JP2008151716A - Temperature indicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indicator for simply and easily monitoring a temperature, an elapsed time, humidity due to outside air and oxygen. <P>SOLUTION: The indicator 10 includes: a package 11 having a ventilation property; an indicator composition 12 having a change generated by air from the outside of the package 11 and recognized from the outside of the package 11; and a volatile material 13 for blocking the change in the indicator composition 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an indicator for monitoring temperature and other humidity.

  In products such as foods and pharmaceuticals, quality may be deteriorated or spoiled by exceeding a predetermined temperature or humidity.

Therefore, in order to confirm the temperature history of the product and the history of the presence or absence of moisture, Patent Document 1 uses a moisturizing agent or a color-changing reagent composed of an organic compound, and the temperature history by a clear and irreversible color tone change. And an indicator that can detect the moisture adhesion history.

Moreover, in order to make temperature history clearer, a product in which a medium such as glucose and frozen baker's yeast are placed in a transparent bag is also commercially available. In this product, the temperature history can be monitored in an integrated manner by changing the shape of the bag by carbon dioxide generated by yeast fermentation.

JP 2004-354323 A

However, the former can only be used to determine the history of either a predetermined temperature excess or moisture adhesion. Moreover, since the latter looks at the volume change by the carbon dioxide produced by yeast fermentation, the change by a history is hard to understand for a user. Furthermore, since the fermentation of yeast is affected by humidity, variations occur in volume changes, and hence changes due to temperature history.

  In addition, miscellaneous fungi, which are one of the causes of quality deterioration and decay, are affected by temperature, humidity, elapsed time, oxygen in the air, and nutrients. Therefore, as a monitoring medium capable of predicting the occurrence and propagation of various fungi, an indicator that can be monitored including not only the temperature and other history of humidity and oxygen but also the elapsed time is required.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an indicator that can easily monitor temperature and elapsed time, and humidity and oxygen due to outside air.

  The indicator according to the present invention is a packaging body having a predetermined air permeability, an indicator composition that is changed by outside air from the outside of the packaging body, and the change is recognizable from the outside of the packaging body, and inhibits a change in the indicator composition. And volatile substances.

Such an indicator has the following functions. When the temperature of the indicator exceeds the boiling point of the volatile substance and the volatile substance is vaporized, the inside of the package is filled with the gas of the volatile substance, so that the change of the indicator composition inside the package is inhibited. . Then, when time elapses in this state, the filled gas diffuses to the outside due to the air permeability of the package, and external air enters from the outside of the package instead. And an indicator composition changes with the external air which penetrate | invaded, and it becomes possible to recognize the penetration | invasion of external air from the package body exterior.

The indicator according to the present invention further includes a holding body for holding a volatile substance.

  With such an indicator, it is possible to more clearly confirm the change in the indicator composition while stably holding the volatile substance.

Here, the indicator according to the present invention is characterized in that the volatile substance contains at least one of fatty acid, alcohol, ether, amine, amide, and hydrocarbon.

  With such an indicator, based on the physical properties of the volatile substance, it is possible to easily select a volatile substance having a boiling point corresponding to the temperature set according to the contents of the germs to be monitored and adjust the amount of addition. Thus, it is possible to easily set the elapsed time.

  In addition, the indicator according to the present invention is characterized in that the volatile substance includes at least one kind of a substance in which a gas composed of an inorganic compound is in a liquid state or a solid state.

  With such an indicator, a volatile substance that can be set at a low temperature such as below freezing point can be easily selected based on the physical properties of the volatile substance.

  Furthermore, the indicator composition in the indicator according to the present invention is a substance that is discolored by moisture.

  If it is such an indicator, it will become discolored by the humidity change by external air invading, and it will become possible to set elapsed time easily by adjusting the addition amount.

  Next, the indicator composition in the indicator according to the present invention may be a substance that changes color when oxidized by oxygen.

  If such an indicator is used, the indicator composition changes color when oxygen enters from outside air, and the elapsed time can be easily set by adjusting the amount of addition.

  Further, in the indicator according to the present invention, the package is constituted by a material that does not have air permeability, and comprises an opening means that shifts to a state in which the package has air permeability by a predetermined operation. And

  If it is such an indicator, it will become possible to estimate the elapsed time from the time when the packaging body obtained air permeability by the opening means.

  Moreover, the manufacturing method of the indicator according to the present invention is characterized in that a packaging body is formed from a material having no air permeability, and the packaging body is perforated to have a predetermined air permeability.

  By manufacturing the indicator in this way, it is possible to obtain an indicator that allows the package to obtain air permeability due to the perforated portion.

With the indicator according to the present invention, it is possible to easily monitor temperature and elapsed time, which are factors such as deterioration of a product, as well as humidity and oxygen from outside air.

  In the present invention, the package body having a predetermined air permeability may be one in which the package body itself is not only air permeable by a vent hole or the like but also air permeable by an opening means such as a needle. Here, the air permeability refers to the property that outside air outside the package is introduced into the package.

In addition, the indicator composition only needs to be made of a substance that changes physically or chemically depending on components contained in the outside air introduced from the outside of the package, and the change can be recognized from the outside of the package. Here, as an aspect of the change, there are a change in the shape of the composition itself, a discoloration, and the like.

  Here, as the indicator composition, a substance whose composition changes color due to reaction with moisture or oxidation with oxygen is more preferable.

Furthermore, the volatile substance may be any substance that can inhibit the change of the indicator composition by being vaporized, and a substance selected from fatty acids, alcohols, ethers, amines, amides, and hydrocarbons is preferable.

Examples of fatty acids include myristic acid, palmitic acid, adipic acid, octanoic acid, tricosanoic acid, and succinic acid.

  Examples of alcohols include ethanol, octadecyl alcohol, cholesterol, arakinyl alcohol, heptatriacontanol, and hexadecan-2-ol.

  Examples of ethers include diethyl ether, dihexadecyl ether, dioctadecyl ether, cytidine, and adenosine.

  Examples of amines include tricosylamine, naphthylamine, ethyl p-aminobenzoate, 1-phenyl-2-thiourea, 4-aminobenzoic acid, sulfamethazine, and guanidine nitrate.

  Examples of amides include hexylamide, octacosylamide, and N-methyldodecylamide.

  Examples of hydrocarbons include hexadecane, tetratriacontane, 2-methylnaphthalene, and hexamethylbenzene.

In addition, as the volatile substance, a substance in which a gas composed of an inorganic compound is in a liquid state or a solid state can be used.

Examples of the substance in which a gas composed of an inorganic compound is in a liquid state or a solid state include dry ice and liquid nitrogen.

Next, the material of the member used as the holding body may be any material that can hold a volatile substance, preferably a material having resistance to the volatile substance, and more preferably a material having permeability.

  Here, by having tolerance, the loss of the volatile substance due to the reaction between the volatile substance and the material can be suppressed, and the quantitativeness can be improved. Moreover, by having permeability, a volatile substance can be stably held, and the setting time can be easily adjusted.

Further, the shape of the member can be selected according to the product form as an indicator and the holding form of the volatile substance. This holding body is preferably one that can maintain the regularity within the range even if there is some degree of expansion and contraction due to wetting of the volatile substance. The shape can be appropriately selected from a flat shape, a spherical shape, and the like, and is preferably a flat plate.

Here, by setting it as flat form, a volatile substance can be hold | maintained uniformly and adjustment of setting time becomes easy with the surface area of a member.

  Further, as an opening means for obtaining a predetermined air permeability in the package, there is a member that closes the hole until use and can obtain air permeability by peeling or removing immediately before use.

  In addition, as a punching means for obtaining a predetermined air permeability in the package, there is a needle for making a hole in the package.

<Example 1>
Hereinafter, an indicator according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an example of an indicator according to an embodiment of the present invention. The indicator 10 is impregnated with silica gel 12 as an indicator composition and ethanol 13 as a volatile substance in a plastic bag 11 used as a package. The filter paper 14 which is a holding body is provided.

  Here, as the plastic bag 11, the bag-shaped thing which consists of high-density film materials, such as PP (polypropylene) and PET (polyethylene terephthalate), is used.

  Moreover, the silica gel 12 can use the silica gel marketed as a hygroscopic agent. Preferably, a color change agent such as cobalt is added to the silica gel and the color is changed by moisture absorption, so that the change can be confirmed by the appearance.

  The filter paper 14, which is a holding body, is impregnated with ethanol 13, and this holding body is enclosed in the plastic bag 11 together with the silica gel 12.

Here, by impregnating the filter paper, ethanol, which is a volatile substance, spreads uniformly in the filter paper, and evaporation is also performed uniformly, so that the quantitativeness can be further improved.

  Further, by using a holding body having a color different from the hue of silica gel, the discoloration of the silica gel can be conspicuous, and the change of the silica gel can be easily recognized from the outside.

  In addition, the component of the volatile substance to be impregnated and the amount thereof can be selected according to the object to be monitored. For example, when monitoring bacteria that propagate in food, select a component that volatilizes at a temperature at which the bacteria tend to proliferate, and to an extent that affects the safety of the food, for example, volatilization is completed when the expiration date has passed. The amount can be adjusted.

  The usage method in the foodstuff of the indicator 10 which concerns on an Example is as follows. First, the indicator 10 is adhered to the food to be monitored by adhesion or the like. Next, at the start of monitoring, as a predetermined operation, a vent 15 is opened in a part of the plastic bag using a needle or the like as a punching means. At this time, the speed at which the volatile substance volatilizes can be adjusted by the number of holes to be opened and the size of the holes to be opened.

First, in a state where there is almost no temperature rise, the volatile substance slightly evaporates inside the plastic bag, and the inside is filled with the volatile substance, so that the silica gel does not change color.

When the temperature of the food rises for some reason during transportation, etc., and exceeds the boiling point of the volatile substance, the volatile substance becomes increasingly volatile, and the volatile substance gradually increases from the vents opened by the opening means. Will run away.

Next, when the set time is exceeded, most of the volatile components contained in the plastic bag escape to the outside, and conversely, outside air enters from the outside. When the outside air enters, the silica gel changes color due to the moisture contained in the outside air, and it is possible to recognize from the outside that the set temperature has passed for the set time or longer. Further, the humidity can be integrated from the ratio of discoloration of the silica gel.

From the above, it is possible to recognize not only the temperature but also the humidity and their elapsed time. In particular, when bacteria are to be monitored, monitoring close to the growth conditions is possible in various conditions of temperature, time, humidity, air (outside air), and nutrition that affect the growth of the bacteria. From this, food safety can be improved.

  Here, in Example 1, as a package, a plastic bag made of a high-density film material that does not have air permeability is used as a material such as PP. However, when using a material that has air permeability by having a gap in the material itself, such as polyethylene, as a packaging body, before using it as an indicator, this packaging body should be made of a film made of a material that does not have air permeability. It is possible to obtain air permeability by removing the film covering as an opening means immediately before use.

  In the first embodiment, as a predetermined operation, a hole as a ventilation portion is opened by a needle or the like as a punching means. In addition, open a plastic bag by cutting it off just before use so that it can be ventilated, or make a hole in the plastic bag beforehand and shield the hole with a sealing means such as a seal. Thus, air permeability can be obtained by an operation of removing the seal immediately before use.

  Next, as an indicator composition that changes color by reaction with moisture, in addition to silica gel, cobalt, butyl cyanoacrylate, octyl cyanoacrylate rhodamine B, rhodamine 6G, indophenol blue, aminonaphthalene sulfonic acid derivative, or the like may be used. it can.

  In addition to ethanol, diethyl ether or the like can be used as the volatile substance. Furthermore, the temperature to be set can be adjusted by appropriately mixing ethanol and diethyl ether which is a low boiling point compound.

  In addition, dry ice or liquid nitrogen can be used as the volatile substance. These can be monitored at low temperatures such as below freezing.

  Further, the holder is not limited to filter paper, and cotton, cloth, sponge, etc. that can be impregnated with volatile liquid can also be used. In addition, when the volatile liquid is held in a capsule or the like and a hole is made in the package by a needle, the capsule can also be made a hole to diffuse the volatile liquid.

<Example 2>
As an indicator according to another embodiment of the present invention, an indicator that can monitor temperature, oxygen, and their elapsed time by using a substance that changes color by oxidation with oxygen, for example, methylene blue, as an indicator composition; It becomes possible to do.

Here, as in the configuration of the indicator, as in FIG. 1, a holding body impregnated with a tablet containing methylene blue as an indicator composition instead of silica gel and ethanol as a volatile substance in a plastic bag used as a package. Is equipped with filter paper.

  The usage is the same as in the first embodiment. In Example 2, in the outside air that enters beyond the set time, the methylene blue reacts with the oxygen contained in the outside air to change the color, and it is recognized from the outside that the set temperature has exceeded the set time by visual recognition or the like. It becomes possible. Also, oxygen can be integrated from the ratio of methylene blue discoloration.

As described above, in Example 2, it is possible to recognize not only temperature but also oxygen and their elapsed time. In particular, in products that hate oxidation, such as oils and reagents, it is possible to monitor the temperature and oxygen, which are indicators of oxidation, together with the elapsed time. From this, the quality of the product can be improved.

Here, as the indicator composition that changes color by reaction with oxygen, iron, manganese, iodine, or the like that changes color by oxidation with oxygen can be used in addition to methylene blue.

  In addition, it goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

  The indicator of the present invention can be applied to fields that require confirmation of product temperature history, history such as humidity, such as food transportation and storage.

The block diagram which shows the indicator which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Indicator 11 ... Plastic bag 12 ... Silica gel 13 ... Ethanol 14 ... Filter paper 15 ... Vent

Claims (8)

A package having a predetermined air permeability;
An indicator composition that changes due to outside air from outside the package, and the change is recognizable from outside the package;
A volatile substance that inhibits a change in the indicator composition.   The indicator according to claim 1, further comprising a holder that holds the volatile substance.   The indicator according to claim 1 or 2, wherein the volatile substance includes at least one of fatty acid, alcohol, ether, amine, amide, and hydrocarbon.   The indicator according to claim 1 or 2, wherein the volatile substance includes at least one kind of substance made of a gas made of an inorganic compound in a liquid state or a solid state.   The indicator according to any one of claims 1 to 4, wherein the indicator composition is a substance that changes color by moisture.   The indicator according to claim 1, wherein the indicator composition is a substance that changes color when oxidized by oxygen. The package is composed of a material that does not have air permeability,
The indicator in any one of Claim 1 thru | or 6 provided with the opening means which transfers to the state which has air permeability to the said package by predetermined operation. Form a package with a non-breathable material,
The manufacturing method of the indicator in any one of Claim 1 thru | or 6 which perforated the said package and was made to have predetermined | prescribed air permeability.