JPS6113118A - Temperature indicating sheet - Google Patents

Abstract

PURPOSE:To use a temperature indicating sheet for managing the preservation of a frozen food, by making a color identifying agent melt above a specified temperature and permeate a diaphragm varied in the thickness so that the color forming rate thereof is varied with the time of permeation to form color in the sheet above a specified temperature. CONSTITUTION:A wax-like substance (e.g. methyl myristate) meltable above a specified temperature and a color identifying agent 2 (e.g. dye) are contained into each of microcapsules 4. These capsules 4 are applied on a sheet together with a binder 5. Then, diaphragms 1 and 1' are applied on the binder 5 with varied thicknesses in ethylene-vinylacetate resin or the like. Then, a display layer 3 adapted to absorb the color identifying agent 2 is applied on the diaphragms to form a temperature indicating sheet. Then, the capsules 4 are broken and stuck on a frozen food. When the frozen food rises above a specified temperature, the color indientifying agent 2 melts, exudes to the binder 5 to form color in the display layer 3, first passing through the thin diaphragm 1' and again, through a thick diaphragm 1 delayed. Thus, this temperature indicating sheet makes it possible to judge on how long the food is exposed to the temperature above a specified value.

Description

[Detailed description of the invention] List of industrial uses The present invention relates to a temperature indication sheet.

Conventional technology Frozen foods and other products stored at low temperatures are usually kept at a specified temperature of -.

If exposed to the above environment, it may change in quality, or if it is stored at a low temperature again, it may become indistinguishable from the unaltered appearance. In order to check in advance for deterioration due to poor management of low-temperature-preserved products along the sales route, and to safely supply products without deterioration to consumers, it is necessary to ensure that low-temperature-preserved products are exposed to a specified temperature field during the process. It is not easy to judge what scales are needed.

An object of the present invention is to provide a temperature indicator that can be attached directly to a low-temperature-preserved product, or inserted or pasted into a package, to indicate when the low-temperature-preserved product is exposed to a temperature higher than a predetermined temperature. , relates to a temperature instruction sheet that changes color depending on temperature and time.

Conventionally, thermochromic materials include electron-donating color-forming organic compounds, electron-accepting organic compounds, alcohols, esters, etc., in place of metal complex crystals or liquid crystals, which are limited in the color-changing temperature range and type of color. Thermochromic compositions consisting of electron-accepting color-changing organic compounds, electron-donating organic nitrogen compounds, alcohols, esters, etc. have been proposed.
Although it is possible to freely select the discoloration temperature range and the type of color over a wide temperature range from 200°C to 200°C, as the object of the present invention, the color change depends on temperature and time. However, it has not yet been possible to provide a composition.

In addition, in a thermochromic composition consisting of a combination of an electron-donating color-forming organic compound and an electron-accepting compound, one of the components is
A heat-accumulating thermochromic composition has also been proposed in which the discoloration depends on two items, time and temperature, by encapsulating one in microcapsules and heating them at a predetermined temperature for a predetermined time to destroy the microcapsules. In this case, the microcapsules are destroyed and the composition changes color when heated to a temperature higher than room temperature, and cannot be applied to low-temperature preservation products as the object of the present invention. As a temperature indicator at low temperatures, a method has been proposed that detects changes in shape or color (combined with dye) when the frozen 7 line thaws, but in this case, the temperature that can be controlled is ()°C or lower. Furthermore, since changes depending on temperature and time cannot be detected, this method is not suitable for the present invention, which aims at managing general low-temperature storage materials including temperatures of 0° C. or higher.

A temperature indicator label that changes color after opening at a certain temperature for a certain period of time has also been proposed (Japanese Patent Application No. 58-64352), but this temperature indicator label needs to be manufactured and stored below the discoloration temperature, and cannot be used. It was inconvenient.

Purpose of the Invention ゛The present invention solves the problems of the prior art.When exposed to a temperature higher than a predetermined temperature in general temperature control of cryogenically preserved items, The purpose is to obtain a temperature instruction sheet that changes color.

Structure of the Invention The present invention provides (i) a coloring agent that melts at a predetermined temperature;
) A diaphragm through which the molten coloring agent permeates, and (I) a display layer that absorbs the molten coloring agent.The coloring agent is encapsulated in microcapsules that can be destroyed by external pressure, and the display layer A temperature indicating sheet is disposed on the opposite side of the display layer and is configured to cause the diaphragm or the molten colorant to be absorbed into the display layer at different times.

The present invention will be explained based on FIGS. 1 to 6.

FIG. 1 shows a temperature indicating sheet with diaphragms (1) and (1') of different thicknesses. A coloring agent (2) that melts at a predetermined temperature is microencapsulated on one side of the diaphragm.
An indicator layer (3) is arranged on the opposite side of the diaphragm. Diaphragms (1) and (1') are made up of the same moons but have different thicknesses.

When a sheet of microcapsules (4) destroyed by external pressure is attached to a frozen food, etc., the frozen food will react at a specified temperature.
When the temperature rises to 2, the coloring agent (2) melts and leaches out of the microcapsules (4). The coloring agent (2) is, for example,
It is a wax-like substance colored with dyes, pigments, etc., which passes through the gaps 11g (1) and (1') and is adsorbed to the display layer (3) over time, and a change in color is observed. Diaphragm (1
) and (1') have different thicknesses, so there is a difference in the time it takes for the molten coloring agent to reach the display layer, making it possible to know the thermal history of the frozen food.

A diaphragm (1) having a thickness of 3 or more may be used, thereby allowing a more detailed thermal history to be known.

Figure 2 shows a coloring agent (
2) is an embodiment in which membranes of the same thickness with different permeation rates are used. Of course, the material and thickness may be changed at the same time. The microcapsules (4) contain a color former (5) (for example, leuco dye) dissolved in wax, and the outside contains a color change agent (6) (for example, phenols). It is located. If a sheet containing destroyed microcapsules is attached to a frozen food before use, when the frozen food reaches a certain temperature, the wax will melt and the coloring agent (5) and color changing agent (6) will come into contact with each other. and cause discoloration. The color changing agent passes through the diaphragms (1) and (1') over time, reaches the display layer (3), is adsorbed, and the color change can be observed. Since the permeation rates of the diaphragms (1) and (1') are different, the thermal history can be known as explained in Figure #1.

FIG. 3 shows an embodiment in which the thickness of the diaphragm (1) changes continuously. Contrary to FIG. 2, the color change agent (6) is microencapsulated together with a waxy substance, and the color forming agent (5) is present on the outside. Of course, the opposite may be true. The principle of measuring the thermal history is the same as that described in the explanation of FIG. FIG. 4 shows an embodiment in which the thicknesses of the diaphragms (1) and (1') are different.

Inside the microcapsules, a coloring agent (
5) is included, and a color change agent (6) is placed on the opposite side of the diaphragm. The coloring agent (wax and coloring agent) melted above a predetermined temperature passes through the diaphragms (1) and (1'), comes into contact with the color-changing agent, changes color, and is adsorbed onto the display layer (3). The adsorption rate in the display layer varies depending on the thickness of the diaphragm, so
The thermal history of frozen foods can be determined by observing the discoloration of the display layer.

FIG. 5 shows an embodiment in which the color change agent (6) in FIG. 4 is microencapsulated and the color former (5) is placed on the opposite side of the diaphragm. The principle of measuring thermal history is the same as that shown in FIG.

FIG. 6 shows an embodiment in which a color change agent (6) and a color former (5) are adsorbed onto the display layer. In this embodiment, the display layer is colored in advance, but by using alcohol as a coloring agent, the color disappears upon contact with the alcohol.

The measurement principle is the same as that explained in FIGS. 1 to 5.

In the present invention, a coloring agent refers to a substance that causes discoloration of the display layer when adsorbed to the display layer; for example, a substance that itself is colored, a substance that is colored with a dye or pigment, and a substance that is colorless itself. It also includes substances that cause discoloration of the display layer by reacting with other components. The coloring agent itself may be a colored one-component system, or a wax-like substance that melts at a predetermined temperature may itself be colored with a dye or the like. Further, a color forming agent (for example, leuco dye) or a color change agent (for example, 7-el) may be dissolved or dispersed and used.

The coloring agent (2) must be melted at a temperature higher than a predetermined temperature. The predetermined temperature refers to the highest temperature at which the test object (for example, frozen food, etc.) must be stored at a low temperature.For example, a temperature support sheet for a test object that must be stored at a temperature lower than 20°C. In this case, the predetermined temperature is 20°C. This temperature is determined by the type of specimen and the required storage temperature, and the coloring agent (2) may be arbitrarily selected depending on the temperature. Usually, it is often stored at a temperature of 5 to 20°C, particularly around 10°C or lower, and materials having a melting point within that range are selected. Of course, this temperature is not limiting.

As mentioned above, the coloring agent is usually used by blending a coloring agent, a coloring agent and/or a color-changing agent with a waxy substance, but it may also be used alone.

Examples of waxy substances used in the present invention include pentadecane, tetradecane, hexatecane, ]-
Aliphatic hydrocarbons such as heptadecane and 1-octadecane,
Aromatic hydrocarbon compounds such as dodecylbenzene, 1]-xylene, tricaprine glyceride, 1-elide-2,
3-tucapulin glyceride, 1-refleo-2,3-laurin glyceride, 2-oleo-1,3-nolaurin glyceride, 1-myristo-2,3-one'olein glyceride, 1-palmito-2,3- Noolein glycerite′
, ethyl myristate, methyl myristate, butyl myristate, methyl caproate, methyl caprate, methyl laurate, ethyl laurate, methyl palmitate,
Esters such as ethyl stearate, methyl stearate, and pentadecyl acetate, alcohols such as 2-undecal, benzyl alcohol, and glycerol, and halogenated hydrocarbons such as tribromomethane and 1,2-silabromoethane. , amines such as monoethanolamine and ethylenenoamine, organic carbonic acids such as formic acid and acetic acid,
Examples include ethers such as nooxane and bennoether.

Examples of dyes or pigments for coloring these waxy substances include Red No. 223, Red No. 225, Yellow No. 204, Red No. 505, and Orange No. 403.

When used in the manner shown in FIGS. 4 and 5, a color forming agent (5) or a color changing agent (6) is used as a coloring agent in combination with a wax.

In this case, if a leuco dye is used as the color former (5) and an organic carboxylic acid is used as the color change agent (6), color development can be suppressed if alcohols such as 2-undecanol or glycerin are used as the wax-like substance. The second
It is not preferable to use the five modes shown in FIGS. On the contrary, these alcohols are effective in decolorizing the display layer colored by leuco dyes and organic carboxylic acids, so they are
It is useful for use in the manner shown in the figure.

When the display layer is colored with a leuco dye and an organic carbonic acid in the embodiment shown in FIG. 6, the coloring agent is as described above.
It may be used that itself has a decolorizing effect, or it may be mixed with another compound having a decolorizing effect. Examples of these compounds having a color erasing effect include alcohols, esters, ketones, ethers, aromatic hydrocarbons, etc. as illustrated below.

Alcohols include monohydric alcohols, polyhydric alcohols, and derivatives thereof. Examples of these compounds are shown below.

n-octyl alcohol, n-nonyl alcohol, ■】
-Decyl Alfuno Mutter I+-Lauryl alcohol, +1
-Myristyl alcohol, 1]-Cetyl alcohol, 1
1-stearyl alcohol, oleyl alcohol, cyclohexyl alcohol, cyclopentamel, benol alcohol, cinnamyl alcohol, ethylene glycol, polyethylene glycol, phlopylene gellicol, trimethylolpropane, pentaerythritol, turpinto, etc. be.

Examples of compounds as esters are shown below.

Amyl acetate, octyl acetate, butyl propionate, ethyl caproate, amino caprylate, ethyl caprate, octyl caprate, lauryl caprate, methyl laurate, octyl laurate, lauryl laurate,
Methyl myristate, 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, cyphthyl cyphtate, noethyl malonate, butyl tartrate, methyl cepatate, 7
Dibutyl talate, octyl phthalate, dibutyl fumarate, diethyl maleate, triethyl citrate, 12
-Hydroxystearic acid triglyceride, castor oil, dioxystearic acid methyl ester, 12-hydroxystearic acid methyl ester, and the like.

The following compounds are exemplified as ketones.

Noethyl ketone, ethyl butyl ketone, methylhexyl ketone, mesityl oxide, cyclohexanone, methylcyclohexanone, acetophene, benzene,
Examples include acetonyl acetone and diacetone alcohol.

The following compounds are exemplified as ethers.

Examples include butyl ether, hexyl ether, nophenyl ether, nooxane, ethylene glycol nophthyl ether, noethylene glycol butyl ether, ethylene glycol diphenyl ether, and ethylene glycol moaphenyl ether.

Aromatic hydrocarbons include I)-xylene, isopropylbenzene, amylbenzene, mesitylene, cymene,
5-Methyl-3-isobutyltoluene, dodecylbenzene, cyclohexylbenzene, biphenyl, methylbiphenyl, ethylbiphenyl, noethylbiphenyl, trimethylbiphenyl, benolbenzene, phenyltolylmethane, xylylphenylmethane, notrylmethane, trioctylnophenylmethane , tribenrunphenylmethane, tolylxylylmethane, tuxylylmethane,
Nophenylethane, tolylphenylethane, tuxylylmethane, phenylisopropylphenylethane, tolylnoisopropylphenylethane, trimethylisopropylphenylethane, nophenylpropane, notrylpropane, phenyltolylmethane, phenylxylylpropane, tolylxylylpropane, Benzylbenzene, Nooctylbenzenethylbenzene, Dibennortoluene, Tetrahydro-7-tylphenylmethane, Tetrahydromethyl-7-tylphenyl ethane, Tetrahydro-7
Examples include tylphenyl ethane, naphthylphenylmethane, and methylnatylphenyl ethane.

Examples of combinations of the color forming agent (5) and color changing agent (6) used in the present invention include the following.

(1) Electron-donating color-forming organic compound (color former) and acids (
(phenolic hydroxyl group-containing compound, organic carboxylic acid, inorganic solid acid, etc.) (color change agent) (ii) pH indicator (color former) and acid base or alkali (color change agent) (iii) Iron compound and 7-element Polyhydric hydroxy compound having a hydroxyl group Examples of the electron-donating color-forming organic compounds used in the present invention include diaryl 7-talides, polyarylcarbyls, leuphoramines, acylouramines, and arylauramines. , rhodamine B lactams, ini/drinols, spiropyrans, fluorans, etc.

Examples of these compounds are shown below.

Crystal violet lactone, malachite green lactone, Michler's hydrocarbon, crystal violet carbyl, malachite green carpinol, N-(2,3-nochloro7-enyl)leucoolamine, N-benzoyl Auramine, N-acetyl auramine, N-phenyl auramine, rhodamine B lactam, 2
-(phenyliminoethanelidene)3,3-dimethylindoline, N-3,3-)tumethylindolinobenzospiropyran, 8'-methoxy-N-3,3-)tumethylindolinobenzosviropyran, 3-') ethylamino-6-methyl-7-chlorofluorane, 3-noethylami-7-7-methoxyfluorane, 3-7ethylamino-6-pen2'-oxyfluorane, 1,2-benz-
Examples include 6-diethylamide/fluoran.

Compounds having a phenolic hydroxyl group include mono 7 ethers to poly 7 ethers, and further substituents thereof include alkyl groups, aryl groups, acyl groups, alfkyl dicarbonyl groups, halogens, etc. . Examples of these compounds are shown below.

Tertiary-butylphenol, nonylphenol, dodecylphenol, a-naphthol, β-su7thol,
Hydroquinyl 7-methyl ether, 1]-Chlor 7-ethyl, p-bromo 7-ethyl, 0-chlorophenol, 0-bromo 7-ethyl, 〇-phenyl 7-ethyl, p-
-phenyl 7-er/-l, methyl p-oxybenzoate, 3
-isopropylic tefur, 1]-tert-butylcatefur, 4,4'-methylene diphenyl, bisphenol A, 1.2-yoxynaphthalene, 2,3-dioxynaphthalene, chlorcatechol, bromocatechol, 2. 4-dihydroxybenzophenone, 7er7-7
Examples include thalein, methyl gallate, ethyl gallate, propyl gallate, butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, stearyl gallate, tannic acid, and phenolic resin.

Inorganic solid acids include silica-alumina, silica-magnesia, bentonite, kaolin, fuller's earth, acid clay, activated clay, montmorillonite, acpal guide, zinc oxide, titanium oxide, calcium sulfate, barium sulfate, aluminum sulfate, and aluminum chloride. , lead chloride, tin chloride, arsenic dioxide, etc.

Organic acids include acetic acid, propionic acid, butyric acid, and cuff 50.
phosphoric acid, etc.

As the iron compound, ferric stearate, ferric myristate, ferric oleate, etc. are used.

Examples of the polyhydric aromatic acid having a phenolic hydroxyl group or its ester include gallic acid, tannic acid, methyl gallate, ethyl gallate, propyl gallate, butyl gallate, octyl gallate, dodecyl gallate, and stearyl gallate. and so on.

In the present invention, the diaphragm through which the molten coloring agent permeates is made of ethylene-vinyl acetate copolymer, acrylic ester copolymer, paper, nonwoven fabric, etc. In particular, ethylene-vinyl acetate copolymer and acrylic ester copolymer are used as the diaphragm. Copolymers are preferred. By selecting the material and thickness, the time required for the molten coloring agent to reach the display layer can be adjusted. In other words, by providing diaphragms with different thicknesses within the same sheet, the melted colorant passes through thinner areas more quickly, discoloring the display layer in that area, or destroying the specimen in a short period of time. When the temperature returns to the freezing temperature, the coloring agent solidifies again in the thicker portions and does not reach the display layer, causing no discoloration. If a frozen food is exposed to a temperature above a predetermined temperature for a long period of time, the display layer corresponding to the thick portion will also change color. As a result, it is possible to know the thermal history (temperature and time) of frozen foods.

Furthermore, by changing the material of the diaphragm (for example, eye crest, affinity for the coloring agent) within the same sheet, the permeation rate of the coloring agent will differ, resulting in partial discoloration of the display layer. It can occur quickly or slowly. Of course, the material and thickness of the diaphragm may be changed at the same time.

The thickness of the diaphragm may be appropriately selected depending on the type of material, the temperature and time required to be controlled, etc., but it is usually 20 μIn or less.

The diaphragm is usually formed by applying a film-forming resin such as ethylene-vinyl acetate copolymer on the microcapsule layer of the coloring agent or on the display layer, but it is applied in a band shape at regular intervals. is valid. Should the sheets themselves be colored differently for areas with different thicknesses of the diaphragm or different materials, or should different types of colorants or coloring agents be applied so that the colors or colors produced are different? , which is easier to understand and more preferable.

The display layer is not particularly limited as long as it can adsorb the molten coloring agent and observe the resulting color change.

Specifically, paper, woven fabric, nonwoven fabric, etc. are exemplified. Typically it is paper. The thickness is not particularly limited, but is 10~
100μ night is preferable. Furthermore, this display layer may be made of a material on which a color former or a color change agent is adsorbed, and a color former containing a color change agent or a color former may be used in combination. Next, the microencapsulation technology used in the present invention is as follows:
A well-known method, the coacelhesion method, is used.
u-polymerization method, interfacial polymerization method, underwater curing coating method, phase separation method from aqueous solution, phase separation method from organic solution.

etc. can be used in thousands of ways.

There are several methods for applying microcapsules containing a coloring agent to the diaphragm 2, such as a knife coater, a 7-lash coater, a reverse roll coater, a bar coater, and an air knife coater. One coater type is preferable. When the sheet is used, the microcapsules containing the coloring agent are destroyed, but the method is not particularly limited or depends on the time and temperature when the entire system is exposed to a temperature above a predetermined temperature. In order to understand changes, it is desirable to destroy the specimen under a constant load using a hand roller or the like.

The microcapsules have a size of about 1 to 3008 m0 so that they can be easily destroyed with a roller or the like during use.

If it is 1 μm or less, it is difficult to break, and if it is 300 μm or more, the particle size is too large, causing problems in the coating process.

The film-forming ingredients used in microcapsules are gelatin,
These include alginic acid, acrylic polymers, methacrylic polymers, melamine, and epoxy polymers, and these are easily destroyed by external force at low temperatures.

Capsules containing a coloring agent that melts at a predetermined temperature may be applied by any suitable means.

As the binder used for coating the microcapsules on the substrate, methods using organic binder solution type binder, non-aqueous emulsion type binder, aqueous emulsion type binder, and aqueous emulsion type binder can be considered.

When an organic solvent-based binder is used, either the organic solvent itself acts as one of the discoloring components, or the organic solvent extracts the microencapsulated components before breaking the microcapsules and discolors the temperature indicator sheet before use. There are cases. As a result, the discoloration change at the discoloration temperature of the temperature instruction sheet becomes unclear, or in some cases, the discoloration cannot be confirmed at all. Furthermore, it is difficult to use industrially because of the odor of organic solvents, flammability, and hygiene problems.

Similarly, in the case of a non-aqueous emulsion, the same drawbacks as those using an organic solvent solution type binder occur.

Furthermore, with aqueous binders, the solution viscosity of the binder is generally high and the solid content of the adhesive cannot be increased, which limits the selection of the microcapsule/adhesive solid content weight ratio during application, making it difficult to achieve the desired discoloration performance. It may not be possible to set it within an appropriate range. Furthermore, when an aqueous binder is used, when the temperature indicator sheet is wound into a roll, it becomes sticky and difficult to unwind (blocking), resulting in a lack of industrial productivity. For the above reasons, organic solvent solution type, non-aqueous emulsion type, and aqueous solution type baingu all have many drawbacks and pose practical problems.

On the other hand, if microcapsules are dispersed in an aqueous emulsion-type baingoo and this is applied onto a substrate, there will be no problems such as discoloration due to external solvents or impregnation/elution of the microcapsules, as seen with the organic solvent-based baingu mentioned above. , the hue change at the color change temperature becomes extremely clear. Moreover, it becomes possible to select the resin material used for the binder from a wide range of materials. Furthermore, since water-based emulsion type paints have a low viscosity compared to their solid content, the selection range of the microcapsule/adhesive solid content weight ratio during application is wide, and the desired color change performance can be adjusted to the temperature indicator sheet. It is possible to hold it. In addition, since it is insoluble in water after application and drying, it is easy to unwind the temperature indicator sheet after it has been rolled up:] It does not stick.

The polymer aqueous emulsion may be anything as long as it prevents contact between components involved in discoloration and does not adversely affect discoloration. Examples include natural polymers such as rubber, glue, and starch, and synthetic polymers such as polyvinyl acetate, vinyl acetate copolymers, acrylic acid ester copolymers, vinylidene chloride polymers, epoxy resins, and butanoene copolymers. Particularly preferred is vinyl acetate-ethylene copolymer.

The solid content concentration of the emulsion is not particularly limited, and it is sufficient that it can be easily coated onto the base sheet when blended with the microcapsules at a desired weight ratio. usually,
It is preferable to have a solid content concentration of about 10 to 70% by weight.

Since the rate of discoloration of the temperature indicator sheet differs depending on the mixing ratio of microcapsules and aqueous emulsion, it is necessary to select the mixing ratio depending on the purpose. If the amount of emulsion is too small, it will no longer function as an adhesive and the microcapsules will peel off from the coated sheet. Furthermore, if the concentration of the solid content of the emulsion becomes too high, the rate of discoloration of the temperature indicator sheet will slow down. Usually, it is appropriate to use a microcapsule/emulsion weight ratio of about 30/1 to 1/2 in terms of solid content.

Additionally, additives for improving necessary conditions may be added to the coloring agent, the substance that interacts with it to cause discoloration, and the diaphragm, to the extent that it does not interfere with irreversible discoloration, which is the objective of the present invention. I can do it.

A typical example of such additives is antioxidants.

These include ultraviolet absorbers, inorganic fillers, pigments, plasticizers, lubricants, antistatic agents, etc.

Methods for attaching the temperature indication sheet of the present invention to low-temperature storage products include pasting it with an adhesive, hanging it as a label, and directly adhering it to a container for low-temperature preservation products.
It is preferable to provide an opaque layer between the adhesive layer and the coloring agent layer to prevent diffusion of the molten coloring agent.

Preferred examples of using a temperature instruction sheet include kamabok, raw noodles, yogurt), -Night L Punk 1? It is not limited to these.

By using the temperature support sheet of the present invention, it is possible to easily determine how long a frozen food has been exposed to a temperature higher than its storage temperature. That is, by knowing the thermal history of frozen foods in more detail, sellers and consumers can easily evaluate the quality of frozen foods by visual inspection at the time of sale or purchase.

Next, specific examples will be shown, but the present invention is not limited thereto.

Example 1 Methyl myristate 20! ? 5% gelatin aqueous solution 1
(ii) Mix thoroughly, warm to 50°C, and form fine oil droplets by stirring.

Subsequently, 75ml of 5% carboxymethylcellulose aqueous solution
g was added to adjust the pH to 4.3, and the mixture was cooled to 5° C. for 11 hours.

After adding 3'7% formalin, the pH was adjusted to 1'(', 1), and the temperature was gradually raised to 5 ()°C. Particle systems 1 to 10
The + system obtained with 1μI microcapsules was concentrated and water/
A microcapsule wet cake of i (ii%) was obtained.Ueso 1 cake and Polysol P-3fl (l;
):1 to prepare an ink.

Commercially available thermal paper was colored on the entire surface, and 5g of Sumikaflex 830 was applied as a diaphragm on one side and the other side] (, +9/
After coating and drying, apply the above ink to the coated surface for 4 f) g/
m2 was applied and dried.

As a permeation prevention agent, Polysol EVA-AD-5 was coated on the ink coated surface at 102/layer 2 and dried.Meanwhile, Nikasol TS-444 was coated on the release paper at 4. (iig/shoulder 2
It was coated, dried, and laminated with the laminated thermal paper to obtain a test label.

Apply a force of about 20~JOOkg/cm” to the label,
The microcapsules were broken and placed in a thermostat at 10°C. When observed one week later, no changes were observed.

After that, when the temperature was raised to 13°C, 5g/g of the diaphragm was removed.
The area coated with m' began to discolor after 3 hours and was completed after 8 hours.

The area to which 1.0 g/u2 of diaphragm was applied began to change color after 10 hours and was completed after 20 hours.

Example 2 20 g of methyl myristate, 10 g of methyl methacrylate
And AIBNSOJI! 7 was mixed and dissolved.

This was dispersed in 100 g of a 0.5% methylcellulose aqueous solution to form minute oil droplets, and reacted at 75° C. for 5 hours to obtain microcapsules with a particle size of 10 to 50 μm.

The system was concentrated to obtain a microcapsule wet cake with a water content of 30%. Wet cake and Polysol MC! 'i was combined with (ff) at a ratio of 3:1 to create an ink.

The entire surface of commercially available thermal paper was colored, and Sumikaflex 830 was applied to one side and Polysol P- was applied to the other side as a diaphragm.
25 was applied for 5 s/#- and dried, and the above-mentioned ink was applied on the coated surface at a rate of 5+', 1 g/m" and dried. As a permeation preventive agent, 5 g of Movinyl] 84 was applied on the ink coated surface. /ff7 was applied and dried.

-・On the release paper, apply 402 liters of NICAZOL T S-444.
/ A final coat was applied, dried, and laminated with the laminated thermal paper to form a test label.

The microcapsules were destroyed by applying a force of about 20-1 (10 kg/cm) to the label and placed in a thermostat at 10°C. When observed after 1 week, no changes were observed. When the temperature was raised to °C, the area where Sumikaflex 830 was applied began to change color after 2 hours, and the process was completed in 5 hours.The area where Polysol P-25 was applied began to change color after 10 hours, and the process was completed after 24 hours. .

Example 3 2 g of alginate and 1 g of gelatin were dissolved in 150 ml of water, and methyl myristate was added dropwise under stirring to form minute oil droplets. The fine oil droplet dispersion was dropped into 500 g of a 10% calcium chloride aqueous solution to obtain microcapsules.

The system was concentrated to obtain a microcapsule wet cake with a water content of 40%. Ink was prepared by mixing wet cake and Sumikaflex 400 at a ratio of 5:1.

Commercially available thermal paper was colored on the entire surface, and Sumikaflex 830 was applied as a diaphragm on one side and 10 g/m in the center.
g/waste 2 and 16 g'/p" on the other side and dried. 30 g/waste 2 of the above ink was applied on the coated surface and dried. Gohsenol GH-20 was applied as a permeation prevention agent to the ink coated surface. 15 g 7 m'' was applied and dried.

On the other hand, 40 g/u of NICAZOL TS-444 was added to the release paper.
2 was applied, dried, and laminated with the laminated thermal paper to obtain a test label.

A force of about 20 to 100 kg/C1+2 was applied to the label to destroy the microcapsules, and the microcapsules were placed in a thermostat at 10°C. When observed one week later, no changes were observed. After that, when the temperature was raised to 13℃, the area where 3g/m2 of diaphragm was applied started to change color after 1 hour.
Completed after hours. The areas coated with 11) g/m'' of diaphragm began to discolor after 6 hours and were finished after 12 hours.

The area coated with 16 g/m2 of diaphragm began to discolor after 20 hours and was completed after 40 hours.

Example 4 An oil-soluble dye (Oil Violet #732: manufactured by Orient Chemical Co., Ltd.) was dissolved in methyl myristate to form a 1% solution. More 7-MMA 40g, the above solution 60y, A
IBN 0.2+7 was uniformly mixed and dispersed in 150 g of a 0.5% methyl cellulose aqueous solution to form minute oil droplets. When reacted at 75°C for 5 hours, particle system 10-5
Microcapsules of 0 μm were obtained. After filtering, the solid content is 6
A 5% cake was obtained.

This wet cake was mixed with Sumikaflex I 830 (manufactured by Sumitomo Chemical Co., Ltd.) as bangu in a ratio of 3:1,
It was applied to the surface of 55 g of high-quality paper. Coating amount is 40g/m
It was 2. After cooling this capsule processed paper to -10℃,
20-II) When the microcapsules were destroyed by applying a force of about 1 kg/#" and left at room temperature, the back surface immediately began to change color to light purple, and color development was completed in 1 to 2 hours.13 When measured at 10°C, discoloration started after 1 hour, completed in about 6 hours, and no coloration was observed even after being left overnight at 10°C.

Next, when the amount of microcapsules applied was 70 g/m'', the behavior of color development was similar to that of 40 g/m2, or the color developed more clearly.

Next, in order to control the speed of color development, we investigated a transmission control membrane. Movinyl 184E (Hoechst Synthesis Co., Ltd.)
Co., Ltd.) was applied to the base paper with a thickness of 3 g/u2, and after drying,
Microcapsule ink was applied at 70 g/m''. When the microcapsules were destroyed and left at room temperature, color development started after 1 hour. At 13°C, color development started after 5 hours and color development was completed after about 10 hours. did.

Example-y Crystal highlet lactone (CVL) (1°52) was dissolved in 60.i of methyl myristate.As monomers, 4.0 g of MMA, 60 g of ordinary solution, AIB No.
2 g was uniformly dissolved and dispersed in 150 seconds of 5% methylcellulose solution using a homogenizer to form minute oil droplets. After reacting at 75°C for 5 hours, filter and
A wet cake of 50 μm microcapsules was obtained. This wet cake (solid content 68%) and Polysol Mc-
s<manufactured by Showa Kobunshi Co., Ltd.; solid content 50%) 3:1
The mixture was mixed with After being destroyed, it was left in a thermostat at 13°C, and color development started in about 1 hour and was completed in about 6 hours.

Next, add 3g of Sumikaflex #830 to the back of the bottom paper.
/n', and then a color development test similar to that in which microcapsules were applied at 40 g/r was conducted.

There was no change at all for about 3 hours, but after that, the color started to change gradually and was completed in 8 hours.

Similarly, 3 g/m2 of Polysol P-25 (manufactured by Showa Kobunshi Co., Ltd.) was applied to the back side of the bottom paper, and 40 g
/m2 coated with microcapsules started discoloring in about 6 hours at 13°C and completed in 10 hours.

Example 6 Ethyl laurate 507 was mixed with 1% Neelamine P-6300 aqueous solution + SO to form minute oil droplets.

1] H was adjusted to 4-5 and reacted at 50°C for 5 hours to obtain microcapsules. The system was concentrated to obtain a microcapsule wet cake with a water content of 30%. An ink was prepared by mixing end cake and polysol MC-5 at a ratio of 5:1.

Commercially available thermal paper was colored on the entire surface, and Sumikaflex 830 was applied at 52g/a on one side and 10g/a on the other side as a diaphragm on the back side of the coloring.
Apply 2 coats, dry, and apply 40g/J of the above ink to the coated surface.
12 coats were applied and dried. As a permeation prevention agent, Polysol EVA-AD-5 was coated with H2/final on the in-coating section and dried.

Ichiriki, 4 pieces of Kocasor T S-444 on the fAIF pattern paper.
0g/rrr'coating and drying, and the laminated thermal paper and 11
The old labels were combined and used as test labels. 20-1 on the label
The microcapsules were broken by applying a force of fl fl kg/cm and placed in a -15°C incubator. 2
When observed after a week, no changes were observed.

After that, when the temperature was raised to -5℃, the diaphragm lost 5g/y.
The area where 2 coats were applied began to discolor after 2 days and was completed after 4 days. The area to which 10 g/m2 of diaphragm was applied began to discolor after 4 days and was completed after 7 days.

Kanranmasu terephthalic acid dichloride and methyl laurate 5 (ly
The mixture was mixed with a 1% aqueous sodium hydroxide solution in which 5 g of bisphenol A was dissolved to form minute oil droplets. 50'C
The mixture was reacted for 2 hours to obtain microcapsules. The system was concentrated to obtain a microcapsule "ent cake" having a water content of 40%. The wet cake and Polysol P-300 were mixed at a ratio of 4:1 to prepare an ink.

Commercially available thermal paper was colored on the entire surface, and Sumikaflex 830 was applied as a diaphragm on the back of the coloring, 5y/u on one side and 10y/u on the other side.
'Coat and dry, apply 40g/m of the ink on the coated surface'
Apply and dry. Polysol EV as a permeation prevention agent
10g/l of A-AD-5 on the ink application surface! Two coats were applied and allowed to dry.

On the other hand, add 40g of Nikazol TS-444 to the release paper.
/ JT 2 was coated, dried, and laminated with the laminated thermal paper to obtain a test label. 20 to 1 (',
A force of about 10 kg7 cm' was applied to destroy the microcapsules, and the microcapsules were placed in a thermostat at 0°C. When observed two weeks later, no changes were observed. Then 4°
When the temperature was raised to C, discoloration started to occur after 5 days of application of the diaphragm at 5 g/l, and discoloration was completed after 2 days. 10 diaphragms
g/m' coated area began to discolor after 2 days and was completed after 4 days.

Example 8 8285 g of Epifuto and ethyl myristate were combined to make 200 g of 0.5% carboxymethylcellulose aqueous solution.
8 (5 at 1'C) and gradually add the hardening agent dropwise.
Microcapsules were obtained by reacting for a period of time. Concentrate the system
A microcapsule wet cake with a water content of 3% was obtained. Wet cake and Sumikaflex 400! An ink was prepared by mixing at a ratio of 3:1.

Commercially available thermal paper was colored on the entire surface, and 5g of Sumikaflex 830 was applied on one side and IJ7/i on the other side as a diaphragm on the back side of the coloring.
+' Apply and dry, apply 40 coats of the above ink on the coated surface.
m'' and dried. Polysol EVA-AD-5 was applied as a permeation prevention agent to the ink coated surface] 0g7ml!
Apply and dry.

On the other hand, add 40g of Nikazol TS-444 to the release paper.
/rn'' was applied, dried, and laminated with the laminated thermal paper to make a test label.
cm: Destroy the microcapsules by applying a certain amount of force, 5
It was placed in a thermostat at °C. When observed after 10 days, no change was observed. After that, when the temperature was raised to 8°C, the area where the diaphragm was applied at 59 g/m began to change color after 6 hours, and it was completed after 10 hours.
2 coated areas began to discolor after 16 hours and was complete after 24 hours.

The materials or product names used in Examples 1 to 8 are products of the following companies: Commercially available thermal paper: manufactured by Honshu Paper Co., Ltd.; 5H-
65BX'-10 Polysol・・・・・・・・・ Showa Kobunshi Co., Ltd. Sumikaflex・Taiha Kagaku Kogyo Co., Ltd. Gohsenol・
... Nippon Gosei Kagaku Kogyo Co., Ltd. Movinyl...
... Hoechst Synthesis Co., Ltd. Kokazol ...
・・・ Nippon Carbide Co., Ltd. Neelamine ・・・・・・
・・・ Mitsui Toatsu Chemical Co., Ltd. Epicote ・・・・・・
・・Shell Chemical Co., Ltd.

[Brief explanation of drawings]

@Drawings 1 to 6 are schematic cross-sectional views of the temperature indicating sheet of the present invention. (1), (1') Diaphragm (2) Wax-like substance (3) Display layer (4) Microcapsule (5) Color former (
6) Color change agent Figure 1 Figure 2 Figure 3 Figure 4 Procedural amendment (voluntary) August 28, 1980 Patent application No. 134844 2 Name of invention Temperature instruction sheet 3 Case of person making amendment Relationship with Patent Applicant Address 2-1-3 Shibukawa-cho, Yao-shi, Osaka Name Matsumoto Kosan Co., Ltd. Representative Timber Okabe 4 Agent 5 Date of correction order (voluntary) 7. Contents of amendment (1) Specification Page 10, line 4 from the bottom, j-red 223”
a? Corrected to "Red No. 223." (2) On page 27, line 10, page 28, line 4 from the bottom, and page 31, line 4 from the bottom, the words "particle system" were corrected to "particle diameter." (3) On page 33, line 5 of the same page, the phrase ``normal solution'' is corrected to read ``all 1 of the above solutions''. (4) On the last line of page 33 of the same page, the phrase ``same as what was applied'' was corrected to ``same as the whole area that was applied.'' (5) On page 37, line 2, does it say "3% moisture"? Correct to "30% moisture". that's all

Claims (1)

[Claims] 1. (i) A color former that melts at a predetermined temperature; (ii) a diaphragm through which the melted color former passes; (iii) a display layer that absorbs the melted color former; The agent is encapsulated in microcapsules that can be ruptured by external pressure and placed on the opposite side of the display layer via a diaphragm, and the diaphragm is configured such that the molten coloring agent is adsorbed to the display layer at different times. Temperature instruction sheet. 2. The sheet according to item 1, in which the diaphragm has portions with different thicknesses. 3. The sheet according to item 1, wherein the diaphragm is partially made of different materials.