JP2009128137A - Temperature history display material - Google Patents

Abstract

The present invention provides a temperature history display material that has a simple configuration, is easy to manage from manufacture to use, and is difficult to counterfeit thermal history.
A temperature history display material including a light-transmitting sealed container, a substance sealed in the sealed container, and a photochromic material dissolved or dispersed in the substance. Placing the temperature history display material below the freezing point of the substance causes the substance to solidify. With the substance solidified, the photochromic material is colored using light. When this temperature history display material is exposed to a temperature equal to or higher than the control temperature, the solidified substance dissolves and the color pattern is lost. If the coloring pattern is characterized, even if it is cooled again, the same pattern cannot be obtained.
[Selection] Figure 2

Description

  The present invention relates to a novel temperature history display material.

  With the development of freezing and refrigeration technologies, many foods and pharmaceuticals have been able to maintain quality and safety over a long period of time. In addition, with the development and popularization of low-temperature transport technology, various frozen and refrigerated foods are also on the market. For this reason, temperature control in the distribution process or storage process is important. In particular, in the case of food, if the prescribed temperature control cannot be performed due to an unforeseen event such as a power failure, bacteria will propagate and cause spoilage and alteration. In addition, at present, when goods are being distributed internationally, in the food logistics industry, temperature management (safety) of goods during shipping along the equator is a problem. Whether or not an article has been exposed to a temperature higher than the control temperature even once is difficult to understand simply by looking at the article. For this reason, it has been attempted to perform temperature management of an article by attaching a temperature indicator, a temperature-sensitive color material, or the like to an individual article such as a cryopreserved food.

In order to easily determine that an article has been exposed to a temperature higher than the control temperature even once, the color changes when the article is exposed to a temperature higher than the control temperature, and the state is maintained for a long time thereafter. It is desirable. That is, it is desirable that the color change is irreversible. As a temperature history display body that is irreversibly colored at a low temperature, for example, a temperature history display body including a color former layer, a temperature detecting layer, and a developer layer has been developed (see, for example, Patent Document 1). In addition, a dye precursor on the support and a heat-sensitive recording layer containing as a main component a developer that forms a colored body by reacting with the dye precursor upon heating, a permeation layer mainly containing a pigment and a binder, A temperature indication label has been developed in which a microcapsule-containing layer containing a temperature sensitive substance having a melting point of 0 ° C. or higher and a protective layer are sequentially laminated (for example, see Patent Document 2)
Japanese Patent Laid-Open No. 10-287863 JP 2004-184920 A

  However, the temperature history display body and the temperature label described in these documents use a temperature detecting agent and a temperature sensitive substance having a specific melting point. For this reason, it is necessary to set the temperature history display body and the temperature indicating label to a predetermined temperature or lower during transportation and storage until the use state is reached. Further, once the color is developed, it cannot be actually used because it is irreversible. For this reason, these temperature history display bodies and temperature indication labels need to be provided with a switch-on mechanism that enables the temperature change mechanism to operate.

  As described above, the conventional temperature history display body and the temperature indication label have a complicated structure, and it is necessary to perform a pretreatment for enabling the temperature change mechanism in use. Further, when a label or the like is attached, there is a risk of peeling due to a physical action.

  That is, the present invention has been made in view of the above problems, and an object of the present invention is to provide a temperature history display material that has a simple configuration and can be easily managed after being manufactured and used.

  Another object of the present invention is to provide a temperature history display material that has a simple configuration and is difficult to counterfeit the heat history.

  As a result of intensive studies on the above problems, the present inventors have found that the present invention provides a temperature history display material including a sealed container, a substance sealed in the sealed container, and a photochromic material dissolved or dispersed in the substance. Was completed.

  In the temperature history display material of the present invention, at least a part of the sealed container may be light transmissive.

  When the temperature history display material of the present invention is placed below the freezing point of the substance, the substance is solidified. With the substance solidified, the photochromic material is colored using light. When this temperature history display material is exposed to a temperature equal to or higher than the control temperature, the solidified substance dissolves and the color pattern is lost. If the coloring pattern is characterized, even if it is cooled again, the same pattern cannot be obtained. As a result, the temperature history can be displayed with a simple configuration. Further, since the color is developed after solidification, the temperature history until solidification is not reflected. Furthermore, since a photochromic material is used, even if it is colored before use, it can be decolored, for example, by irradiation with visible light.

  In the temperature history display material of the present invention, the photochromic material may be a photochromic material that develops a different color depending on the wavelength of irradiation, or may be a photochromic material that irreversibly develops color when irradiated. . Alternatively, an adhesive layer may be provided on the surface of the sealed container, and an ultraviolet photosensitive layer may be provided on at least a part of the surface of the sealed container.

  By adopting such a configuration, forgery of the temperature history can be easily prevented.

  Since the temperature history display material of the present invention includes a sealed container, a substance sealed in the sealed container, and a photochromic material dissolved or dispersed in the substance, it has a simple configuration and is used after being manufactured. A temperature history display material that is easy to manage can be provided.

  The temperature history display material of the present invention includes a sealed container, a substance sealed in the sealed container, and a photochromic material dissolved or dispersed in the substance.

[Sealed container]
The shape, material, and the like of the sealed container used in the present invention are not particularly limited as long as the substance and the photochromic material can be enclosed. What is necessary is just to select timely according to a use. Specific examples include a bag-like container with a film attached thereto, a flexible plastic container, or a molded container such as glass or hard plastic. The size of the sealed container is not particularly defined as long as it can be visually discriminated.

  At least a part of the sealed container may be light transmissive. When the photochromic material is colored, for example, light such as laser light or an ultraviolet lamp is irradiated. For that purpose, it needs to be light transmissive. Further, at least a part of the sealed container needs to be transparent or translucent.

[material]
The substance that can be used for the temperature history display material of the present invention may be any substance that can dissolve or disperse the photochromic material. Such a substance may be a low molecular compound or a polymer.

  As the low molecular weight compound, a compound having a melting point near the desired management temperature can be used as appropriate. For example, water (melting point: 0 ° C.), hydrocarbon compound, alcohol compound, halogenated hydrocarbon compound, phenol compound, ether compound, ketone compound, fatty acid, ester compound, nitrogen compound, sulfur compound, two or more functional groups And the like. These substances may be used singly or as a mixture of two or more substances having a melting point near the desired management temperature.

  Examples of hydrocarbon compounds include pentane (melting point: -130 ° C), 2-methylbutane (melting point: -160 ° C), hexane (melting point: -95.3 ° C), 2-methylpentane (melting point: -154 ° C), 2 , 2-dimethylbutane (melting point: −100 ° C.), 2,3-dimethylbutane (melting point: −128.4 ° C.), heptane (melting point: −91 ° C.), octane (melting point: −56.8 ° C.), isooctane (Melting point: −107 ° C.), nonane (melting point: −53.5 ° C.), 2,5,5-trimethylhexane (melting point: −105.8 ° C.), decane (melting point: −30 ° C.), dodecane (melting point: -9.5 ° C), 1-heptene (melting point: 119 ° C), saturated unsaturated aliphatic hydrocarbons such as docosan (melting point: 43 ° C to 46 ° C), benzene (melting point: 5.5 ° C), toluene ( Melting point: -95 ° C), o-xylene (melting point: 25 ° C.), m-xylene (melting point: −48 ° C.), p-xylene (melting point: 13 ° C.), ethylbenzene (melting point: −95 ° C.), cumene (melting point: −96 ° C.), mesitylene (melting point: −45 ° C.) ), Naphthalene (melting point: 80 ° C.), tetralin (melting point: −35.7 ° C.), butylbenzene (n-isomer: melting point: −88 ° C., sec-isomer: melting point: −75 ° C., tert-isomer: melting point: -58 ° C), p-cymene (melting point: -68 ° C), cyclohexylbenzene (melting point: 7 ° C), diethylbenzene (o-isomer: melting point: -31 ° C, m-isomer: melting point: -84 ° C, p-isomer) : Melting point: −43 ° C., pentylbenzene (melting point: −75 ° C.), dipentylbenzene (melting point: −75 ° C.), dodecylbenzene (melting point: −7 to 3 ° C.), biphenyl (melting point: 69 ° C.), styrene ( Melting point: -31 ° C), bibenzyl ( Points: 50 ° C. to 54 ° C.), etc., cyclopentane (melting point: −94 ° C.), methylcyclopentane (melting point: −142.5 ° C.), cyclohexane (melting point: 6.5 ° C.), methyl Cyclohexane (melting point: −127 ° C.), ethylcyclohexane (melting point: −111.3 ° C.), bicyclohexyl (cis-cis isomer: melting point: −2.25 ° C.), cyclohexene (melting point: −103.5 ° C.), α -Cycloaliphatic hydrocarbons such as pinene (melting point: -64 ° C), dipentene (melting point: -96.6 ° C), decalin (cis isomer: melting point: -43 ° C, trans isomer: melting point: -30.4 ° C) Etc.

  Examples of the alcohol compound include methanol (melting point: −97.5 ° C.), ethanol (melting point: −114.5 ° C.), 1-propanol (melting point: −126.2 ° C.), 2-propanol (melting point: −89.5). ° C), 1-butanol (melting point: -89.8 ° C), 2-butanol (melting point: -114.7 ° C), isobutanol (melting point: -108 ° C), tert-butanol (melting point: -26 ° C), 1-pentanol (melting point: -78.2 ° C), 3-methyl-1-butanol (melting point: -117.2 ° C), 2-methyl-2-butanol (melting point: -12 ° C), 2,2- Dimethyl-1-propanol (freezing point: 53 ° C.), 1-hexanol (freezing point: −44.6 ° C.), 4-methyl-2-pentanol (freezing point: −90 ° C.), 2-ethyl-1-butanol (freezing point) : -114.4 ° C 1-heptanol (freezing point: -35 ° C), 3-heptanol (freezing point: -70 ° C), 1-octanol (freezing point: -15.2 ° C), 2-octanol (melting point: -38 ° C), 2-ethyl -1-hexanol (freezing point: −70 ° C.), 1-nonal (freezing point: −5 ° C.), 3,5,5-trimethyl-1-hexanol (melting point: −70 ° C. or less), 1-decanol (freezing point: 6) 9 ° C), 1-undecanol (freezing point: 19 ° C), 1-dodecanol (freezing point: 24 ° C), allyl alcohol (melting point: -129 ° C), 2-propyn-1-ol (freezing point: -51.8 ° C) ), Benzyl alcohol (melting point: −15 ° C.), cyclohexanol (melting point: 25 ° C.), 1-methylcyclohexanol (melting point: 20-22 ° C.), 2-methylcyclohexanol (melting point: − ° C. (cis), −20.5 ° C. (trans), α-terpineol (melting point: 36 ° C.), 1,2-ethanediol (melting point: −12.6 ° C.), 1,2-propanediol (pour point) : -59.5 ° C), 1,3-propanediol (melting point: -32 ° C), 1,3-butanediol (melting point: -50 ° C or lower), 1,4-butanediol (melting point: 20 ° C), 2,3-butanediol (melting point: 34.2 to 34.4 ° C), 1,5-pentanediol (melting point: -15.6 ° C), 2-butene-1,4-diol (melting point: 4 ° C, 11.8 ° C.), 2-methyl-2,4-pentanediol (melting point: −50 ° C. or lower), 2-ethyl-1,3-hexanediol (melting point: −40 ° C.), 3-hexadecyloxy-1 , 2-propanediol (melting point: 64 ° C.), glycerin (melting point: 18 ° C.) 2-ethyl-2- (hydroxymethyl) -1,3-propanediol (melting point: 58.5 ° C.), 2- (trifluoromethyl) phenethyl alcohol (melting point: −3 ° C. to −2 ° C.), and the like. It is done.

  Examples of halogenated hydrocarbons include dichlorobenzene (o-isomer: melting point: −17 ° C., m-isomer: melting point: −25 ° C., p-isomer: melting point: 53 ° C.), 1,2,4-trichlorobenzene (melting point). : 17 ° C), 1-chloronaphthalene (melting point: -2.3 ° C), 1,1,2,2-tetrabromoethane (melting point: 0.1 ° C), 1,2-dibromoethane (melting point: 10 ° C) ), O-dibromobenzene (melting point: 5 ° C.), 1-bromonaphthalene (melting point: 6 ° C.), and the like.

  Phenols include phenol (melting point: 41 ° C.), cresol (o-isomer: melting point: 31 ° C., m-isomer: melting point: 12 ° C., p-isomer: melting point: 35 ° C.), xylenols (2,3- Body: melting point: 72-75 ° C., 2,4-body: melting point: 24.5-26 ° C., 2,5-body: melting point 74.5-76 ° C., 2,6-body: melting point: 45.5 48 ° C, 3,4-isomer: melting point: 62-65 ° C, 3,5-isomer: melting point: 63-66 ° C), butylphenol (melting point: -7 ° C), and the like.

  Examples of ether compounds include phenetole (melting point: −30. ° C. to −28.6 ° C.), diphenyl ether (melting point: 28 ° C.), dibenzyl ether (melting point: 4 to 5 ° C.), veratrol (melting point: 22.5 ° C.). , Dioxane (melting point: 11.8 ° C.), trioxane (melting point: 64 ° C.), cineol (melting point: 1.3 ° C.), crown ether (melting point: 26 ° C. or lower to 209 ° C.), and the like.

  Examples of ketone compounds include acetonyl acetone (melting point: −9 ° C.), phorone (melting point: 28 ° C.), isophorone (melting point: −8 ° C.), methylcyclohexanone (melting point: −20 ° C.), acetophenone (melting point: 20 ° C.). ), Camphor (melting point: 178.8 ° C.), and the like.

  As fatty acids, formic acid (melting point: 8.3 ° C.), acetic acid (melting point: 16.7 ° C.), propionic acid (melting point: −21 ° C.), butyric acid (melting point: −5.2 ° C.), isobutyric acid (melting point: -46 ° C), pivalic acid (melting point: 35 ° C), caproic acid (melting point: -4 ° C), caprylic acid (melting point: 16.5 ° C), oleic acid (melting point: 13.4 ° C), and the like.

  Examples of the ester compound include stearic acid ester (ethyl stearate (melting point: 33 ° C. to 35 ° C.), butyl stearate (melting point: 27.5 ° C.), pentyl stearate (melting point: 30 ° C.)), benzoic acid ester (benzoic acid) Methyl acid (melting point: −12.5 ° C.), ethyl benzoate (melting point: −35 ° C.), propyl benzoate (melting point: −51.6 ° C.), butyl benzoate (melting point: −22.4 ° C.), benzoic acid Benzyl acid (melting point: 21 ° C.), ethyl cinnamate (melting point: 12 ° C.), dipentyl oxalate (melting point: −9 ° C.), maleate ester (dimethyl maleate (melting point: −19 ° C.), diethyl maleate ( Melting point: -8.8 ° C), dibutyl tartrate (melting point: 21 ° C), tributyl citrate (melting point: -20 ° C), dibutyl sebacate (melting point: 1 ° C), dimethyl phthalate (melting point: 0.5 ° C.), dioctyl phthalate (melting point: −25 ° C.), lauric acid monoester (melting point: 27.5 ° C.), palmitic acid monoester (melting point: 47.5 ° C. to 51.5 ° C.), ethyl palmitate (Melting point: 20 ° C to 25 ° C), methyl palmitate (melting point: 25 ° C to 31 ° C)), stearic acid monoester (melting point: 56 ° C to 58.5 ° C), ethyl stearate (melting point: 33 ° C to 35 ° C) ° C), oleic acid monoester (melting point: 1 ° C), methyl tridecanoate (melting point: 5.5 ° C), ethyl myristate (melting point: 10 ° C to 13 ° C), formic acid diester (melting point: -10 ° C), laurin Acid diester (melting point: 49 ° C to 54 ° C), myristic acid diester (melting point: 63 ° C to 64 ° C), palmitic acid diester (melting point: 65 ° C to 72 ° C), stearic acid diester (melting point: 3 ° C to 79 ° C), ethylene carbonate (melting point: 36.4 ° C), tributyl phosphate (melting point: 71 ° C to 75 ° C), triphenyl phosphate (melting point: 49 ° C to 51 ° C), tricresyl phosphate (o -Body: melting point: 90 ° C to 91 ° C, m-form: melting point: 25 ° C to 26 ° C, p-form: melting point: 77.5 ° C to 78 ° C) and the like.

  Nitrogen compounds (melting point: 5.76 ° C.), succinonitrile (melting point: 57.9 ° C.), benzonitrile (melting point: −12.75 ° C.), aniline (melting point: −6 ° C.), N, N-dimethylaniline (melting point: 2.0 ° C.), N, N-diethylaniline (melting point: −21.3 ° C., −34, 4 ° C.), o-toluidine (melting point: −24.4 ° C. (α type)) -16.3 ° C (β type)), p-toluidine (melting point: 43.7 ° C to 45 ° C), cyclohexylamine (melting point: -17.7 ° C), dicyclohexylamine (melting point: -0.1 ° C) , Pyrrole (melting point: −24 ° C.), piperidine (melting point: −9 ° C.), β-picoline (melting point: −17.7 ° C.), γ-picoline (melting point: 4.3 ° C.), 2,6-lutidine ( Melting point: -6.16 ° C to -5.9 ° C), quinoline (melting point: -15.6) ), Isoquinoline (melting point: 24.6 ° C to 26.5 ° C), ethylenediamine (melting point: 10.65 ° C to 11.3 ° C), acetamide (melting point: 69.5 ° C), N-methylacetamide (melting point: 30). .55 ° C.), 2-pyrrolidone (melting point: 25 ° C.), ε-caprolactam (melting point: 69.2 ° C.), methyl carbamate (melting point: 54.2 ° C.), ethyl carbamate (melting point: 48.2 ° C.) Etc.

  Examples of sulfur compounds include thiophene (melting point: −38.3 ° C.), dimethyl sulfoxide (melting point: 18.5 ° C.), sulfolane (melting point: 28.5 ° C.), 1,3-propane sultone (melting point: 31 ° C.), etc. Is mentioned.

  Examples of the compound having two or more functional groups include 2-phenoxyethanol (melting point: 14 ° C.), furfuryl alcohol (melting point: −29 ° C. (metastable state), −14.6 ° C. (stable state)), diethylene glycol ( Melting point: 10.45 ° C to -6.5 ° C), triethylene glycol (melting point: -7.2 ° C to -4.3 ° C), polyethylene glycol (melting point: -15 ° C to 63 ° C), 2-amino Ethanol (melting point: 10.5 ° C), diethanolamine (melting point: 28 ° C), triethanolamine (melting point: 21.5 ° C), triisopropanolamine (melting point: 46 ° C, 58 ° C), 2,2'-thiodiethanol (Melting point: −10 ° C.), o-nitroanisole (melting point: 9.4 ° C.), methyl salicylate (melting point: −8.6 ° C.), 2-phenoxyethyl acetate (melting point: −2.7) ), And the like.

  In addition, a known freezing point depressant such as sodium chloride may be added to the solvent to adjust the melting point of the solvent.

  Examples of polymers that can be used include polyoxymethylene (melting point: 184 ° C.), polyethylene oxide (melting point: 69 ° C.), polytetramethylene oxide (melting point: 57 ° C.), poly-ε-caprolactone (melting point: 64 ° C.). Etc. Alternatively, a phase transition of a liquid crystal polymer can be used. For example, liquid crystals such as polycondensates of ethylene terephthalate and parahydroxybenzoic acid, polycondensates of phenol and phthalic acid and parahydroxybenzoic acid, and polycondensates of 2,6-hydroxynaphthoic acid and parahydroxybenzoic acid. Use polymer.

[Photochromic materials]
Examples of the photochromic material that can be used in the present invention include known photochromic materials. The photochromic material refers to a compound having a function capable of reversibly changing the absorption wavelength by light. Any chromophore of the photochromic material may be used. For example, fulgides, diarylethenes, azobenzenes, spiropyrans, spirooxazines, cyclophanes, stilbenes, dihydropyrenes, thioindigos, bipyridines, aziridines, aromatic polycycles, allylidene anilines And xanthenes.

  The kind of the photochromic material used for the temperature history display material of the present invention is not particularly limited, and may be appropriately selected from known or unknown photochromic materials. Preferably, it is a photochromic material that can maintain thermal stability at a use temperature for a certain period (for example, half a year).

  A photochromic material develops color when irradiated with ultraviolet rays or the like. The colored light of the photochromic material used for the temperature history display material of the present invention is not particularly limited. Preferably, when observing from the outside of the temperature history display material, a material that can easily grasp the color change may be selected and used.

  Moreover, a photochromic material may be used independently and may be used in mixture of 2 or more types. In particular, it is preferable to use a mixture of photochromic materials having different colors depending on the wavelength of light to be irradiated.

  Below, although the photochromic material which can be used for the temperature history display material of this invention is illustrated using diarylethenes, it is not limited to these.

(1) Photochromic material showing red color

Photochromic material showing blue

Photochromic material showing yellow

Photochromic material showing green

Alternatively, as shown below, a photochromic material that irreversibly develops color when irradiated with light may be used.

  The inclusion is obtained by dissolving or dispersing a photochromic material in the above substance. The amount of the photochromic material added to the substance may be such that the color change of the photochromic material can be visually recognized. For example, it is about 1 mg / mL to 4 mg / mL. Further, a material obtained by encapsulating a photochromic material in an encapsulating material such as a microcapsule may be dispersed in a substance.

  Moreover, you may use what added surfactant, such as glycerine fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, propylene glycol fatty acid ester, or lecithin, to a solvent as needed. By adding a surfactant, for example, even a photochromic material insoluble in water can be dissolved or dispersed in water.

  The temperature history display material of the present invention can usually be stored and transported at room temperature. For example, when used as a low-temperature compensation material for frozen foods, a substance having a melting point of 0 ° C. or lower is used, and the substance is solidified at a temperature lower than the melting point. After solidifying the substance, the photochromic material is colored by irradiating with ultraviolet rays using a laser or an ultraviolet lamp. In this case, it is preferable to add a pattern such as a date or a pattern using a photomask or the like. The temperature history display material is distributed, for example, in a frozen food individual package or in a box containing a plurality of individual packages. When the frozen food exceeds the control temperature, the solvent dissolves and the colored state changes. Thereby, it can be easily determined that the frozen food has exceeded the control temperature. In particular, when a pattern is applied, the pattern collapses when the temperature is once exceeded the control temperature and again set below the control temperature. As a result, it can be seen that the temperature has once exceeded the management temperature and has been again set below the management temperature.

  The temperature history display material after coloring the photochromic material is preferably placed in a light-shielded state. Thereby, it can prevent that the attached pattern is destroyed. Usually, it may be distributed in a packaging material capable of shielding light. Furthermore, the temperature history display material of the present invention can be used effectively even under light irradiation by putting it in a bag or container that can shield light, or covering it with a light shielding sealant. .

  A plurality of temperature history display materials using substances having different melting points may be used. Thereby, when it exceeds management temperature, the time and temperature history in the meantime can be evaluated.

  The temperature history display material of the present invention can be easily prevented from being misrepresented by using it in the following manner.

  (1) For example, a plurality of types of photochromic materials having different color development depending on the wavelength of light to be irradiated are used. When applying the pattern, the irradiation wavelength can be changed for patterning. For example, a plurality of barcodes having different colors and color densities are attached to the same temperature history display material. This makes it difficult to create the same pattern once the pattern is lost.

  (2) You may use the photochromic material which colors irreversibly by irradiating above-mentioned light. As a result, once the applied pattern is exposed to a temperature equal to or higher than the control temperature and is destroyed, the entire temperature history display material is lightly colored with the color of the previously developed pattern. For this reason, even if the same pattern is given again, places other than the pattern are lightly colored. Thereby, it can be easily determined that the pattern is added again.

  (3) FIG. 1 is a diagram for explaining an example in which the temperature history display material of the present invention is used to prevent spoofing of the temperature history. In the example of FIG. 1, a certain pattern (“A” in the example of FIG. 1) is attached to the first temperature history display material 1, and another pattern (FIG. In the example of FIG. The first temperature history display material 1 and the second temperature history display material 2 are bonded via an adhesive layer 3. The adhesive layer 3 uses a light transmissive material. The adhesive layer 3 may be provided on the temperature display material in advance or may be provided at the time of adhesion. When the pattern is lost when the temperature history display material is placed at a temperature higher than the control temperature, when the pattern is formed again, the pattern of the first temperature history display material 1 and the second temperature history display material 2 is changed. Be the same. For this reason, spoofing of the temperature history can be effectively prevented.

  In addition, in the example of FIG. 1, although the pattern was attached | subjected to both the 1st temperature history display material 1 and the 2nd temperature history display material 2, you may attach a pattern to either one. In addition, when the first temperature history display material 1 and the second temperature history display material 2 are bonded via the adhesive layer 3, the first temperature history display material 1 and the second temperature history display material 2 An ultraviolet photosensitive material may be sandwiched between and adhered.

  (4) FIG. 2 is a diagram for explaining another example in which the temperature history display material of the present invention is used to prevent spoofing of the temperature history. In the example of FIG. 2, a photosensitive layer 5 is provided on a part of the light irradiation surface of the temperature history display material 4. After the temperature history display material 4 is irradiated with ultraviolet rays to form a pattern, the photosensitive layer 5 is provided. As a result, when the temperature history display material is placed at a temperature equal to or higher than the control temperature and the pattern is lost, it is easy for the photosensitive layer 5 to be exposed and re-patterned even if the pattern is formed again. Can be judged.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this Example.

(Example 1)
Photochromic compound 1 (2 mg) represented by the following chemical formula was dissolved in 10 mL of cyclohexane, placed in a plastic bag (7 cm wide, 10 cm long), and sealed. It put into the -10 degreeC freezer and solidified. When the photomask was irradiated with ultraviolet light, the photomask pattern appeared in red. The pattern did not disappear when stored in the freezer for more than a month. However, when the mixture was allowed to stand at room temperature for 30 minutes, the cyclohexane in the contents melted and became a uniform solution. It was stored again in the freezer, but it was completely different from the one that formed the pattern.

(Example 2)
Photochromic compound 2 (2 mg) represented by the following chemical formula was dissolved in 10 mL of cyclohexane, placed in a plastic bag (7 cm wide, 10 cm long), and sealed. It put into the -10 degreeC freezer and solidified. When the photomask was irradiated with ultraviolet light, the photomask pattern appeared in blue. The pattern did not disappear when stored in the freezer for more than a month. However, when the mixture was allowed to stand at room temperature for 30 minutes, the content of cyclohexane melted and became a uniform solution. It was stored again in the freezer, but it was completely different from the one that formed the pattern.

(Example 3)
Photochromic compound 1 (2 mg) was dissolved in a small amount of a surfactant (sodium dodecyl sulfate) and 10 mL of water, put in a plastic bag (7 cm wide, 10 cm long), and sealed. It put into the -10 degreeC freezer and solidified. When the photomask was irradiated with ultraviolet light, the photomask pattern appeared in red. The pattern did not disappear when stored in the freezer for more than a month. However, when left at room temperature for 30 minutes, the contents melted and became a uniform solution. It was stored again in the freezer, but it was completely different from the one that formed the pattern.

Example 4
Photochromic compound 4 (3 mg) was dissolved in 10 mL of cyclohexane, placed in a plastic bag (7 cm wide, 10 cm long), and sealed. It put into the -10 degreeC freezer and solidified. When the photomask was irradiated with ultraviolet light, the photomask pattern appeared in yellow. The pattern did not disappear when stored in the freezer for more than a month. However, when the mixture was allowed to stand at room temperature for 30 minutes, the content of cyclohexane melted and became a uniform solution. It was stored again in the freezer, but it was completely different from the one that formed the pattern.

(Example 5)
Photochromic compound 5 (5 mg) was dissolved in 10 mL of cyclohexane, placed in a plastic bag (7 cm wide, 10 cm long), and sealed. It put into the -10 degreeC freezer and solidified. When the photomask was irradiated with ultraviolet light, the photomask pattern appeared in red. The pattern did not disappear when stored in the freezer for more than a month. However, when the mixture was allowed to stand at room temperature for 30 minutes, the content of cyclohexane melted and became a uniform solution. It was stored again in the freezer, but it was completely different from the one that formed the pattern.

(Comparative Example 1)
Photochromic compound 3 (2 mg) was dissolved in 10 mL of cyclohexane, placed in a plastic bag (7 cm wide, 10 cm long), and sealed. It put into the -10 degreeC freezer and solidified. Although the photomask was used for ultraviolet light irradiation, the photomask pattern was not clearly visible.

FIG. 1 is a diagram illustrating an example in which the temperature history display material of the present invention is used to prevent spoofing of the temperature history. FIG. 2 is a diagram illustrating another example in which the temperature history display material of the present invention is used to prevent spoofing of the temperature history.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st temperature history display material 2 2nd temperature history display material 3 Adhesive layer 4 Temperature history display material 5 Photosensitive layer

Claims (6)

  A temperature history display material comprising a sealed container, a substance sealed in the sealed container, and a photochromic material dissolved or dispersed in the substance.   The temperature history display material according to claim 1, wherein at least a part of the sealed container is light transmissive.   The temperature history display material according to claim 1, wherein the photochromic material is a photochromic material that develops a different color depending on an irradiation wavelength.   3. The temperature history display material according to claim 1, wherein the photochromic material is a photochromic material that irreversibly develops color when irradiated.   The temperature history display material according to any one of claims 1 to 4, wherein an adhesive layer is provided on a surface of the sealed container. The temperature history display material according to any one of claims 1 to 4, wherein an ultraviolet photosensitive layer is provided on at least a part of the surface of the sealed container.

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