JPH01134219A - Temperature history detecting material - Google Patents

Abstract

PURPOSE:To easily detect the temperature history of an article which is frozen and stored from a change in color for temperature history detection added to the article by charging a coloring material in a capsule which is broken in a freezing stage and coloring a base material such as paper with the coloring material. CONSTITUTION:When food is frozen and stored, the liquid in the microcapsule is solidified and while the solid state is maintained at freezing temperature and the volume increases, a film of paraffin shrinks and breaks. When the freezing state is maintained as it is, filter paper is still white, but when the temperature of the article rises once up to, for example, room temperature, the red solution in the microcapsule melts and leaks out of the tear of the film of the microcapsule to dye (color) the filter paper. Thus, whether or not the frozen food is exposed to unfreezing temperature after being frozen can be detected at a glance from the change in color.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a temperature history detection material that detects the temperature history of frozen foods, medicines, preserved blood, and other articles to be frozen and stored from changes in color.

[Conventional technology] Cold chain systems have developed in recent years due to improvements in dietary habits and the convenience of instant foods.

Along with this, chilled foods and cold drinks have become popular, and raw vegetables, fish and shellfish, fruits, and the like have come to be frozen and provided to consumers in a state where they maintain their freshness for a long period of time. In addition, with the improvement of civil society, preserved blood is of course
Many pharmaceutical products increasingly rely on frozen storage9.

Under such circumstances, it is desirable to provide consumers and medical professionals with products that maintain their freshness at all times, but currently, the temperature at which they are delivered from the production site or manufacturing factory to the consumer through the distribution channel is limited. The management is unclear, and there is no way to detect the temperature history, so consumers can only judge the temperature control when displaying end products.

For example, even if the production management, shipping speed, storage, and display of frozen foods at supermarkets, etc., are strictly controlled at temperature, if temperature control is poor at other stages of distribution (e.g., storage at room temperature), freshness will decrease. do. In such cases, consumers have no way of determining whether appropriate temperature control has been carried out.

The use of temperature-sensitive materials can be considered as a means to detect the temperature layer JM of frozen products, but many materials that change color reversibly and irreversibly due to temperature changes have been developed as temperature-sensitive materials. There is, though.

As shown in Figure 3 (a), existing temperature-sensitive materials begin to be used at room temperature and gradually change color as the temperature changes from point A at room temperature to point B, which is a certain temperature as the temperature decreases, and then the temperature changes. Irreversible temperature-sensitive materials that do not change color even when
As shown in Figure (b), it starts to be used at a low temperature, and as the temperature rises from the low temperature 0 point to the high temperature point D, the color gradually changes.
There are also irreversible temperature-sensitive materials that do not change color even if the temperature changes thereafter, and temperature-sensitive materials that repeatedly change color due to temperature changes from point A to point B, as shown in FIG. For example, in the case of a temperature-sensitive material that exhibits red at point A and white at point B, the color gradually changes from red at point A to white as the temperature decreases, and then from white at point B to gradually red as the temperature increases. There are also reversible temperature-sensitive materials that change color over and over again in response to repeated temperature changes, but they do not change color even when used at room temperature and are exposed to low temperatures; There is still no temperature-sensitive material that does not change color even when exposed to low temperatures again.

The present invention was made in view of the current situation.

It is an object of the present invention to provide a means for easily detecting the temperature history of an article to be stored in a frozen state from a change in color of a temperature history detecting material attached to the article.

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the present invention provides a material that is suitable for visual inspection such as paper, cloth, and a colored material that can be colored in a liquid state but cannot be colored in a cold solid state. and.

The object of the present invention is to provide a temperature history detecting material which is different from capsules which are sealed with the colored material and which break during the freezing stage, and which is characterized by the fact that the capsules are buried in linen or buried in the base material.

[Effect]

Since the present invention is configured as described above, it has the following effects.

At the time of manufacturing or shipping an article to be frozen, that is, a frozen article, the above-mentioned temperature history sensing material is attached to an arbitrary position on the surface of the frozen article or on the surface of a packaging case, etc., and then the article is frozen.

The freezing point of the colored liquid in the microcapsules is higher than the frozen storage temperature of the frozen product, and when the frozen product is frozen, the colored liquid in the microcapsules solidifies, expands in volume, and breaks the microcapsules.

At the freezing temperature of frozen products, the liquid inside the microcapsules remains in a solid state when stored or transported.

For example, frozen foods are displayed in front of consumers after passing through each distribution channel. If the temperature in the distribution channel is raised above the temperature at which thawing occurs, for example to room temperature, the liquid inside the microcapsules will melt and leak out from the cracks in the microcapsules.

Paper that allows the leaked liquid to come into contact with the microcapsules.

It adheres to materials such as cloth and colors them (including dyeing, coloring, discoloration, etc.). This makes it possible to clearly determine that there is a history of temperature rise due to failure to maintain frozen storage.

〔Example〕

An embodiment of the present invention will be described.

First, a certain amount of an aqueous solution containing red ink was poured into paraffin in a hot bath at a temperature of 60°C or higher.

Force mix to form a red water bath emulsion.

When this emulsion is forcibly taken out of the system by a centrifugal IU separation method and cooled, a red aqueous solution is mixed with a paraffin membrane to obtain a large amount of microcapsules each having a diameter of several tens of microns.

A large number of microcapsules made of this paraffin film are coated on a piece of white, water-absorbing paper at appropriate intervals. The two papers coated with the microcapsules are attached, for example, to a frozen food by pasting or other means. In this state, one sheet of paper remains white.

When this frozen food is stored frozen, the liquid inside the microcapsule solidifies and expands in volume while maintaining its solid state at freezing temperatures, while the paraffin membrane contracts and ruptures. Koo
If you keep the tt frozen, the P paper will be white, but once the temperature of the item rises, for example to room temperature, the red aqueous solution inside the microcapsules will melt and leak out through the tears in the microcapsule membrane. Then, dye (color) the P paper.

In this way, it is possible to detect at a glance whether the frozen food has been exposed to a temperature higher than that at which it thaws after being frozen, from a change in color.

FIG. 1 is a graph showing the relationship between the temperature change described above and the dyeing of P paper.

In the figure, microcapsules are placed at intervals on white P paper (not coated on the entire surface) during the manufacturing stage at a temperature of around 25°C.
Apply.

P paper is still white (paraffin is also white).

This is attached to ornaments and other goods, frozen and shipped.

If the item is kept frozen during the distribution stage, the P paper will remain white and the item will be delivered to the user as is.

However, as shown in Figure 1, once in the distribution channel.

When the temperature rises to around room temperature, the frozen red aqueous solution melts and oozes out, exhibiting a red color, and remains red even after sufficient freezing. Therefore, consumers can divide the red dyeing into temperature layers ff! ! It becomes possible to know.

Note that the substance of the capsule f dyeing material used in the configuration of the present invention is not particularly limited to the above-mentioned examples, and any substance can be used as long as it exhibits the same properties and actions as the above-mentioned substances. Can be done.

Next, another embodiment of the present invention will be described.

This example is an example that utilizes a color change reaction caused by acid or alkali.

First, a tj1mIII solution of about 1- is prepared, paraffin is dissolved in a hot bath of 60°C or higher, and sulfur I is dissolved in the paraffin. ! ! A certain amount of the solution is added and forcedly mixed once to form an emulsion of the sulfuric acid solution. When this sulfuric acid emulsion is forcibly taken out of the system by centrifugation and cooled, a large amount of microcapsules each having a particle size of 10 μm is obtained, the sulfuric acid solution being coated with a paraffin film.

A large number of microcapsules ftP)i coated with this paraffin film are coated on test paper (yellow) at appropriate intervals.

The PH test paper coated with microcapsules is attached to the frozen food at room temperature by pasting or other means. In this state, the PH test paper remains yellow.

When this frozen food is stored frozen, the liquid inside the microcapsule solidifies and expands in volume while maintaining a solid state at freezing temperatures, while the paraffin membrane contracts and breaks. If you keep it frozen for a while, the PH test #1#v will remain yellow, but if the temperature of the item rises, for example to room temperature, the sulfuric acid f in the microcapsules will turn yellow! The liquid will melt.

It leaks out from the cracks in the microcapsule membrane and comes into contact with the PH test paper.

At this time, the PH test paper changes color from yellow to red due to reaction with the acid.

In this way, it is possible to detect at a glance whether the frozen food has been exposed to a temperature higher than the temperature at which it thaws after being frozen, from a change in color. FIG. 2 is a graph showing the relationship between the temperature change and the color development of the PHK test paper in this example. In the case of this figure: 1 As shown in the figure, unless the pH test paper that is the base material is subjected to the reaction of the sulfuric acid solution leaking from inside the microcapsules.

Same as Figure 1 except that the yellow color is maintained.

The explanation will be omitted.

Note that when an alkaline solution is sealed in the microcapsules instead of the sulfuric acid solution and the operation of the above example is performed, the P)1 test paper changes color from yellow to back color.

The two embodiments of dyeing and discoloration have been described above, but the present invention can also be used in cases where a colorless liquid leaks from inside a capsule onto a colorless base material and causes a coloring reaction, or where fluorescence is emitted. Included in the coloring range. Further, although the explanation has been given as an example in which the capsules are applied to a base material, they may be pasted or embedded, or they may be mixed with a base material in advance and then molded into a single base material. As shown in one example of capsule rupture.

It is not necessary to burst at the freezing temperature, but it may burst at any stage of freezing as long as it is within a temperature range where one material cannot be colored.

The base material is not limited to paper, but also cloth, plastic,
It may be made of wood or other materials, and the shape may be a plate, a rod, or
It may be in the shape of a string or any other shape that does not impede transportation. For example, it may be a temperature history detecting material in which a transparent bag made of vinyl or the like is filled with a mixture of powders having a high affinity with the colored material and capsules (innumerable numbers). In this case, powder coloring (dying).

The temperature history can be determined by the presence or absence of color development, discoloration, etc.).

In addition, although the above embodiments have all been explained as examples applying to frozen foods, the target is not limited to cold yL foods, but is also applicable to pharmaceuticals, stored blood, etc. If the temperature is raised above a specified temperature, denaturation or other problems may occur. It may be any object whose temperature history is difficult to understand from the outside, even though it may cause a problem.

In short, it applies to all objects that do not depart from the purpose of the invention.

〔Effect of the invention〕

According to the course of the present invention, temperature control JM will be conducted to determine whether or not frozen foods such as one-dish liquids of frozen foods and frozen products such as pharmaceuticals have been subjected to optical freezing control in the distribution channels after manufacture and shipment. It has the unique effect that it can be easily detected and confirmed by the user or consumer at the stage of reaching the end consumer, and the user etc. can always obtain fresh products.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the change in color due to the temperature history of frozen products in nine cases by applying one embodiment of the present invention, and Fig. 2 is a graph corresponding to Fig. 1 above in another embodiment of the present invention. , 3rd
FIG. 4 is an explanatory diagram illustrating the change in color due to temperature of a conventional temperature-sensitive material, and FIG. 4 is an explanatory diagram illustrating the change in color due to temperature of another conventional temperature-sensitive material. Agent Patent Attorney Akatsuki Sakama Soto 2 Taba 1 Gin Seki (6r) H2A Gin Seki ('Ar) 3 Sen Cα) (No H4 Dan Kimon and fLr)

Claims (1)

[Claims] It consists of a material suitable for visual inspection such as paper, cloth, a colored material that can be colored in a liquid state but cannot be colored in a cold solid state, and a capsule that seals the colored material and can be broken during the freezing stage. A temperature history detection material characterized by being attached to or buried in a base material.