Cold storage material composition and its use

Abstract

The present invention addresses the problem of providing: a cold storage medium composition that is capable of maintaining, for a long period, a constant temperature of a temperature-control-target article in various control temperature regions in the range of -75.0 to -66.0°C and that exhibits excellent handleability; and a technology for using the same. The above problem is solved with a cold storage medium composition that contains lithium ions and bromide ions in specific amounts with respect to 100 moles of water and that has a melting temperature in the range of -75.0 to -66.0°C.

Description

Technical Field

[0001] The present invention relates to a cold storage material composition for performing temperature management of articles and a utilization technology thereof, and more specifically, relates to a cold storage material composition, a cold storage material provided with the cold storage material composition, a transport container provided with the cold storage material, a method for producing the cold storage material composition, and a method for using the cold storage material composition.

Background Art

[0002] Conventionally, various heat storage material compositions or cold storage material compositions utilizing latent heat are known, and these heat storage material compositions or cold storage material compositions are used in various fields such as air conditioning systems or storage and transportation of articles.

[0003] For example, some of pharmaceuticals and specimens handled in medical institutions such as hospitals, as well as foods handled in supermarkets and the like, need to be kept warm within a predetermined temperature range for a predetermined time during transportation or storage in order to maintain their quality.

[0004] Conventionally, as a method for transporting or storing articles such as pharmaceuticals, medical devices, cells, specimens, organs, chemical substances or foods in a kept warm state, the following method can be mentioned. That is, a pre-frozen and solidified cold storage material is arranged in a heat-insulating container to form a heat-retaining container, and the latent heat of fusion of the cold storage material is utilized to maintain the temperature of the article accommodated in the heat-retaining container for transportation or storage. In order to maintain the aforementioned article to be kept warm (hereinafter sometimes referred to as "temperature management target article") within a predetermined temperature (hereinafter sometimes referred to as "management temperature") range for a long time, it is considered preferable to use a cold storage material having a melting temperature within the predetermined temperature range.

[0005] Some temperature-controlled items require transport at controlled temperatures such as -30°C or below, preferably -50°C or below, and even more preferably -66°C or below. Conventionally, dry ice has been used as a cold storage material to meet these controlled temperatures. However, although dry ice is inexpensive and versatile, it undergoes volume expansion due to sublimation (phase transition from solid to gas), and is treated as a hazardous material during transport, especially by air. This leads to problems such as limitations on the amount that can be loaded as a cold storage material in insulated containers (transport containers).

[0006] As a cold storage material that can be used in low-temperature regions and does not involve a phase transition to a gas, a cold storage material composition utilizing an aqueous solution of an inorganic salt containing water and a specific inorganic salt has been disclosed.

[0007] For example, Patent Document 1 discloses a cold storage material composition containing 6 moles of calcium chloride (5.6 moles of the total molar amount of the cold storage material composition) and 2 moles of sodium chloride (1.9 moles of the total molar amount of the cold storage material composition) per 100 moles of water, and also containing 1% by weight of high-viscosity type hydroxyethyl cellulose as a thickener relative to the total weight of the cold storage material composition, with a melting temperature of -54.7°C.

[0008] Furthermore, Patent Document 2 discloses a coolant comprising water and a solute containing lithium chloride and sodium chloride, characterized in that lithium chloride has the highest weight-based content among the components of the solute. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] International Public Publication WO2016 / 204284 [Patent Document 2] Japanese Patent Publication No. 2017-128622 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, the conventional thermal storage material compositions described above still had room for improvement in terms of melting temperature, temperature retention performance, and handling.

[0011] One embodiment of the present invention has been made in view of the above-mentioned problems, and its objective is to provide a novel cold storage material composition and a technology for using the same that can maintain a temperature-controlled article at a constant temperature for a long period of time in various controlled temperature ranges from -75.0°C to -66.0°C, and that is easy to handle. [Means for solving the problem]

[0012] As a result of diligent research to solve the aforementioned problems, the inventors have discovered a novel finding that by including specific amounts of lithium ions and bromide ions in water, a cold storage material composition can be obtained that has a melting temperature in the range of -75.0°C to -66.0°C, can maintain the temperature of temperature-controlled articles at a constant temperature for a long period of time, and has excellent handling properties. This led to the completion of the present invention.

[0013] In other words, the thermal storage material composition according to one embodiment of the present invention contains 8.1 moles to 12.6 moles of lithium ions and 7.6 moles to 14.6 moles of bromide ions per 100 moles of water, and has a melting temperature in the range of -75.0°C to -66.0°C.

[0014] Furthermore, a method for using a thermal storage material composition according to one embodiment of the present invention includes a solidification step of solidifying the thermal storage material composition by storing the thermal storage material composition containing water, lithium ions, and bromide ions at a temperature lower than the melting temperature of the thermal storage material composition, and a maintenance step of maintaining part or all of an object at -75.0°C to -66.0°C in a temperature environment exceeding the melting temperature of the thermal storage material composition, wherein the thermal storage material composition contains 8.1 moles to 12.6 moles of lithium ions and 7.6 moles to 14.6 moles of bromide ions per 100 moles of water. [Effects of the Invention]

[0015] According to one embodiment of the present invention, it is possible to provide a cold storage material composition, etc., that can maintain the temperature of a temperature-controlled item at a constant temperature for a long period of time in various controlled temperature ranges from -75.0°C to -66.0°C, and that is easy to handle. [Brief explanation of the drawing]

[0016] [Figure 1] This graph plots the temperature of the cold storage material composition against time when the temperature of the constant temperature bath is raised from an extremely low temperature (e.g., -80°C) at a constant heating rate after the cold storage material composition in a solidified state according to one embodiment of the present invention has been placed in the constant temperature bath. [Figure 2] 201 is a schematic perspective view showing an example of a thermal storage material according to one embodiment of the present invention, and 202 is a schematic exploded perspective view showing an example of a transport container according to one embodiment of the present invention. [Figure 3] 301 is a schematic perspective view showing the interior of a transport container according to one embodiment of the present invention, and 302 is a schematic cross-sectional view showing the cross-section of 301 along line AA. [Modes for carrying out the invention]

[0017] One embodiment of the present invention is described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications are possible within the scope of the claims. The present invention also includes embodiments and examples obtained by appropriately combining the technical means disclosed in different embodiments and examples. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic and patent documents mentioned herein are incorporated as references herein. Unless otherwise specified herein, "A to B" representing a numerical range means "A or greater (including A and greater than A) and B or less (including B and less than B)."

[0018] [1. Technical idea of one embodiment of the present invention] As a result of intensive studies by the present inventors, it has been found that the techniques described in the above-mentioned prior art documents 1 and 2 have room for improvement or problems as shown below.

[0019] For example, Patent Document 1 discloses a cold storage material composition containing water, calcium chloride and sodium chloride and having a melting temperature of -54.7°C. However, for the storage or transportation of various articles such as pharmaceuticals, medical devices, specimens, organs, chemical substances or foods, a control temperature of -66.0°C or lower may be required. Therefore, the technique of Patent Document 1 still has room for improvement from the viewpoint of melting temperature.

[0020] Further, Patent Document 2 discloses a cold insulating agent comprising water and a solute containing lithium chloride and sodium chloride. However, in the technique of Patent Document 2, the content ratio of lithium chloride in terms of weight among the components of the solute is the highest. Here, lithium chloride is a substance suspected of being hazardous to the aquatic environment and having reproductive toxicity, and is a substance that requires careful handling. Lithium chloride can be used in a small amount if risk countermeasures such as labeling for handling precautions to users are taken, but when used in a large amount as in the technique described in Patent Document 2, the toxicity (chemical risk) can be said to be high. That is, the technique of Patent Document 2 has room for improvement from the viewpoint of the handleability (low toxicity) of the cold insulating agent.

[0021] From the above, the present inventors have conducted intensive studies with the aim of providing a novel cold storage material composition that can maintain the temperature of an article to be temperature-controlled at a constant temperature for a long time in various control temperature ranges of -75.0°C to -66.0°C, and is excellent in handleability.

[0022] As a result, the inventors independently discovered the following findings and completed the present invention: By creating a composition that is above its melting temperature and contains specific amounts of lithium ions and bromide ions relative to water in a liquefied state, it is possible to obtain a cold storage material composition that has a melting temperature in the range of -75.0°C to -66.0°C, can maintain the temperature of temperature-controlled articles at a constant temperature for a long period of time, and has excellent handling properties.

[0023] [2. Cold storage material composition] The thermal storage material composition according to one embodiment of the present invention contains lithium ions (Li) per 100 moles of water. + ) 8.1 moles to 12.6 moles, and bromide ions (Br - It contains 7.6 moles to 14.6 moles of ) and has a melting temperature in the range of -75.0°C to -66.0°C.

[0024] With the above configuration, the cold storage material composition according to one embodiment of the present invention has the advantage of being able to maintain the temperature of temperature-controlled items at a constant temperature for a long period of time in various controlled temperature ranges from -75.0°C to -66.0°C, and also has excellent handling properties. In this specification, "excellent handling properties" means that, as a result of conducting a chemical risk assessment evaluation of chemical substances under Japan's Industrial Safety and Health Act, the chemical risk is below a certain value. In this specification, a cold storage material composition that can maintain the temperature of temperature-controlled items at a constant temperature for a long period of time is referred to as a cold storage material composition having constant temperature retention properties. That is, the cold storage material composition according to one embodiment of the present invention can also be said to be a cold storage material composition having constant temperature retention properties due to the above configuration. Such a cold storage material composition having constant temperature retention properties also has the advantage of having excellent temperature retention properties, a long duration of maintaining the constant temperature state, and being usable as a substitute for dry ice. "Constant temperature retention properties," "temperature retention properties," and "maintenance time" will be described in detail later.

[0025] In this specification, "a thermal storage material composition according to one embodiment of the present invention" may also be simply referred to as "the thermal storage material composition."

[0026] This thermal storage material composition can be used as a latent heat type thermal storage material by absorbing thermal energy during the phase transition from a solidified state to a molten state (liquid) (in other words, during melting). This thermal storage material composition can also be called a "molten latent heat thermal storage material composition." Note that the molten state also includes the "gel-like" state described later.

[0027] The types and amounts of ions contained in this cold storage material composition are intended to be those present when the cold storage material composition is in a liquefied state at room temperature (at least 20°C or higher). Note that "liquefied state" also includes "gelled state." "Gelling" will be described in detail later. The types and amounts of ions contained in this cold storage material composition can be measured, for example, at room temperature (e.g., 30°C) using ion chromatography. Known methods can be used for measurement. Furthermore, consider the case in which a cold storage material composition is manufactured by performing only a mixing step to form a mixture containing specific ions that can dissociate at room temperature, without performing a removal step to remove specific components from the mixture. In this case, the types and amounts of ions contained in the obtained cold storage material composition may be theoretically calculated from the chemical formula and amount of the specific compound used in the mixing step. Examples of the mixing step include the following steps (1) or (2): (1) a step of mixing a specific compound that can dissociate at room temperature with water; or (2) a step of mixing aqueous solutions containing specific compounds that can dissociate at room temperature. Furthermore, removal steps include, for example, a step of cooling the mixture to precipitate compounds (e.g., salts) into the mixture, and then removing the precipitated compounds from the mixture by filtration or other means. In this specification, "dissociation" means "ionization" and "dissociation." The terms "dissociation," "ionization," and "ionization" are mutually interchangeable.

[0028] Below, we will first describe the components contained in this thermal storage material composition, and then describe the physical properties (e.g., melting temperature) and manufacturing method of this thermal storage material composition.

[0029] [2-1. Components contained in the cold storage material composition] This cold storage material composition only needs to contain 8.1 to 12.6 moles of lithium ions and 8.1 to 14.6 moles of bromide ions per 100 moles of water, and the other components are not particularly limited. Having the above configuration, this cold storage material composition has the advantage of being able to maintain the temperature of temperature-controlled items at a constant temperature for a long period of time in various controlled temperature ranges from -75.0°C to -66.0°C, and is easy to handle. Furthermore, having the above configuration, this cold storage material composition has the advantages of being able to maintain a constant temperature, having excellent temperature retention properties, maintaining a constant temperature state for a long time, and being usable as a substitute for dry ice.

[0030] The thermal storage material composition preferably contains 8.1 to 12.5 moles of lithium ions per 100 moles of water, more preferably 8.1 to 12.0 moles, even more preferably 8.1 moles or more and less than 11.3 moles, and particularly preferably 8.1 to 11.0 moles. With this configuration, the resulting thermal storage material composition has the advantage of maintaining a constant temperature state for a longer period of time. Furthermore, when the lithium ion content in the thermal storage material composition is 11.0 moles or less, it also has the advantage of improving the -78°C freezing stability, which is an indicator that the thermal storage material composition will reliably freeze in a typical -80°C type deep freezer, as described later. Moreover, when the lithium ion content in the thermal storage material composition is 8.0 moles or more, the constant temperature retention of the thermal storage material composition tends to be better.

[0031] The cold storage material composition preferably contains 7.6 moles to 14.5 moles of bromide ions per 100 moles of water, preferably 7.6 moles to 13.5 moles, preferably 7.6 moles to 13.0 moles, more preferably 7.6 moles or more and less than 12.7 moles, more preferably more than 9.3 moles and less than 12.7 moles, even more preferably 9.6 moles or more and less than 12.7 moles, and particularly preferably 9.6 moles to 12.5 moles. With this configuration, the resulting cold storage material composition has the advantage of maintaining a constant temperature state for a longer period of time.

[0032] In this cold storage material composition, the total content of lithium ions and bromide ions is preferably 15.7 to 27.2 moles per 100 moles of water, more preferably 15.7 to 26.5 moles, more preferably 15.7 to 26.0 moles, more preferably 15.7 to 25.7 moles, more preferably 16.3 to 25.7 moles, more preferably 16.9 to 25.7 moles, more preferably 16.9 to 25.0 moles, more preferably 16.9 to 24.3 moles, more preferably 17.2 to 25.5 moles, even more preferably 17.7 to 24.0 moles, and particularly preferably 18.2 to 23.5 moles. With this configuration, the resulting cold storage material composition has the advantage of maintaining a constant temperature state for a longer period of time.

[0033] In this cold storage material composition, the form (in other words, the origin) of lithium ions is not particularly limited. Examples of lithium ion donation forms include lithium salts such as lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium oxide, lithium sulfide, lithium nitride, lithium phosphide, lithium phosphate, lithium carbide, lithium carbonate, lithium nitrate, lithium molybdate, and lithium boride. These lithium salts may be used individually or in combination. (a) The compounds are easy to handle and safe, (b) The compounds are inexpensive, and (c) The duration of maintaining a constant temperature in the resulting cold storage material composition is longer. Therefore, in this cold storage material composition, it is preferable that the lithium ions are derived from lithium bromide and / or lithium chloride. In this cold storage material composition, it is particularly preferable that the lithium ions are derived from lithium bromide because the resulting cold storage material composition is easy to handle. Among the lithium salts mentioned above, lithium nitrate and lithium molybdate can function as supercooling inhibitors as described later.

[0034] In this cold storage material composition, the form (in other words, the origin) of the bromide ions is not particularly limited. Examples of bromide ion donation forms include (a) bromide salts such as ammonium bromide, potassium bromide, sodium bromide, lithium bromide, magnesium bromide, and zinc bromide, and (b) hydrobromic acid. These bromide salts may be used individually or in combination. In order to maintain a constant temperature state for a longer period of time in the resulting cold storage material composition, the bromide ions in this cold storage material composition are preferably derived from lithium bromide and / or sodium bromide, and are particularly preferably derived from lithium bromide. Sodium bromide has the advantage of being easy to handle and having excellent safety as a compound. Furthermore, because the compound is easy to handle and has excellent safety, the bromide ions may be derived from ammonium bromide and / or potassium bromide. Among the bromide salts mentioned above, sodium bromide can function as a crystal nucleating agent as described later. Furthermore, the hydrobromic acid mentioned above can function as a supercooling inhibitor, as will be discussed later.

[0035] The cold storage material composition preferably further contains chloride ions. When the cold storage material composition further contains chloride ions, it has the advantages of (a) shortening the time from the start of cooling to the start of solidification (hereinafter sometimes referred to as the time related to the start of solidification) compared to when the cold storage material composition does not contain chloride ions, and / or (b) preventing the solidification start temperature of the cold storage material composition from becoming too low (the difference between the solidification start temperature and the melting temperature is small). When the cold storage material composition further contains chloride ions, it also has the advantage of further reducing the melting temperature compared to when the cold storage material composition does not contain chloride ions.

[0036] If the cold storage material composition further contains chloride ions, the cold storage material composition preferably contains 0.3 moles or more and less than 5.5 moles of chloride ions per 100 moles of water, more preferably 0.3 moles to 3.4 moles, more preferably 0.3 moles to 2.7 moles, more preferably 0.6 moles to 2.7 moles, more preferably more than 1.5 moles and 2.7 moles or less, even more preferably 1.8 moles to 2.7 moles, and particularly preferably 1.8 moles to 2.1 moles. With this configuration, the resulting cold storage material composition has the advantage that (a) the time required for the cold storage material composition to begin solidification is shortened, and / or (b) the difference between the solidification start temperature and the melting temperature of the cold storage material composition is smaller.

[0037] If the cold storage material composition further contains chloride ions, it is preferable that the molar amount of bromide ions in the cold storage material composition is greater than the molar amount of chloride ions. This configuration has the advantage of extending the time that the constant temperature state can be maintained between -75.0°C and -66.0°C.

[0038] If the thermal storage material composition further contains chloride ions, the molar amount of bromide ions in the thermal storage material composition is preferably 0.1 times or more the molar amount of chloride ions, more preferably 0.5 times or more, more preferably 1.0 times or more, more preferably 1.5 times or more, even more preferably 2.0 times or more, and particularly preferably 2.5 times or more. This configuration has the advantage that the thermal storage material composition has excellent constant temperature retention properties.

[0039] In this cold storage material composition, the form (in other words, the source) of chloride ions is not particularly limited. Examples of chloride ion donation forms include chloride salts such as sodium chloride, ammonium chloride, lithium chloride, potassium chloride, magnesium chloride, zinc chloride, strontium chloride, and aluminum chloride. These chloride salts may be used individually or in combination. Among the above-mentioned chloride salts, sodium chloride can function as a crystal nucleating agent as described later. Also, among the above-mentioned chloride salts, strontium chloride can function as a supercooling inhibitor as described later.

[0040] The cold storage material composition preferably further contains a crystal nucleating agent. When the cold storage material composition further contains a crystal nucleating agent, it has the advantages of (a) shortening the time required for the cold storage material composition to begin solidification, and / or (b) preventing the solidification start temperature of the cold storage material composition from becoming too low (the difference between the solidification start temperature and the melting temperature is small). In other words, a compound that shortens the time required for the cold storage material composition to begin solidification, and / or increases the solidification start temperature of the cold storage material composition (reduces the difference between the solidification start temperature and the melting temperature) is called a crystal nucleating agent.

[0041] The nucleating agent is not particularly limited, and known nucleating agents can be used. Examples of nucleating agents include sodium chloride, sodium bromide, ammonium chloride, calcium carbonate, calcium silicate, ammonium chloride, sodium tetraborate, and magnesium chloride. These nucleating agents may be used individually or in combination of multiple types. Among these nucleating agents, sodium chloride and sodium bromide are preferred because they (a) have a significant effect in shortening the time required for the start of solidification of the cold storage material composition, (b) have a significant effect in raising the solidification start temperature of the cold storage material composition, and / or (c) have excellent freeze stability (e.g., freeze stability at -78°C) of the cold storage material composition. In other words, the cold storage material composition preferably contains at least one of sodium chloride and sodium bromide as a nucleating agent, and more preferably contains both sodium chloride and sodium bromide. Furthermore, since the melting temperature of the thermal storage material composition is lower, when the thermal storage material composition contains sodium chloride and sodium bromide as crystal nucleating agents, it is preferable that the amount of sodium chloride (in moles) is greater than the amount of sodium bromide (in moles).

[0042] If a compound used as a crystal nucleating agent dissociates and exists as ions in the liquefied state of the cold storage material composition, the amount of these ions is also included in the amount of ions contained in the cold storage material composition. For example, sodium chloride and sodium bromide dissociate in the liquefied state of the cold storage material composition and exist as chloride ions and sodium ions, and bromide ions and sodium ions, respectively. Therefore, the amounts of chloride ions and bromide ions derived from crystal nucleating agents such as sodium chloride and sodium bromide are also included in the amounts of chloride ions and bromide ions in the cold storage material composition.

[0043] If the cold storage material composition further contains a nucleating agent, the content of the nucleating agent in the cold storage material composition is not particularly limited. The content of the nucleating agent in the cold storage material composition is preferably 0.1 moles to 10.0 moles, more preferably 0.5 moles to 8.0 moles, more preferably 0.5 moles to 7.0 moles, more preferably 1.0 moles to 6.0 moles, more preferably 1.0 moles to 5.0 moles, more preferably 1.4 moles to 4.0 moles, even more preferably 1.5 moles to 4.0 moles, and particularly preferably 2.0 moles to 4.0 moles, per 100 moles of water. Furthermore, the content of the nucleating agent in the cold storage material composition may be, for example, 3.0 moles or less per 100 moles of water. Furthermore, the content of the nucleating agent in the cold storage material composition may be, for example, 3.0 moles or more per 100 moles of water. The above configuration has the advantages of (a) a shorter time required for the solidification of the thermal storage material composition, (b) a smaller difference between the solidification start temperature and the melting temperature of the thermal storage material composition, (c) a more stable solidification start temperature, enabling reproducible solidification at a constant temperature, and / or (d) excellent freeze stability (e.g., -78°C freeze stability) of the thermal storage material composition. In particular, if the content of the nucleating agent in the thermal storage material composition is 2.0 moles or more, it is possible to provide a thermal storage material composition with excellent -78°C freeze stability, as described later, which serves as an indicator of reliable freezing in a typical -80°C type deep freezer.

[0044] Preferably, the cold storage material composition further contains a supercooling inhibitor. The supercooling inhibitor plays a role in assisting the effect of the crystal nucleating agent. When the cold storage material composition further contains a supercooling inhibitor in addition to the crystal nucleating agent, it has the advantages of (a) a shorter time required for the cold storage material composition to begin solidification, and / or (b) the fact that the solidification start temperature of the cold storage material composition does not become too low (the difference between the solidification start temperature and the melting temperature becomes smaller). In other words, a compound that, when used in combination with a crystal nucleating agent, shortens the time required for the cold storage material composition to begin solidification compared to the case of a crystal nucleating agent alone, and / or raises the solidification start temperature of the cold storage material composition compared to the case of a crystal nucleating agent alone (making the difference between the solidification start temperature and the melting temperature smaller), is called a supercooling inhibitor. Furthermore, because the cold storage material composition also contains a supercooling inhibitor in addition to the crystal nucleating agent, the temperature required to solidify the cold storage material composition does not become too low. This has the advantage of allowing the cold storage material composition to be stably solidified in a more versatile freezer (for example, a -80°C type deep freezer).

[0045] The supercooling inhibitor is not particularly limited, and known supercooling inhibitors can be used. Examples of supercooling inhibitors include lithium nitrate, lithium molybdate, strontium chloride, and hydrobromic acid. These supercooling inhibitors may be used individually or in combination of multiple types. Among these supercooling inhibitors, lithium nitrate and hydrobromic acid are preferred because they have a significant effect in (a) shortening the time required for the solidification of the cold storage material composition, and / or (b) raising the solidification start temperature of the cold storage material composition.

[0046] If a compound used as a supercooling inhibitor dissociates and exists as ions in the liquefied cold storage material composition, the amount of these ions is also included in the amount of ions contained in the cold storage material composition. For example, lithium nitrate and hydrobromide dissociate in the liquefied cold storage material composition to exist as nitrate ions and lithium ions, and bromide ions and hydrogen ions, respectively. Therefore, the amounts of lithium ions and bromide ions derived from supercooling inhibitors such as lithium nitrate and hydrobromide are also included in the amounts of lithium ions and bromide ions in the cold storage material composition.

[0047] If the cold storage material composition further contains a supercooling inhibitor, the content of the supercooling inhibitor in the cold storage material composition is not particularly limited. The content of the supercooling inhibitor in the cold storage material composition is preferably, for example, 0.0001 moles to 0.10 moles, more preferably 0.0003 moles to 0.07 moles, more preferably 0.0005 moles to 0.05 moles, more preferably 0.001 moles to 0.03 moles, more preferably 0.001 moles to 0.02 moles, even more preferably 0.002 moles to 0.01 moles, and particularly preferably 0.002 moles to 0.008 moles per 100 moles of water. This configuration has the advantages of (a) a shorter time required for the cold storage material composition to begin solidification, (b) a smaller difference between the solidification start temperature and the melting temperature of the cold storage material composition, and / or (c) a stabilized solidification start temperature, enabling reproducible solidification at a constant temperature.

[0048] As mentioned above, lithium chloride is a substance suspected of being harmful to aquatic environments and reproductively toxic, and therefore requires careful handling. From the viewpoint of ease of handling, it is preferable that the amount of lithium chloride in the cold storage material composition be as small as possible. The amount of lithium chloride in the cold storage material composition is preferably 10.0 moles or less, more preferably 9.0 moles or less, more preferably 8.0 moles or less, more preferably 7.0 moles or less, even more preferably 6.0 moles or less, and particularly preferably 5.5 moles or less per 100 moles of water. The amount of lithium chloride in the cold storage material composition may be 5.0 moles or less, 4.0 moles or less, 3.0 moles or less, 2.0 moles or less, or 1.0 mole or less. The cold storage material composition does not have to contain lithium chloride. When we say that the cold storage material composition does not contain lithium chloride, we mean that the amount of lithium chloride in the cold storage material composition is 0.1 moles or less per 100 moles of water.

[0049] The amount of calcium ions in the thermal storage material composition is not particularly limited, but a smaller amount is preferable. A smaller amount of calcium ions in the thermal storage material composition has the advantage of stabilizing the melting temperature of the thermal storage material composition. The amount of calcium ions in the thermal storage material composition is preferably 5.0 moles or less, more preferably 4.0 moles or less, more preferably 3.0 moles or less, more preferably 2.0 moles or less, more preferably 1.0 mole or less, even more preferably 0.5 moles or less, and particularly preferably 0.1 moles or less, per 100 moles of water. It is most preferable that the thermal storage material composition does not contain calcium ions. When we say that the thermal storage material composition does not contain calcium ions, we mean that the amount of calcium ions in the thermal storage material composition is 0.1 moles or less per 100 moles of water.

[0050] The amount of ammonium ions in the cold storage material composition is not particularly limited, but a smaller amount is preferable. A smaller amount of ammonium ions in the cold storage material composition has the advantage of stabilizing the melting temperature of the cold storage material composition. The amount of ammonium ions in the cold storage material composition is preferably 5.0 moles or less, more preferably 4.0 moles or less, more preferably 3.0 moles or less, more preferably 2.0 moles or less, more preferably 1.0 mole or less, even more preferably 0.5 moles or less, and particularly preferably 0.1 moles or less, per 100 moles of water. It is most preferable that the cold storage material composition does not contain ammonium ions. When we say that the cold storage material composition does not contain ammonium ions, we mean that the amount of ammonium ions in the cold storage material composition is 0.1 moles or less per 100 moles of water.

[0051] In one embodiment of the present invention, the compound added to the thermal storage material composition is not particularly limited, but it is preferable that it does not pose a concern for the generation of harmful fumes and / or does not have properties such as being a strong alkali or a strong acid. The above configuration has the advantage of making the thermal storage material composition easy to manufacture and handle. In other words, in this specification, "easy to handle" means that the substances (compounds) contained in the thermal storage material composition and the thermal storage material composition itself do not pose a concern for the generation of harmful fumes and / or do not have properties such as being a strong alkali or a strong acid. For example, zinc chloride can generate harmful fumes and potassium hydroxide is a strong alkali, so zinc chloride and potassium hydroxide can be said to be compounds that are difficult to handle.

[0052] Examples of compound combinations to be mixed with water to produce this cold storage material composition include: (i) lithium bromide; (ii) lithium bromide and lithium chloride; (iii) lithium bromide and sodium chloride; (iv) lithium bromide, lithium chloride and sodium chloride; (v) lithium bromide and sodium bromide; (vi) lithium bromide, lithium chloride and sodium bromide; (vii) lithium bromide, sodium chloride and sodium bromide; (viii) lithium bromide, lithium chloride, sodium chloride and sodium bromide; (ix) lithium bromide and any chloride salt; (x) lithium bromide and any nucleating agent; (xi) lithium bromide, any chloride salt and any nucleating agent.

[0053] This thermal storage material composition may contain compounds such as lithium salts, bromides, and chlorides that have not dissociated (become ions) at 30°C. If the compounds contained in this thermal storage material composition have not dissociated at 30°C, even if the compounds contain elements such as lithium, bromine, and chlorine, the amount of such compounds will not affect the amount of lithium ions, bromides, and chlorides contained in this thermal storage material composition.

[0054] The water in this cold storage material composition is not particularly limited and may be, for example, tap water or other water that can be used as drinking water, and more specifically, it may be soft water, hard water, or pure water.

[0055] As described later, a cold storage material composition according to one embodiment of the present invention can be filled into a container or bag to form a cold storage material, and this cold storage material can be placed inside a transport container for use. However, if the container forming the cold storage material is damaged during transport or handling, the cold storage material composition that was filled inside the container will leak out from the damaged container. In this case, there are concerns that the temperature-controlled article may be contaminated and rendered unusable.

[0056] Therefore, in order to minimize the leakage of the cold storage material composition even if the container or the like filled with the cold storage material composition is damaged during transport or handling, it is preferable that the cold storage material composition according to one embodiment of the present invention further contains a thickening agent and becomes solid (including gel-like).

[0057] The aforementioned thickening agent is not particularly limited, but examples include superabsorbent resins (e.g., starch-based, acrylate-based, polyvinyl alcohol-based, and carboxymethylcellulose-based), attapulgite clay, gelatin, agar, silica gel, xanthan gum, gum arabic, guar gum, carrageenan, cellulose, and konjac.

[0058] Furthermore, the thickening agent may be an ionic thickening agent or a nonionic thickening agent. It is preferable to select a nonionic thickening agent that does not affect the ions contained in the refrigerant composition. Examples of nonionic thickening agents include guar gum, dextrin, polyvinylpyrrolidone, and hydroxyethylcellulose. Among these nonionic thickening agents, hydroxyethylcellulose is particularly preferred because it exhibits excellent gel stability and high environmental compatibility.

[0059] The lithium ions and bromide ions contained in this thermal storage material composition, as well as optionally included chloride ions, may form salts over time due to temperature changes, depending on their concentrations, and these formed salts may precipitate. If this thermal storage material composition contains a thickener, the thickener not only makes the thermal storage material composition gel-like but also efficiently disperses the ions dissolved in the thermal storage material composition, thereby preventing salt precipitation.

[0060] If the thermal storage material composition contains a thickening agent, the thermal storage material composition may gel in an environment above its melting temperature. The thermal storage material composition containing a thickening agent may undergo a phase transition from a solidified state to a molten state (gel).

[0061] In addition to the above-mentioned components, this cold storage material composition may optionally contain phase separation inhibitors (e.g., oleic acid, sodium oleate, potassium oleate, potassium metaphosphate, sodium silicate, or potassium isostearate), fragrances, colorants, antibacterial agents, high molecular weight polymers, other organic compounds, or other inorganic compounds.

[0062] This thermal storage material composition may contain other substances and / or other ions other than lithium ions, bromide ions, and chloride ions in its liquefied state, as long as its melting temperature is within the range of -75.0°C to -66.0°C, and is above its melting temperature. Examples of such other substances include metals such as light metals and heavy metals. Examples of light metals include aluminum, magnesium, beryllium, and titanium. Examples of heavy metals include iron, lead, gold, platinum, silver, copper, chromium, cadmium, mercury, zinc, arsenic, manganese, cobalt, nickel, molybdenum, tungsten, tin, bismuth, uranium, and plutonium. Examples of such other ions include metal ions such as light metal ions and heavy metal ions, which consist of the light metals and heavy metals mentioned above.

[0063] The raw materials (compounds and water, etc.) used in the manufacture of this thermal storage material composition may contain the metals mentioned above.

[0064] [2-2. Physical properties of the cold storage material composition] (Melting temperature) A thermal storage material composition according to one embodiment of the present invention is characterized by having a melting temperature in the range of -75.0°C to -66.0°C.

[0065] In this specification, the "melting temperature" of a thermal storage material composition means "the temperature exhibited by the thermal storage material composition while it is in a solid state and is melting and liquefying." Note that "liquefaction" also includes the "gelation" described above. The "melting temperature" will be explained in more detail using Figure 1. Figure 1 is a graph plotting the temperature of the thermal storage material composition against time when a thermal storage material composition according to one embodiment of the present invention in a solidified state is placed in a constant temperature bath, and the temperature of the constant temperature bath is raised from a cryogenic temperature at a constant heating rate. As shown in Figure 1, compared to the temperature of the constant temperature bath which is rising at a constant rate, the temperature of the thermal storage material composition changes in the following order (1) to (3): (1) It rises at a constant or approximately constant rate from a cryogenic temperature to a certain temperature (let's call it temperature T1); (2) From temperature T1 to a certain temperature (let's call it temperature T2), it hardly changes due to the latent heat of the thermal storage material composition; (3) It resumes rising at temperature T2. In this specification, temperature T1 is referred to as the "melting start temperature," and temperature T2 is referred to as the "melting end temperature." The temperature T3, which is the midpoint between temperatures T1 and T2, is defined in this specification as the "melting temperature."

[0066] Furthermore, with respect to a thermal storage material composition according to one embodiment of the present invention, "constant temperature maintenance" is defined as a state in which the temperature of the thermal storage material composition is maintained for a certain period of time or longer (for example, 10 minutes or more) from the melting start temperature T1 to the melting end temperature T2 (within the range of melting start temperature T1 + 2.5°C) due to the latent heat action of the thermal storage material composition. When a thermal storage material composition exhibits constant temperature maintenance, it can be said that the thermal storage material composition has "constant temperature maintenance properties". This thermal storage material composition is a thermal storage material composition that has constant temperature maintenance properties; in other words, this thermal storage material composition can be said to be a thermal storage material composition that exhibits constant temperature maintenance when evaluated according to the above criteria. A more specific evaluation method for the constant temperature maintenance properties of the thermal storage material composition is as described in the examples.

[0067] The melting temperature of the cold storage material composition is not particularly limited as long as it is within the range of -75.0°C to -66.0°C, and can be appropriately set to match the various control temperatures required by various temperature-controlled items. For example, the storage or transportation of various items such as pharmaceuticals, medical devices, specimens, organs, chemical substances, or food may require a control temperature of -66.0°C or lower. Furthermore, among temperature-controlled items, the storage or transportation of biopharmaceuticals, regenerated cells, vaccines, antibodies, and gene therapy vectors may require a control temperature of -68.5°C or lower. Therefore, from the viewpoint of being usable for a wider range of temperature-controlled items, the cold storage material composition preferably has a melting temperature within the range of -75°C to -68.5°C. The cold storage material according to one embodiment of the present invention also preferably has a melting temperature within the above range, similar to the cold storage material composition.

[0068] The melting temperature of a thermal storage material composition can be measured by placing the sample in a constant temperature bath equipped with a commercially available temperature control unit, raising or lowering the temperature of the bath at a constant rate, and monitoring the sample temperature using a thermocouple.

[0069] (-78℃ freezing stability) In one embodiment of the present invention, a cold storage material composition exhibiting excellent freeze stability at -78°C is provided.

[0070] The cold storage material composition is usually in a molten state (liquid or gel-like), and in order to exhibit constant temperature retention, it is necessary to solidify the cold storage material composition, that is, to solidify (freeze) the cold storage material composition by storing it at a temperature lower than its melting point (storage temperature).

[0071] One method for solidifying a cold storage material composition, such as the present cold storage material composition, which has a melting temperature at a low temperature (for example, in the range of -75.0°C to -66.0°C), is to use a freezer (deep freezer) that can control the temperature of the cold storage material composition to a temperature lower than the melting temperature.

[0072] Incidentally, among commercially available deep freezers, the control temperature of commonly used freezers (general-purpose freezers) is approximately -85°C to approximately -80°C. However, considering the number of years of use of the freezer, the degree of frost buildup, the amount of material loaded in the freezer, variations depending on the placement of the material in the freezer, and product tolerances, it is desirable that the cold storage material composition freezes stably even at -76°C.

[0073] While deep freezers capable of controlling temperatures to extremely low levels of -120°C or below (cryogenic freezers) are commercially available, the environments in which such cryogenic freezers can be introduced and operated are limited due to their price, size, and maintenance costs. Therefore, for cold storage material compositions that require such cryogenic freezers instead of general-purpose freezers to solidify, the environments in which they can be used, and consequently the applications of the cold storage material compositions, may be limited.

[0074] Therefore, from the viewpoint of providing a cold storage material composition that can be used in a wider range of environments and, consequently, can be applied to a wider range of uses, it is preferable that this cold storage material composition can be stably solidified in a general-purpose freezer, in other words, stably solidified in a temperature range of -85°C to -76°C.

[0075] As a result of diligent research to provide a thermal storage material composition that can solidify stably in the temperature range of -85°C to -76°C, the inventors have surprisingly discovered that the freezing stability of the thermal storage material composition at -78°C can be improved by satisfying either of the following conditions: (condition i) adjusting the amount of lithium ions in the thermal storage material composition to a specific amount, or (condition ii) including a specific amount of crystal nucleating agent in the thermal storage material composition. Since the freezing stability of the thermal storage material composition at -78°C can be further improved, it is preferable in one embodiment of the present invention to satisfy both conditions (i) and (ii) above.

[0076] Here, "-78°C freezing stability" of the cold storage material composition is a novel physical property value related to the cold storage material composition discovered by the present inventors. The fact that the cold storage material composition has excellent "-78°C freezing stability" means that the cold storage material composition can stably solidify (freeze) in the temperature range of -85°C to -76°C, or in other words, it can stably solidify even when using a general-purpose freezer.

[0077] Therefore, a preferred embodiment of the present invention, a cold storage material composition having a melting temperature in the range of -75.0°C to -66.0°C, excellent handling properties, and excellent "-78°C freeze stability," can be expressed, for example, as follows: a cold storage material composition containing 8.1 to 11.0 moles of lithium ions and 9.6 to 12.5 moles of bromide ions per 100 moles of water, having a melting temperature in the range of -75.0°C to -66.0°C, and further containing a crystal nucleating agent, wherein the content of the crystal nucleating agent is 2.0 moles or more per 100 moles of water.

[0078] Furthermore, the -78°C freezing stability of the cold storage material composition can be measured and evaluated by the method described in the examples.

[0079] [2-3. Method for producing the cold storage material composition] The method for preparing the thermal storage material composition according to one embodiment of the present invention is not particularly limited, and known methods can be employed. For example, the thermal storage material composition can be prepared by the following method (I-1) to (I-2): (I-1) Pre-mixing lithium salt and bromide salt (or lithium bromide), and optionally chloride salt, crystal nucleating agent, supercooling inhibitor and thickener using a tumbler or ribbon blender; (I-2) Then, transfer the obtained mixture to a container, pour water into the container, and stir the mixture in the container with a mixer or the like while cooling the container. Furthermore, the cold storage material composition can also be prepared by the following methods (II-1) to (II-3): (II-1) Prepare an aqueous solution of lithium salt and an aqueous solution of bromide salt (or an aqueous solution of lithium bromide), and optionally an aqueous solution of chloride salt, an aqueous solution of supercooling inhibitor, and an aqueous solution of crystal nucleating agent; (II-2) Mix an aqueous solution of crystal nucleating agent with a thickener to prepare an aqueous solution of crystal nucleating agent in which the thickener is dispersed; (II-3) Mix an aqueous solution of lithium salt and an aqueous solution of bromide salt (or an aqueous solution of lithium bromide), and optionally an aqueous solution of chloride salt, an aqueous solution of supercooling inhibitor, and an aqueous solution of crystal nucleating agent in which the thickener is dispersed. Furthermore, the cold storage material composition can also be prepared by the following methods (III-1) to (III-3): (III-1) Prepare an aqueous solution containing a lithium salt and a bromide salt (or lithium bromide), and optionally a chloride salt, a supercooling inhibitor, and a crystal nucleating agent; (III-2) Mix water and a thickener to prepare an aqueous solution in which the thickener is dispersed; (III-3) Mix an aqueous solution containing a lithium salt and a bromide salt (or lithium bromide), and optionally a chloride salt, a supercooling inhibitor, and a crystal nucleating agent with an aqueous solution in which the thickener is dispersed.Furthermore, the cold storage material composition can also be prepared by the following methods (IV-1) to (IV-3): (IV-1) Prepare an aqueous solution containing a lithium salt and a bromide salt (or lithium bromide), and optionally a supercooling inhibitor, and an aqueous solution containing a chloride salt as a crystal nucleating agent; (IV-2) Mix an aqueous solution of the crystal nucleating agent (chloride salt) with a thickener to prepare an aqueous solution of the crystal nucleating agent (chloride salt) in which the thickener is dispersed; (IV-3) A method of mixing an aqueous solution containing a lithium salt and a bromide salt (or lithium bromide), and optionally a supercooling inhibitor, with an aqueous solution of the crystal nucleating agent (chloride salt) in which the thickener is dispersed. Furthermore, the cold storage material composition can also be prepared by the following methods (V-1) to (V-3): (V-1) Prepare an aqueous solution containing a lithium salt and a bromide salt (or lithium bromide), and optionally a supercooling inhibitor, and an aqueous solution containing a chloride salt and a bromide salt as a crystal nucleating agent; (V-2) Mix an aqueous solution of the crystal nucleating agent (chloride salt and bromide salt) with a thickener to prepare an aqueous solution of the crystal nucleating agent (chloride salt and bromide salt) in which the thickener is dispersed; (V-3) Mix an aqueous solution containing a lithium salt and a bromide salt (or lithium bromide), and optionally a supercooling inhibitor, with an aqueous solution of the crystal nucleating agent (chloride salt and bromide salt) in which the thickener is dispersed.

[0080] The following are specific examples of a method for manufacturing a thermal storage material composition according to one embodiment of the present invention.

[0081] [A] A method of mixing water and lithium bromide and, if necessary, lithium nitrate, and, if necessary, further mixing sodium chloride and / or hydroxyethylcellulose into the resulting mixture.

[0082] [B] A method of mixing water, lithium bromide and lithium chloride and, if necessary, lithium nitrate, and, if necessary, further mixing sodium chloride and / or hydroxyethyl cellulose into the resulting mixture.

[0083] [C] A method of mixing water and lithium bromide and, if necessary, lithium nitrate, and, if necessary, further mixing sodium bromide and / or hydroxyethyl cellulose into the resulting mixture.

[0084] [D] A method of mixing water, lithium bromide and lithium chloride and, if necessary, lithium nitrate, and, if necessary, further mixing sodium bromide and / or hydroxyethyl cellulose into the resulting mixture.

[0085] [E] A method of mixing water and lithium bromide and, if necessary, lithium nitrate, and, if necessary, further mixing sodium chloride, sodium bromide and / or hydroxyethyl cellulose with the resulting mixture.

[0086] [F] A method of mixing water, lithium bromide and lithium chloride, and lithium nitrate if necessary, and further mixing sodium chloride, sodium bromide and / or hydroxyethylcellulose to the resulting mixture if necessary.

[0087] In the above [A] to [F], the amounts used of lithium bromide, lithium chloride, lithium nitrate, sodium chloride and / or sodium bromide can be appropriately set so that the amounts of lithium ions, bromide ions and chloride ions in the resulting cold storage material composition are as described above.

[0088] Next, I will explain "cold storage materials".

[0089] [3. Cold storage material] The thermal storage material according to one embodiment of the present invention may be any material comprising the thermal storage material composition described above, and is not limited to other components, materials, etc.

[0090] A thermal storage material according to one embodiment of the present invention can be used as a latent heat type thermal storage material because the thermal storage material composition forming the thermal storage material absorbs thermal energy when it undergoes a phase transition from a solidified state to a molten state (liquid) (in other words, when it melts). The thermal storage material according to one embodiment of the present invention can also be called a molten latent heat thermal storage material. Note that the molten state includes the "gel-like" state described above.

[0091] For example, a thermal storage material according to one embodiment of the present invention may be a thermal storage material composition described above that is filled into a container or bag or the like.

[0092] The container or bag is preferably made mainly of resin (e.g., synthetic resin) from the viewpoint of preventing liquid leakage caused by rust and corrosion due to the cold storage material composition. In other words, the cold storage material according to one embodiment of the present invention includes the cold storage material composition and resin according to the above embodiment of the present invention.

[0093] Examples of the aforementioned resins include polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate, polystyrene, nylon, and polyester.

[0094] These materials may be used individually, or two or more of them may be used in combination to enhance heat resistance and barrier properties (for example, by using a multilayer structure). From the standpoint of handling and cost, it is preferable to use containers or bags made of polyethylene.

[0095] The shape of the container or bag is not particularly limited, but from the viewpoint of efficiently exchanging heat between the thermal storage material composition and the temperature-controlled article or the surrounding space via the container or bag, a shape that is thin and has a large surface area is preferred. A thermal storage material can be formed by filling these containers or bags with the thermal storage material composition.

[0096] For more specific examples of the container or bag, the container or bag disclosed in Japanese Patent Publication No. 2015-78307 may be used. This document is incorporated herein by reference.

[0097] The melting temperature of the thermal storage material according to one embodiment of the present invention can be considered to be the same as the melting temperature of the thermal storage material composition contained in the thermal storage material.

[0098] Next, we will explain "transport containers".

[0099] [4. Transport containers] A transport container according to one embodiment of the present invention may be any container equipped with the cold storage material according to the above-described embodiment of the present invention, and there are no particular limitations on other specific configurations, materials, etc.

[0100] Figure 2 shows an example of a transport container according to one embodiment of the present invention. Figure 201 is a schematic perspective view showing a thermal storage material 10 according to one embodiment of the present invention, and Figure 202 is a schematic exploded perspective view showing a transport container 1 according to one embodiment of the present invention.

[0101] As shown in Figures 201 and 202, the opening of the thermal storage material 10 in this embodiment is closed by the lid 11 of the thermal storage material. The thermal storage material 10 is filled with a thermal storage material composition 20 according to one embodiment of the present invention through the opening, and the thermal storage material 10 can be used by being stored or placed inside an insulated container 40. In other words, the transport container according to one embodiment of the present invention includes the thermal storage material and insulated container according to the above embodiment of the present invention.

[0102] The materials for the cold storage material 10 and the lid 11 of the cold storage material are not particularly limited, and conventionally known materials can be used as appropriate.

[0103] The aforementioned insulated container 40 is configured to have heat insulation properties by using, for example, a box body 41 and a lid 42 that fits into the opening 410 of the box body.

[0104] The material of the insulated container 40 is not particularly limited as long as it has insulating properties, but foamed plastic is preferably used from the viewpoint of being lightweight, inexpensive, and able to prevent condensation. Vacuum insulation material is also preferably used as the material of the insulated container 40 from the viewpoint of having very high insulating properties, a long temperature retention time, and being able to prevent condensation. Specifically, foamed plastics include polyurethane, polystyrene, polyethylene, polypropylene, AS resin, or ABS resin, which are foamed. As for vacuum insulation material, for example, those using silica powder, glass wool, or glass fiber as the core material are used. Furthermore, the insulated container 40 may be constructed by a combination of foamed plastic and vacuum insulation material. In that case, an insulated container 40 with high insulating performance can be obtained by means of (i) covering the outer or inner surface of the box body 41 and lid 42 made of foamed plastic with vacuum insulation material, or (ii) embedding vacuum insulation material inside the walls that make up the box body 41 and lid 42 made of foamed plastic.

[0105] Figure 301 is a schematic perspective view showing the interior of the transport container 1, and Figure 302 is a schematic cross-sectional view showing the section along line AA of Figure 301.

[0106] As shown in 202 of Figure 2, the insulated container 40 comprises a box body 41 and a lid 42, and the transport container 1 according to one embodiment of the present invention comprises the insulated container 40, a thermal storage material 10 and a spacer 6. In other words, the transport container according to one embodiment of the present invention includes the thermal storage material, insulated container and spacer according to the above embodiment of the present invention. As shown in Figures 2 and 3, the transport container 1 according to one embodiment of the present invention may also be provided with a spacer 6 to (1) fill the space between the surface of the lid 42 covering the space inside the box body, the side portion 412 of the box body, and the bottom portion 411 of the box body and the thermal storage material 10, and (2) secure a space 5 for accommodating temperature-controlled items, as shown in 302 of Figure 3.

[0107] In Figures 2 and 3, the transport container 1 is equipped with 10 cold storage materials 10, but the number of cold storage materials equipped in the transport container 1 is not particularly limited as long as it is one or more. From the viewpoint of storing or transporting temperature-controlled articles for a long period of time and / or stably at a controlled temperature, the number of cold storage materials 10 equipped in the transport container 1 is preferably two or more, more preferably four or more, even more preferably six or more, and particularly preferably ten or more. The number of cold storage materials 10 equipped in the transport container 1 may be appropriately selected depending on the size of the cold storage materials 10, the storage or transport time of the temperature-controlled articles, and the ambient temperature during storage or transport of the temperature-controlled articles.

[0108] The material of the spacer 6 is not particularly limited, but examples include polyurethane, polystyrene, polyethylene, polypropylene, AS resin or ABS resin, and foamed plastics obtained by foaming these resins.

[0109] In one embodiment of the present invention, a pair of spacers 6 are arranged facing each other inside the insulated container 40. The transport container 1 according to one embodiment of the present invention has spacers 6, which determines the placement position of the cold storage material 10, thus making packing easier. The size and number of spacers 6 provided in the transport container 1 are not particularly limited and may be set as appropriate depending on the size of the transport container 1, the cold storage material 10, and the temperature-controlled items.

[0110] In Figures 2 and 3, the transport container 1 has one space 5 for containing temperature-controlled items, but the number of spaces 5 in the transport container 1 is not particularly limited as long as it is one or more, and it may have multiple spaces 5. For example, a space 5 may be divided and used by placing a thermal storage material 10 and / or a spacer 6 inside one space 5.

[0111] A transport container according to one embodiment of the present invention can store or transport articles requiring temperature control (temperature-controlled articles) while maintaining a temperature within the range of -75.0°C to -66.0°C for extended periods, regardless of ambient temperature. The transport container of this embodiment can be suitably used for the storage or transport of various articles requiring temperature control, such as cells, pharmaceuticals, medical devices, specimens, organs, chemical substances, or food. As described above, since the transport container according to one embodiment of the present invention can maintain temperature-controlled articles within the range of -75.0°C to -66.0°C for extended periods, it can also be called a "thermal insulated container."

[0112] Furthermore, among temperature-controlled items, the storage or transport of biopharmaceuticals, regenerated cells, vaccines, antibodies, and gene therapy vectors may require a controlled temperature of -68.5°C. For these applications, a transport container capable of maintaining storage or transport at -68.5°C or below (for example, a transport container capable of maintaining storage or transport at -75.0°C to -68.5°C) is suitably used. Examples of applications for transport containers that maintain storage or transport at -68.5°C or below include cell transport (for example, transport of frozen cells within a cell culture center, inter-facility transport of frozen cells from a cell bank to a cell culture center, etc.) and cell storage (for example, temporary storage of frozen cells in a sterile room or clean bench, storage (backup) when a deep freezer used in a cell bank or cell culture center experiences a power outage, etc.).

[0113] Furthermore, a more specific configuration of the aforementioned heat-insulating container can be found in Japanese Patent Publication No. 2015-78307. This document is incorporated herein by reference.

[0114] Next, we will explain "How to use the cold storage material composition."

[0115] [5. Method of using the cold storage material composition] A method for using a thermal storage material composition according to one embodiment of the present invention includes a solidification step of solidifying the thermal storage material composition, which contains water, lithium ions, and bromide ions, by storing it at a temperature lower than the melting temperature of the thermal storage material composition, and a maintenance step of maintaining part or all of an object at -75.0°C to -66.0°C in a temperature environment exceeding the melting temperature of the thermal storage material composition, wherein the thermal storage material composition contains 8.1 moles to 12.6 moles of lithium ions and 7.6 moles to 14.6 moles of bromide ions per 100 moles of water.

[0116] Herein, in this specification, “subject matter” means the temperature-controlled article and / or the environment surrounding the temperature-controlled article (including the gas phase, liquid phase, or solid phase).

[0117] In the method of using the cold storage material composition according to one embodiment of the present invention, the cold storage material composition is preferably the cold storage material composition according to one embodiment of the present invention, and the description in section [2. Cold Storage Material Composition] may be appropriately referenced in the description of the cold storage material composition.

[0118] Furthermore, the cold storage material composition used in the method of using the cold storage material composition according to one embodiment of the present invention is preferably a cold storage material composition manufactured by the method for manufacturing the cold storage material composition according to one embodiment of the present invention. The description in section [2-3. Method for manufacturing the cold storage material composition] may be appropriately referenced in the description of the method for manufacturing the cold storage material composition.

[0119] A method of use relating to one embodiment of the present invention may specifically be any of the following (1) to (5).

[0120] (1) The cold storage material composition is filled into a container or the like to produce the cold storage material described in section [3. Cold Storage Material]. Then, the cold storage material is stored at a temperature lower than the melting temperature of the cold storage material composition to solidify (solidification step). The solidified cold storage material is placed in a transport container described in section [4. Transport Container], and the object is stored and / or transported while maintaining the temperature at -75.0°C to -66.0°C in a temperature environment exceeding the melting temperature of the cold storage material composition (maintenance step). This is a method of using the cold storage material composition.

[0121] (2) The cold storage material described in section [3. Cold Storage Material] is prepared by filling a freezer or cryogenic freezer, etc., that is operating at a temperature lower than the melting temperature of the cold storage material composition, and is placed in advance (solidification step). This is a method of using the cold storage material composition to maintain the temperature of the object inside the freezer or cryogenic freezer at -75.0°C to -66.0°C (maintenance step) during a power outage.

[0122] (3) When preparing a cold storage material as described in section [3. Cold Storage Material] by filling a container with the cold storage material composition, the object to be stored is placed in the container together with the liquid cold storage material composition, and the object to be stored is embedded in the cold storage material composition. Subsequently, the cold storage material is stored at a temperature lower than the melting temperature of the cold storage material composition and allowed to solidify (solidification step). This is a method of using the cold storage material composition, in which the object to be stored and / or transported is maintained at -75.0°C to -66.0°C in a temperature environment above the melting temperature of the cold storage material composition (maintenance step).

[0123] (4) The cold storage material composition is filled into a container or the like to produce the cold storage material described in section [3. Cold Storage Material]. The cold storage material is then stored at a temperature lower than the melting temperature of the cold storage material composition to solidify (solidification step). The solidified cold storage material is brought into contact with an object that is in a temperature environment above the melting temperature of the cold storage material composition. This maintains the contacted portion (part) of the object at -75.0°C to -66.0°C (maintenance step). This is a method of using the cold storage material composition.

[0124] (5) A method of using a cold storage material composition involves embedding a liquid cold storage material composition inside an object, then storing the cold storage material composition at a temperature lower than its melting point to allow it to solidify (solidification step). This allows the object to be stored and / or transported at a temperature of -75.0°C to -66.0°C in an environment exceeding the melting point of the cold storage material composition (maintenance step).

[0125] In the methods of use described in (1) to (5) above, specific methods for storing and solidifying the cold storage material composition, or the cold storage material described in section [3. Cold Storage Material], at a temperature lower than the melting temperature of the cold storage material composition include the following: That is, placing the cold storage material composition or the cold storage material in a commercially available -85°C, -80°C freezer, preferably an ultra-low temperature freezer that can be adjusted to a temperature lower than the melting temperature of the cold storage material composition (for example, -120°C), and solidifying them. In the methods of use described in (1) to (5) above, the cold storage material composition, or the cold storage material described in section [3. Cold Storage Material], may be stored at a temperature lower than the solidification start temperature of the cold storage material composition, and the cold storage material composition or the cold storage material may be solidified.

[0126] In the solidification process, the temperature lower than the melting temperature is preferably -80°C or lower. This configuration has the advantage of allowing the cold storage material composition to solidify sufficiently and in a short time.

[0127] The cold storage material composition according to one embodiment of the present invention exhibits excellent freezing stability at -78°C, and therefore can be stably frozen even in the temperature range of -85°C to -76°C, which is adjustable in a general-purpose freezer. In other words, it can be stably frozen even when using a general-purpose freezer. Therefore, in another embodiment of the present invention, in the solidification step, it is preferable that the temperature lower than the melting temperature is -85°C to -76°C. This configuration has the advantage that the cold storage material composition can be stably solidified even when using a general-purpose freezer.

[0128] As described above, several specific examples of how to use the thermal storage material composition have been given, but the methods of using the thermal storage material composition according to one embodiment of the present invention are not limited to these methods. The methods of using the thermal storage material composition provided by one embodiment of the present invention include all methods that include (i) a solidification step of solidifying the thermal storage material composition by storing the thermal storage material composition according to one embodiment of the present invention, or a thermal storage material composition manufactured by a method for manufacturing the thermal storage material composition according to one embodiment of the present invention, at a temperature lower than the melting temperature of the thermal storage material composition, and (ii) a maintenance step of maintaining part or all of an object at -75.0°C to -66.0°C by utilizing the latent heat of fusion of the solidified thermal storage material composition in a temperature environment exceeding the melting temperature of the thermal storage material composition.

[0129] One embodiment of the present invention may include the following configuration:

[0130] [1] A cold storage material composition containing 8.1 moles to 12.6 moles of lithium ions and 7.6 moles to 14.6 moles of bromide ions per 100 moles of water, and having a melting temperature in the range of -75.0°C to -66.0°C.

[0131] [2] The cold storage material composition according to [1], further comprising chloride ions.

[0132] [3] The cold storage material composition according to [2], wherein the molar amount of bromide ions is greater than the molar amount of chloride ions.

[0133] [4] The cold storage material composition according to [2] or [3], wherein the molar amount of bromide ions is 2.5 times or more the molar amount of chloride ions.

[0134] [5] A thermal storage material composition according to any one of [1] to [4], comprising 8.1 to 11.0 moles of lithium ions per 100 moles of water.

[0135] [6] A cold storage material composition according to any one of [1] to [5], further comprising a crystal nucleating agent.

[0136] [7] The cold storage material composition according to [6], wherein the content of the crystal nucleating agent is 2.0 moles or more per 100 moles of water.

[0137] [8] A cold storage material composition according to any one of [1] to [7], further comprising a thickening agent.

[0138] A cold storage material comprising the cold storage material composition described in any one of [9], [1], to [8].

[0139] A transport container equipped with the cold storage material described in

[10] and [9].

[0140]

[11] A method for using a cold storage material composition comprising: a solidification step of solidifying the cold storage material composition by storing the cold storage material composition containing water, lithium ions, and bromide ions at a temperature lower than the melting temperature of the cold storage material composition; and a maintenance step of maintaining part or all of an object at -75.0°C to -66.0°C in a temperature environment exceeding the melting temperature of the cold storage material composition, wherein the cold storage material composition contains 8.1 moles to 12.6 moles of lithium ions and 7.6 moles to 14.6 moles of bromide ions per 100 moles of water.

[0141]

[12] The method of using the cold storage material composition according to

[11] , wherein in the solidification step, the temperature lower than the melting temperature is a temperature of -80°C or lower.

[0142]

[13] The method of using the cold storage material composition according to

[11] , wherein in the solidification step, the temperature lower than the melting temperature is a temperature of -85°C to -76°C. [Examples]

[0143] One embodiment of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0144] The raw materials used in the examples and comparative examples are as follows: <Inorganic salts> Lithium bromide aqueous solution [manufactured by Honjo Chemical, lithium bromide aqueous solution (lithium bromide concentration 55.0% by weight)]. Lithium chloride aqueous solution [Manufactured by Honjo Chemical Co., Ltd., lithium chloride aqueous solution (lithium chloride concentration 40.0% by weight)] Calcium chloride aqueous solution [Manufactured by Tosoh Corporation, calcium chloride aqueous solution (calcium chloride concentration 40.0% by weight)]. <Crystallizing agent> Sodium chloride [manufactured by Nippon Shokuhin Seizo, refined salt] Sodium bromide [manufactured by Manac, sodium bromide] <Thickening agent> Hydroxyethylcellulose [HEC Daicel, manufactured by Daicel Finechem] <Supercooling prevention agent> Lithium nitrate [Manufactured by Honjo Chemical Co., Ltd., lithium nitrate] <Water> Drinking tap water.

[0145] <Preparation of thermal storage material composition> For the inorganic salts, commercially available aqueous solutions were used for lithium bromide, lithium chloride, and calcium chloride, as described above. For the crystal nucleating agent and supercooling inhibitor, aqueous solutions were prepared in advance by dissolving each compound in water at room temperature.

[0146] After heating an aqueous solution of an inorganic salt to 40°C, the aqueous solution of the inorganic salt was mixed with an aqueous solution of a crystal nucleating agent at room temperature to prepare the cold storage material compositions of Examples 1-3 and Comparative Examples 1-6.

[0147] After heating an aqueous solution of an inorganic salt to 40°C, the aqueous solution of the inorganic salt, an aqueous solution of a crystal nucleating agent at room temperature, and an aqueous solution of a supercooling inhibitor at room temperature were mixed to prepare the cold storage material composition of Example 4.

[0148] The thickening agent was first dispersed in an aqueous solution of the nucleating agent at room temperature to prepare an aqueous solution of the nucleating agent containing the dispersed thickening agent. Then, an aqueous solution of the inorganic salt at 40°C and the aqueous solution of the nucleating agent containing the dispersed thickening agent (at room temperature) were mixed to prepare the cold storage material compositions of Examples 5, 7-45 and Comparative Examples 7-8.

[0149] The thickening agent was first dispersed in an aqueous solution of the nucleating agent at room temperature to prepare an aqueous solution of the nucleating agent containing the dispersed thickening agent. Next, an aqueous solution of the inorganic salt at 40°C, an aqueous solution of the supercooling inhibitor at room temperature, and the aqueous solution of the nucleating agent containing the dispersed thickening agent (at room temperature) were mixed to prepare the cold storage material composition of Example 6.

[0150] In each example and comparative example, the cold storage material composition was prepared by adjusting and mixing the amounts of each component so that the content of each component in the resulting cold storage material composition was as shown in Tables 1 to 5.

[0151] Measurements and evaluations in the examples and comparative examples were performed under the following conditions and methods.

[0152] <Melting temperature> The cold storage material composition was filled into a polypropylene cryovial and left to solidify for more than 12 hours in an ultra-deep freezer [AFZ-1423, ADD] heated to -120°C. The solidified cold storage material composition was left to solidify for 1 hour in a constant temperature bath [Cryoporter® CS-80CP, Cynix Corporation, ultra-low temperature aluminum block constant temperature bath] heated to -80°C. Subsequently, the temperature was increased at a rate of 0.5°C / minute within a temperature range of -80°C to 20°C.

[0153] During the temperature rise process of the constant temperature bath, the temperature of the refrigerant composition in the constant temperature bath against time was plotted and is shown in Figure 1. As shown in Figure 1, compared to the temperature of the constant temperature bath which rose at a constant rate, the temperature of the refrigerant composition changed in the following order (1) to (3): (1) It rose at a constant or nearly constant rate from -80°C to a certain temperature (let's call it temperature T1); (2) From temperature T1 to a certain temperature (let's call it temperature T2), it hardly changed due to the latent heat of the refrigerant composition; (3) At temperature T2, the rise resumed. In this specification, temperature T1 is referred to as the "melting start temperature" and temperature T2 is referred to as the "melting end temperature". In this specification, the temperature T3, which is the midpoint between temperature T1 and temperature T2, is defined as the "melting temperature". Furthermore, for the evaluation of the melting temperature, a value of -66.0°C or lower was marked with ○ (good), and a value of -66.0°C or higher was marked with × (poor).

[0154] <Constant temperature retention> The temperature change plot of the cold storage material composition during the temperature rise process (0.5°C / min) in an ultra-low temperature aluminum block constant temperature bath was evaluated for temperature retention and maintenance time. Subsequently, the constant temperature retention of the cold storage material composition was evaluated based on the evaluation results for temperature retention and maintenance time. Specifically, the cold storage material composition was evaluated as having "constant temperature retention" if both the evaluation of temperature retention and maintenance time were ○ (good) or better, that is, if the temperature of the cold storage material composition was maintained within the range of melting start temperature T1 + 2.5°C from melting start temperature T1 to melting end temperature T2 due to the latent heat effect of the cold storage material composition, and the maintenance time (in other words, the time from melting start temperature T1 to melting end temperature T2) was 10 minutes or more. Furthermore, for the evaluation of constant temperature retention, ○ (good) was used if constant temperature retention was used, and × (poor) was used if it was not. The following definitions and criteria were used to evaluate temperature retention and maintenance time. <Temperature maintenance> In a temperature change plot of the cold storage material composition during the temperature rise process (0.5°C / min) in an ultra-low temperature aluminum block constant temperature bath, the temperature difference from the melting start temperature T1 to the melting end temperature T2 was measured, and the temperature retention performance of the cold storage material composition was evaluated based on the measurement results. In the evaluation of temperature retention performance, if the melting end temperature T2 was T1 + 2.5°C or higher, it was evaluated as × (poor); if it was T1 + 2.0°C or higher and less than T1 + 2.5°C, it was evaluated as ○ (good); and if it was less than T1 + 2.0°C, it was evaluated as ◎ (very good).

[0155] <Duration> In the temperature change plot of the cold storage material composition during the temperature rise process (0.5°C / min) in an ultra-low temperature aluminum block constant temperature bath, the time from the melting start temperature T1 to the melting end temperature T2 was measured and defined as the "maintenance time". The maintenance time was evaluated as follows: less than 10 minutes was marked × (poor), 10 minutes or more but less than 16 minutes was marked ○ (good), and 16 minutes or more was marked ◎ (very good).

[0156] <Crystal precipitation after solidification-melting cycles (3 times)> 300g of the cold storage material composition was placed in a glass container, and the glass container containing the cold storage material composition was left to stand for more than 12 hours in an ultra-deep freezer [ADD AFZ-1423] heated to -120°C to solidify the cold storage material composition. After that, the glass container containing the cold storage material composition was removed from the ultra-deep freezer and left at room temperature to melt the cold storage material composition. These operations of solidifying and melting the cold storage material composition are called the "solidification-melting cycle". After repeating the solidification-melting cycle three times, the state of salt precipitation and / or salt sedimentation in the cold storage material composition in a melted state at room temperature was checked. If salt precipitation and / or salt sedimentation was present, it was marked as × (poor), and if neither salt precipitation nor salt sedimentation was present, it was marked as ○ (good).

[0157] <Supercooling suppression effect> A cold storage material composition is filled into a polypropylene cryovial and then heated to -110°C, -100°C, or -90°C in an ultra-deep freezer [ADD Co., Ltd.]. The refrigerant composition was left standing in [AFZ-1423] for 12 hours to attempt to solidify. After 12 hours, the refrigerant composition was removed from the ultra-deep freezer, and its solidification state was visually confirmed. The supercooling suppression effect was evaluated based on the following criteria: × (Poor) if no solidification occurred at -110°C, -100°C, or -90°C; △ (Pass) if solidification occurred at -110°C but not at -100°C or -90°C; ○ (Good) if solidification occurred at -110°C and -100°C but not at -90°C; and ◎ (Very Good) if solidification occurred at all three temperatures.

[0158] <Handling (low toxicity)> A risk assessment evaluation of chemical substances was conducted for the cold storage material composition in accordance with Japan's Industrial Safety and Health Act. A chemical risk of 5 was marked as × (poor), a chemical risk of 4 as △ (acceptable), and a chemical risk of 3 or less as ○ (good).

[0159] <-78℃ freezing stability> The freezing stability of the cold storage material composition at -78°C was evaluated by the following method: (1) The cold storage material composition was filled into a polypropylene cryovial and placed in a constant temperature bath [Cynoporter® CS-80CP, ultra-low temperature aluminum block constant temperature bath manufactured by Cynics Co., Ltd.]; (2) The temperature inside the constant temperature bath was lowered from room temperature to -78°C at a rate of 0.5°C / min; (3) The temperature inside the constant temperature bath was maintained at -78°C for 1 hour; (4) After maintenance, the temperature inside the constant temperature bath was raised from -78°C to -30°C at a rate of 0.5°C / min; (5) The temperature inside the constant temperature bath was lowered from -30°C to -78°C at a rate of 0.5°C / min. (6) The operation in (3) to (5) was repeated 20 times, and the temperature change of the cold storage material composition in process (4) for each repetition (20 times in total) was measured; (7) Based on the measurement results of the temperature change of the cold storage material composition, the temperature retention of the cold storage material composition was evaluated in each of the 1 to 20 repetitions (20 times in total) based on the method described in the <Constant Temperature Retention> section above; (8) The freeze stability of the cold storage material composition at -78°C was evaluated based on the following criteria: ◎(Good): In all 20 evaluations, the cold storage material composition demonstrated constant temperature retention; ○ (Pass): In 18 to 19 out of 20 evaluations, the cold storage material composition demonstrated constant temperature retention; △(Caution): Out of 20 evaluations, the cold storage material composition showed constant temperature retention in 15 to 17 instances. × (Poor): Out of 20 evaluations, the thermal storage material composition showed constant temperature retention 14 times or less.

[0160] <Test Results> The results of each test are shown in Tables 1 to 5. All cold storage material compositions prepared in Examples 1 to 45 contain water, lithium ions, and bromide ions. Furthermore, lithium bromide, lithium chloride, sodium chloride, and sodium bromide used in Examples 1 to 45 all dissociate in water at room temperature. In addition, no compounds were removed from the prepared mixtures in Examples 1 to 45. Therefore, the amounts of lithium ions, bromide ions, and chloride ions in Examples 1 to 45 are values ​​that were theoretically calculated from the chemical formulas and amounts used of lithium bromide, lithium chloride, sodium chloride, and sodium bromide. [Table 1] [Table 2] [Table 3] [Table 4] [Table 5] [Industrial applicability]

[0161] A cold storage material composition according to one embodiment of the present invention, a cold storage material equipped with the cold storage material composition, and a transport container, as well as a cold storage material composition manufactured by a method for manufacturing a cold storage material composition according to one embodiment of the present invention, are easy to handle and enable the storage or transport of temperature-controlled articles with a control temperature range of -75.0°C to -66.0°C at a constant temperature for a long period of time within the control temperature range of each article in a specific environment. Furthermore, according to a method of using the cold storage material composition according to one embodiment of the present invention, it is possible to store or transport temperature-controlled articles with a control temperature range of -75.0°C to -66.0°C at a constant temperature for a long period of time within the control temperature range of each article in a specific environment. Therefore, one embodiment of the present invention can be suitably used for the storage and transport of, for example, cells, pharmaceuticals, regenerated cells, specimens, or food.

Claims

1. For 100 moles of water, (i) Lithium bromide, (ii) Lithium chloride (optionally), and (iii) Lithium nitrate (optionally) are present in amounts of 8.1 to 12.6 moles, (i) containing 7.6 moles to 14.6 moles of bromide ions derived from lithium bromide and (ii) optionally sodium bromide, Furthermore, it contains a crystal nucleating agent, The nucleating agent is at least one of sodium chloride and sodium bromide. The content of the nucleating agent is 0.1 moles to 10.0 moles per 100 moles of water. A cold storage material composition having a melting temperature in the range of -75.0°C to -66.0°C.

2. Furthermore, the cold storage material composition according to claim 1, further comprising chloride ions.

3. The cold storage material composition according to claim 2, wherein the molar amount of bromide ions is greater than the molar amount of chloride ions.

4. The cold storage material composition according to claim 2, wherein the molar amount of bromide ions is 2.5 times or more the molar amount of chloride ions.

5. The thermal storage material composition according to claim 1, comprising 8.1 moles to 11.0 moles of lithium ions per 100 moles of water.

6. The cold storage material composition according to claim 1, wherein the content of the nucleating agent is 2.0 moles to 10.0 moles per 100 moles of water.

7. Furthermore, the cold storage material composition according to claim 1, wherein the thickener is a nonionic thickener.

8. A cold storage material comprising the cold storage material composition according to any one of claims 1 to 7.

9. A transport container comprising the cold storage material described in claim 8.

10. A solidification step involves solidifying a cold storage material composition containing water, lithium ions, and bromide ions by storing it at a temperature lower than the melting point of the cold storage material composition. The process includes a maintenance step of maintaining part or all of the object at -75.0°C to -66.0°C in a temperature environment exceeding the melting temperature of the aforementioned cold storage material composition, The aforementioned thermal storage material composition contains, per 100 moles of water, 8.1 moles to 12.6 moles of lithium ions derived from (i) lithium bromide, (ii) optionally lithium chloride, and (iii) optionally lithium nitrate, (i) containing 7.6 moles to 14.6 moles of bromide ions derived from lithium bromide and (ii) optionally sodium bromide, Furthermore, it contains a crystal nucleating agent, The nucleating agent is at least one of sodium chloride and sodium bromide. A method for using a cold storage material composition, wherein the content of the nucleating agent is 0.1 moles to 10.0 moles per 100 moles of water.

11. The method for using the cold storage material composition according to claim 10, wherein in the solidification step, the temperature lower than the melting temperature is a temperature of -80°C or lower.

12. The method for using the cold storage material composition according to claim 10, wherein in the solidification step, the temperature lower than the melting temperature is a temperature of -85°C to -76°C.

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