JP2001066196A - Temperature control member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute uniformly initialization of a temperature sensitive member. SOLUTION: In this temperature control member 1 on which a temperature sensitive member 2 whose color is changed corresponding to a temperature is installed partly, the temperature sensitive member 2 is irreversible in the environmental temperature, and after being initialized by being heated and cooled rapidly, a color concentration of an initialized part is changed corresponding to the temperature and the time in the standing atmosphere. A blank layer 3 having a prescribed thickness is formed around the temperature sensitive member 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control member formed so as to control the temperature of fruits and vegetables, fresh products, and the like using a temperature indicating member that changes color depending on the temperature.

[0002]

2. Description of the Related Art Among the conventionally used temperature indicating members, examples of a temperature indicating material whose color changes in response to temperature include, for example,
Thermochromic organic dyes such as spiropyrans, ethylene derivatives substituted for condensed aromatic rings such as bianthrone and dixanthylene, and CoCl2.2 (CH2) 6N4.10.
There are metal complex salt crystals such as H2O and those comprising a combination of an electron donating compound, an electron accepting compound and a polar organic compound. For a temperature management label or the like using such a temperature indicating material, the appearance of a color change depending on the temperature is visually observed to determine the temperature of an environment where the temperature is left.

[0003] The temperature indicating materials are roughly classified into a reversible type and an irreversible type. The reversible type is a type in which the color changes as many times as the temperature rises and falls, and the irreversible type changes the color at a certain temperature. Then it is a type that does not return.

[0004] In the case of the reversible type, it is used as a sign for drinking a drink such as beer, or when it is necessary to visually call attention.

The irreversible type (low temperature) is used for controlling the temperature of fruits and vegetables, fresh foods, and the like, and is described in Japanese Patent Publication No. 58-10709 and the like as having a temperature history. That is, ink whose viscosity changes with temperature (for example, ink in which a dye is dissolved in oleyl alcohol) penetrates through the penetrating material, and how long it takes to reach a temperature equal to or higher than the set temperature depending on the permeation length. You can check if you have been exposed.

Further, a plurality of layers including an ink layer, a separate layer, a porous layer, and a display section are formed on the label. Here, the separate layer is removed when the temperature control is started, and the porous layer is a layer for controlling the permeation time. In any case, in order to realize low-temperature irreversibility (when the set temperature is lower than room temperature), a storage method when temperature control is not started and its means are necessary, which has an expensive and complicated structure.

Japanese Patent Application Laid-Open No. H8-197853 discloses a method in which a glass transition temperature is set to a set temperature, and a warning is issued by utilizing the fact that the diffusion rate of molecules rapidly changes when the glass transition temperature is exceeded. Has been described.

[0008]

After initialization by heating and quenching using a thermal head or the like, a portion of the initialized portion which is exposed to a temperature higher than a set temperature and whose coloring density changes with temperature and time is shown. A temperature management member is formed using the member. In such a temperature control member, a partially provided temperature indicating member has a step in its periphery due to its thickness, and due to the step, the entire temperature uniform member is uniformly initialized when initialized by a thermal head. Could not be converted. Since the temperature indicating member could not be uniformly initialized, the energy for the initialization was partially different, and the color development rate upon exposure to high temperature was changed, so that stable temperature indicating characteristics were not exhibited.

[0009]

According to the present invention, there is provided a temperature control member partially provided with a temperature indicating member whose color changes in response to temperature, wherein the temperature indicating member is irreversible at an ambient temperature;
After being initialized by heating and quenching, the color density of the initialized portion changes according to the temperature and time in the standing atmosphere. A blank layer having a predetermined thickness was provided around the temperature indicating member.

[0010]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIGS. First, FIG. 1 shows a temperature management member 1. A temperature-controlling member 1 partially provided with a temperature-indicating member 2 that responds to temperature. The temperature-indicating member 2 is heated and quenched to change the color density according to the temperature and time after initialization. A blank layer 3 having substantially the same thickness as the temperature indicating member 2 is provided around the temperature indicating member 2 so as to reduce a step near the temperature indicating member 2. The blank layer 3 is formed of a transparent ink.

The temperature control member 1 is provided with a temperature indicating member 2 whose color development proceeds with temperature and time after initialization, and a density pattern 4 indicating the degree of color development of the temperature indicating member 2 with colored ink. When the density becomes approximately the same as the density pattern 4, exposure information 5 is provided below the density pattern 4, and by recognizing the exposure information 5, the state of the article to which the temperature management member 1 is attached is known. It becomes possible.

Here, the color of the used temperature indicating member 2 progresses as a function of temperature and time after initialization by heating and rapid cooling.

The temperature indicating member 2 used here is a member that develops color as a function of temperature and time after initialization. The temperature indicating member 2 of the present embodiment can use a rewritable material, and can have the following configuration.

Electron-donating color-forming compounds (leuco dyes) Phenylmethane compounds (various fluorans, phenylphthalides, etc.), various indolyl phthalides, spiropyrans, leuco auramines, acyl or aryl auramines, etc.・ Electron-accepting compound (color developer) Compound having phenolic hydroxyl group, metal salt of compound having phenolic hydroxyl group, various triazoles, carboxylic acids, metal salt of carboxylic acid, etc. ・ Reversible material Steroid-based material, for example , Pregnenolone, methylandrostandiol, cholesterol and the like can be used.

Temperature-controlling agent (not necessary in some cases) Cycloalkanols which are stable in a crystalline state at normal temperature can be used. For example, cyclododecanol.

The above-mentioned three-component containing no temperature-controlling agent or a four-component system containing the temperature-controlling agent is applied in a state of being dispersed in a binder resin.

As the resin, styrene resin, styrene methacrylic acid, acrylic resin and the like can be used.

More specifically, the composition of the temperature indicating member 2 is as follows. <Temperature indicating member> Leuco dye: H3035 (manufactured by Yamada Chemical Co., Ltd.) 1 part by weight Developer: propyl gallate (PG) 1 part by weight Reversible agent: pregnenolone (PRN) 10 parts by weight Temperature-controlling agent: cyclododecanol (CD) 5 parts by weight Binder resin: styrene methacrylic acid (A-91: manufactured by Dainippon Ink Co., Ltd.) ... 5 parts by weight <Production method> A mixed solvent of toluene and cyclohexanone (4:
1) A binder resin is dissolved in 84 parts by weight, a leuco dye, a developer, a reversible agent, and a temperature-controlling agent are added, and the mixture is stirred for 2 hours with a paint shaker to obtain a coating solution.

The coating solution obtained as described above is applied onto the substrate 6 by gravure printing (synthetic paper obtained by coating high-quality paper with PET7 and further surface-treating to improve adhesion). Was dried so as to have a dry film thickness of 10 μm (partially applied). Further, H of the densities a, b, and c is obtained by offset printing according to the color density of the temperature indicating member 2.
Three types of density patterns 4 in which the density is changed in the same cyan color as 3035 are printed. The density pattern 4 is from a to b, c
Under the density pattern 4, the content indicating the state when the attached article is exposed to a high temperature is provided under the density pattern 4 under the condition that the temperature indicating member 2 is colored when the density pattern 4 matches the density pattern 4. It is described in Exposure Information 5. here,
The storage status “freshness” is printed under a, the storage status “early” is printed under b, and the storage status “attention” is printed under c.

On the temperature indicating member 2, a protective layer 8 (OP varnish) is provided by offset printing for initialization by a thermal head. If necessary, a hard protective layer made of a UV curable resin is provided, and the protective layer 8 is formed thereon. The temperature management member 1 provided in this way makes it easy to know the storage environment state of the temperature management member 1 while comparing the progress of color development of the temperature indicating member 2 with the density pattern 4.

FIG. 2 is a sectional view of the temperature control member 1. As shown in FIG. After forming the temperature indicating member 2 and the blank layer 3 of the transparent ink on the base material 6 by gravure printing at 10 μm, the density pattern 4 and the product information 9 are printed by offset printing, and the protective layer 8 is formed by offset printing at 1 μm to complete. I do.

The principle and characteristics of the temperature indicating member 2 will be described with reference to FIGS. The temperature indicating member 2 is composed of an electron donating color-forming compound and an electron accepting compound, a reversible material, a temperature indicating property controlling agent, and a binder resin. Generally, an electron-donating color-forming compound refers to a precursor compound that develops color, and an electron-accepting compound refers to a developer, and the interaction between the electron-donating color-forming compound and the electron-accepting compound is The color develops when it becomes strong, and disappears when its action is weak. The reversible material used in the present embodiment indirectly enhances or weakens the interaction with the electron donating color forming compound or the electron accepting compound, so that the electron donating color forming compound or the electron accepting compound is indirectly linked to the electron donating color forming compound. Refers to a material capable of reversibly changing the interaction of an acidic compound. The temperature indicating characteristic controlling agent is a material for controlling the color development time and temperature, and is a material related to the reversible material and the color developer.

FIG. 3 briefly shows the principle. The case where CVL is used for the leuco dye (A), propyl gallate is used for the color developer (B), PRN is used for the reversible material (C), and the temperature control agent (D) is shown.

In the decoloring mode, the interaction between the leuco dye (A) and the color developer (B) is weak, and the color developer (B) interacts with the reversible material (C) and the temperature-control characteristic (D). Is strengthening. In the color development mode, the interaction between the leuco dye (A) and the developer (B) is strong, and the interaction between the reversible material (C) and the temperature-controlling agent (D) is weak in the developer (B). .

The thermodynamic reversibility of this system will be described with reference to FIG. In the color-developed state, the interaction between the leuco dye (A) and the color developer (B) is strong, and the reversible material (C) and the temperature-controlling agent (D) exist alone in a crystalline state. When heated from this state to a temperature higher than the melting point Tm of the temperature indicating member 2, the state changes to a fluid state, the interaction between the leuco dye (A) and the developer (B) is weakened, and the developer (B) and the reversible material The interaction between (C) and the thermodynamic characteristic controlling agent (D) is strengthened. When rapidly cooled from this state, the reversible material (C) and the temperature-control characteristic agent (D) solidify (amorphous state) while incorporating the color developer (B), and the decolored state is maintained. From that state,
When heated to a temperature equal to or higher than the glass transition temperature Tg, the molecules of the color developer (B) diffuse, so that color development starts. The diffusion rate of the color developer (B) changes dramatically around the glass transition temperature Tg (glass transition temperature of the entire system). Further, when the heating is performed in a range from the crystallization temperature (Tc) to the melting point (Tm), the diffusion speed is further increased, and the color is instantly formed.

In the invention described in Japanese Patent Application Laid-Open No. H8-197853, it is described that the glass transition temperature Tg can be used for a temperature control member. ) Is a method using the diffusion speed. That is, this is a method of detecting the boundary with that of FIG.

On the other hand, in the present embodiment,
In the principle diagram of FIG. 4, the following area is used. Is used for specifying the temperature as will be described later, and can be used as a warning.

The temperature indicating member 2 is used after being initialized by heating and rapid cooling. The initialization is performed using, for example, a thermal head.

FIG. 5 shows the initialization characteristics. Increasing the energy applied to the thermal head increases the reflectance (discolors).
The thermal head is KBE-56-8MG made by Kyocera.
Using K1-MG, the applied power is 0.3 W, printing cycle 4
ms / line. The applied energy was controlled by controlling the pulse width. In the temperature indicating member 2 using PRN as the reversible material (C), the reflectance becomes almost maximum (erased) at an energy of 0.82 mJ / dot.

The reflectance was measured using a colorimeter manufactured by Minolta Co., and the reflectance was measured at a point having a wavelength of 620 nm.

FIG. 6 shows the relationship between the time and the reflectance at 15 ° C., 20 ° C., and 25 ° C. of the sample initialized by applying 0.82 mJ / dot. At 15 ° C., the color development is rather slow, but at 20 ° C. and 25 ° C., the color development progresses with time. That is, it turns out that it is a function of temperature and time.

When the storage condition of an article to be stored changes depending on the temperature and time, in order to notify the state of the high-temperature exposure of the article, the same coloration as when the temperature indicating member 2 is initialized and then developed by the high-temperature exposure is used. The state is printed on density pattern 4 in advance. Further, below the density pattern 4, a warning of the storage state when the temperature indicating member 2 of the article to be stored reaches the density can be issued. For example, the density pattern 4 having the same color tone as the temperature indicating member 2 and the reflectance (620 nm) of 0.5, the exposure information 5 of the storage condition “good freshness”, and the density pattern 4 of 0.4
And the exposure information 5 of the storage state “ASAP”, the density pattern 4 of 0.3, and the exposure information 5 of the storage state “Caution” are provided.
This means that when the article to be stored is stored at 20 ° C., the reflectance is 0.5 or less for about 9 hours, 0.4 for 14 hours, and 0.3 for 19 hours in this environment. At the same time, it is possible to easily understand the danger by reading the exposure information 5 of the article. If the reflectance of the temperature indicating member 2 is in the middle or the like and does not match,
It turns out that it is in the intermediate state. For example, the temperature indicating member 2
Is 0.6, it means that the image has been stored in a state better than the storage state "good freshness". Also. When the reflectivity is 0.45, it means that the storage state is between "good freshness" and "early". As described above, the storage state can be determined while comparing with the density pattern 4. Here, an example in the case of 20 ° C. is shown, but the same applies to each temperature. If the storage temperature is higher than 20 ° C., the time required to reach each reflectance is increased. In the case of a low temperature, the color development progresses slowly, so that a state better than the state of the long-term storage state “good freshness” is maintained.

That is, temperature management is performed while comparing the degree of color development of the temperature indicating member 2 with the density pattern 4, and when the temperature indicating member 2 and the density pattern 4 match or are close to each other, the status is managed while confirming the exposure information 5. can do. Here, the case where the density pattern 4 is of three types has been described. However, if the density pattern 4 is represented by more types, stricter management is possible. When a plurality of temperature indicating members 2 are provided, by providing a blank layer 3 formed of a plurality of transparent inks around the temperature indicating members 2 in the same manner, steps around each of the temperature indicating members 2 can be absorbed, and the thermal head can be used. Initialization becomes possible. Further, by providing a plurality of temperature indicating members 2, more detailed management becomes possible.

A second embodiment of the present invention will be described with reference to FIG. In the above-described case, the blank layer 3 is provided around the entire periphery of the temperature indicating member 2. However, unlike the above, the blank layer 3 is provided before the temperature indicating member 2 to be initialized so as not to be affected by a step when the initialization is performed by the thermal head. This is provided with a blank layer 3 made of transparent ink and having substantially the same thickness as the temperature indicating member 2. Here, an example in which the blank layer 3 is formed of transparent ink has been described, but the present invention is not limited to this, and a colored ink may be used. Although the example of the film thickness is almost the same, it is sufficient that the film thickness is such that it can be properly initialized when the temperature indicating member 2 is initialized by the thermal head. Since there is no step, initialization is performed with uniform energy, so that stable temperature characteristics are exhibited (unless the initialization energy is uniform, the color development speed at high temperature exposure is different).

The temperature indicating member 2 of the above embodiment is not limited. For example, leuco auramines, diaryl phthalides, polyaryl carbinols, acyl auramines, aryl auramines as electron-donating color-forming compounds. Examples include amines, rhodamine B lactams, indolines, spiropyrans, fluorans, cyanine dyes, and electron donating organic substances such as crystal violet.

More specifically, when a red light source is used as the light source, a leuco dye that emits blue, black, or blue-green light can be used.

As <Black>, the following leuco dyes and the like can be used (not limited to these). PSD-15
0, PSD-184, PSD-300, PSD-80
2, PSD-290 (manufactured by Nippon Soda), CP-101, B
LACK-15, ODB (Yamamoto Kasei), ETAC,
ATP, BLACK-100, S-205, BLACK
-305, BLACK-500 (Yamada Chemical Co., Ltd.), TH
-107 (manufactured by Hodogaya Chemical Co., Ltd.) <blue> can use (but is not limited to) the following leuco dyes. CVL, BLMB (Nippon Soda Co., Ltd.), BLUE-
63, BLUE-502 (manufactured by Yamamoto Kasei), BLUE-
220 (manufactured by Yamada Chemical Co., Ltd.) and BLUE-3 (manufactured by Hodogaya Chemical Co., Ltd.) For <blue-green>, the following materials can be used (not limited thereto). GN-169, GN-2, Gr
een-40 (Yamamoto Kasei), Green-300
(Yamada Chemical Co., Ltd.) In addition, red-based or yellow-based dyes may be used, and may be mixed instead of one kind of material.

The electron accepting compound is described as PG in the color developer of the present embodiment, but is not limited to PG, but is not limited to phenols, phenol metal salts, carboxylic acid metal salts, sulfonic acid, sulfonic acid salt, phosphoric acid. Oxides such as acids, metal phosphates, acid phosphates, acid phosphates metal salts, phosphorous acid, metal phosphites and the like can be used. For example, 2,4-dihydroxyacetophenone (2,4-HAP), 2,5-HAP, 2,6-H
AP, 3,5-HAP, 2,3,4-HAP, 2,4-
Dihydroxybenzophenone (2,4-HBP), 4,
4'-HBP, 2,3,4-HBP, 2,4,4'-H
BP, 2,2 ′, 4,4′-HBP, 2,3-dihydrobenzoic acid, methyl 3,5-dihydrobenzoate, 4,4 ′
-Biphenol, 2,3,4,4'-tetrahydroxybenzophenone and the like can be used.

The electron-accepting compound largely depends on the color-forming speed (the time from the separation of the electron-accepting compound from the reversible material to the association with the electron-donating compound to form a color greatly depends on the material). Depending on the selection, the temperature control time can be changed in various ways.

Further, it is possible to change the temperature range in which the temperature is to be controlled by using a reversible material. The glass transition temperature of the three components in the case of using the pregnenolone shown in the present embodiment is 44 ° C., and at this temperature, the coloring speed changes greatly, but the coloring starts even below the glass transition temperature. If a reversible material of another steroid is used, the reaction temperature can be changed. For example, cholesterol, stigmasterol and the like can be used.

By using a plurality of reversible materials or by mixing them, a desired temperature control member can be obtained.

As the binder resin, those having an appropriate glass transition temperature (or softening temperature) in consideration of the color development speed and the measurement temperature range can be used.

Examples of such resins include polyethylenes, chlorinated polyethylenes, ethylene / vinyl acetate copolymers, ethylene / acrylic acid / maleic anhydride copolymers and other ethylene copolymers, polybutadienes, polyethylene terephthalate, Polybutylene terephthalate, polyesters such as polyethylene naphthalate, polypropylenes, polyisobutylenes, polyvinyl chlorides,
Polyvinylidene chlorides, polyvinyl acetates, polyvinyl alcohols, polyvinyl acetal, polyvinyl butyrals, fluororesins, acrylic resins, methacrylic resins, acrylonitrile copolymers, polystyrene, halogenated polystyrene, styrene methacrylic acid Styrene copolymers such as polymers, acetal resins, polyamides such as nylon 66 (trade name), polycarbonates, cellulose resins, phenol resins, urea resins, epoxy resins, polyurethane resins, diaryl Examples include phthalate resins, silicone resins, polyimide amides, polyether sulfones, polymethyl pentenes, polyether imides, polyvinyl carbazoles, and amorphous polyolefins. These resins are used by mixing one or more resins.

In each embodiment, the base material 6 is made of P
ET coated was used, but not limited to this. Further, the base material 6 may be a thermal paper or the like.

In addition, here, a rewritable material of a type in which the density of color changes is used, but the material is not limited to this, and a material that changes color as a function of temperature and time after initialization by heating and quenching can also be used. It is.

In addition, a rewritable color, which has a stable coloring state, is erased by a thermal head at the time of initialization, and develops color as a function of temperature and time, is not limited to this. It goes without saying that a material of a type capable of decoloring may be used.

Although the temperature indicating member 2 and the blank layer 3 are provided by gravure printing, they may be manufactured by a printing method such as screen printing. The temperature management member 1 thus obtained is inexpensive, and the temperature management member 1 that can be uniformly initialized can be obtained reliably.

[0048]

As described above, the present invention relates to a temperature control member partially provided with a temperature indicating member whose color changes in response to temperature, wherein the temperature indicating member is irreversible at an ambient temperature. After being initialized by heating and quenching, the color density of the initialized portion changes according to the temperature and time in the standing atmosphere, and a blank layer of a predetermined thickness is provided around the temperature indicating member. Thus, the step of the temperature indicating member can be reduced, and the initialization by the thermal head can be performed reliably.

Further, although there was a problem that the initializing energy changes due to the vicinity of the thermal head and the color developing speed changes depending on the temperature, since the initialization can be performed uniformly, a stable temperature indicating characteristic is obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a temperature management member according to a first embodiment.

FIG. 2 is a sectional view of a temperature management member.

FIG. 3 is an explanatory view showing the principle of coloring and decoloring of the temperature indicating member.

FIG. 4 is a thermodynamic principle diagram of the temperature indicating member.

FIG. 5 is a graph showing erasing characteristics of a temperature indicating member.

FIG. 6 is a graph showing temperature characteristics of the temperature indicating member.

FIG. 7 is a plan view of a temperature management member according to the second embodiment.

[Explanation of symbols]

 1 temperature control member 2 temperature indicating member 3 blank layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yuichiro Hatanaka 6-78, Minamimachi, Mishima-shi, Shizuoka F-term in Toshiba Tec Corporation Technical Research Institute 2F056 VA01 VA02 VA05 VA10 2G066 BA60 BB11 CA20 2H026 AA07 AA09 AA28 BB01 DD56 2H111 HA12 HA18 HA34

Claims (2)

[Claims] 1. A temperature control member partially provided with a temperature indicating member that changes color in response to temperature, wherein said temperature indicating member is irreversible at an ambient temperature, and after being initialized by heating and rapid cooling. A temperature control member wherein a color density of an initialized portion changes according to a temperature and a time in a leaving atmosphere, and a blank layer having a predetermined thickness is provided around the temperature indicating member. 2. The temperature control member according to claim 1, wherein the temperature indicating member is initialized by a thermal head.