Heat sensitive device showing thermal history to specified temperature

【0001】

[Technical field to which the invention belongs]

The present invention relates to a temperature indicator capable of displaying a temperature history due to irreversible changes when exposed to a predetermined temperature. More specifically, the present invention comprises a transparent cover portion capable of seeing through information recorded on an information display member such as a barcode label, and a temperature-sensitive substance whose state changes depending on temperature. A temperature-sensitive material storage unit that can store the material, a diffusion layer for changing the state of the substance of the temperature-sensitive material when a predetermined temperature is passed, and flowing out or permeating into the cover unit, and the feeling before use. The present invention relates to a temperature indicator provided with a barrier portion for preventing the temperature material from flowing out from the temperature sensitive material storage portion. In the temperature indicating device of the present invention, when a predetermined temperature, for example, a state of 3 ° C. or higher is recorded for a predetermined time or longer, the state of the temperature sensitive material stored in the temperature sensitive material storage unit changes, for example, melts. When it flows out, passes through the diffusion layer, and reaches the cover part, it becomes impossible to read the information recorded on the information display member such as the barcode label under the cover part, and the temperature control of the product is controlled. It relates to a temperature indicator for notifying that it was inconvenient.

【0002】

[Conventional technology]

With the development of freezing technology and refrigerating technology, many foods have become able to maintain their safety for a long period of time. In addition, a large number of low-temperature preserved foods have been commercialized due to the development of low-temperature transportation technology such as cold chains.

【0003】

On the other hand, food safety has become an even bigger problem in recent years. Despite improvements in food storage technology, it is said that more than 10,000 people suffer from food poisoning every year, and the number is increasing year by year. The reason for this is that the number of people with weak resistance to bacteria is increasing, but it has been said that there is also a cause in the handling of foods. Generally, the number of bacteria per gram of food is 10⁵If it is as follows, it is said that a healthy person does not develop the disease, and various methods are used as a method for preventing the growth of bacteria in food. For example, in order to suppress the increase of bacteria during food preservation, there are means such as adding chemicals such as preservatives and increasing the salt content, but these methods affect the taste and quality of food. From this, it is clear that the storage of foods at low temperatures is excellent. In addition, there is a tendency toward health in recent years, and the use of additives tends to be avoided as much as possible, so low-temperature storage is attracting more and more attention.

【0004】

However, when foods are stored at low temperatures, the number of bacteria increases exponentially and often does not meet safety standards if the temperature is not adequately controlled during the manufacture, transportation and sale of foods. It can happen. For example, when the storage temperature rises to 10 ° C when it should be kept at 3 ° C, it is said that in E. coli, it doubles in 2 hours. In addition, as the temperature rises, the water in the food expands, creating gaps between the foods, from which nutrients in the food are pushed out to the surface of the food together with the water by capillarity, supplying nutrients for the growth of bacteria. Become. Furthermore, when this is cooled again, the water extruded on the surface is pulled back to the inside of the food, and the bacteria existing on the surface of the food at this time invade the inside of the food together with the water, and the bacterial contamination reaches the inside of the food. It will be expanded. Recooling suppresses the rate of bacterial division, but when the temperature rises again, the reaction may cause the rate of bacterial division to increase faster than normal. As described above, for foods stored at low temperatures, raising and lowering the temperature has become a very big problem from the viewpoint of food hygiene management.

【0005】

It is not so difficult to keep the temperature below 3 ° C in a food factory during the food manufacturing process, but it is not so difficult when it is shipped from the factory and shipped, or when it is sold at retail stores such as supermarkets and convenience stores. , Keeping below 3 ° C at all times is not so easy. In addition, the current situation is that consumers cannot know what kind of temperature history the food has undergone before the consumer consumes the food. Various measures have been taken so that consumers can know the temperature history of food, and one of them is the development of a temperature history display. For example, in a temperature history display body that irreversibly develops color by the reaction of a plurality of substances at a predetermined temperature, a temperature history display body including a color former, a temperature detector layer, and a color developer layer (see Patent Document 1) and the like. Has been reported. In the present invention, the color-developing agent layer and the color-developing agent layer are separated by a temperature-developing agent layer, and when the temperature rises above a predetermined temperature, the temperature-developing agent layer melts and the color-developing agent layer and the color-developing agent layer come into contact with each other to develop a color. Since the reaction occurs irreversibly, it is possible to know whether or not the temperature has exceeded a predetermined temperature by the color development of the temperature history display. Although this method is irreversible and effective, it requires the use of color formers and color developers, which not only complicates the structure of the temperature history display, but is also costly. It cannot be said that it is a practical method. In addition, temperature-sensitive colorants and color formers are also used in other temperature history indicators, and the current situation is that they have not been widely used. The present inventors have invented a simpler temperature history display body in order to improve such a defect (see Patent Document 2).

【0006】

[Patent Document 1]

Japanese Patent Application Laid-Open No. 10-287863 [Patent Document 2]

Japanese Patent Application No. 2001-26 1094 [0007]

[Problems to be Solved by the Invention]

In the conventional temperature history display body, since the heat sensitive material and the information display unit are integrated with the temperature history display body, the temperature history display body is manufactured, information is printed on the temperature history display body, and the temperature history display body is displayed. Must be stored below the heat sensitive temperature. In particular, when it is necessary to keep the temperature below 0 ° C, it is necessary to print information, such as a bar code, under the condition of 0 ° C or less, which makes it difficult to handle the temperature history display. An object of the present invention is to solve such a problem, and a temperature history display with improved operability, which can be handled independently of an information display member on which information such as a barcode is recorded, is displayed. It is intended to provide a body, i.e. a temperature indicator.

【0008】

[Means for solving problems]

The present invention can house a temperature-sensitive material composed of a transparent cover portion capable of seeing through information recorded on an information display member such as a barcode label, and a substance whose state changes depending on temperature. A temperature-sensitive material storage unit, a diffusion layer for changing the state of the substance of the temperature-sensitive material when a predetermined temperature is passed and flowing out or permeating into the cover portion, and a temperature-sensitive material before use. The present invention relates to a temperature indicator provided with a barrier portion for preventing the material from flowing out from the material storage portion. The present invention also relates to a method for controlling the temperature of a product using the temperature indicating device of the present invention described above. Furthermore, the present invention relates to a container for temperature control in which the above-mentioned temperature indicator of the present invention is installed. The "temperature indication" in the present invention means the presence or absence of a heat history with respect to a predetermined temperature.

【0009】

The temperature indicating device of the present invention will be described with reference to an example. FIG. 1 shows an example of the temperature indicator of the present invention. The temperature indicator 1 is a transparent cover portion 2 capable of seeing through information recorded on an information display member such as a barcode label on a transparent substrate 7, and a substance whose state changes depending on temperature. A temperature-sensitive material storage unit 3 that can store a temperature-sensitive material, a diffusion layer 5 that changes the state of the substance of the temperature-sensitive material when a predetermined temperature is recorded, and flows out or permeates into the cover unit. The barrier portion 4 for preventing the temperature-sensitive material from flowing out from the temperature-sensitive material storage portion before use is provided. The temperature indicator 1 shown in FIG. 1 is provided with two temperature-sensitive material injection units 6 at the corners of the temperature-sensitive material storage unit 3. FIG. 2 is a cross-sectional view taken along the A-A'plane of the example of the temperature indicator of the present invention shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the B-B'plane. The temperature indicating device 1 of the present invention is provided on the transparent substrate 7, for example, and is adhered to the release sheet 8 by the adhesive layer 9.

【0010】

The temperature sensitive material of the temperature indicator 1 in this example is designed so that the temperature sensitive material flows out or permeates into the cover portion 2 when the temperature of 10 ° C. or higher is experienced for 15 minutes or longer. As the temperature sensitive material, for example, 65% concentration of oleyl alcohol is used. When the temperature indicating device 1 of this example is stored at room temperature, the temperature sensitive material melts, so that the temperature sensitive material is contained in the storage portion 3 by the barrier portion 4 so that the melted temperature sensitive material does not flow out to the cover portion. Has been done. The barrier unit 4 prevents the temperature-sensitive material from flowing out when the temperature-indicating device is not operating, and the temperature-sensitive material when the liquid temperature-sensitive material is stored in the temperature-sensitive material storage unit 3 by heating. Plays a role in preventing outflow or permeation into the cover portion 2.

【0011】

First, the temperature-sensitive material is injected from the injection unit 6 into the temperature-sensitive material storage unit 3 of the temperature indicator 1. When the temperature-sensitive material is in a solid state, it is liquefied by heating or the like and injected from the injection unit 6 with a syringe or the like. If necessary, the air existing in the storage unit 3 can be discharged from the other injection unit 6. Since the injected temperature-sensitive material is confined in the temperature-sensitive material storage unit 3 by the barrier unit 4, it can be stored as it is until the time of use. When the temperature indicator 1 is used, the temperature-sensitive material is solidified and then the barrier portion 4 is destroyed by keeping the temperature below the history set temperature. When the barrier portion 4 is made of a film such as a metal thin film, the thin film may be extracted or the thin film may be broken with a needle or the like. By destroying the barrier portion 4 by such a breaking means, the temperature-sensitive material stored in the temperature-sensitive material storage portion 3 and the diffusion layer 5 come into close contact with each other. Next, the release sheet 8 is peeled off to expose the adhesive layer 9, and the information display portion such as the barcode label affixed to the product container or the product transportation container, for example, the portion on which the barcode is printed is displayed. Attach it so that the cover part 2 of the temperature indicator 1 comes to. By doing so, since the cover portion 2 of the temperature indicating device 1 is excellent in transparency, the information recorded on the information display member such as the bar code label, for example, the bar code can be used in the temperature indicating device 1 of the present invention. It can be seen through from the top of the cover part 2.

【0012】

If the container to which the temperature indicating device 1 of the present invention is attached does not history the temperature conditions set by the temperature sensitive material of the temperature indicating device 1, the cover portion 2 of the temperature indicating device 1 remains transparent and passes through the cover portion 2. It is possible to read information such as barcodes. However, when the container to which the temperature indicating device 1 of the present invention is attached has a history of exceeding the temperature condition set by the temperature sensing material of the temperature indicating device 1, it feels as if it is stored in the temperature sensing material storage unit 3. The warm material melts, the liquefied temperature sensitive material flows out or permeates into the diffusion layer 5, the temperature sensitive material that has passed through the diffusion layer 5 reaches the cover portion 2, and a part or all of the cover portion 2 is the temperature sensitive material. When filled with, the cover portion 2 becomes opaque due to the temperature-sensitive material, and it is no longer possible to read information such as a bar code on the lower side of the cover portion 2 from above the cover portion 2. Information display parts such as bar code labels affixed to product containers and product transportation containers, for example, the fact that the bar code cannot be read means that the temperature sensitive material has reached the cover part 2 of the temperature indicator 1. That is, the container in such a state has a history of exceeding the temperature condition set by the temperature-sensitive material, which means that there is an inconvenience in the temperature control of the product.

【0013】

FIG. 4 shows another example of the temperature indicator of the present invention. The temperature indicator 10 has a transparent groove-shaped cover portion 12 capable of seeing through information recorded on an information display member such as a bar code label on a transparent substrate 17, and the state depends on the temperature. A temperature-sensitive material storage unit 13 that can store a temperature-sensitive material made of a changing substance, a diffusion layer for changing the state of the substance of the temperature-sensitive material when a predetermined temperature is recorded and flowing out or permeating into the cover unit. It is provided with 15 and a barrier portion 14 for preventing the temperature-sensitive material from flowing out from the temperature-sensitive material storage portion before use. The temperature indicator 10 shown in FIG. 4 is provided with two temperature-sensitive material injection units 16 at the corners of the temperature-sensitive material storage unit 13. FIG. 5 is a cross-sectional view taken along the A-A'plane of the example of the temperature indicator of the present invention shown in FIG. 4, and FIG. 6 is a cross-sectional view taken along the B-B'plane. The temperature indicating device 10 of the present invention is provided on the transparent substrate 17, for example, and is adhered to the release sheet 18 by the adhesive layer 19.

【0014】

The temperature-sensitive material of the temperature indicator 10 in this example can also set the temperature conditions in the same manner as in the above-mentioned example. When the temperature indicating device of this example is stored at room temperature, the temperature sensitive material is melted, so that the temperature sensitive material is contained in the storage portion 13 by the barrier portion 14 so that the melted temperature sensitive material does not flow out to the cover portion. ing. The barrier portion 14 prevents the temperature-sensitive material from flowing out when the temperature-indicating device is not operated, and when the temperature-sensitive material is heated and stored in the temperature-sensitive material storage unit 13, the temperature-sensitive material is stored. Plays a role of preventing outflow or permeation into the cover portion 12.

【0015】

The temperature indicator of this example can also be used in the same manner as in the case of the above-mentioned example. That is, first, the temperature-sensitive material is injected from the injection unit 16 into the temperature-sensitive material storage unit 13 of the temperature indicating device 10. Since the injected temperature-sensitive material is confined in the temperature-sensitive material storage unit 13 by the barrier unit 14, it can be stored as it is until the time of use. When the temperature indicator 10 is used, the temperature sensitive material is solidified in a state of the history set temperature or lower, and then the barrier portion 14 is destroyed in the same manner as in the above example. By destroying the barrier portion 14 by such a breaking means, the temperature-sensitive material stored in the temperature-sensitive material storage portion 13 and the diffusion layer 15 are brought into close contact with each other. Next, the release sheet 18 is peeled off to expose the adhesive layer 19, and the information display portion such as the barcode label affixed to the product container or the product transportation container, for example, the portion on which the barcode is printed is displayed. Attach the temperature indicating device 10 so that the groove-shaped cover portion 12 comes to the surface. By doing so, since the cover portion 12 of the temperature indicating device 10 is excellent in transparency, the information recorded on the information display member such as the bar code label, for example, the bar code can be used in the temperature indicating device 10 of the present invention. It can be seen through from above the cover portion 12.

【0016】

Unless the container to which the temperature indicating device 10 of the present invention is attached does not history the temperature conditions set by the temperature sensitive material of the temperature indicating device 10, the cover portion 12 of the temperature indicating device 10 remains transparent and passes through the cover portion 12. Information such as barcodes can be read. However, when the container to which the temperature indicating device 10 of the present invention is attached has a history of exceeding the temperature condition set by the temperature sensing material of the temperature indicating device 10, it feels as if it is stored in the temperature sensing material storage unit 13. The warm material melts, the liquefied temperature sensitive material flows out or permeates into the diffusion layer 15, and the temperature sensitive material that has passed through the diffusion layer 15 reaches the groove-shaped cover portion 12, and part or all of the cover portion 12 When it is filled with the temperature sensitive material, the cover portion 12 becomes opaque due to the temperature sensitive material, and it is no longer possible to read all the information such as the bar code on the lower side of the cover portion 12 from the top of the cover portion 12. Become. Information display parts such as bar code labels affixed to product containers and product transportation containers, for example, the fact that the bar code cannot be read means that the temperature sensitive material has reached the cover part 12 of the temperature indicator 10. That is, the container in such a state has a history of exceeding the temperature condition set by the temperature-sensitive material, which means that there is an inconvenience in the temperature control of the product.

【0017】

FIG. 7 shows still another example of the temperature indicator of the present invention. The temperature indicator 20 has a cover portion 22 capable of storing an information display member on which information such as a barcode label is recorded on the transparent substrate 27, and the temperature sensitive material storage portion 23 is made of natural or non-natural rubber. A temperature-sensitive material made of a substance whose state changes depending on the temperature enclosed in the barrier portion 24 made of a material or the like can be stored, and when a predetermined temperature is passed, the substance of the temperature-sensitive material is stored. It is provided with a diffusion layer 25 for flowing out or permeating into the cover portion 22 when the state changes, and a transparent upper lid portion 21 bonded to the upper part of the temperature sensitive material storage portion 23. FIG. 8 is a cross-sectional view taken along the A-A'plane of the example of the temperature indicator of the present invention shown in FIG. 1, and FIG. 9 is a cross-sectional view taken along the B-B'plane. FIG. 9 also shows an information display member 35 in which the information 36 stored in the cover portion 22 is recorded. The temperature indicating device 20 of the present invention is provided on the transparent substrate 27, for example, and is adhered to the release sheet 28 by the adhesive layer 29.

【0018】

As the temperature sensitive material of the temperature indicator 20 of this example, the above-mentioned material can be used. The temperature sensitive material 26 in this example is enclosed in a flexible material (barrier portion 24) such as natural or non-natural rubber. In the case of the temperature indicating device 20 of this example, first, the temperature sensitive material 26 is solidified by setting the temperature to the history set temperature or lower, and then a part or all of the barrier portion 24 is destroyed to destroy the temperature sensitive material storage unit 23. Store in. The temperature-sensitive material 26 stored in the temperature-sensitive material storage unit 23 and the diffusion layer 25 are in close contact with each other. Next, the information display member 35 (not shown in FIG. 7) in which the information 36 is recorded is housed in the bottom of the cover portion 22, the upper lid portion 21 is covered with the information display member 35, and the information display member 35 is adhered. Next, the release sheet 28 is peeled off to expose the adhesive layer 29, and the adhesive layer 29 is attached to a product container or a product transportation container. By doing so, since the upper lid portion 21 of the temperature indicating device 20 is excellent in transparency, the information recorded on the information display member such as the bar code label, for example, the bar code can be used in the temperature indicating device 20 of the present invention. It can be seen through from above the upper lid portion 21.

【0019】

Unless the container to which the temperature indicating device 20 of the present invention is attached does not history the temperature conditions set by the temperature sensitive material 26 of the temperature indicating device 20, the cover portion 22 of the temperature indicating device 20 remains transparent and the upper lid portion 21 Information such as barcodes can be read through. However, when the container to which the temperature indicating device 20 of the present invention is attached has a history of exceeding the temperature condition set by the temperature sensing material 26 of the temperature indicating device 20, it is stored in the temperature sensing material storage unit 23. The temperature-sensitive material 26 melts, the liquefied temperature-sensitive material flows out or permeates into the diffusion layer 25, and the temperature-sensitive material 26 that has passed through the diffusion layer 25 reaches the cover portion 22, and part or all of the cover portion 22 When the temperature-sensitive material 26 is filled, the cover portion 22 becomes opaque due to the temperature-sensitive material 26, and it is no longer possible to read the information 36 of the information display member 35 stored in the cover portion 22 from above the cover portion 22. It becomes impossible. Information display parts such as bar code labels affixed to product containers and product transportation containers, for example, the fact that the bar code cannot be read means that the temperature sensitive material has reached the cover part 22 of the temperature indicator 20. That is, the container in such a state has a history of exceeding the temperature condition set by the temperature-sensitive material, which means that there is an inconvenience in the temperature control of the product. In this example, the top lid 21 is glued at the protrusions of the substrate 27, such as 30 and 31 in FIG. 8, 32, 33, and 34 in FIG. 9, or at the outer periphery of these protrusions. It is preferable to keep it. As the bonding means, various means such as heat fusion, bonding with an adhesive, and joining with a meshing structure can be adopted.

【0020】

The temperature-sensitive material of the present invention is a substance that melts or softens to become a liquid or sol when the temperature exceeds a predetermined temperature, and reduces transparency, preferably becomes opaque, or records information such as printing ink. A substance consisting of one or more substances capable of dissolving or diffusing the substance is preferable. Specific examples of preferred temperature sensitive materials include heat-melting substances such as paraffin, higher fatty acids, higher fatty acid esters and higher alcohols. These temperature-sensitive materials have a melting point near the target predetermined temperature, and are melted or softened to become a liquid, which reduces the transparency of the cover portion, makes it opaque, or an information display member. Any medium such as printing ink that can dissolve or disperse a medium on which information is recorded may be used as long as it can be in direct contact with the ink. In addition, if these substances themselves are transparent when liquefied, opaque substances can be mixed or dissolved before use. In addition, since a device that reads information such as a barcode uses red light to read the information, a substance that can absorb the red light (for example, a green dye) should be dissolved or mixed. You can also.

【0021】

If you do not want to expose to a relatively high temperature like industrial products, you can use a substance with a high melting point, and if you do not want to expose it to room temperature or higher like pharmaceuticals, use a substance with a melting point near room temperature. Just do it. Further, when it is not desired to expose even at a relatively low temperature such as food, a substance having a relatively low melting point may be adopted. The melting point of these substances may be selected from those in the range of -50 ° C to 100 ° C for industrial products, and about 10 ° C to 80 ° C for pharmaceuticals and products stored at room temperature. It may be selected from the range, and in the case of foods, it may be selected from the range of about -30 ° C to 50 ° C. These temperature sensitive materials may be one kind of substance, but can also be used as a mixture of two or more kinds of substances. Further, if necessary, additives such as a lubricant, a thickener, and a colorant may be added. Further, when a substance having an appropriate melting point is not found in the vicinity of a predetermined temperature, two or more kinds of substances can be mixed and set to a predetermined temperature by utilizing a melting point lowering action or the like.

【0022】

Specific examples of the temperature-sensitive material include paraffins having 10 to 30, preferably 12 to 20, and more preferably 12 to 18 carbon atoms; the carbon number of lauric acid, stearic acid, 2-oxymyristic acid, and the like. 10 to 30, preferably 12 to 20, more preferably about 12 to 18 substituted or unsubstituted higher fatty acids; esters of the above-mentioned higher fatty acids such as ethyl myristate, stearyl laurate, dioctyl phthalate; n-cetyl. Substituted or unsubstituted higher alcohols having 6 to 30, preferably 6 to 20, and more preferably about 10 to 18 carbon atoms such as alcohols, oleyl alcohols, n-octyl alcohols, and tetradecanols; methylhexyl ketones, benzophenones, etc. Ketones; higher ethers such as diphenyl ethers, distearyl ethers; higher fatty acid amides such as oleic acid amides, stearic acid amides, lauric acid N-octylamides, caproic acid anilides; isopropylbenzene, dodecylbenzene, biphenyl, trimethylbiphenyl, Examples include, but are not limited to, aromatic hydrocarbons such as diphenylethane, dibenzyltoluene and propylnaphthalene, and various organic solvents such as dimethylsulfoxide (DMSO). As these thermostat components, paraffins, higher fatty acids, higher fatty acid esters, higher alcohols and the like are more preferable in consideration of cost.

【0023】

The thickness of the cover portion of the temperature indicating device of the present invention may be a thickness sufficient to reduce the transparency of the cover portion, and preferably the liquid temperature-sensitive material permeates the cover portion by the capillary phenomenon. The thickness may be about 0.1 to 0.5 mm, preferably about 0.2 to 0.3 mm. The size of the cover portion may be a size that can read information such as a barcode under the cover portion. The information in the information display member is not particularly limited, and information that can be read optically is preferable. For example, a bar code of a product, a warning about a temperature display, or the like may be described. When a state exceeding a predetermined temperature condition is recorded, it is sufficient that the information cannot be read due to the permeation of the temperature-sensitive material, and the bar code may be set so that all the information such as the bar code cannot be read. It may be possible to prevent reading only a part of the information such as. Further, it may be set so that the temperature history can be understood to some extent depending on the amount of information that can be read.

【0024】

The diffusion layer in the temperature indicating device of the present invention may be a porous material such as paper or a minute substance as long as it can be impregnated or passed through a temperature-sensitive material exposed to a predetermined temperature or higher and can act on the cover portion. Resins with holes can be used. The diffusivity of the temperature-sensitive material can be controlled by the material, size, thickness, and length of the diffusion layer, and the temperature conditions can be set more strictly. The temperature-sensitive material storage portion of the temperature-sensitive device of the present invention may have a volume capable of storing a sufficient amount of the temperature-sensitive material. As the barrier portion of the temperature indicating device of the present invention, various materials such as a metal thin film, a plastic, and a natural or non-natural rubber material can be used. The barrier portion is intended to retain the temperature-sensitive material during manufacturing, distribution, and storage of the temperature-indicating device, and is destroyed during use, so that liquid leakage does not occur. , Those that are relatively easy to destroy are preferable. It is preferable that the thin film has little interaction with the temperature-sensitive material and can be easily broken by pulling during use.

【0025】

Since the temperature indicating device of the present invention can exist independently of the information display member, a conventional information display member, for example, a bar code label or the like can be used as it is. Further, since the temperature indicating device of the present invention is provided with a barrier portion and can be manufactured, distributed and stored at room temperature, it is easy to handle and does not require a special device for handling. As a means for fixing the temperature indicating device of the present invention to the container, adhesion by an adhesive layer as illustrated is simpler and preferable, but the method is not limited thereto. It can be done by various means such as gluing, laminating, inserting the container into a pocket, and using a suction cup. It can also be fixed with a seal that covers the entire temperature indicating device of the present invention. Further, a printed recording film such as a bar code printed on the container can be used as the information display member of the present invention. That is, the temperature history of the container can be managed by installing the existing container so that the cover portion of the temperature indicating device of the present invention touches the print.

【0026】

Examples of the container of the present invention include various containers such as a container for a product that requires display of a temperature history, a packaging container for the product, and a transport container. For example, containers for various beverages such as milk, tea and coffee, containers for various foods such as lunch boxes, cakes and sandwiches, containers for pharmaceuticals and cosmetics, etc., but further exposed to high temperatures such as semiconductors and aerosol products. Examples include industrial products or their containers that they do not want, and transportation products or their containers that require low-temperature transportation. In addition to these containers, they may be fixed to the packaging container in which these products are packaged, or they may be fixed to the transport container of these products. The temperature indicating device of the present invention may be fixed to a container or the like at the time of shipment from a factory, at the time of transportation, or at the time of sale at a store. For example, in the case of a low-temperature transported product, the temperature indicating device of the present invention can be fixed to the transported product at the start of transportation, or can be fixed to the container at the time of sale, such as a cake.

【0027】

Therefore, by fixing the temperature indicating device according to the present invention to a low temperature holding food or an industrial product or a container thereof, when a consumer purchases or consumes the low temperature holding product, the thermal history of the product is recorded in the present invention. It can be visually checked depending on the state of the temperature indicator. In addition, retailers and manufacturers can not only observe the thermal history of products with the naked eye, but also cannot read barcodes with a barcode reader due to the destruction of information such as barcodes, so barcode input At that time, it is also possible to mechanically judge the suitability of the heat history.

【0028】

[Example]

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

【0029】

Example 1 The temperature indicator shown in FIG. 1 The temperature indicator shown in FIG. 1 was manufactured using an OHP sheet as the basic skeleton as the base material. Kitchinto's cooking paper was used as the diffusion layer, and oleyl alcohol (Wako Pure Chemical, 65% purity) was used as the temperature-sensitive material.

【0030】

Example 2 Differential calorimetry (DSC) of various temperature-sensitive materials Analysis of various temperature-sensitive materials by differential calorimetry (DSC) was performed under the following measurement conditions.<img file="JP2004257828A_D0001.tif" />The results are shown in Fig. 10 (Sample (1)), Fig. 11 (Sample (2)), Fig. 12 (Sample (3)), Fig. 13 (Sample (4)), Fig. 14 (Sample (5)), and Fig. It is shown in 15 (Sample (6)) respectively. The horizontal axis of each figure is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec). Negative indicates endothermic. Since the purpose of use of the temperature-sensitive material is mainly to control the temperature of fresh food, we selected and analyzed materials with low hazards such as danger and toxicity. Pentadecane and oleic acid are suitable for use in terms of temperature characteristics, but considering compatibility with thermal paper, it is difficult to select a thermal agent, so it is preferable to use mainly alcohol-based reagents. ..

【0031】

Example 3 Test of the material of the diffusion layer The material of the diffusion layer was examined. As a material for the diffusion layer, the optical microscope image of each paper was examined, and the diffusion ability of each paper was actually examined. As a result, it was found that a non-woven fabric-like structure such as cooking paper or oil removing paper is suitable as the material.

【0032】

Example 4 Response test to temperature Regarding the permeation of the temperature-sensitive material in the temperature-sensitive device, 10 ° C, 14 ° C, 18 by the temperature-sensitive device using 65% oleyl alcohol as the temperature-sensitive material and cooking paper as the diffusion layer. The response characteristics of the temperature indicator at ° C and 23 ° C were investigated. At the corresponding temperature, the barcode was read by a barcode reader, and the time (seconds) at which the barcode could not be read was defined as the response time. The result is shown in FIG. The horizontal axis of FIG. 16 is the temperature (° C), and the vertical axis is the average response time (seconds).

【0033】

[Effect of the invention]

The present invention provides a temperature indicating device that can be manufactured, distributed, and stored independently of an information display member such as a bar code label. Since the temperature indicating device of the present invention can exist independently of the information display member, a conventional information display member, for example, a bar code label or the like can be used as it is. Further, since the temperature indicating device of the present invention is provided with a barrier portion and can be manufactured, distributed and stored at room temperature, it is easy to handle and does not require a special device for handling.

[Simple explanation of drawings]

FIG. 1 is a plan view showing an example of a temperature indicator of the present invention.

FIG. 2 is a cross-sectional view of the temperature indicator of the present invention shown in FIG. 1 on the AA'planet.

FIG. 3 is a cross-sectional view of the temperature indicator of the present invention shown in FIG. 1 on the B-B'plane.

FIG. 4 is a plan view showing another example of the temperature indicator of the present invention.

FIG. 5 is a cross-sectional view taken along the AA'plane of the temperature indicator of the present invention shown in FIG.

FIG. 6 is a cross-sectional view taken along the B-B'plane of the temperature indicator of the present invention shown in FIG.

FIG. 7 is a plan view showing still another example of the temperature indicator of the present invention.

FIG. 8 is a cross-sectional view of the temperature indicator of the present invention shown in FIG. 7 on the AA'planet.

FIG. 9 is a cross-sectional view of the temperature indicator of the present invention shown in FIG. 7 on the B-B'plane.

FIG. 10 shows the results of differential calorimetry (DSC) analysis of 65% oleyl alcohol. The horizontal axis of FIG. 10 is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec).

FIG. 11 shows the results of differential calorimetry (DSC) analysis of 85% oleyl alcohol. The horizontal axis of FIG. 11 is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec).

FIG. 12 shows the results of differential calorimetry (DSC) analysis of 95% oleyl alcohol. The horizontal axis of FIG. 12 is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec).

FIG. 13 shows the results of differential calorimetry (DSC) analysis of 65% oleyl alcohol and ethyl cellulose (thickener). The horizontal axis of FIG. 13 is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec).

FIG. 14 shows the results of analysis of 97% pentadecane by differential calorimetry (DSC). The horizontal axis of FIG. 14 is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec).

FIG. 15 shows the results of differential calorimetry (DSC) analysis of oleic acid. The horizontal axis of FIG. 15 is the temperature (° C), and the vertical axis is the differential calorimetry (mcal / sec).

FIG. 16 shows the results of temperature responsiveness tests at 10 ° C, 14 ° C, 18 ° C, and 23 ° C when 65% oleyl alcohol was used as the temperature sensitive material. The horizontal axis of FIG. 16 is the temperature (° C), and the vertical axis is the average response time (seconds).

[Explanation of symbols]

1, 10, 20 Temperature indicator 2, 12, 22 Cover section 3, 13, 23 Temperature sensitive material storage section 4, 14, 24 Barrier section 5, 15, 25 Diffusion layer 6, 16 Injection section for temperature sensitive material 26 Temperature sensitive material 7, 17, 27 Substrate 8, 18, 28 Release sheet 9, 19, 29 Adhesive layer