JPH0843214A - Thermosensitive indicator - Google Patents

Abstract

PURPOSE:To obtain a highly accurate thermosensitive indicator which can clearly indicate the presence/absence of a reaction to heat by constituting the indicator so that a hot-melt coloring substance melts and infiltrates into an absorber when the temperature of the indicator becomes higher than a set temperature. CONSTITUTION:A hot-melt coloring substance and absorber 3 are respectively put in the projected sections which become the first chamber 7 and second chamber 8 of a film 4. The thermosensitive indicator is constituted by thermally bonding the film 4 to another film 5 after applying a bonding agent to a communicative section 1 and welding the peripheries of the chamber 7 and 8 except the communicative section 1. The indicator is cooled so as to solidify the hot- melt coloring substrate before using and pressurized so as to strip off the bonding agent 11 in the communicative section 1 so that the hot-melt coloring substance can pass through the communicative section 1 by applying a pressure to the chamber 7 at the time of using the indicator. The hot-melt coloring substance melts and infiltrates into the absorber 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is irreversibly indicated when the temperature exceeds a preset temperature,
The present invention relates to a heat sensitive indicator used for low temperature control in the medical field.

[0002]

2. Description of the Related Art In recent years, many foods controlled at low temperatures have been used in dietary habits. If the temperature of the food or the raw material of the food is erroneous, there is a risk that the quality may be deteriorated or spoiled, and further the food poisoning bacteria may grow. In particular, low-temperature distributed foods are easily affected by temperature rise, and many foods are discarded due to fear of microbial contamination. Further, recently, there is a concern that food poisoning may become larger. Also in the medical field, the role of low-temperature management of special medicines, blood, specimens, etc. is very important. These products not only lead to deterioration in quality when the product temperature rises, but may also become unusable. Therefore, temperature control of these products,
Strict monitoring and recording of cold storage during distribution are required.

The use of a heat sensitive indicator is one of the means for continuously monitoring the storage temperature of low-temperature storage items. For example, JP-A-50-60262 and JP-A-51
-33432 and Japanese Patent Application Laid-Open No. 4-72045 describe a time-temperature integrating type monitor showing a temperature history. JP-A-61-113116 and JP-A-62-1
In JP 97486, a temperature-time monitor using microcapsules is described. Japanese Patent Laid-Open No. 59-16
Japanese Patent No. 4929 and Japanese Patent Laid-Open No. 59-175172 describe indicators utilizing the capillary phenomenon.

[0004]

When food or the like is stored in freezing or refrigeration, the temperature history is complicated and it is very difficult to actually monitor the storage temperature. When the temperature is monitored by the heat-sensitive indicator, the indicator is cooled to the temperature inside the refrigerator to be monitored and then set to a predetermined monitoring state. The timing to set the monitoring state is difficult, and the mechanism itself for starting the monitoring state is complicated. The indicator contains a substance that senses temperature changes in the low temperature range.
This substance is very volatile at room temperature. The volatility reduces the accuracy of the thermal indicator and makes it difficult to store the thermal indicator itself. Further, there is a problem that it is unclear whether or not there is a reaction to heat.

The present invention has been made to solve the above-mentioned problems, and it can be stored in a sufficiently stable manner even at room temperature, the mechanism for setting a predetermined temperature monitoring state is simple, and the presence or absence of reaction to heat is extremely high. The object is to provide a heat sensitive indicator which is clear, has high accuracy and is inexpensive.

[0006]

As shown in FIGS. 1 and 2, the heat-sensitive indicator of the present invention made to achieve the above object is airtight from the outside and contains the colored heat-meltable substance 2. The communicating portion 1 between the opened first chamber 7 and the second chamber 8 in which the absorber 3 is housed so that it can be observed from the outside is the adhesive 1
1, the adhesive 11 is peeled off by the pressure applied to the first chamber 7 from the outside, the first chamber 7 and the second chamber 8 communicate with each other, and the colored heat-meltable substance 2 absorbs the colored substance. Can be absorbed by 3. As shown in FIG. 4, on the communication portion 1 side in the second chamber 8,
The carrier 9 holding the colored heat-fusible substance 2 may be housed in contact with the end of the absorber 6.

The shape of the first chamber 7 may be a pentagon, a triangle, a hemisphere or the like as long as the colored heat-meltable substance 2 can be stored therein.

The first chamber 7 and the second chamber 8 are formed of a film, and the material of the film which does not allow the colored heat-melting substance 2 to pass through and can be airtightly stored for a certain period of time, for example, polyvinyl chloride, polystyrene, or non-axially oriented polypropylene. , High density polyethylene, polyethylene terephthalate, polycarbonate,
Examples include non-axially stretched nylon, acrylonitrile and cellulose acetate. Also, a material obtained by mixing a plurality of these may be used.

The adhesive 11 is a thermoplastic resin selected from low density polyethylene, linear low density polyethylene, ionomer, polypropylene, ethylene / acrylic acid copolymer, ethylene / ethyl acrylate copolymer, polymethylpentene and polyester. Aqueous adhesive selected from vinyl acetate, acrylic ester, ethylene / vinyl acetate copolymer, natural rubber, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, starch, dextrin, glue, casein, carboxymethyl cellulose, Examples thereof include water-soluble adhesives selected from resins such as sodium silicate and polyurethane adhesives. In some cases, these may be adjusted with a solvent or the like and used, as long as the communicating portion 1 can be temporarily adhered.

The colored hot melt material 2 contains a hot melt material and a dye. The heat-melting substance which is the main component of the colored heat-melting substance 2 is a substance that melts at a desired temperature, such as alcohols, esters, hydrocarbon compounds, ketones, ethers, inorganic and organic freezing points. An example is an aqueous solution of a substance that falls.

Alcohols include n-octyl alcohol, n-nonyl alcohol, n-decyl alcohol, and n.
-Lauryl alcohol, n-myristyl alcohol, n
-Cetyl alcohol, n-stearyl alcohol, olein alcohol, cyclohexanol, cyclopentanol, benzyl alcohol, cinnamyl alcohol, ethylene glycol, polyethylene glycol, propylene glycol, trimethylolpropane, pentaerythritol, sorbit.

The esters include amyl acetate, octyl acetate, butyl propionate, ethyl caproate, amyl caprylate, ethyl caprate, octyl caprate, lauryl caprate, methyl laurate, octyl laurate, lauryl laurate, myristin. Methyl acid, hexyl myristate, stearyl myristate, butyl palmitate, myristyl palmitate, methyl stearate, ethyl stearate, lauryl stearate, butyl benzoate, amyl benzoate, phenyl benzoate, ethyl acetoacetate, methyl oleate , Butyl acrylate, Butyl oxalate, Diethyl malonate, Dibutyl tartrate, Dimethyl sebacate, Dibutyl phthalate, Dioctyl phthalate, Dibutyl fumarate, Diethyl maleate, Triethyl citrate 1,2-hydroxystearic acid triglyceride, castor oil, and dioxy stearic acid methyl ester.

Examples of the hydrocarbon compounds include aliphatic hydrocarbons such as pentadecane, tetradecane, hexadecane, 1-heptadecane, 1-octadecane, aromatic hydrocarbons such as p-xylene and dodecylbenzene.

Examples of ketones include diethyl ketone, ethyl butyl ketone, methylhexyl ketone, methyl oxide, cyclohexanone, methylcyclohexanone, acetophenone, benzophenone, acetonylacetone and diacetone alcohol.

Examples of ethers include butyl ether, hexyl ether, diphenyl ether, dioxane, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diphenyl ether, and ethylene glycol monophenyl ether.

Aqueous solutions of inorganic and organic freezing point depressants are sodium carbonate, ammonium hydrogen carbonate, potassium hydrogen carbonate, ammonium chloride, potassium chloride, sodium chloride, magnesium chloride, calcium chloride, sodium nitrate, ammonium nitrate, urea, carbonic acid. Examples thereof include aqueous solutions of sodium hydrogen, sodium thiosulfate, glucose, sucrose and fructose. Also, water alone may be used.

These heat-meltable substances may be used alone or in a mixture.

The dye which is the other component of the colored heat-fusible substance 2 may be any dye that can be dissolved in the heat-fusible substance. Examples thereof include oil-soluble dyes, direct dyes, acid dyes, basic dyes, mordant dyes, sulfur dyes, sulfur vat dyes, vat dyes, azoic dyes, disperse dyes, reactive dyes, and oxidation dyes. A pigment may be used depending on the case. Specific examples of oil-soluble dyes include Wako Pure Chemical Industries, Ltd., Sudan IV, Orient Chemical Co., Ltd., Oil Red 5B, Oil Red RR, Oil.
Orange 201, Oil Blue 2N, Oplas Violet 732, Oil Yel
low 3G, Oil Brown BB, Oil Brown GR, Oil Green BG,
Diaresin Blue J, Diaresin manufactured by Mitsubishi Chemical Corporation
Blue N, Kayalon Fast Brillian manufactured by Nippon Kayaku Co., Ltd.
t Green is mentioned.

The absorber 3 is preferably one that allows the colored heat-fusible substance 2 to permeate stably. For example, porous film, qualitative filter paper, quantitative filter paper, glass fiber filter paper, filter paper selected from filter paper for chromatography, pulp, cotton, non-woven fabric, silk gel, porous inorganic sintered body, and a mixture of a plurality of these Is mentioned.

Examples of the carrier 9 include glass fiber filter paper, chromatography filter paper, pulp, powder filter paper, and powder silka gel. Of these, glass fiber filter paper is particularly preferable.

[0021]

The function of the heat sensitive indicator of the present invention is shown in FIGS.
As shown in, inside the first chamber 7 and the second chamber 8, the communicating portion 1 between the colored heat-fusible substance 2 and the absorber 3 is sealed with the adhesive 11 and is stably stored. As shown in FIG. 3, pressure is applied to the first chamber 7 to peel off the adhesion of the communicating portion 1 and
When the chamber 7 and the second chamber 8 are penetrated, when the temperature exceeds the set temperature, the colored heat-meltable substance 2 is detected and melted, and the melted colored heat-meltable substance 2 becomes By penetrating and coloring the absorber 3, it is possible to visually confirm that the environment in which the heat sensitive indicator is used has reached the set temperature or higher.

As shown in FIG. 4, when the carrier 9 is placed in the second chamber 8, the dissolved colored heat-fusible substance 2 permeates into the carrier 9 first and then into the absorber 3. go. Therefore, by utilizing the carrier 9, the permeation rate of the colored heat-meltable substance 2 into the absorber 3 can be controlled.

[0023]

EXAMPLES Examples of the present invention will be described in detail below. FIG. 1 is a perspective view of an embodiment of a heat-sensitive indicator to which the present invention is applied, and FIG. 2 is a sectional view of a main part. In the heat-sensitive indicator of the present invention, as shown in the figure, a transparent film 4 having two convex portions and a flat transparent film 5 are fused together leaving a communicating portion 1. Communication part 1 of film 4
Are sealed with an adhesive 11 to form a first chamber 7 and a second chamber 8. The blockade can be easily peeled off by an external pressure such as finger pressure. The first chamber 7 contains the colored heat-meltable substance 2, and the second chamber 8 contains the absorber 3.

The heat sensitive indicator of the present invention is manufactured as follows. The colored heat-fusible substance 2 and the absorber 3 are attached to the film 4
Of the first chamber 7 and the second chamber 8, respectively. An adhesive 11 is applied to the communicating portion 1, the film 4 and the film 5 are combined and heat-bonded, and the periphery of the first chamber 7 and the second chamber 8 excluding the communicating portion 1 is fused to form a heat sensitive indicator. If necessary, the carrier 9 may be provided on the communication portion side of the second chamber 8 with the absorber 6
Part of the sheets are stacked and stored (see FIG. 4). This heat-sensitive indicator is cooled before use to solidify the colored heat-fusible substance 2, and as shown in FIG. Let The colored heat-fusible substance 2 is dissolved by the temperature rise and penetrates into the absorber 3.

Example 1 As the films 4 and 5, polyvinyl chloride films having a thickness of 200 μm are used. Oil Blue 603 was added to the sesame oil 99.9 g as the colored heat-melting substance 2 in the first chamber 7.
(Orient Chemical Co., Ltd.) 0.1 g of a blue-colored solution was added and 0.1 g of the solution was put into the second chamber 8 as the absorber 3 and a 5 mm × 50 mm filter paper for chromatography (Toyo Roshi Kaisha, Ltd.). Company: 514A). A vinyl acetate adhesive 11 is applied to the communicating portion 1 to thermally bond the film 4 and the film 5, and the periphery of the first chamber 7 and the second chamber 8 excluding the communicating portion 1 is ultrasonically fused. It was fused and used as a heat sensitive indicator.

The heat sensitive indicator was cooled at -16 ° C. for 1 hour to solidify the colored heat fusible substance 2. Then, a penetration test was conducted as follows.

The first in which the colored heat-fusible substance 2 is enclosed
The chamber 7 is pushed with a finger to peel off the adhesive 11 from the communicating portion 1, and the heat sensitive indicator is set to the temperature monitoring state. When this thermosensitive indicator is placed in a constant temperature bath at 0 ° C., the solidified colored heat-fusible substance 2 is gradually dissolved with a rise in temperature,
It penetrated into the absorber 3. The permeation distance of the colored heat-meltable substance 2 into the absorber 3 and the elapsed time were measured, and the relationship is shown in FIG.
It was shown to. As shown in the figure, the heat sensitive indicator showed stable penetration.

Example 2 As the film 4 and the film 5, polyvinyl chloride films having a thickness of 200 μm are used. In the first chamber 7, as coloring heat-fusible substance 2, 99.8 g of erucic acid and Oil Brown BB
(Orient Chemical Co., Ltd.) 0.2g was added and 0.1g of the solution colored brown was put, and the absorber 6 was placed in the second chamber 8.
As the carrier 9, 5 mm × 35 mm quantitative filter paper (manufactured by Toyo Roshi Kaisha, Ltd.) is put in, and 5 mm × 9.2 mm glass fiber filter paper (manufactured by Toyo Roshi Kaisha, Ltd.) is put in (see FIG. 4). An adhesive 11 containing carboxymethylcellulose as a main component is applied to the communicating portion 1 to thermally bond the film 4 and the film 5, and the periphery of the first chamber 7 and the second chamber 8 excluding the communicating portion 1 is ultrasonically fused. A heat sensitive indicator was obtained by fusion using a machine.

The heat sensitive indicator was cooled at 15 ° C. for 1 hour to solidify the colored heat fusible substance 2. Then, a penetration test was conducted as follows.

The first in which the colored heat-fusible substance 2 is enclosed
Push the chamber 7 with a spoon to peel off the adhesive 11 from the communication part 1,
Set the thermal indicator to the temperature monitoring state. When this thermosensitive indicator is placed in a constant temperature bath at 30 ° C., the solidified colored heat-fusible substance 2 gradually dissolves as the temperature rises, and the solution permeates the carrier 9 and eventually permeates the absorber 6. I went. The permeation distance of the colored heat-meltable substance 2 into the absorber 6 and the elapsed time were measured, and the relationship is shown in FIG. As shown in the figure, the heat sensitive indicator showed stable penetration.

Example 3 50.0 g of decyl alcohol as coloring heat-fusible substance 2
Oil Blue to a mixture of 150.0g of lauryl alcohol
A heat sensitive indicator was prepared in the same manner as in Example 1 except that 0.2 g of 2N (manufactured by Orient Chemical Co., Ltd.) was added and 0.1 g of a blue-colored solution was used.

The heat sensitive indicator was cooled at -16 ° C. for 1 hour to solidify the colored heat fusible substance 2. Then, a penetration test was conducted as follows.

The first in which the colored heat-fusible substance 2 is enclosed
The chamber 7 is pushed with a finger to peel off the adhesive 11 from the communicating portion 1, and the heat sensitive indicator is set to the temperature monitoring state. When this thermosensitive indicator was placed in a thermostatic chamber at 10 ° C., the solidified colored heat-fusible substance 2 gradually dissolved as the temperature increased and penetrated into the absorber 3. The permeation distance of the colored heat-meltable substance 2 into the absorber 3 and the elapsed time were measured, and the relationship is shown in FIG. 7. As shown in the figure, the heat sensitive indicator showed stable penetration.

[0034]

As described above in detail, when the thermosensitive indicator of the present invention is used, the temperature history of low-temperature-preserved foods and medical products during low-temperature control can be easily checked by visual inspection, so that temperature control is easy. Is. Since the colored heat-fusible substance is hermetically stored, it does not volatilize and can be stably stored even at room temperature. In addition, the temperature monitoring state can be easily established simply by applying pressure to the first chamber with finger pressure or the like. Moreover, the heat-sensitive indicator of the present invention is thin and compact because a sheet is molded and used, and it is easy to enclose the colored heat-melting substance and the absorber and the price is low.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a heat sensitive indicator to which the present invention is applied.

FIG. 2 is a cross-sectional view of essential parts of an embodiment of a heat sensitive indicator to which the present invention is applied.

FIG. 3 is a cross-sectional view of essential parts showing a usage state of an embodiment of the heat-sensitive indicator to which the present invention is applied.

FIG. 4 is a perspective view of another embodiment of the heat-sensitive indicator to which the present invention is applied.

5 is a diagram showing a relationship between a permeation distance of a colored heat-fusible substance and time in Example 1. FIG.

FIG. 6 is a diagram showing a relationship between a permeation distance of a colored heat-fusible substance and time in Example 2.

FIG. 7 is a diagram showing the relationship between the permeation distance of a colored heat-fusible substance and time in Example 3.

[Explanation of symbols]

Reference numeral 1 is a communicating portion, 2 is a colored heat-fusible substance, 3.6 is an absorber, 4.5 is a film, 7 is a first chamber, 8 is a second chamber, 9 is a carrier, and 11 is an adhesive.

Claims (2)

[Claims] 1. A communication part between a first chamber, which is airtight from the outside and contains a colored heat-fusible substance, and a second chamber, in which the absorber is observable from the outside, is sealed with an adhesive. The adhesive is peeled off by an external pressure applied to the first chamber, the first chamber and the second chamber communicate with each other, and the colored heat-meltable substance can be absorbed by the absorber. A heat sensitive indicator. 2. The heat-sensitive indicator according to claim 1, wherein a carrier holding a colored heat-fusible substance is stored in contact with an end of the absorber on the side of the communicating portion in the second chamber. .