JP2008281912A - Label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a label that is easy in determining the authenticity even with a small area and difficult in analysis thereof. <P>SOLUTION: The label includes at least a light diffraction structure layer, reflective material layer, adhesive layer, and covering material, which are sequentially formed on one side of a transparent plastic substrate. A thermosensitive discoloring material layer is formed at least at either one of a portion of the area between the transparent plastic substrate and the light diffraction structure layer, between the light diffraction structure layer and the reflective material layer, and between the reflective material layer and the adhesive layer. On the reflective material layer, a metal material with a refractive index lower than that of the light diffraction structure layer is formed in the thickness of 0.005 μm to 0.02 μm. An optically detectable material is mixed in the adhesive layer. The adhesion between respective layers including the adhesion with an initial material layer formed by the transparent plastic substrate is made larger than the adhesion of the adhesive layer and the covering material, and made smaller than the adhesion between the adhesive layer and a pasting object. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a label having a light diffraction structure layer.

In recent years, in order to prevent forgery, a light diffraction structure (hereinafter also simply referred to as a hologram) such as a hologram or a diffraction grating is formed and used on a part of a credit card or securities. In addition, since holograms have a high design effect, holograms have been used by being affixed to some printed materials and molded products.
Many of these holograms irradiate the object with light, condense the object light reflected from the object and the reference light using an optical system such as a lens, and form interference fringes on the surface of the recording medium coated with the photosensitive agent. It is produced by the method.
In addition to the above-described method for producing a hologram with interference fringes, there is also a method for producing interference fringes on a recording surface by calculation using a computer. The hologram produced by such a method is called a computer generated hologram or CGH (Computer Generated Hologram). This computer generated hologram is produced by performing an optical interference fringe generation process by computer simulation and recording acquired image data on a medium.

On the other hand, when a credit card or a hologram formed on securities is easily peeled off to prevent counterfeiting, there is a risk of being analyzed and copied.
In order not to be peeled off and abused in this way, “invisible individual information recording material, invisible individual information pasting label, and invisible individual information transfer sheet” have been proposed (for example, see Patent Document 1).

The “label for invisible individual information pasting” disclosed in Patent Document 1 is formed by sequentially forming a transparent substrate, a hologram forming layer, a reflective layer, a pressure-sensitive adhesive layer, or a heat-sensitive adhesive layer. A set of fine areas having different reflectivities is formed, and a moire pattern is generated by a separate confirmation pattern to determine true / false.
The technique disclosed in Patent Document 1 uses a hologram for a label to give a characteristic appearance and manufacturing difficulty, and forms individual invisible information by a laser or the like on the reflection layer of the hologram. The information is used for authenticity determination.
Individual invisible information is difficult to analyze because it is difficult to separate from the hologram, and even if the appearance is faithfully reproduced, it is possible to easily determine fraud by overlaying a confirmation pattern on the individual invisible information described above Yes.

JP 2002-31835 A

  However, in order to generate a moire pattern, it is necessary to increase the area of the hologram portion, and noise may occur in the moire when applied to the above-described computer generated hologram. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a label that is easy to determine authenticity even in a small area and difficult to analyze.

  In order to achieve the object, the first aspect of the label of the present invention is such that at least a light diffraction structure layer, a reflective material layer, an adhesive layer, and a coating material are sequentially formed on one side of a transparent plastic substrate. A temperature sensitive at least in a partial region between the transparent plastic substrate and the light diffractive structure layer, between the light diffractive structure layer and the reflective material layer, or between the reflective material layer and the adhesive layer. A color-changing material layer is formed, and the reflective material layer is formed with a metal material having a refractive index lower than that of the light diffraction structure layer with a thickness of 0.005 μm to 0.02 μm. Adhesive strength between each layer, including the adhesive strength with the first material layer formed on the transparent plastic substrate, mixed with a detectable substance, is greater than the adhesive strength between the adhesive layer and the coating material, and is applied to the adhesive layer. Characterized by having a smaller adhesive strength than the object It is.

  Further, the second aspect is the temperature-sensitive discoloration formed in at least a partial region between the transparent plastic substrate and the light diffractive structure layer or between the light diffractive structure layer and the reflective material layer in the first aspect. The material layer is characterized in that a temperature-sensitive color-changing material is formed which is colorless and transparent at 37 ° C. or more and colored and transparent at 13 ° C. or less.

  The third aspect is the first aspect, wherein the temperature-sensitive color-changing material layer formed in at least a partial region between the reflective material layer and the pressure-sensitive adhesive layer is colorless and transparent at 50 degrees Celsius or higher, and A temperature-sensitive color-changing material having a color and opacity is formed at 10 degrees or less.

1) A label in which at least a light diffraction structure layer, a reflective material layer, an adhesive layer, and a coating material are sequentially formed on one side of a transparent plastic substrate as in the first embodiment, A temperature-sensitive color-changing material layer is formed in at least a part of the region between the light diffraction structure layer, the light diffraction structure layer and the reflective material layer, and between the reflective material layer and the pressure-sensitive adhesive layer. Is formed of a metal material having a refractive index lower than that of the light diffractive structure layer in a thickness of 0.005 μm to 0.02 μm, and an optically detectable substance is mixed in the pressure-sensitive adhesive layer. By making the adhesive force between each layer including the adhesive force with the first material layer formed on the material larger than the adhesive force between the pressure-sensitive adhesive layer and the coating material, and smaller than the adhesive force between the pressure-sensitive adhesive layer and the pasting object, Warmed with warming at least some areas colored The part becomes transparent, and the pattern of the layer formed on the back side and the presence of special materials can appear.
In addition, the adhesive strength between each layer, including the adhesive strength with the first material layer formed on the transparent plastic substrate, is greater than the adhesive strength between the adhesive layer and the coating material, and the adhesive strength between the adhesive layer and the object to be applied. By making it smaller, the label once pasted cannot be peeled off from the object to be pasted, making it difficult to analyze the entire label.
2) In addition, as in the second aspect, in the first aspect, it is formed in at least a partial region between the transparent plastic substrate and the light diffractive structure layer or between the light diffractive structure layer and the reflective material layer. The temperature-sensitive color changing material layer is formed of a temperature-sensitive color-changing material that is colorless and transparent at 37 degrees Celsius or higher, and is colored and transparent at temperatures below 13 degrees Celsius. When it is formed between the substrate and the light diffraction structure layer, it must be confirmed for the first time by heating the hologram design of the part hidden at room temperature or the presence of an optically detectable substance that cannot be seen at room temperature. Can be effective in finding counterfeit products.
In addition, when the temperature-sensitive color changing material layer is formed between the light diffraction structure layer and the reflective material layer, it can be confirmed for the first time by heating the presence of an optically detectable substance that cannot be visually recognized at room temperature. , Can be effective in finding counterfeit products.
3) Further, as in the third aspect, in the first aspect, the temperature-sensitive color changing material layer formed in at least a partial region between the reflective material layer and the pressure-sensitive adhesive layer is colorless at 50 degrees Celsius or higher. By forming a temperature-sensitive color-changing material that is transparent and colored and has an opacity below 10 degrees Celsius, it is possible to confirm the presence of a material that changes color by heating through a translucent reflective material layer. Thus, it is possible to find a counterfeit product without using a special device.

Hereinafter, the label of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining a label of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.
In FIG. 1, a temperature-sensitive color-changing material layer, which will be described later, will be described as an example formed between a transparent plastic substrate and a light diffraction structure layer.

The label of the present invention will be described with reference to FIG.
The label 1 of the present invention shown in FIG. a is a plan view of the label 1 as seen from the transparent plastic substrate side.
Further, FIG. B shows a state in which the temperature-sensitive color changing portion 121 of the label 1 shown in FIG. A is heated to change color transparently so that the hologram design 1301 hidden behind the temperature-sensitive color changing portion 121 is visible. It is a figure which shows having become.
In FIG. a, the label 1 of the present invention has at least three layers of a light diffractive structure layer, a reflective material layer, and an adhesive layer on one of the front and back surfaces of a transparent plastic substrate and one coating material. Is formed.
In FIG. 1, as described above, the temperature-sensitive color-changing material layer is an example formed between the transparent plastic substrate and the light diffractive structure layer. You may form in any between a layer and an adhesive layer.

In the example of the label 1 shown in FIG. 1a, a temperature-sensitive color changing portion 121 made of a temperature-sensitive color changing material is formed in a circular pattern on the back side of a transparent plastic substrate (not shown), and a light diffraction structure is formed on the back side layer. A layer (not shown) is formed.
The light diffraction structure layer is formed in a pattern on the label 1. On the layer on which the patterned light diffraction structure 130 is formed, the letters “SUN” are formed by a hologram or a diffraction grating by CGH. On the back side of the temperature-sensitive color changing portion 121, “SUN” as shown in FIG. The hologram pattern 1301 corresponding to “is hidden.

In FIG. 1, the temperature-sensitive color changing portion 121 made of a temperature-sensitive color changing material may be formed in a pattern shape by a layer to be formed, formed in a belt shape, or formed on the entire surface.
Further, the light diffraction structure 130 may be partially formed or formed on the entire surface.
In the example shown in FIG. 1, a temperature-sensitive color-changing material capsule that is opaque at 13 degrees Celsius or less and transparent at 37 degrees Celsius or more is mixed with silk screen printing ink and printed in a pattern as a temperature-sensitive color-changing portion 121. The label 1 is prepared, and the temperature-sensitive discoloration portion 121 of the label 1 attached to the object is rubbed with a finger to change it transparently, and the hologram pattern 1301 of FIG. Authenticity is discriminated.

  In addition, with the label 1 attached to the object, ultraviolet rays, infrared rays, etc. are irradiated from the transparent plastic substrate side, and the temperature-sensitive color changing material layer, the light diffraction structure layer, the transparent reflective material layer, or 0.005 μm to 0 The authenticity of the label is determined by confirming the presence of an optically detectable substance (not shown) mixed in the adhesive through a reflective material layer made of a metal material having a thickness of 0.02 μm.

In addition, each layer including the adhesive strength with the first material layer formed on the transparent plastic substrate so that the label once pasted cannot be peeled off from the pasted object (the state of the original label) Is set to be larger than the adhesive force between the pressure-sensitive adhesive layer and the coating material and smaller than the adhesive force between the pressure-sensitive adhesive layer and the object to be pasted.
As a result, after peeling off the coating material from the label and sticking it on the object to be pasted, when trying to peel the label back to its original label using the transparent plastic substrate as a clue, it will be peeled off or destroyed between any layers. It is supposed to end up.

With reference to FIG. 2, the AA line cross section of FIG. 1 is demonstrated.
As described in FIG. 1, the label 1 of the present invention has at least a temperature-sensitive color changing material layer 12, a light diffraction structure layer 13, a reflective material layer 14, a pressure-sensitive adhesive layer 15, and a coating on one side of a transparent plastic substrate 11. The material 16 is formed sequentially. In the figure, the temperature-sensitive color changing material layer 12 is formed between the transparent plastic substrate 11 and the light diffractive structure layer 13, but between the light diffractive structure layer 13 and the reflective material layer 14, the reflective material layer 14 is adhered. It may be formed anywhere between the agent layers.

In FIG. 2, the temperature-sensitive color changing material layer 12 is formed in a pattern on the back side of the transparent plastic substrate 11, but it may be formed in a strip shape or formed entirely on the formed layer.
Further, the light diffraction structure layer 13 may be partially formed or formed on the entire surface.
As described in FIG. 1, when the temperature-sensitive color changing material layer 12 is formed in a pattern, for example, a temperature-sensitive color changing material that is opaque at 13 degrees Celsius or less and transparent at 37 degrees Celsius or higher is formed. By rubbing the temperature-sensitive color changing portion with a finger, the temperature-sensitive color changing portion is changed to be transparent, and the hologram pattern of the light diffraction structure layer 13 hidden on the back side is caused to appear to determine authenticity.

In addition, with the label 1 attached to the object, ultraviolet rays, infrared rays, etc. are irradiated from the transparent plastic substrate side, and the temperature-sensitive color changing material layer, the light diffraction structure layer, the transparent reflective material layer, or 0.005 μm to 0 The optically detectable substance 151 mixed in the pressure-sensitive adhesive layer 15 can be confirmed in the portion where the temperature-sensitive color changing material layer is not formed through the reflective material layer made of a metal material having a thickness of 0.02 μm. .
When the temperature-sensitive color changing material layer is formed on the entire surface, the optically detectable substance 151 mixed in the pressure-sensitive adhesive layer 15 can be confirmed by heating the temperature-sensitive color changing material to make it transparent. .

  In addition, each layer including the adhesive force between the transparent plastic substrate 11 and the temperature-sensitive color-changing material layer 12 so that the label once pasted cannot be peeled off from the object to be pasted (original label state). Is set to be larger than the adhesive force between the pressure-sensitive adhesive layer 15 and the covering material 16 and smaller than the adhesive force between the pressure-sensitive adhesive layer 15 and the object to be pasted (not shown).

An example of the material used for the label 1 will be described with reference to FIG.
For the transparent plastic substrate 11, for example, polyethylene terephthalate (polyester), polyvinyl chloride, polycarbonate, polyimide, polyamide, cellulose triacetate, polystyrene, acrylic, polypropylene, polyethylene and the like can be used.

A temperature-sensitive color changing material (also referred to as a temperature-sensitive colorant) formed in the temperature-sensitive color changing material layer 12 will be described.
Among leuco dyes having a heterocyclic ring, there is a dye that exhibits a color developing action by opening a part of the ring of the dye by a proton donor substance.
The chemical reaction of coloring / decoloring accompanying ring opening / closing is reversible, and the physical properties of the coexisting proton donating substance repeat coloring / decoloring by amorphous / crystalline transformation at a predetermined temperature. Is expressed.
As the proton donor substance, an organic phosphoric acid compound, an aliphatic carboxylic acid compound or a phenol compound is used. In order to stably use the thermosensitive coloring agent in various products, the thermosensitive coloring agent and the proton donating substance are often encapsulated in a microcapsule.
About the above-mentioned thermosensitive coloring agent, the material described in detail in patent 3134108, Unexamined-Japanese-Patent No. 2000-62075, etc. and the well-known material marketed can be obtained and used.
In order to form the temperature-sensitive color-changing portion in a pattern, a temperature-sensitive color-changing material is mixed in a silk screen medium ink and printed by a silk screen printing method.
In the case of forming the entire surface of the label or a strip instead of the pattern, it is formed by a roll coating method, a gravure printing method, a flexographic printing method, or the like.

  For the light diffraction structure layer 13, resins such as acrylic, polystyrene, polyvinyl chloride, polycarbonate, melamine, epoxy, polyester, and urethane can be used alone or in combination, and further, radically polymerizable unsaturated. A thermoformable substance having a group, or a radically polymerizable unsaturated monomer added thereto to make it ionizing radiation curable can be used.

For the reflective material layer 14, a metal thin film that reflects light or an oxide of these metals is preferably used. The reflective material layer 14 is formed by a thin film forming method such as a vacuum deposition method, a sputtering method, or an ion plating method.
When the reflective material layer 14 is a thin film having a refractive index smaller than that of the light diffractive structure layer 13, that is, when used as an opaque layer, in addition to commonly used aluminum, for example, chromium, iron, cobalt, nickel, A metal such as copper, silver, gold, magnesium, lead, tin, cadmium, bismuth, titanium, zinc, or indium, or an oxide, nitride, or alloy of these metals is used.

  When the reflective material layer 14 is a thin film having a refractive index larger than that of the light diffraction structure layer 13, that is, when used as a transparent layer, zinc sulfide, titanium oxide, aluminum oxide, silicon oxide, antimony sulfide, or the like is used.

  The thickness of the reflective material layer 14 is set according to the purpose. In many cases, a thickness of 0.005 μm to 0.1 μm is used, but the reflective material layer 14 is used as a thin film having a refractive index smaller than that of the light diffraction structure layer 13 as in the present invention to provide transparency. In this case, it is used within the range of 0.005 μm to 0.02 μm.

Examples of the adhesive layer 15 include an acrylic resin, an acrylate resin, or a copolymer thereof, natural rubber, a styrene-butadiene copolymer, casein, gelatin, a rosin ester, a terpene resin, a phenol resin, and a styrene resin. Select from silicone resin.
The pressure-sensitive adhesive layer 15 is preferably used in a thickness of 3 μm to 50 μm.

For the coating material 16, for example, a material obtained by applying polyethylene, wax, silicon or the like to the surface of semi-bleached paper, high-quality paper, glassine paper, or the like is used.
In addition to the above, a plastic film such as a polyester film is also used for the coating material 16.

The optically detectable substance 151 will be described.
In the present invention, the optically detectable substance used by being mixed in the pressure-sensitive adhesive layer is called a fine fine particle “taggant” that is identified by the detection device.
A taggant is recognized in response to an external stimulus. For example, when white light, ultraviolet light, or infrared light is irradiated, light such as fluorescence is emitted in a certain wavelength range.
The detection device determines the authenticity by identifying a specific material (fine fine particles) associated with the emitted light and comparing it with information programmed in the device.
In addition to the taggant, there are multi-layered colored thin films other than the above, and the layered color pattern is magnified with a magnifying glass or the like and confirmed as a tracking additive to determine whether it is authentic or not.

As a material for adjusting the adhesive strength between each layer, transparent resin which is easily broken by peeling, for example, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, styrene polymer, styrene-butadiene rubber, various waxes, rosin , Terpene resins, terpene polymers, and the like.
For example, it is used as a blend resin in which 30% by mass of wax is blended with an ethylene-vinyl acetate copolymer, or as a blend resin in which polypropylene is blended with polyethylene or ethylene-vinyl acetate copolymer.

  Affixed to high-priced items, cards, gift certificates, checks, bills, stock certificates, admission tickets, etc., and can be used as a means of preventing counterfeiting.

It is a figure for demonstrating the label of this invention. It is the sectional view on the AA line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Label 11 Transparent plastic base material 12 Temperature-sensitive color-change material layer 13 Light diffraction structure layer 14 Reflective material layer 15 Adhesive layer 16 Coating material 121 Temperature-sensitive color change part 130 Light diffraction structure 151 Optically detectable substance 1301 Hologram pattern

Claims (3)

A label in which at least a light diffraction structure layer, a reflective material layer, an adhesive layer, and a coating material are sequentially formed on one side of a transparent plastic substrate,
A temperature-sensitive color changing material layer is formed in at least a partial region between the transparent plastic substrate and the light diffractive structure layer, between the light diffractive structure layer and the reflective material layer, or between the reflective material layer and the adhesive layer. ,
In the reflective material layer, a metal material having a refractive index lower than that of the light diffraction structure layer is formed with a thickness of 0.005 μm to 0.02 μm,
The adhesive layer is mixed with an optically detectable substance,
The adhesive strength between each layer including the adhesive strength with the first material layer formed on the transparent plastic substrate is larger than the adhesive strength between the pressure-sensitive adhesive layer and the coating material, and smaller than the adhesive strength between the pressure-sensitive adhesive layer and the object to be applied. A label characterized by The label of claim 1,
The temperature-sensitive color changing material layer formed in at least a partial region between the transparent plastic substrate and the light diffractive structure layer or between the light diffractive structure layer and the reflective material layer is colorless and transparent at 37 degrees Celsius or higher, A label characterized in that a temperature-sensitive color-changing material having a color and transparency is formed at 13 degrees Celsius or less. The label of claim 1,
The temperature-sensitive color-changing material layer formed in at least a partial region between the reflective material layer and the pressure-sensitive adhesive layer is colorless and transparent at 50 ° C. or higher, and is colored and opaque at 10 ° C. or lower. A label characterized in that is formed.

Images