the type of the fine particle material. In the case of using a resin component, a method of applying a fine particle material can be mentioned. Moreover, when using a metal and a metal compound, the method of vapor-depositing the material for fine particles is mentioned. In the case of metal, a plating method can also be applied.
The method for solidifying the fine particle material is appropriately selected according to the type of the fine particle material. When the resin component is a curable resin component, a curing method using light or heat is used. When the resin component is a thermoplastic resin component, a cooling method is used.

The resin used for the resin layer for embossing the original plate may be the same as that described in the above section “A. Fine particles”.
After embossing the original plate on the resin layer, the fine particles can be produced by punching the resin layer. When the resin layer is punched, the resin layer may be punched with a mold after the stamping. When the original is made of metal, the stamping may be performed with the original and at that time. Further, after embossing, the fine particles can be produced by cutting the resin layer with a laser.

The fine particles obtained may be classified. This is because very small particles that make it difficult to identify the three-dimensional shape can be removed.
Since the other points of the fine particles are the same as those described in the above section “A. Fine particles”, description thereof is omitted here.

3. Other Embodiments In the present invention, a predetermined three-dimensional shape or a reverse three-dimensional shape can be formed by cutting or laser processing the resin layer or the metal layer. The cutting and laser processing are not particularly limited as long as a predetermined three-dimensional shape can be formed, and known methods can be used.
In the present invention, a predetermined three-dimensional shape or a reverse three-dimensional shape can also be formed by stereolithography. As the optical modeling method, a known method can be applied.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Hereinafter, the present invention will be specifically described with reference to examples.
(Sacrificial layer formation)
On a 100 mm x 100 mm x 0.7 mm non-alkali glass (HOYA NA35) substrate, a 20 wt% solid polyvinyl alcohol aqueous solution is applied with a spin coater at 550 rpm and dried on a hot plate at 110 ° C for 10 minutes. As a result, a polyvinyl alcohol layer having a thickness of 1 μm was formed.

(Formation of photosensitive resin layer)
After the substrate on which the sacrificial layer was formed was dehydrated and baked, a gas obtained by vaporizing hexamethylzine lazan was sprayed to perform an adhesion improving process (HMDS process). Next, a positive resist material (PMER-HA1300PM manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the sacrificial layer with a spin coater at 350 rpm, and dried on a hot plate at 130 ° C. for 15 minutes, so that the film thickness is 25 μm. A functional resin layer was formed.

(Exposure development)
Using a positive tone mask composed of a fine dot pattern on which patterns of 10,000 teapots of 100 μm × 100 μm were drawn, UV light of 365 nm was irradiated with 800 mJ from a UV aligner. After developing for 5 minutes using a positive resist developer (NMD-3 manufactured by Tokyo Ohka Kogyo Co., Ltd.), it was rinsed with water for 10 seconds. The photosensitive resin layer was patterned into the shape of 10,000 teapots of 100 μm × 100 μm × 20 μm, and the shape of each teapot was a shape having a three-dimensional curved surface corresponding to the gradation mask.

(Particle collection process)
The substrate after development was immersed in water, placed in an ultrasonic treatment water tank, and ultrasonic waves were applied for 3 minutes. The sacrificial layer was dissolved and the teapot pattern was peeled off from the substrate. By collecting and drying the soaked water, it was possible to extract 10,000 fine particles of 100 μm × 100 μm × 20 μm having a teapot-type solid curved surface shape.

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C ... Fine particle 2 ... Solid shape 3 ... Mark 5 ... Fine particle surface 6 ... Fine particle back surface 10, 40 ... Laminate 12, 42 ... Substrate 13 ... Sacrificial layer 14a, 44a ... Photosensitive resin layer 14b ... Particle layer 20 ... Anti-counterfeit sheet 21 ... Transparent resin 22 ... Fine particle-containing layer 23 ... Release layer 24 ... Adhesive layer 25 ... Base material 26 ... Hard coat layer 27 ... Hologram layer 30 ... Anti-counterfeit medium 31 ... Support 41 ... Original edition

Claims (4)

A method for producing fine particles having a three-dimensional shape that can be identified by magnifying and observing, wherein the three-dimensional shape has at least a curved surface,
Information that can be identified by magnifying and observing is the three-dimensional shape, and the fine particles have a surface having the three-dimensional shape and a back surface facing the surface, and 50% or more of the fine particle surface is a curved surface. Configured,
A laminate preparation step of preparing a laminate in which a sacrificial layer having solvent solubility and a photosensitive resin layer are sequentially laminated on a substrate;
An exposure development step of performing gradation exposure on the photosensitive resin layer, performing development processing, and forming the three-dimensional shape;
And a sacrificial layer dissolving step for dissolving the sacrificial layer. A method for producing fine particles having a three-dimensional shape that can be identified by magnifying and observing, wherein the three-dimensional shape has at least a curved surface,
Information that can be identified by magnifying and observing is the three-dimensional shape, and the fine particles have a surface having the three-dimensional shape and a back surface facing the surface, and 50% or more of the fine particle surface is a curved surface. Configured,
A laminate preparation step of preparing a laminate in which a photosensitive resin layer is formed on a substrate, and gradation exposure is performed on the photosensitive resin layer, development processing is performed, and the three-dimensional shape or the opposite of the three-dimensional shape is performed. An exposure development process for forming a three-dimensional shape of, and a master forming process for forming a master;
And a fine particle forming step of forming the fine particles using the original plate. Wherein the gradation exposure for exposure and development steps, the production method of fine particles according to claim 1 or claim 2, characterized in that the direct drawing by the drawing device to the photosensitive resin layer. The exposure in the gradation exposure development step, method for producing fine particles according to claim 1 or claim 2, characterized by using the gradation mask.