JP7317628B2 - Composition for cold storage material, cold storage material, and method for producing cold storage material - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a cold storage material and a manufacturing method thereof.

2. Description of the Related Art Conventionally, as a cold storage material, there has been known a cold storage material that is used by freezing a cold storage liquid contained in a container such as a container (see, for example, Patent Document 1).

JP 2006-97984 A (paragraph [0021])

In contrast to conventional cold storage materials, it is desired to make it easier to visually recognize whether or not the cold storage liquid is frozen.

A first aspect of the invention , which has been made to solve the above problems, is a container or bag in which the inside can be viewed, and a cold storage that is stored in the container and becomes a transparent liquid at room temperature and decreases in transparency when frozen. a liquid; and a gel body contained in the container, colored with a pigment in a color different from that of the container and the cold storage liquid at room temperature, and visible through the container and the cold storage liquid at room temperature. , is a cold storage material.

A second aspect of the invention is the cold storage material according to the first aspect , wherein the cold storage liquid is colored transparently with a dye.

A third aspect of the invention is the cold storage material according to the second aspect , wherein the color of the cold storage liquid and the color of the gel body are in a substantially complementary color relationship.

A fourth aspect of the invention is according to any one of the first to third aspects, wherein the gel body occupies 10 to 90% by volume of the entirety of the gel body and the cold storage liquid. It is a cold storage material.

A fifth aspect of the invention is the cold storage material according to any one of the first to fourth aspects , wherein the concentration of the pigment in the gel body is higher than the concentration of the pigment in the cold storage liquid. be.

A sixth aspect of the invention is the cold storage material according to any one of the first to fifth aspects, wherein the gel body is formed by cross-linking carboxymethyl cellulose.

In a seventh aspect of the invention , the cold storage liquid and the gel are made by adding the pigment, carboxymethyl cellulose, and a cross-linking agent to water, and the pigment is added in an amount of 0.0005 to 0.0005 to 100 parts by weight of the water. The cold storage material according to the sixth aspect , to which 0.01 part by weight is added.

An eighth aspect of the invention is the cold storage material according to the seventh aspect , wherein 0.5 to 1.5 parts by weight of the carboxymethyl cellulose is added to 100 parts by weight of the water.

A ninth aspect of the invention is the cold storage material according to the seventh aspect or the eighth aspect , wherein the cross-linking agent is potassium alum.

A tenth aspect of the invention is the cold storage material according to the ninth aspect , wherein the potash alum is added in an amount of 0.2 to 2 times the weight of the carboxymethyl cellulose.

In an eleventh aspect of the invention , a container or bag having a visible interior is prepared, a mixed solution is prepared by adding a pigment, carboxymethyl cellulose, and potassium alum to a transparent solvent, and the mixed solution is added to the container. to form a cold storage liquid that becomes a transparent liquid at room temperature and whose transparency decreases when frozen, and a gel body that is visible through the storage body and the cold storage liquid at room temperature, and as the pigment , the gel body is colored in a color different from that of the container and the cold storage liquid at room temperature, and in preparing the mixed liquid, the carboxymethyl cellulose is mixed with the solvent and then the potassium alum is added. Alternatively, a method for producing a cold storage material, wherein carboxymethyl cellulose and the potassium alum are added to the solvent at the same time.

A twelfth aspect of the invention is the method for producing a cold storage material according to the eleventh aspect , wherein the potash alum is added to the mixed liquid in an amount of 0.2 to 2 times the weight of the carboxymethyl cellulose.

A thirteenth aspect of the invention is the method for producing a cold storage material according to the eleventh aspect or the twelfth aspect , wherein the solvent is colored transparently with a dye when preparing the mixed solution.

A fourteenth aspect of the invention is any one of the eleventh to thirteenth aspects, wherein 0.5 to 1.5 parts by weight of the carboxymethyl cellulose is added to 100 parts by weight of water as the solvent. 3. A method for producing a cold storage material according to .

In the cold storage material of the first aspect of the invention and the cold storage material manufactured by the manufacturing method of the eleventh aspect of the invention , at room temperature, that is, when the cold storage liquid is not frozen, the container and the cold storage liquid have a different color. Since the gel body can be visually recognized, it becomes easier to visually confirm that the cold storage liquid is not frozen, as compared with the conventional structure in which only the cold storage liquid is stored in the container. In addition, when the cold storage liquid is frozen, the transparency of the cold storage liquid is lowered, so that the gel body becomes more difficult to see than at room temperature. That is, in addition to the decrease in the transparency of the cold storage liquid, the gel becomes difficult to visually recognize, so that freezing of the cold storage liquid becomes easier to visually recognize than in the conventional case. As described above, according to this aspect , it is possible to easily visually recognize whether or not the cold storage liquid is frozen.

Also, in the eleventh aspect of the invention , potassium alum is added after the carboxymethyl cellulose is mixed with the solvent. Thereby, it becomes possible to separate and form the lump-like gel body from the cold storage liquid in the container.

In the second aspect and the thirteenth aspect of the invention , by coloring the cold storage liquid, it becomes possible to make it more difficult to visually recognize the gel body when the cold storage liquid is frozen, making it easier to recognize that the cold storage liquid is frozen. can.

In the third aspect of the invention , since the color of the cold storage liquid and the color of the gel body are in a substantially complementary color relationship, it is possible to make the gel body more conspicuous at room temperature.

In the fourth aspect of the invention , since the gel body occupies 10% by volume or more of the entire gel body and cold storage liquid, the gel body can be easily noticeable at room temperature. In addition, since the gel body is 90% by volume or less of the entire gel body and cold storage liquid, the cold storage effect of the frozen cold storage liquid can be improved, and when the cold storage liquid is frozen, the gel body can be used. can be made more difficult to see.

In the fifth aspect of the invention , since the concentration of the pigment in the gel body is higher than the concentration of the pigment in the cold storage liquid, it is possible to make the color of the gel body more conspicuous at room temperature.

The gel body may be formed by cross-linking carboxymethyl cellulose ( sixth aspect of the invention ). In this case, the cold storage liquid and the gel are preferably made by adding a pigment, carboxymethyl cellulose and a cross-linking agent to water. More preferably, it is added in parts by weight ( seventh aspect of the invention ). By using 0.0005 parts by weight or more of the pigment, the gel can be made more noticeable at room temperature. Also, by setting the pigment to 0.01 parts by weight or less, it is possible to suppress the precipitation of the pigment in the cold storage liquid.

In the eighth aspect and the fourteenth aspect of the invention , 0.5 to 1.5 parts by weight of carboxymethyl cellulose is added to 100 parts by weight of water, so that the gel separated from the cold storage liquid can be easily formed. can be done.

In the ninth aspect of the invention , since the cross-linking agent is potassium alum, it is possible to facilitate the cross-linking of carboxymethyl cellulose.

In the 10th and 12th aspects of the invention , potassium alum is added in an amount of 0.2 to 2 times the weight of carboxymethyl cellulose, which facilitates the formation of a massive gel.

(A) Perspective view of cold storage material, (B) Plan view of cold storage material according to the first embodiment of the present disclosure Enlarged cross-sectional view of cold storage material (A) Conceptual diagram showing dispersed state of pigment and dye in mixed liquid, (B) Conceptual diagram showing arrangement of pigment and dye when gel is formed in container (A) Perspective view of cold storage material, (B) Plan view of cold storage material according to the second embodiment Enlarged sectional side view of a cold storage material according to the second embodiment Table showing each experimental example in the confirmation experiment

[First Embodiment]
As shown in FIGS. 1 and 2, the cold storage material 10 of the first embodiment contains a cold storage liquid 20 in a container 11 whose interior is visible. The container 11 has thermal conductivity, and the cold storage material 10 is used by freezing the cold storage liquid 20 . The container 11 may be colorless and transparent, or may be colored and transparent, and is made of resin, for example. The container 11 is flat and rectangular in plan view, and has a filling port for the cool storage liquid 20 on one short side, and the filling port is closed with a cap 12 .

The cold storage liquid 20 is a transparent liquid at room temperature. The cold storage liquid 20 becomes less transparent when frozen. In this embodiment, the cold storage liquid 20 is colored transparently with a dye 41 (see FIG. 3). In this embodiment, the solvent of the cold storage liquid 20 is water, and the dye 41 is dissolved in the water.

As shown in FIG. 1B, in the cold storage material 10 of the present embodiment, the gel body 30 floats in the cold storage liquid 20 inside the container 11 . The gel body 30 preferably occupies 10 to 90% by volume, more preferably 30 to 70% by volume, of the gel body 30 and the cooling liquid 20 as a whole.

The gel body 30 is colored in a color different from that of the container 11 and the cold storage liquid 20 at room temperature, and is visible through the container 11 and the cold storage liquid 20 at room temperature. In this embodiment, the color of the gel body 30 is substantially complementary to the color of the cold storage liquid 20 . For example, the color of the gel body 30 is a yellowish color, and the cold storage liquid 20 is a blueish color. In the present disclosure, “transparent” with respect to the container 11 and the cold storage liquid 20 means that the gel body 30 has at least transparency that allows the gel body 30 to be visually recognized through the container 11 and the cold storage liquid 20 at room temperature. Yes, including being translucent.

The gel body 30 is colored with a pigment 42 (see FIG. 3). Pigment 42 is dispersed within gel body 30 . In the cold storage material 10 , the concentration of the pigment 42 in the gel body 30 (the weight of the pigment 42 per unit volume) is higher than the concentration of the pigment 42 in the cold storage liquid 20 . In this embodiment, the pigment 42 in the container 11 is unevenly distributed in the gel body 30 and the dye 41 in the container 11 is unevenly distributed in the cold storage liquid 20 .

The gel body 30 is preferably made by cross-linking a gelling agent such as carboxymethylcellulose (CMC). Examples of gelling agents that can be used include agar, gelatin, thickening polysaccharides, polyacrylic acid derivatives, and the like. Examples of thickening polysaccharides include locust bean gum, dulan gum, carrageenan, xanthan gum, carboxymethylcellulose and the like. Examples of polyacrylic acid derivatives include sodium polyacrylate, sodium polymethacrylate, polyvinyl alcohol, polyacrylamide derivatives (2-acrylamide-2-2-methylpropylsulfonic acid, dimethylaminopropylacrylamide, isopropylacrylamide, hydroxyethylacrylamide or dimethyl Acrylamide) and the like can be used singly or in combination.

In this embodiment, the gel body 30 is formed by adding carboxymethyl cellulose as a gelling agent, a cross-linking agent for cross-linking the gelling agent, and a pigment 42 to water as a solvent. In this embodiment, potassium alum is used as the cross-linking agent.

As the cross-linking agent, for example, a polyvalent metal salt can be used. As the polyvalent metal salt, a divalent or trivalent one is used, and potassium alum, aluminum sulfate, aluminum acetate, aluminum hydroxide, ferrous sulfate, ferrous chloride, zinc sulfate, barium chloride, chromium nitrate, Examples include lead acetate, cupric chloride, tin chloride, and silver nitrate. Among these, potassium alum is preferable from the viewpoint of ease of cross-linking of carboxymethyl cellulose. Moreover, ion-exchanged water is preferable as the solvent for the cold storage liquid 20 .

Examples of the pigment 42 include phthalocyanine, azo, perylene, perinone, anthraquinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethineazo, diketopyrrolopyrrole, Examples include, but are not limited to, organic pigments such as isoindoline-based pigments. More specifically, examples of the pigment 42 include phthalocyanine blue, phthalocyanine green, disazo yellow, perylene red, perinone orange, quinacridone magenta, quinacridone red, thioindigo magenta, thioindigo bordeaux, dioxazine violet, and isoindolinone yellow. , Carmine 6B, Lake Red C, Permanent Red 2B, Pyrazolone Orange, Carmine FB, Chromophtal Yellow, Chromophtal Red, Indanthrone Blue, Pyrimidine Yellow, Aniline Black, Diketopyrrolopyrrole Red, Brilliant First Scarlet, etc. can be done. The above pigments may be used singly or in combination of two or more.

As the dye 41, for example, Blue No. 1, Blue No. 2, Blue No. 202, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Yellow No. 402, Red No. 2, Red No. 3, Red No. 102, Red No. 104, Red No. 105, Red No. 106, Red No. 227, Red No. 502, Orange No. 205, Orange No. 207, Green No. 3, Green No. 204, Green No. 205, Purple No. 401, Black No. 401 , Brown No. 201, and basic dyes such as Basic Blue 99, Basic Yellow 57, Basic Red 76, Basic Brown 16, Basic Brown 17, and the like. The above dyes can be used singly or in combination of two or more.

Note that the cold storage liquid 20 may be a solvent in which an inorganic salt is further dissolved. In this case, by dissolving the inorganic salt, the freezing point of the cold storage liquid 20 can be lowered, and the cold storage effect can be enhanced. In addition, when a large amount of inorganic salt is added, when the cold storage liquid 20 freezes, the cold storage liquid 20 can be easily made cloudy, and the transparency can be easily lowered. Examples of inorganic salts include sodium chloride, potassium chloride, calcium chloride, ammonium chloride, sodium sulfate, potassium sulfate, magnesium sulfate, aluminum sulfate, potassium nitrate, calcium nitrate and the like.

The cold storage material 10 of this embodiment is manufactured, for example, as follows. First, the container 11 is prepared. Also, a mixture 43 (see FIG. 3A) is prepared in which the pigment 42, carboxyalkyl cellulose, and cross-linking agent are mixed in a transparent solvent. The dye 11 is also mixed in the mixed liquid 43 . In this embodiment, water is used as the solvent, and potassium alum is used as the cross-linking agent. As the pigment 42, an organic pigment is used that colors the gel body 30 in a color different from that of the container 11 and the cold storage liquid 20 at room temperature (that is, the color of the dye 41). In FIG. 3A, the dye 41 is represented by small dots, and the pigment 42 is represented by large dots.

The pigment 42 is preferably added in an amount of 0.0005 parts by weight or more and 0.01 parts by weight or less with respect to 100 parts by weight of water. Moreover, it is preferable that 0.5 parts by weight or more and 1.5 parts by weight or less of carboxymethyl cellulose be added to 100 parts by weight of water. Potassium alum is preferably added in an amount of 0.2 to 2 times the weight of carboxymethyl cellulose.

Here, in preparing the mixed liquid 43, potassium alum as a cross-linking agent is added after the carboxymethyl cellulose and the pigment 42 are mixed with the solvent. The mixture 43 obtained in this manner is enclosed in the container 11 (see FIG. 3A).

Then, as shown in the change from FIG. 3(A) to FIG. 3(B), the cold storage liquid 20 and the gel body 30 are formed from the mixed liquid 43 in the container 11 with the lapse of time. To separate.

Here, in preparing the mixed liquid 43, if the order of addition is reversed from that of the present embodiment, and after the potassium alum is mixed with the solvent, the carboxymethyl cellulose is added, the mass gel body 30 separated from the cold storage liquid 20 is formed. The cold storage liquid 20 is simply thickened as a whole without being formed. On the other hand, in the present embodiment, as described above, potassium alum is added after mixing carboxymethyl cellulose with the solvent, so that the bulky gel body 30 separated from the cold storage liquid 20 is formed in the container 11 . becomes possible. Moreover, by using potassium alum as a cross-linking agent, it becomes possible to facilitate cross-linking of carboxymethyl cellulose. Furthermore, by adding 0.5 parts by weight or more of carboxymethylcellulose to 100 parts by weight of water, the gel can be formed more easily. In addition, by using 1.5 parts by weight or less of carboxymethyl cellulose with respect to 100 parts by weight of water, the gel body 30 is not dispersed throughout the cold storage liquid 20, but is formed in a mass separated from the cold storage liquid 20. can be made easier. Furthermore, by adding potassium alum in an amount of 0.2 to 2 times the weight of carboxymethyl cellulose, it is possible to facilitate the formation of the massive gel body 30 . Even if the amount of potassium alum exceeds the above range, it is possible to form the massive gel body 30, but since the amount of potassium alum becomes excessive, it is preferably within the above range.

Here, as shown in the change from FIG. 3A to FIG. can be separated from the cold storage liquid 20 . On the other hand, the dye 41 is dissolved in water, and even if the gel body 30 is formed, it remains uniform in the cold storage liquid 20 and can be separated from the gel body 30 . That is, even if the colors of the pigment 42 and the dye 41 are mixed immediately after the mixed liquid 43 is obtained, when the gel body 30 and the cooling liquid 20 are formed with the lapse of time, the pigment 42 and the dye 41 are mixed. The dye 41 can be separated into the gel body 30 and the cold storage liquid 20 respectively. Then, the gel body 30 is colored with the pigment 42 and the cold storage liquid 20 is colored with the color of the dye 41 . For example, when the pigment 42 is yellow and the dye 41 is blue, the green mixed liquid 43 gradually separates into the yellow gel body 30 and the blue cold storage liquid 20 . Such a phenomenon can be considered to occur because the pigment 42 is hydrophobic and has a low affinity with water (that is, the cold storage liquid 20), so that the pigment 42 tends to exist in the gel body 30 relatively easily. In addition, since the pigment 42 is hydrophobic as described above, it easily precipitates in the cold storage liquid 20 using water as a solvent. By being done, it becomes difficult to settle. By dispersing the pigment 42 well in the mixed liquid 43 , the pigment 42 can be easily dispersed in the gel body 30 . The separation of the pigment 42 and the dye 41 into the gel body 30 and the cold storage liquid 20 is also confirmed by [confirmation experiment] described later.

In the cold storage material 10 of the present embodiment, when the room temperature is normal, that is, when the cold storage liquid 20 is not frozen, the storage body 11 and the gel body 30 having a color different from that of the cold storage liquid 20 are visible. It becomes easier to visually confirm that the cold storage liquid 20 is not frozen, as compared with the conventional configuration in which only the cold storage liquid 20 is stored in the container. In addition, when the cold storage liquid 20 freezes, the transparency of the cold storage liquid 20 is lowered, so that the gel body 30 becomes more difficult to see than at room temperature. That is, in addition to the decrease in the transparency of the cold storage liquid 20, the gel body 30 becomes difficult to visually recognize, so that freezing of the cold storage liquid 20 becomes easier to visually recognize than in the conventional case. As described above, according to the cold storage material 10, it is possible to easily visually recognize whether or not the cold storage liquid 20 is frozen. In addition, in the conventional cold storage material, if the cold storage liquid is transparent at room temperature, the cold storage liquid may appear frozen depending on the color of the background of the cold storage material. Even in such a case, provision of the gel body 30 makes it easier to visually confirm whether or not the cold storage liquid 20 is frozen.

In this embodiment, by coloring the cold storage liquid 20, it becomes possible to make the gel body 30 more difficult to see when the cold storage liquid 20 is frozen, and it is possible to make it easier to recognize that the cold storage liquid 20 is frozen. In addition, since the color of the cold storage liquid 20 and the color of the gel body 30 are in a substantially complementary color relationship, it is possible to make the gel body 30 more conspicuous at room temperature. In the present embodiment, the gel body 30 is colored with the pigment 42, and the concentration of the pigment 42 in the gel body 30 (the weight of the pigment 42 per unit volume) is higher than the concentration of the pigment 42 in the cold storage liquid 20. ing. This makes it possible to make the color of the gel body 30 more conspicuous at room temperature.

As in the present embodiment, the cold storage liquid 20 and the gel body 30 are preferably made by adding the pigment 42, carboxymethyl cellulose and the cross-linking agent to water. On the other hand, it is more preferable that 0.0005 to 0.01 parts by weight of pigment 42 is added. By setting the pigment 42 to 0.0005 parts by weight or more, the gel body 30 can be easily conspicuous at room temperature. Also, by setting the content of the pigment 42 to 0.01 part by weight or less, precipitation of the pigment 42 in the cold storage liquid 20 can be suppressed.

In the present embodiment, the gel body 30 occupies 10% by volume or more (preferably 30% by volume or more) of the gel body 30 and the cold storage liquid 20 as a whole. can be made more noticeable. In addition, since the gel body 30 is 90% by volume or less (more preferably 70% by volume or less) with respect to the entirety of the gel body 30 and the cold storage liquid 20, the cold storage effect of the frozen cold storage liquid 20 can be obtained. In addition, when the cold storage liquid 20 is frozen, the gel body 30 can be made more difficult to see.

[Second embodiment]
FIGS. 4(A) and 4(B) show the cold storage material 10V of the second embodiment. The cold storage material 10V of the present embodiment is obtained by changing the shape of the container 11 from the cold storage material 10 of the first embodiment.

As shown in FIGS. 4A and 5, in the present embodiment, the container 11V is flat and rectangular in plan view, like the container 11 of the first embodiment. More specifically, the container 11V is provided with a pair of opposing walls 14, 14 that face each other across the inner region that accommodates the cold storage liquid 20 and the gel body 30 in the thickness direction of the container 11V. , the opposing wall portions 14, 14 are connected to each other and penetrates the inner region of the container 11V. In this embodiment, since the ribs 13 are provided, even when the cool storage liquid 20 expands, the container 11V can be prevented from expanding such that the opposing walls 14, 14 move away from each other, and the container 11V bursts. is suppressed.

In this embodiment, the rib 13 has a constricted shape and tapers toward the center in the thickness direction of the container 11 (more specifically, it tapers). Thereby, an annular concave portion 13U is formed on the outer peripheral surface of the rib 13. As shown in FIG. More specifically, in this embodiment, the rib 13 has a structure in which the bottom portions of a pair of cup portions 15C are butted against each other, and each cup portion 15C opens to the outside of the opposing wall portion 14. As shown in FIG. The housing body 11 is formed by joining together rectangular dish-shaped plate portions 15 each having an opposing wall portion 14 and a cup portion 15C. there is In addition, in this embodiment, a plurality of ribs 13 (for example, a plurality of ribs in the long side direction of the container 11) are provided.

Here, in the present embodiment, the gel body 30V is annular and formed so as to surround the rib 13 . Furthermore, the inner peripheral portion of the gel body 30V is received in the annular concave portion 13U of the outer peripheral surface of the rib 13 (see FIG. 5). In this case, it is preferable that the inner peripheral portion of the gel 30V is received in the annular concave portion 13U over the entire circumferential direction.

In the present embodiment, in the same manner as in the first embodiment, a mixed liquid 43 is prepared and sealed in the container 11V when manufacturing the cold storage material 10V. Then, in the same manner as in the first embodiment, the cold storage liquid 20 and the gel body 30V are formed from the mixed liquid 43 over time (see FIGS. 4(B) and 5). At this time, in the containing body 11V of the present embodiment having the ribs 13, it is possible to form the gel body 30V in an annular shape surrounding the ribs 13 within the containing body 11V. In addition, in the present embodiment, the rib 13 has a constricted shape that tapers toward the center in the thickness direction of the container 11V. It becomes possible to receive the inner peripheral portion of the body 30V in the constricted portion of the rib 13 .

According to the cold storage material 10V of this embodiment, it is possible to obtain the same effects as those of the first embodiment. Further, in the present embodiment, the gel body 30V is formed in an annular shape so as to surround the rib 13 . Therefore, the ribs 13 can restrict the movement of the gel body 30B inside the container 11V. This makes it difficult to change the position of the gel body 30V and facilitates visual recognition of the gel body 30V at room temperature. Moreover, the ribs 13 can serve both to reinforce the container 11V and to restrict the movement of the gel body 30V, so that the ribs 13 can be used effectively. In addition, in the present embodiment, since the inner peripheral portion of the gel body 30V is received in the annular concave portion 13U of the rib 13, the gel body 30V can be easily fixed to the central side in the thickness direction of the container 11V. The body 30V can be facilitated to be spaced apart from each opposing wall portion 14 . As a result, the gel body 30V can be easily hidden by the cold storage liquid 20 when the cold storage liquid 20 is frozen.

This embodiment includes the following features 1 to 3.

[Feature 1]
a containing body formed of a container, the inside of which can be visually recognized;
a cold storage liquid that is contained in the container, becomes a transparent liquid at room temperature, and decreases in transparency when frozen;
a gel body contained in the container, colored with a pigment in a color different from that of the container and the cold storage liquid at room temperature, and visible through the container and the cold storage liquid at room temperature. A cold storage material,
A cold storage material, wherein the containing body is provided with a movement restricting portion that regulates the movement of the gel body within the containing body.

[Feature 2]
A communication portion (rib 13) that connects opposing wall portions of the container that face each other and penetrates the internal region of the container,
The gel body has an annular shape and is arranged to surround the connecting portion,
The cold storage material according to feature 1, wherein the movement restricting portion is configured by the connecting portion.

[Feature 3]
The cold storage material according to feature 2, wherein the connecting portion is provided with a constricted portion, and an annular recess for receiving the inner peripheral portion of the gel body is formed on the outer peripheral surface of the constricted portion.

In the cold storage materials of the features 1 to 3, the gel body is restricted from moving in the storage body by the housing body, so that the position of the gel body is difficult to change, and the gel body can be easily visually recognized at room temperature. In the cold storage material of feature 2, the communication portion can serve both to reinforce the containing body and to regulate the movement of the gel body. In the cold storage material of feature 3, since the inner peripheral portion of the gel body is received in the annular concave portion of the connecting portion, the movement range of the gel body in the facing direction of the opposing wall portion can be restricted, and the gel body can be placed in each of the opposing walls. It can be made easier to dispose away from the wall. This makes it easier to hide the gel body when the cold storage liquid freezes.

[Confirmation experiment]
By the following confirmation experiments, the visibility of the presence or absence of freezing of the cold storage liquid 20 was confirmed for the cold storage material 10 and the like including the cold storage liquid 20 and the gel body 30 as in the first embodiment and the second embodiment.

1. Configuration of cold storage material <Experimental examples 1 to 7>
In Experimental Examples 1 to 7, a mixed liquid obtained by mixing the blended raw materials shown in FIG. 6 in the same manner as in the manufacturing method of the above embodiment was sealed in a container to obtain a cold storage material. The details of the raw material composition of the liquid mixture sealed in the containers in Experimental Examples 1 to 7 are shown in FIG. 6 and as follows. Numerical values in the table of FIG. 1 represent parts by weight of each raw material component. In the experimental examples in which carboxymethylcellulose and potassium alum were added, the latter was added after the former. In order to facilitate dispersion, the pigment was diluted 10 times with water and alcohol (ethanol) and dispersed in advance before being added (Experimental Examples 1 to 4).

Solvent; water inorganic salt; (1) sodium chloride, (2) ammonium chloride pigment; (1) cyanine blue: trade name “FASTOGEN (registered trademark) BLUE FA5380” manufactured by DIC Corporation; Company product name “SYMULER (registered trademark) FAST YELLOW 4340”
Gelling agent; Carboxymethyl cellulose (CMC): trade name "F350HC-4" manufactured by Nippon Paper Industries Co., Ltd.
Cross-linking agent; potassium alum: trade name "potash alum" manufactured by Taimei Chemical Industry Co., Ltd.
Dyes; (1) Blue No. 1: Daiwa Kasei Co., Ltd. trade name "Blue No. 1", (2) Blue No. 2: Daiwa Kasei Co., Ltd. trade name "Blue No. 2", (3) Yellow No. 4 : Product name “Yellow No. 4” manufactured by Daiwa Kasei Co., Ltd.

The container is a substantially rectangular parallelepiped container, and the size of the area occupied by the liquid mixture contained in the container is 150 mm×200 mm×20 mm.

2. Evaluation method <Color before freezing>
The color of the cold storage liquid was visually confirmed through the container at room temperature after the mixture was stored in the container and left at room temperature for 3 days.

<Decrease in color and transparency after freezing>
After confirming the color of the cold storage liquid before freezing, the cold storage material was put into the freezer, and the cold storage liquid was frozen at -30°C. After that, immediately after taking out the cold storage material from the freezer, the color of the cold storage liquid was visually confirmed through the container 11 . When deterioration of the transparency of the cold storage liquid due to freezing (for example, cloudiness) was observed, it was evaluated as "○", and when deterioration of the transparency of the cold storage liquid was not observed, it was evaluated as "X".

<Presence or absence of gel body, change in visibility of gel body>
When checking the color of the pre-frozen cold storage liquid, the presence or absence of the gel and the color of the gel were visually checked. In addition, the change in visibility of the gel before and after freezing the cold storage liquid was evaluated. If there is a clear change in the visibility of the gel before and after freezing the cold storage liquid (when it is clearly seen that it has become difficult to see, etc.), "○" is given, and no change is observed or almost no change is observed. If it is not possible, it is indicated as “x”. In other words, an experimental example in which no gel was originally present was evaluated as "x".

<Pigment Precipitation>
Precipitation of the pigment was visually confirmed when checking the color before freezing. When no pigment sedimentation was observed, it was evaluated as "good", and when pigment precipitation was observed, it was evaluated as "poor".

<Weather resistance evaluation>
Using a fade meter (JIS B7751 compliant), a test was conducted at 63° C. for 48 hours, and the change in color before and after the test was visually confirmed. When no change in color was observed, it was evaluated as "good", and when change in color (fading) was observed, it was evaluated as "poor".

3. Evaluation Results As shown in FIG. 6, in Experimental Examples 1, 3, 5, and 6 in which carboxymethylcellulose and potassium alum were added, it was confirmed that massive gel bodies were formed before freezing. In addition, from the results of Experimental Examples 1 and 3 containing pigment, it was confirmed that the pigment was retained in the gel body and separated from the cold storage liquid. Furthermore, from the results of Experimental Examples 5 and 6, it was confirmed that the dye hardly entered the gel body and remained in the cold storage liquid. Furthermore, from the results of Experimental Example 3, it was confirmed that when a liquid mixture of pigment and dye was sealed in the container, the pigment and dye were separated into a gel body and a cold storage liquid, respectively. Specifically, in Experimental Example 3, in which a yellow pigment and a blue dye were used, the mixture was green immediately after the pigment and dye were mixed, but the mixture changed color over time. , it was confirmed that the gel was separated into a yellow gel body holding the pigment and a blue cold storage liquid in which the dye was dissolved. Further, from the results of Experimental Example 2, it was confirmed that even if carboxymethyl cellulose was contained, no gel was formed when potassium alum was not contained.

In Experimental Examples 1 and 3, a gel colored with a pigment in a color different from that of the cold storage liquid was formed in the cold storage liquid at room temperature, and the gel was easily visible through the container and the transparent cold storage liquid at room temperature. there were. Moreover, in Experimental Examples 1 and 3, the cloudiness (decrease in transparency) of the cold storage liquid due to freezing was also sufficient. Therefore, in Experimental Examples 1 and 3, it was easier to visually confirm whether or not the cold storage liquid was frozen, as compared with the other Experimental Examples. In Experimental Examples 5 and 6, although the cold storage liquid was transparent at room temperature, the visibility of the gel body was poor.

From a comparison of Experimental Examples 1 to 4 and Experimental Examples 5 to 7, it was confirmed that the weather resistance evaluation was "○" when the pigment was included, and "X" when the pigment was not included. rice field. In addition, from the results of Experimental Example 4, the composition that did not contain carboxymethyl cellulose and potassium alum resulted in the result of "x" due to precipitation of the pigment.

From the above results, it was confirmed that Experimental Examples 1 and 3, in which the pigment, carboxymethylcellulose, and potassium alum were added, were good in all evaluated items. Note that Experimental Examples 1 and 3 correspond to "Examples", and Experimental Examples 2, 4 to 7 correspond to "Comparative Examples".

[Other embodiments]
(1) In the above embodiment, the cold storage liquid 20 is colored, but it may be colorless.

(2) In the above embodiment, when preparing the mixture 43, potassium alum is added after mixing carboxymethyl cellulose with the solvent, but carboxymethyl cellulose and potassium alum may be added simultaneously with the solvent. Even in this case, it is possible to separate the bulky gel body 30 from the cold storage liquid 20 in the container 11 .

(3) In the manufacturing method of the cold storage material 10 of the above-described embodiment, the gel body 30 is formed inside the housing body 11 , but the gel body 30 may be formed and then housed in the housing body 11 .

(4) In the above embodiment, the container 11 was a container, but the container 11 may be a bag.

REFERENCE SIGNS LIST 10, 10V cold storage material 11, 11V container 12 cap 13 rib 14 opposing wall portion 20 cold storage liquid 30, 30V gel body 41 dye 42 pigment 43 mixed liquid

Claims (17)

a container or a bag, the inside of which can be viewed;
a cold storage liquid that is contained in the container, becomes a transparent liquid at room temperature, and decreases in transparency when frozen;
a gel body contained in the container, colored with a pigment in a color different from that of the container and the cold storage liquid at room temperature, and visible through the container and the cold storage liquid at room temperature. Cold storage material. 2. The cold storage material according to claim 1, wherein said cold storage liquid is colored transparently with a dye. 3. The cold storage material according to claim 2, wherein the color of said cold storage liquid and the color of said gel are substantially complementary. The cold storage material according to any one of claims 1 to 3, wherein said gel body occupies 10 to 90% by volume of said gel body and said cold storage liquid as a whole. The cold storage material according to any one of claims 1 to 4, wherein the concentration of the pigment in the gel body is higher than the concentration of the pigment in the cold storage liquid. The cold storage material according to any one of claims 1 to 5, wherein said gel body is formed by cross-linking carboxymethyl cellulose. The cold storage liquid and the gel are made by adding the pigment, carboxymethyl cellulose and a cross-linking agent to water,
7. The cold storage material according to claim 6, wherein 0.0005 to 0.01 parts by weight of said pigment is added to 100 parts by weight of said water. 8. The cold storage material according to claim 7, wherein 0.5 to 1.5 parts by weight of said carboxymethyl cellulose is added to 100 parts by weight of said water. The cold storage material according to claim 7 or 8, wherein the cross-linking agent is potassium alum. 10. The cold storage material according to claim 9, wherein said potassium alum is added in an amount of 0.2 to 2 times the weight of said carboxymethyl cellulose. Prepare a containing body consisting of a container or a bag whose inside can be seen,
Prepare a mixture of pigment, carboxymethyl cellulose and potash alum in a clear solvent,
a cold accumulating liquid containing the mixed liquid in the container, which becomes a transparent liquid at room temperature and whose transparency decreases when frozen, and a gel body that is visible through the containing body and the cold accumulating liquid at room temperature; to form
As the pigment, a pigment that colors the gel body in a color different from that of the container and the cold storage liquid at normal temperature is used,
A method for producing a cold storage material, wherein in preparing the mixed solution, the potassium alum is added after the carboxymethyl cellulose is mixed with the solvent, or the carboxymethyl cellulose and the potassium alum are added simultaneously to the solvent. 12. The method for producing a cold storage material according to claim 11, wherein the potassium alum is added to the mixed liquid in an amount of 0.2 to 2 times the weight of the carboxymethyl cellulose. 13. The method for producing a cold storage material according to claim 11, wherein the solvent is colored transparently with a dye when preparing the mixed liquid. 14. The method for producing a cold storage material according to any one of claims 11 to 13, wherein 0.5 to 1.5 parts by weight of the carboxymethyl cellulose is added to 100 parts by weight of water as the solvent. Cold storage liquid that is transparent at room temperature and becomes less transparent when frozen,
A composition for a cold storage material, comprising: a gel body that is colored with a pigment in a color different from that of the cold storage liquid at room temperature and that is visible through the cold storage liquid at room temperature. 16. The composition for a cold storage material according to claim 15, wherein the cold storage liquid is colored transparently with a dye. 17. The composition for cold storage material according to claim 15 or 16, wherein the color of the cold storage liquid and the color of the gel body are substantially complementary.

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