JP2009229574A - Heat history display label, self-adhesive label, and labeled article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a label peeled off with the use of heat from being used wrongfully. <P>SOLUTION: A heat history display label 10 comprises: a base material 111; a first ink 114a that is supported by the base material 111 and changes colors irreversibly by being heated to a first temperature or higher; and a second ink 114b that is supported by the base material 111 and changes colors by being cooled to a second temperature or lower. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a label for displaying a thermal history.

  With the increase in counterfeit products in recent years, there are increasing opportunities to use labels with anti-counterfeit technology. For example, many companies supply goods with a label called a brand protection label to the market as genuine products. Patent Document 1 describes an example of a label subjected to a forgery prevention technique.

  Such a label is effective in preventing forgery. However, when the label can be easily peeled from the article and the peeled label can be used illegally, a high anti-counterfeiting effect cannot be achieved.

  Regarding unauthorized use of labels, there have been reports of cases where labels are peeled from articles using a knife or solvent. In response to this, many brand protection labels are applied with technology for preventing unauthorized use after peeling.

  For example, a brittle label with a notch and / or perforation may be used as a brand protection label. When such a label is used, if the label is peeled off using a knife, the label breaks. Therefore, the label after peeling cannot be used illegally. However, if the adhesive layer that is attaching the label to the article is soluble in the solvent, it is possible to peel the label from the article without breaking. Therefore, in many cases, a brittle label is used as a brand protection label, and this is adhered to an article using a solvent-resistant adhesive layer.

By the way, recently, a case where a label was peeled off from an article using heat was reported. Specifically, when heated by blowing hot air or subjected to a cycle of heating and cooling, the label may float from the article. In this case, even if the above technique is applied, the label can be easily peeled from the article without causing breakage.
Japanese Patent Laid-Open No. 11-2224050

  An object of the present invention is to prevent unauthorized use of a label peeled off by using heat.

  According to the first aspect of the present invention, a base material, a first ink supported by the base material and irreversibly discolored by being heated to a first temperature or higher, and supported by the base material, a second temperature or lower. There is provided a heat history display label comprising a second ink that changes color upon cooling.

  According to a second aspect of the present invention, the heat history display label according to the first aspect and an adhesive layer supported by the base material with the first and second inks interposed therebetween are provided. An adhesive label is provided.

  According to a third aspect of the present invention, there is provided a labeled article comprising an article and the thermal history display label according to the first side surface supported by the article.

  According to the present invention, it is possible to prevent a label peeled off using heat from being used illegally.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same referential mark is attached | subjected to the component which exhibits the same or similar function through all the drawings, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a plan view schematically showing an adhesive label according to one embodiment of the present invention. 2 is a cross-sectional view of the pressure-sensitive adhesive label shown in FIG. 1 along the line II-II.

  This adhesive label 10 includes a heat history display label 11 and an adhesive layer 12. Usually, the adhesive label 10 before use is affixed on the release paper so as to be peelable.

  The thermal history display label 11 includes a base material 111, a relief structure forming layer 112, a reflective layer 113, and ink layers 114a and 114b.

  As the base material 111, for example, a transparent plastic film or sheet can be used. As a material of the base material 111, for example, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, triacetyl cellulose, or polyvinyl chloride can be used.

  The substrate 111 may have a single layer structure or a multilayer structure. Further, the substrate 111 may be optically isotropic or optically anisotropic. That is, a functional film or sheet may be used as the substrate 111. As the functional film or sheet, for example, an optical variable film, a cholesteric liquid crystal film, a deflection film, or a sheet thereof, or a deposition hologram can be used.

  The thickness of the base material 111 is, for example, in the range of 16 μm to 125 μm. In this case, the heat history display label 11 that is particularly excellent in strength, handleability, and the like is obtained.

  The base material 111 may be provided with notches and / or perforations. Alternatively, the heat history display label 11 may be provided with notches and / or perforations. When such a structure is adopted for the heat history display label 11, the heat history display label 11 can be made brittle.

  The relief structure forming layer 112 is formed on one main surface of the substrate 111. The relief structure forming layer 112 is a transparent layer having a relief structure on the surface. This relief structure forms, for example, a diffraction grating and / or a hologram.

  As a material of the relief structure forming layer 112, for example, a thermoplastic resin, a thermosetting resin, or a photocurable resin can be used. As the thermoplastic resin, for example, acrylic resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polystyrene, or polycarbonate can be used. As thermosetting resin, for example, epoxy resin, unsaturated polyester, polyester methacrylate, urethane methacrylate polymer, epoxy methacrylate polymer, polyether methacrylate, melamine methacrylate polymer, triazine acrylic resin or polyol methacrylate polymer are used. can do. As a photocurable resin, the composition containing a thermosetting resin and a photoinitiator can be used, for example.

  The relief structure forming layer 112 made of a thermoplastic resin is formed, for example, by forming a thermoplastic resin layer on the substrate 111 and embossing the thermoplastic resin layer using a stamper (mold) provided with a relief structure. It can form by providing. The relief structure forming layer 112 made of a thermosetting resin is obtained, for example, by pressing a stamper against the base material 11 with a layer containing a thermosetting resin interposed therebetween and heating the previous layer in this state. . The relief structure forming layer 112 made of a photo-curing resin, for example, presses a stamper against the base material 11 with a layer containing the photo-curing resin in between, and in this state irradiates the previous layer with light such as ultraviolet rays. Can be obtained.

  The reflective layer 113 is formed on the relief structure forming layer 112. The reflective layer 113 covers at least a part of the relief structure. The relief structure provided on the surface of the relief structure forming layer 112 is provided on the relief structure forming layer 112 in a region covering the relief structure forming layer 112 on the surface of the reflective layer 113 facing the substrate 111. This produces a relief structure similar to that of

  As the reflective layer 113, for example, a vapor deposition film obtained by a vapor deposition method such as vacuum vapor deposition or sputtering can be used. This deposited film may have a single layer structure or a multilayer structure. Examples of the material of the reflective layer 113 include metals, alloys such as aluminum, tin, nickel, bismuth and indium, alloys, compounds containing metal elements such as zinc sulfide and nonmetal elements, nonmetal compounds such as silicon oxide, or A combination of them can be used. As the reflective layer 113, a layer made of ink or paint having a metallic luster may be used. However, from the viewpoint of the visibility of the image formed by the relief structure, it is preferable to use a metal vapor deposition layer as the reflective layer 113.

  When the reflective layer 113 is not light transmissive, the reflective layer 113 has at least a part of the ink layer 114a and at least a part of the ink layer 114b hidden behind the reflective layer 113 when viewed from the substrate 111 side. Form so that there is no. For example, an opening is provided in the reflective layer 113. When the reflective layer 113 is light transmissive, the reflective layer 113 may be patterned or may not be patterned. Here, as an example, it is assumed that the reflective layer 113 is a metal layer that does not have optical transparency and has openings with shapes corresponding to the character strings “SECURITY” and “NG”.

  The reflective layer 113 may be omitted. When the reflective layer 113 is omitted, the relief structure forming layer 112 may or may not be omitted. However, the thermal history display label 11 including the reflective layer 113 can display a diffraction image with better visibility on the relief structure as compared to a label in which the thermal history display label 11 is omitted. Further, the heat history display label 11 including the relief structure forming layer 112 provided with the relief structure is less likely to be counterfeited compared to a label in which this is omitted.

  Ink layers 114 a and 114 b are formed on the relief structure forming layer 112 at positions corresponding to the openings provided in the reflective layer 113. The ink layers 114 a and 114 b cover the entire area exposed from the reflective layer 113 in the surface of the relief structure forming layer 112. The ink layers 114 a and 114 b further cover a region adjacent to the opening in the surface of the reflective layer 113. When such a structure is adopted, high accuracy is not required for alignment of the ink layers 114a and 114b with respect to the reflective layer 113.

  The ink layers 114 a and 114 b may cover only a part of the area exposed from the reflective layer 113 on the surface of the relief structure forming layer 112. In this case, the shape of the opening provided in the metal reflective layer 113 is arbitrary.

  The ink layers 114a and 114b do not have to cover the surface of the reflective layer 113, and may cover the entirety thereof. If the ink layers 114a and 114b do not cover the surface of the reflective layer 113, higher accuracy is required for the alignment of the ink layers 114a and 114b with respect to the reflective layer 113, but the ink layers 114a and 114b are formed with a smaller amount of material. Can be formed. If the ink layers 114a and 114b cover the entire surface of the reflective layer 113, more material is required to form the ink layers 114a and 114b, but it is necessary to align the ink layers 114a and 114b with the reflective layer 113. Accuracy is lower.

  The ink layer 114a is made of a first ink that irreversibly discolors when heated to the first temperature T1 or higher. Here, the term "changes color" means changing from a colorless transparent state to a colorless opaque state, changing from a colorless transparent state to a colored transparent state, changing from a colorless transparent state to a colored opaque state, colored Changing from a transparent state to a colored opaque state, changing from a colored transparent state to a colorless transparent state, changing from a colored transparent state to a colored opaque state, changing from a colored opaque state to a colored transparent state Changing from a colored opaque state to a colored opaque state, changing from a colored opaque state to a colorless transparent state, changing from a colored transparent state to a different colored transparent state, and a colored opaque It encompasses everything from a state to a different colored opaque state. Here, as an example, it is assumed that the first ink is ink that changes from an opaque state to a transparent state when heated to a temperature T1 or higher.

  As the first ink, for example, a powdery compound or composition can be used. When such a first ink is used, the ink layer 114a is light-scattering due to powder in the initial state. When the ink layer 114a is heated to a temperature T1 or higher, the powder is melted, and as a result, the particle size of the powder becomes larger or the melt forms a layer. Therefore, the ink layer 114a becomes transparent when heated to the temperature T1 or higher.

  As the powdery compound, for example, trilaurin, myristic acid, behenic acid or stearamide can be used. When trilaurin is used, the temperature T1 can be about 45 ° C. When myristic acid is used, the temperature T1 can be about 50 ° C. When behenic acid is used, the temperature T1 can be about 70 ° C. When stearic acid amide is used, the temperature T1 can be about 95 ° C.

  As the powdery composition, for example, a wax containing a linear hydrocarbon as a main component can be used. When wax is used, the first ink may further contain a thickening agent such as ethyl cellulose. When using a wax, the temperature T1 can be changed according to the composition of the wax.

  The first ink may further contain a heat-stable dye and / or pigment. That is, the first ink may further include a dye and / or pigment that does not cause a color change in response to a temperature change. In this way, the color exhibited by the ink layer 114a can be changed with almost no change in the temperature T1.

  The temperature T1 is set so that the ink layer 114a does not change color in the usage environment of the adhesive label 10. The temperature T1 is, for example, in the range of 40 ° C. to 120 ° C., and typically in the range of 80 ° C. to 120 ° C. In addition, depending on the use environment of the adhesive label 10, the temperature T1 may be a lower temperature or a higher temperature. The temperature T1 can be set in increments of about 5 ° C., but an error of ± 2 ° C. may occur.

  The ink layer 114b is made of the second ink that changes color when cooled to the second temperature T2 or lower. The second ink may be an ink that changes color reversibly when cooled to a temperature T2 or lower, or may be an ink that changes color irreversibly when cooled to a temperature T2 or lower. Typically, the second ink changes from the first color to the second color by cooling to a temperature T2 or lower, and the second ink is heated to a third temperature T3 or higher, which is higher than the temperature T2. It is an ink that changes color from the first color, that is, an ink that exhibits hysteresis. Here, as an example, the second ink is ink that exhibits this hysteresis.

  As the second ink, for example, a composition containing an electron-donating color-forming organic compound, an electron-accepting compound, and a substance that controls the color reaction of these compounds, a microcapsule containing this composition, Alternatively, a mixture containing the microcapsules and a binder resin can be used. As the electron-donating color-forming organic compound, for example, diphenylmethane phthalides or phenylindaryl phthalides can be used. As the electron-accepting compound, for example, a compound having a phenolic hydroxyl group can be used. As the substance that controls the color reaction, for example, an ester compound can be used.

  The second ink may further contain a heat-stable dye and / or pigment. That is, the second ink may further contain a dye and / or a pigment that does not cause a color change according to a temperature change. In this way, the color exhibited by the ink layer 114b can be changed without substantially changing the temperatures T2 and T3.

  The temperature T2 is typically lower compared to the temperature T1. The temperature T3 may be higher than the temperature T1, may be lower than the temperature T1, or may be the same as the temperature T1.

  The temperature T2 is set so that the ink layer 114b does not discolor in the environment where the pressure-sensitive adhesive label 10 is used. The temperature T2 is set, for example, within a range of −20 ° C. to −10 ° C. The temperature T3 is set within a range of 40 ° C. to 60 ° C., for example. Depending on the use environment of the pressure-sensitive adhesive label 10, the temperatures T2 and T3 may be lower or higher.

  The ink layers 114a and 114b can be formed by printing or application, for example.

  The ink layers 114 a and 114 b may be interposed between the substrate 111 and the relief structure forming layer 112, or may be interposed between the relief structure forming layer 112 and the reflective layer 113. You may provide in the back surface of the surface in which the structure formation layer 112 was formed. However, the ink layers 114 a and 114 b are preferably disposed between the base material 111 and the adhesive layer 12 from the viewpoint of wear resistance and weather resistance.

  The heat history display label 11 may further include a heat-stable colored layer covering at least one of the ink layers 114a and 114b. That is, the heat history display label 11 may further include a colored layer that covers at least one of the ink layers 114a and 114b and does not cause a color change according to a temperature change. For example, when the ink layers 114a and 114b are coated with a heat-stable colored layer and are normally light-transmitting or exhibit light-transmitting properties by heating or cooling, the color of the colored layer is displayed. Available to:

  The heat history display label 11 may further include a reflective layer that covers at least one of the ink layers 114a and 114b. For example, when the ink layers 114a and 114b are coated with a heat-stable colored layer and are normally light-transmitting or exhibit light-transmitting properties by heating or cooling, the reflected light from the reflecting layer is reduced. Available for display.

  The adhesive layer 12 covers the surface of the heat history display label 11 on the ink layers 114a and 114b side. The material of the adhesive layer 12 is typically a solvent-resistant adhesive that has a strong adhesive force and does not dissolve or hardly dissolves in an organic solvent.

  The adhesive layer 12 may further contain components other than the adhesive. For example, the pressure-sensitive adhesive layer 12 may further include a solvent coloring material that changes color when brought into contact with an organic solvent in addition to the pressure-sensitive adhesive.

  Next, an image displayed by the adhesive label 10 will be described. In addition, description about the diffraction image resulting from a relief structure is abbreviate | omitted here.

  FIG. 3 is a plan view schematically showing an example of an image that can be displayed by the adhesive label 10 shown in FIGS. 1 and 2. FIG. 4 is a plan view schematically showing another example of an image that can be displayed by the adhesive label 10 shown in FIGS. 1 and 2. FIG. 5 is a plan view schematically showing still another example of an image that can be displayed by the adhesive label 10 shown in FIGS. 1 and 2.

  The adhesive label 10 displays images I1 and I2 shown in FIG. 1 in its initial state. Here, the image I1 is a character string “SECURITY”, and the image I2 is a character string “NG”. The images I1 and I2 do not have to be character strings. For example, the images I1 and I2 may be images other than character strings such as symbols and graphics.

  In the initial state, it is assumed that the ink layer 114a is white and opaque and the ink layer 114b is colorless and transparent. In this case, the image I1 looks white or almost the same color, and the image I2 looks like the background color of the ink layer 114b or almost the same color.

  The ink layers 114a and 114b do not change color as long as their temperature is higher than the temperature T2 and lower than the temperature T1. Therefore, as long as the temperature is within the above range and the previous background color is constant, the images I1 and I2 do not change color.

  When the pressure-sensitive adhesive label 10 is heated to a temperature T1 or higher, as shown in FIG. 3, the ink layer 114a does not change color and the ink layer 114a changes color. For example, the ink layer 114a changes from white opaque to colorless and transparent. Therefore, the image I1 appears to be the background color of the ink layer 114a or a color approximately equal to it. The color of the image I2 is the same as in the initial state.

  As described above, the discoloration of the ink layer 114a is irreversible. Accordingly, the ink layers 114a and 114b do not change color as long as their temperature is higher than the temperature T2. Therefore, after this color change occurs, the images I1 and I2 do not change color as long as the temperature is higher than the temperature T2 and the previous background color is constant.

  When the pressure-sensitive adhesive label 10 in the initial state is cooled to a temperature T2 or lower, as shown in FIG. 4, the ink layer 114b does not change color and the ink layer 114b changes color. For example, the ink layer 114b changes color from colorless and transparent to colored and transparent. Therefore, the image I2 looks almost equal to the color obtained by subtractive color mixing of the color of the ink layer 114b and its background color. The color of the image I1 is the same as in the initial state.

  As described above, the discoloration of the ink layer 114b is reversible. However, the discolored ink layer 114b does not return to the original color unless heated to the third temperature T3 or higher. Thus, if the temperature T3 is equal to or lower than the temperature T1, the ink layers 114a and 114b do not change color as long as their temperature is below the temperature T3. Therefore, after this color change has occurred, the images I1 and I2 do not change color as long as the temperature is within the above range and the previous background color is constant.

  When the temperature T3 is higher than the temperature T1, the ink layers 114a and 114b do not change color as long as their temperature is lower than the temperature T1. Therefore, after this color change has occurred, the images I1 and I2 do not change color as long as the temperature is within the above range and the previous background color is constant.

  When the pressure-sensitive adhesive label 10 is heated to a temperature T1 or higher and then cooled to a temperature T2 or lower, both the ink layers 114a and 114b change color as shown in FIG. Similarly, when the pressure-sensitive adhesive label 10 is cooled to a temperature T2 or lower and then heated to a temperature T1 or higher, both ink layers 114a and 114b change color. For example, the ink layer 114a changes from white opaque to colorless and transparent, and the ink layer 114b changes from colorless and transparent to colored and transparent. Therefore, the image I1 appears to be the background color of the ink layer 114a or a color substantially equal to it, and the image I2 appears to be a color approximately equal to the color obtained by subtractive color mixing of the color of the ink layer 114b and its background color.

  The discoloration of the ink layer 114a is irreversible. Thus, the ink layers 114a and 114b do not change color as long as their temperature is below the temperature T3. Therefore, after this color change occurs, the images I1 and I2 do not change color as long as the temperature is below the temperature T3 and the previous background color is constant.

  As described above, when the pressure-sensitive adhesive label 10 is exposed to a high temperature or a low temperature that is not exposed in the usage environment, the color of the image I1 or I2 is changed. The color of the discolored image I1 does not return to the original color. In order to return the color of the discolored image I2 to the original color, it is necessary to heat the adhesive label 10 to a temperature T3 or higher.

  When the temperature T3 is equal to or higher than the temperature T1, when the pressure-sensitive adhesive label 10 where the image I1 is not discolored is heated to the temperature T3 or higher in order to return the color of the discolored image I2 to the original color, the image I1 is discolored. Therefore, when the temperature T3 is equal to or higher than the temperature T1, it is impossible to return both the images I1 and I2 to the initial colors when the image I1 or I2 is changed in color.

  When the temperature T3 is lower than the temperature T1, if the adhesive label 10 is heated to the temperature T3 or higher and lower than the temperature T1, the color of the discolored image I2 is changed to the original color without changing the image I1. Can be returned. However, it is difficult for those who perform cheating to examine such a temperature range. And even if this temperature range is known, if the temperature T3 is close to the temperature T1, it is difficult to control the temperature within the previous temperature range at all portions of the adhesive label 10. That is, even when the temperature T3 is lower than the temperature T1, if the color change of the image I1 or I2 occurs, it is almost impossible to return both the images I1 and I2 to the initial colors.

  Therefore, it can be determined that the pressure-sensitive adhesive label 10 in which at least one of the images I1 and I2 is discolored has been exposed to a high temperature or a low temperature that is not exposed in the usage environment. That is, when the heat history display label 11 included in the adhesive label 10 is peeled off from the article using heat and used illegally, it can be immediately determined that an illegal act has been performed.

Therefore, even if this heat history display label 11 is peeled from the article using heat, it is difficult to use it illegally.

The adhesive label 10 can be variously modified.
FIG. 6 is a plan view showing a modification of the pressure-sensitive adhesive label shown in FIGS. 1 and 2.
The adhesive label 10 shown in FIG. 6 is the same as the adhesive label 10 described with reference to FIGS. 1 and 2 except that the following configuration is adopted. That is, in this adhesive label 10, the ink layers 114a and 114b partially overlap. The ink layer 114a is the same as the ink layer 114a of the pressure-sensitive adhesive label 10 described with reference to FIGS. The ink layer 114b is the same as the ink layer 114b of the pressure-sensitive adhesive label 10 described with reference to FIGS. 1 and 2 except that the ink layer 114b further covers the reflective layer 113 and the ink layer 114b.

  When such a structure is employed, the color of the ink layer 114b may affect the color of the image I1, but a color change similar to that described with reference to FIGS. 1 and 5 occurs. Therefore, substantially the same effect as described above can be obtained.

This adhesive label 10 can be affixed to various articles.
FIG. 7 is a perspective view schematically showing an example of a labeled article.

  The labeled article shown in FIG. 7 includes an article 20 and an adhesive label 10 attached thereto.

  The article 20 is, for example, an article that should be prevented from forgery, a packaging material that wraps it, or a package that includes an article that should be prevented from forgery and the packaging material that wraps it. .

  The surface of the article 20 to which the adhesive label 10 is affixed may be composed of any material. For example, the material constituting the surface of the article 20 to which the adhesive label 10 is attached may be paper such as fine paper, coated paper, coated cardboard and cardboard, such as polyethylene terephthalate, polypropylene and polyethylene. It may be a soft resin, a hard resin such as vinyl chloride, polycarbonate, and acrylonitrile-butadiene-styrene resin, or a metal material such as aluminum, iron, and stainless steel.

  As described above, even if the heat history display label 11 included in the pressure-sensitive adhesive label 10 is peeled off from the article using heat, it is difficult to use it illegally. Therefore, even if the heat history display label 11 is peeled off from the article 20 by the previous method and attached to an improper product, whether or not an illegal act has been performed by checking the colors of the images I1 and I2 is determined. Can be determined.

  As described above, the example in which the adhesive label 10 and the heat history display label 11 are applied to the anti-counterfeiting technology has been described. However, the adhesive label 10 and the heat history display label 11 can be used for other purposes. For example, when the previous adhesive label 10 is attached to an article that needs to be transported and / or stored under a controlled temperature, the labeled article can be obtained by checking the colors of the images I1 and I2. It is possible to determine whether or not the product has been transported and / or stored under proper temperature control. In this case, if the heat history display label 11 can be supported by the article, the adhesive layer 12 is unnecessary.

The top view which shows roughly the adhesive label which concerns on 1 aspect of this invention. Sectional drawing along the II-II line of the adhesive label shown in FIG. The top view which shows roughly an example of the image which the adhesive label 10 shown in FIG.1 and FIG.2 can display. The top view which shows roughly the other example of the image which the adhesive label 10 shown in FIG.1 and FIG.2 can display. The top view which shows schematically the further another example of the image which the adhesive label 10 shown in FIG.1 and FIG.2 can display. The top view which shows the modification of the adhesive label shown in FIG.1 and FIG.2. The perspective view which shows an example of an article | item with a label roughly.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Adhesive label, 11 ... Thermal history display label, 12 ... Adhesive layer, 20 ... Article, 111 ... Base material, 112 ... Relief structure forming layer, 113 ... Reflective layer, 114a ... Ink layer, 114b ... Ink layer.

Claims (10)

A substrate;
A first ink supported by the substrate and irreversibly discolored by heating above the first temperature;
A heat history display label, comprising: a second ink which is supported by the substrate and changes color when cooled to a second temperature or lower.   The heat history display label according to claim 1, wherein the second temperature is lower than the first temperature.   The second ink is changed from the first color to the second color by cooling to the second temperature or lower, and the second ink changed to the second color is compared with the second temperature. The heat history display label according to claim 2, wherein the color is changed from the second color to the first color by heating to a higher third temperature or higher.   The thermal history display label according to claim 3, wherein the third temperature is higher than the first temperature.   The said 1st and 2nd ink forms the 1st and 2nd ink layer, respectively, and adjoins in the direction parallel to the main surface of the said base material, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. Thermal history display label as described in.   The first and second inks form first and second ink layers, respectively, and the first and second ink layers partially overlap each other. Thermal history display label as described in. The first and second inks form first and second ink layers, respectively, and the thermal history display label is:
A relief structure forming layer interposed between the base material and the first and second ink layers, and having a relief structure on a main surface on the first and second ink layers side;
The thermal history display label according to any one of claims 1 to 4, further comprising a reflective layer covering at least a part of the relief structure.   An adhesive comprising the heat history display label according to any one of claims 1 to 7 and an adhesive layer supported by the base material with the first and second inks interposed therebetween. label.   An article with a label comprising the article and the thermal history display label according to any one of claims 1 to 7 supported by the article.   An adhesive layer interposed between the thermal history display label and the article is further provided, and the base material faces the article with the first and second inks interposed therebetween. 9. The labeled article according to 9.

Images