KR20210156505A - Humidity Recognizable Means Preventing Forgery and Falsification - Google Patents

Abstract

The present invention provides a humidity recognition type forgery prevention means, which comprises: a film layer; a light emitting layer over the film layer; and a reflective layer over the light emitting layer. The reflective layer and the light emitting layer having two or more wet discoloration structures have different physical properties. The reflective layer has a transmittance of 70% or more so that the light emission of the light emitting layer can be confirmed. The color when visible light is incident and the color when UV light is incident appear as different color changes depending on the wet content.

Description

Humidity Recognizable Means Preventing Forgery and Falsification

The present invention relates to a humidity-aware type forgery prevention means, and more particularly, to a humidity-aware type forgery prevention means comprising a film layer, a light emitting layer on the film layer, and a reflective layer on the light emitting layer.

With the industrial development of the 21st century, the level of awareness of general users about products and technologies is increasing. Products that are unavoidable for mass distribution, such as food, medical products, and cosmetics, are threatened by counterfeit products, which is a serious social problem. The world and all industries are paying attention to the anti-counterfeiting and falsification technology that has been applied only to the banking sector connected with finance.

In general, among the technologies for activation, holograms and QR codes are easy to duplicate because of their low technical difficulty, and technologies such as NFC, RFID, and Dot-code are difficult to be applied to general food or cosmetics fields due to their high unit prices. There is a continuous demand for new technologies that can be solved.

In general, the difficulty of technology is connected with the differentiation of materials, which strengthens the security of anti-counterfeiting and falsification technology by improving the functional aspect through the fusion of known materials in the product to be applied along with the new development of the material itself. will do

For this reason, materials for preventing forgery and falsification are often used together with basic technology and materials with different functions. Ink (photochromic ink), optical variable ink (optical variable ink), magnetic ink (magnetic ink), etc. are widely applied.

Recently, as in the above example, studies on photonic crystals, which are materials that can express colors even when they do not have chromophores that can express specific colors depending on various types of externally applied energy, are being actively studied. In addition, product development is being made in various forms for the purpose of forgery prevention means.

A photonic crystal is a material in which light is selectively reflected by a nano-structure. As representative examples, if you look at opal jewels, winged butterflies and peacock feathers, various colors are observed due to the regular formation of nanostructures. That is, the fine nano gratings reflect a specific color by diffraction of light.

An example of an active photonic crystal having a photonic crystal structure according to the type of externally applied energy by using the photonic crystal basic principle is a humidity color changeable photonic crystal. In order to realize the photonic crystal color by humidity, the material itself or the material surrounding the material absorbs the humidity and swells, so that the nanostructure change must occur.

Looking at the prior art of causing photonic crystal color change by humidity, in KR Patent Application No. 10-2015-0049832 (Title of the invention: photonic crystal humidity sensor and manufacturing method thereof), a photonic crystal template containing colloidal polymer particles ( template) is formed, the hydrogel is photopolymerized between the photonic crystal templates to fix it, and the photonic crystal template is removed to form a reverse-opal photonic crystal hydrogel structure, and ions are added to the reverse-opal photonic crystal hydrogel structure. A photonic crystal humidity sensor is manufactured by forming a medium containing a sexual liquid, and the hydrogel surrounding the inverted opal photonic crystal absorbs moisture, thereby changing the nano-lattice spacing of the inverted opal photonic crystal, thereby realizing a photonic crystal color. there is,

Looking at the patent literature that causes color change using a porous material, KR Patent Application No. 10-2018-0122459 (Title of the invention: Method for manufacturing distributed Bragg reflective porous silicon film and distributed Bragg reflective porous silicon film-based explosive detection In the chemical sensor), (a) forming a distributed Bragg reflective porous silicon having a reflection wavelength characteristic for selectively reflecting a specific wavelength region on the surface of the silicon wafer by first etching a silicon wafer; (b) separating the formed distributed Bragg reflective porous silicon from the silicon wafer through secondary etching to prepare a distributed Bragg reflective porous silicon film; and (c) permeating a photoluminescent polymer solution into the distributed Bragg reflective porous film.

However, in the case of the above-mentioned patent documents, there is an advantage that a means for checking a specific state such as forgery can be easily manufactured. There is a disadvantage in that it is easy to check whether forgery or not.

Numerous papers and patent documents are referenced throughout this specification and their citations are indicated. The disclosures of the cited papers and patent documents are incorporated herein by reference in their entirety to more clearly describe the level of the technical field to which the present invention pertains and the content of the present invention.

The inventors of the present invention made intensive research efforts to develop a forgery prevention means capable of detecting forgery and falsification even without a separate forgery confirmation device as well as forgery is very difficult, manufacturing is simple, and manufacturing cost is low. As a result, when manufacturing a humidity-aware type forgery prevention means including a film layer, a light emitting layer on the upper part of the film layer, and a reflective layer on the upper part of the light emitting layer, when humidity is supplied to the forgery prevention means by breathing, the color changes. Because it can be checked in two steps under irradiation with general visible light and under irradiation with UV light, forgery is very difficult, manufacturing is simple, and manufacturing cost is low. The present invention was completed by finding that it is possible.

Accordingly, an object of the present invention is to provide a humidity-aware type forgery prevention means.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention, claims and drawings.

In the present invention, a photonic crystal structure is manufactured by sequentially stacking two types of materials having porosity that can absorb humidity and having different refractive indices, and by inserting a fluorescent material layer in the lower layer, two different particles swell at a constant humidity. As the swelling occurs, the particle size changes, and the structure color is induced due to the change in the nano-lattice spacing. It relates to forgery prevention technology that can change the color of the structure.

The present invention provides a forgery prevention means.

The inventors of the present invention made intensive research efforts to develop a forgery prevention means capable of detecting forgery and falsification even without a separate forgery confirmation device as well as forgery is very difficult, manufacturing is simple, and manufacturing cost is low. As a result, when manufacturing a humidity-aware type forgery prevention means including a film layer, a light emitting layer on the upper part of the film layer, and a reflective layer on the upper part of the light emitting layer, when humidity is supplied to the forgery prevention means by breathing, the color changes. Because it can be checked in two steps under irradiation with general visible light and with UV light, forgery is very difficult, easy to manufacture, and inexpensive to manufacture. It has been confirmed that this is possible.

According to an aspect of the present invention, the present invention includes a film layer, a light emitting layer on the film layer, and a reflective layer on the light emitting layer, wherein the reflective layer and the light emitting layer having two or more types of wet discoloration structures have different physical properties, , the reflective layer has a transmittance of 70% or more so that the light emission of the following light emitting layer can be confirmed, and the color when the visible light is incident and the color when the UV light is incident appears as a different color change depending on the moisture content. Provide forgery prevention means.

The term 'forgery' used in this specification may refer to any act of creating a new non-existing object for the purpose of use by an unauthorized person, or any act of making changes to an existing object without authorization.

According to a preferred aspect of the present invention, the humidity-aware forgery prevention means of the present invention may include a wet discoloration film structure in which fluorescence and reflection in one film show different discolorations at the same humidity.

According to a preferred aspect of the present invention, an adhesive layer and a stretched film layer above the adhesive layer are preferably added to the upper portion of the reflective layer of the present invention to prevent diffuse reflection, and to change color due to a change in refractive index difference with the reflective layer. may include

According to a preferred aspect of the present invention, the reflective layer of the present invention may be composed of nanoparticles having at least two or more types of porosity, preferably having different refractive indexes.

According to a preferred aspect of the present invention, the refractive index of the porous particles of the above species or more of the present invention may be preferably 0.01 or more.

According to a preferred aspect of the present invention, the two or more kinds of porous particles of the present invention are preferably silicon (SiO ₂ ) Series, alumina (Al ₂ O ₃ ) series, polystyrene (polystyrene) series, polyurethane (polyurethane) and polyacrylate (polyacrylate) may be two different series of the series selected from the group including the series.

According to a preferred aspect of the present invention, the size of the porous particles of the present invention may be preferably 10 nm to 200 nm.

According to a preferred aspect of the present invention, the reflective layer of the present invention is preferably composed of a single type of porous particles, and the surface of the particles may be coated with an inorganic material in order to increase the refractive index of the particles.

According to a preferred aspect of the present invention, the inorganic material of the present invention may be in the form of a metal oxide or a metal atom itself. Preferably, the oxide _{may be selected from the group comprising iron oxide (Fe 3} O ₄ ), titanium oxide (TiO ₂ ) zirconium oxide (ZrO ₂ ), and zinc oxide (ZnO ₂ ), and the metal atom is gold (gold). ), platinum (platinium) and nickel (nickel) may be selected from the group consisting of.

According to a preferred aspect of the present invention, the coated particles of the present invention preferably occupy 10% or more of the total particles, so that the difference in refractive index between the particles is adjusted to 0.01 or more.

According to a preferred aspect of the present invention, the single type of porous particles of the present invention may be to control the nanoscale distance between particles according to the increase in particle size by preferably controlling the wettability of the particles.

According to a preferred aspect of the present invention, the porous particles of the present invention are preferably treated with a carboxyl group, an amine group or a hydroxyl group, which is a functional group that increases the hydrophilicity on the surface, or The wettability may be controlled by treating a fluoro group or an alkyl group, which is a functional group that reduces hydrophilicity.

According to a preferred aspect of the present invention, the light emitting layer of the present invention may be preferably an organic compound having fluorescence or quantum dots. It is not limited to that type.

According to a preferred aspect of the present invention, the light emitting layer and the reflective layer of the present invention are preferably laminated without a step, and the sum of the thicknesses of the two layers may be 1-30 μm.

According to a preferred aspect of the present invention, the porous particles of the present invention preferably have the following range of change in the size of the porous particles according to the humidity content: (a) 30 nm -> 40 nm (RH: 40%~60 %); (b) 30 nm -> 50 nm (R: 60%~70%); and (c) 30 nm -> 50 nm (RH: 70%-90%).

According to a preferred aspect of the present invention, the color change time of the present invention may be preferably 0.5 sec to 1 min.

According to a preferred aspect of the present invention, according to the thickness (number of coating layers) of the reflective layer of the present invention, the following discoloration characteristics can be exhibited before and after wet color change: (a) Discoloration change range according to the reflective layer thickness: 60 nm -> 180 nm (violet->green); (b) Color change range according to reflective layer thickness when wet: 80 nm -> 270 nm (blue->orange); and (c) the range of color change according to the thickness of the light emitting layer when wet: 80 nm -> 270 nm (green->red).

The features and advantages of the present invention are summarized as follows:

(a) the present invention includes a film layer, a light emitting layer on the film layer, and a reflective layer on the light emitting layer, wherein the reflective layer and the light emitting layer having two or more types of wet discoloration structures have different physical properties, and the reflective layer includes To ensure that the light emitting layer emits light, the transmittance is 70% or more, and the color when the visible light is incident and the color when the UV light is incident appears as a different color change depending on the wet content. do.

(b) the humidity-aware type forgery prevention means of the present invention is very difficult to forgery, is easy to manufacture, and has a low manufacturing cost.

1 shows a cross-sectional view of the humidity-aware type forgery prevention means of the present invention.
Figure 2 shows a cross-sectional view of the humidity-aware type forgery prevention means of the present invention.
3 shows the thickness of the reflective layer included in the humidity-aware forgery prevention means of the inventor, and the change in the thickness and color of the reflective layer according to absorption.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show a cross-sectional view of the humidity-aware forgery prevention means according to an embodiment of the present invention, an enlarged view of the light emitting layer and the reflective layer, and the thickness and color change of the reflective layer according to the thickness of the reflective layer and absorption This is shown.

1 to 3 , the humidity-aware forgery prevention means according to an embodiment of the present invention includes a film layer, a light emitting layer on the film layer, and a reflective layer on the light emitting layer.

Here, the reflective layer and the light emitting layer having two or more types of wet discoloration structures have different physical properties.

In addition, the reflective layer has a transmittance of 70% or more so that light emission of the following light emitting layer can be confirmed, and the color when the visible light is incident and the color when the UV light is incident appears as a different color change depending on the wet content.

Referring to FIG. 1 , the humidity-aware forgery prevention means according to an embodiment of the present invention includes a wet discoloration film structure in which fluorescence and reflection in one film exhibit different discolorations at the same humidity.

In the humidity-aware forgery prevention means, a reflective layer and a light emitting layer on the reflective layer are coated on a film layer, which is a transparent film.

Here, as the film layer, various types of transparent films used in the art, such as PET, PE, PP, and PDMS, may be used.

Referring to FIG. 1 , the light emitting layer and the reflective layer, except for the film layer, are stacked separately as a lower layer and an upper layer. For example, a film layer, a light emitting layer on the film layer, and a reflective layer on the light emitting layer may be stacked in this order.

Referring to FIG. 1 , the reflective layer stacked on the film layer and the light emitting layer is made of at least two types of porous particles.

Here, there should be a difference in the refractive index of the two porous particles, and the refractive index of the two porous particles may be 0.01 or more.

The porous particles are silicon (SiO ₂ ) Series, alumina (Al ₂ O ₃ ) series, polystyrene (polystyrene) series, polyurethane (polyurethane) and polyacrylate (polyacrylate) series may be two different from each other. The size of the porous particles is 10 nm to 200 nm.

If, when using the same particles as the porous particles, iron oxide (Fe ₃ O ₄ ), titanium oxide (TiO ₂ ) zirconium oxide (ZrO ₂ ) and zinc oxide (ZnO ₂ ) Can be selected from the group consisting of, and , the metal atom may be coated with an inorganic material having a high refractive index, such as gold, platinum, and nickel.

Here, the volume of the porous particles coated with the inorganic material occupies 10% or more of the total to adjust the refractive index difference to 0.01 or more.

In addition, when the same particle is used as the porous particle, it is possible to control the distance between particles according to the increase in particle size by controlling the wettability of the particle by changing the property of absorbing moisture on the particle surface.

The porous particles are treated with a carboxyl group, an amine group or a hydroxyl group, which is a functional group that increases the hydrophilicity on the surface, or a fluorine group or an alkyl group that is a functional group that reduces the hydrophilicity (alkyl group) can be introduced to change the wettability.

Referring to FIG. 1 , at least one light emitting layer included in the humidity-aware forgery prevention means according to an embodiment of the present invention includes an organic fluorescent material.

Here, the light emitting layer included in the humidity-aware forgery prevention means according to an embodiment of the present invention may be an organic fluorescent material or quantum dots.

The organic fluorescent material and quantum dots may be one of raw materials generally used in the art.

Referring to FIG. 1 , the light emitting layer and the reflective layer except for the film layer are laminated without a step, and the sum of the thicknesses of the two layers may be 30 μm or less.

Here, the reflective layer and the light emitting layer having two or more types of wet discoloration structures have different characteristics.

In addition, the reflective layer does not have a large difference in refractive index with the light emitting layer, so it is transparent so that light emission of the light emitting layer below can be confirmed, and the transmittance is 70% or more.

And, depending on the wet content contained in the film, the light reflectivity of the reflective layer and the photoluminescence of the light emitting layer appear as different discolorations within the film within a few seconds according to the injected incident light.

The size change range of the humidity-sensitive porous particles included in the reflective layer according to the humidity content is as follows: 30 nm -> 40 nm (RH: 40% to 60%), 30 nm -> 50 nm (RH: 60%) ~70%), 30 nm -> 50 nm (RH :70%~90%).

The discoloration time of the humidity-aware forgery prevention means according to an embodiment of the present invention may be 0.5 sec to 1 min.

An upper portion of the reflective layer may further include a stretched film and an adhesive to prevent diffuse reflection and change color due to a change in refractive index difference with the reflective layer.

The reflective layer and the light emitting layer having two or more types of wet discoloration structures included in the humidity-aware forgery prevention means according to an embodiment of the present invention exhibit different discolorations depending on the thickness of the reflective layer and whether moisture is absorbed.

Depending on the thickness of the coating layer of the reflective layer, different discolorations may be exhibited before and after wet discoloration.

Here, the color change range according to the thickness of the reflective layer is as follows: 60 nm -> 180 nm (violet-> green).

In addition, the range of color change according to the thickness of the reflective layer in a state where the film absorbs moisture is as follows: 80 nm -> 270 nm (blue->orange).

And in the state where the film absorbs moisture, the range of color change according to the thickness of the light emitting layer is as follows: 80 nm -> 270 nm (green->red).

Claims (12)

film layer,
a light emitting layer on the film layer; and
a reflective layer on the light emitting layer;
The reflective layer and the light emitting layer having two or more wet discoloration structures have different physical properties,
The reflective layer has a transmittance of 70% or more so that the light emission of the following light-emitting layer can be confirmed,
The color when visible light is incident and the color when UV light is incident appear as different color changes depending on the wet content.
Humidity-aware forgery prevention means.
The method of claim 1,
The humidity-aware-type forgery prevention means includes a wet-discoloration film structure in which fluorescence and reflection in one film show different colors at the same humidity.
3. The method of claim 2,
The reflective layer is a humidity-aware forgery prevention means, characterized in that composed of at least two or more types of porous particles having different refractive indexes.
4. The method of claim 3,
Humidity-aware forgery prevention means, characterized in that the refractive index of the at least two porous particles is 0.01 or more.
5. The method of claim 4,
The two or more kinds of porous particles are silicon (SiO ₂ ) Humidity awareness, characterized in that it is two different series among the series selected from the group including series, alumina (Al ₂ O _{3 ) series, polystyrene series, polyurethane (polyurethane) and polyacrylate series} Form forgery prevention means.
6. The method of claim 5,
Humidity-aware forgery prevention means, characterized in that the size of the porous particles is 10 nm to 200 nm.
7. The method of claim 6,
The light emitting layer is a humidity-aware forgery prevention means, characterized in that the organic material or quantum dots (quantum dots) having a fluorescence.
8. The method of claim 7,
The light emitting layer and the reflective layer are laminated without a step, and the humidity-aware type forgery prevention means, characterized in that the sum of the thicknesses of the two layers is 1-30 μm.
10. The method of claim 9,
The porous particle is a humidity-aware forgery prevention means, characterized in that the range of change in the size of the porous particle according to the humidity content is as follows:
(a) 30 nm -> 40 nm (RH: 40% to 60%);
(b) 30 nm -> 50 nm (R: 60%~70%); and
(c) 30 nm -> 50 nm (RH: 70%-90%).
10. The method of claim 9,
Humidity-aware forgery prevention means for reversely discoloring the porous particles to their original color when the amount of humidity is reduced:
(a) 40 nm -> 30 nm (RH: 40% or less);
(b) 50 nm -> 30 nm (RH: 60% or less).
11. The method of claim 10,
Humidity-aware forgery prevention means, characterized in that it exhibits the following color change characteristics before and after wet color change according to the thickness of the reflective layer (the number of coating layers):
(a) Change range of discoloration according to reflective layer thickness: 60 nm -> 180 nm (violet->green);
(b) Color change range according to reflective layer thickness when wet: 80 nm -> 270 nm (blue->orange); and
(c) The range of color change according to the thickness of the light emitting layer when wet: 80 nm -> 270 nm (green->red).
12. The method of claim 11,
Humidity-aware forgery prevention means, characterized in that it further comprises an adhesive layer and a stretched film layer on the adhesive layer on the upper portion of the reflective layer to prevent diffuse reflection, and to change color due to a change in refractive index difference with the reflective layer.

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