Inorganic latent heat storage material composition and use thereof

Abstract

The purpose of the present invention is to provide an inorganic latent heat storage material composition having high thermal stability. Provided is an inorganic latent heat storage material composition containing: calcium chloride hexahydrate; and a metal soap formed of strontium ions and anions derived from a fatty acid.

Description

Inorganic latent heat storage material composition and use thereof

[0001] The present invention relates to an inorganic latent heat storage material composition and its use.

[0002] BACKGROUND ART In recent years, from an environmental perspective, research and development efforts have been actively undertaken in the field of building materials technology to more effectively utilize thermal energy generated during indoor heating and the like.

[0003] Furthermore, some items, such as reactive substances such as adhesives, precision instruments, semiconductors, pharmaceuticals, investigational drugs, and specimens, are preferably handled within a predetermined temperature range (hereinafter sometimes referred to as "controlled temperature"). Such items are also referred to as "items subject to temperature control." When transporting or storing items subject to temperature control, it is preferable to keep them cold or warm within the controlled temperature range for a predetermined period of time.

[0004] To date, several latent heat storage material compositions (sometimes referred to as "PCMs: Phase Change Materials") have been developed that are suitable for (i) application to wall materials, floor materials, ceiling materials, etc., and / or (ii) for storing or transporting temperature-controlled items that must be temperature-controlled at a controlled temperature above 0°C at a constant or nearly constant temperature.

[0005] For example, inorganic latent heat storage material compositions described in Patent Documents 1 and 2 are known.

[0006] International Publication No. 2022 / 158484 Japanese Patent Application Laid-Open No. 2021-143304

[0007] The above-mentioned conventional inorganic latent heat storage material compositions have room for improvement in terms of thermal stability.

[0008] One embodiment of the present invention has been made in view of the above problems, and its object is to provide an inorganic latent heat storage material composition having high thermal stability.

[0009] The present inventors have conducted extensive research to solve the above problems and have completed the present invention.

[0010] That is, the inorganic latent heat storage material composition according to one embodiment of the present invention is an inorganic latent heat storage material composition containing calcium chloride hexahydrate and a metal soap comprising strontium ions and anions derived from a fatty acid.

[0011] Another embodiment of the present invention provides a method for producing an inorganic latent heat storage material composition, which includes any one of the following mixing steps (A) to (C): a mixing step (A) of mixing calcium chloride hexahydrate with a metal soap comprising strontium ions and an anion derived from a fatty acid; a mixing step (B) of mixing a dispersion containing the metal soap comprising strontium ions and an anion derived from a fatty acid with one or more compounds selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate; or a mixing step (C) of mixing the metal soap comprising strontium ions and an anion derived from a fatty acid with water and one or more compounds selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0012] According to one embodiment of the present invention, it is possible to provide an inorganic latent heat storage material composition having high thermal stability.

[0013] Reference numeral 201 is a perspective view schematically showing an example of a heat storage material according to one embodiment of the present invention, and reference numeral 202 is an exploded perspective view schematically showing an example of a transport container according to one embodiment of the present invention. Reference numeral 301 is a perspective view schematically showing the inside of the transport container according to one embodiment of the present invention, and reference numeral 302 is a cross-sectional view schematically showing the A-A line cross section of 301.

[0014] An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the respective configurations described below, and various modifications are possible within the scope of the claims. Furthermore, embodiments or examples obtained by combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic literature and patent documents described in this specification are incorporated herein by reference. Furthermore, unless otherwise specified in this specification, the term "A to B" representing a numerical range means "greater than or equal to A (including and greater than A) and less than or equal to B (including and less than B)."

[0015] 1. Technical Concept of One Embodiment of the Present Invention The purpose of a PCM is to (i) stably maintain an item subject to temperature control at a predetermined temperature such as room temperature (e.g., 15°C to 30°C), and / or (ii) maintain a living space at a predetermined temperature (e.g., 15°C to 30°C). In this specification, transporting or storing an item subject to temperature control stably at a predetermined temperature (e.g., at a constant or approximately constant temperature) is referred to as "constant temperature transport," and an application for constant temperature transport may be referred to as "constant temperature transport application."

[0016] At present, organic latent heat storage material compositions have been mainly used as latent heat storage material compositions.

[0017] However, organic latent heat storage material compositions needed further improvement for one-way, constant-temperature transportation applications because (i) they are flammable, (ii) the raw materials of the latent heat storage material compositions are often regulated as hazardous materials, (iii) they pose a high environmental impact in the event of a leak, and (iv) the raw materials of the latent heat storage material compositions are expensive.

[0018] Therefore, in the technical field of latent heat storage material compositions, there is a growing need for inorganic latent heat storage material compositions that can solve all of the above-mentioned problems (i) to (iv) seen in organic latent heat storage material compositions. As inorganic latent heat storage material compositions, several inorganic latent heat storage material compositions are known, as described in Patent Documents 1 and 2 above.

[0019] However, the present inventors have independently found that conventional inorganic latent heat storage material compositions have the problem of low thermal stability, for example, being susceptible to deterioration due to heat.

[0020] Therefore, the present inventors have conducted extensive research in order to obtain an inorganic latent heat storage material composition having high thermal stability.

[0021] As a result of extensive research, the present inventor independently discovered a new finding that an inorganic latent heat storage material composition containing a metal soap consisting of strontium ions and anions derived from fatty acids surprisingly has high thermal stability, leading to the completion of the present invention.

[0022] [2. Inorganic Latent Heat Storage Material Composition] An inorganic latent heat storage material composition according to one embodiment of the present invention contains (i) calcium chloride hexahydrate and (ii) a metal soap comprising a strontium ion and an anion derived from a fatty acid.

[0023] In this specification, "inorganic latent heat storage material composition" may be referred to as "composition", and "inorganic latent heat storage material composition according to one embodiment of the present invention" may be referred to as "the composition".

[0024] The present composition has the above-mentioned structure and therefore has the advantage of high thermal stability.

[0025] As used herein, "high thermal stability" means that the difference between the freezing temperature and supercooling temperature of the composition (Δsupercooling) is small (e.g., less than 5.0°C) after a thermal stability test. That is, the present composition has the advantage that the Δsupercooling of the composition is small even after a thermal stability test. In one embodiment of the present invention, after a thermal stability test, the Δsupercooling of the composition is preferably less than 5.0°C, more preferably 4.5°C or less, more preferably 4.0°C or less, more preferably 3.5°C or less, even more preferably 3.0°C or less, even more preferably 2.5°C or less, and particularly preferably less than 2.5°C. Specific methods for thermal stability testing, methods for measuring the freezing temperature, and methods for measuring the supercooling temperature will be described in detail in the Examples below.

[0026] This composition can be used repeatedly. Here, "repeated use" with respect to an inorganic latent heat storage material composition means that the composition is repeatedly melted and solidified. It is preferable that the difference between the freezing temperature and the supercooling temperature of the composition (Δ supercooling) is small (e.g., less than 5.0°C) even after repeated use (e.g., after a cycle test). In one embodiment of the present invention, after a cycle test, the Δ supercooling of the composition is preferably 4.5°C or less, more preferably 4.0°C or less, more preferably 3.5°C or less, even more preferably 3.0°C or less, even more preferably 2.5°C or less, and particularly preferably less than 2.5°C. Specific methods for cycle tests will be described in detail in the examples below.

[0027] It is preferable that the difference between the freezing temperature and the supercooling temperature (Δ supercooling) of the composition is small (e.g., less than 5.0°C) even before repeated use (e.g., immediately after the production of the composition or before use of the composition (e.g., before solidification)). In this specification, "before repeated use" may be referred to as "initial". In one embodiment of the present invention, the initial Δ supercooling of the composition is preferably 4.5°C or less, more preferably 4.0°C or less, more preferably 3.5°C or less, even more preferably 3.0°C or less, even more preferably 2.5°C or less, and particularly preferably less than 2.5°C.

[0028] After a thermal stability test, after a cycle test, immediately after the production of the composition, or before use of the composition, the lower limit of the difference between the freezing temperature and the supercooling temperature of the composition (Δsupercooling) is not particularly reduced and may be, for example, 0° C. That is, in any of the above cases, there may be no difference between the freezing temperature and the supercooling temperature of the composition.

[0029] (2-1. (a) Calcium chloride hexahydrate) The content of calcium chloride hexahydrate in the present composition is the highest. Therefore, calcium chloride hexahydrate can be considered the main ingredient in the present composition and may also be referred to as the "main ingredient."

[0030] The present composition has the advantage that, by using calcium chloride hexahydrate as the main agent, a composition having a melting temperature of 15°C to 30°C can be easily produced.

[0031] In addition to the present composition containing calcium chloride hexahydrate as a main component, inorganic latent heat storage material compositions are known that contain, as a main component, sodium acetate trihydrate, sodium sulfate decahydrate, disodium hydrogen phosphate dodecahydrate, sodium carbonate decahydrate, etc. Compared to such compositions containing inorganic salts other than calcium chloride hexahydrate as a main component, the present composition has the following advantages: (i) the composition can be more suitably used in the temperature range assumed to be the environment in which humans live (human living environment), (ii) the temperature of an item subject to temperature control can be stably maintained at around 15°C to 30°C, and (iii) the resulting composition has excellent durability and less odor.

[0032] The content of calcium chloride hexahydrate in the composition is not particularly limited and can be appropriately set based on the desired melting temperature, viscosity, etc. The composition preferably contains 50.00 wt% or more of calcium chloride hexahydrate, more preferably 55.00 wt% or more, more preferably 60.00 wt% or more, even more preferably 65.00 wt% or more, and particularly preferably 70.00 wt% or more, based on 100 wt% of the composition. When the content of calcium chloride hexahydrate in the composition is within the above-mentioned range, it has the following advantages: (i) a large latent heat per weight is obtained, thereby functioning efficiently as a heat storage material; (ii) the resulting composition can be used in temperatures representative of human living environments; and (iii) the resulting composition has excellent durability and little odor. The upper limit of the calcium chloride hexahydrate content in the composition is not particularly limited and may be, for example, 99.99 wt% or less, based on 100 wt% of the composition.

[0033] (2-2. Metal Soap) The present composition contains a metal soap consisting of strontium ions and anions derived from fatty acids. The metal soap can have the function of preventing the composition from supercooling. Therefore, the metal soap can be said to be a "supercooling inhibitor," "supercooling suppressant," "crystal nucleating agent," "nucleating agent," or "nucleating agent." By including the metal soap in the present composition, the present composition has the advantage of high thermal stability.

[0034] In this specification, unless otherwise specified, the term "metal soap" refers to a "metal soap comprising strontium ions and anions derived from fatty acids." More specifically, the metal soap refers to a substance in which strontium ions (cations) and anions (anions) derived from fatty acids are ionic-bonded.

[0035] In this specification, the fatty acid in the "anion derived from a fatty acid" may be referred to as "fatty acid F." Fatty acid F is not particularly limited, and examples thereof include conventionally known fatty acids having a hydrocarbon chain and a carboxyl group. Fatty acid F is not limited to linear monocarboxylic acids. Fatty acid F may have a functional group such as a hydroxyl group, or may have a cyclic structure.

[0036] The hydrocarbon chain in the fatty acid F may be linear or may contain a branched chain.

[0037] The hydrocarbon chain of the fatty acid F may be saturated or unsaturated. From the viewpoint of suppressing decomposition of the hydrocarbon chain due to oxidation, the hydrocarbon chain of the fatty acid F is preferably a saturated hydrocarbon chain. In other words, the fatty acid F is preferably a saturated fatty acid.

[0038] The number of carbon atoms of fatty acid F is not particularly limited, but is preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, and particularly preferably 12 or more. This configuration has the advantage that the metal soap has crystallinity suitable for controlling the particle size of the metal soap. The number of carbon atoms of fatty acid F may be 14 or more, 16 or more, or 18 or more.

[0039] The upper limit of the number of carbon atoms in fatty acid F is not particularly limited, but may be 30 or less, 28 or less, 26 or less, 24 or less, 22 or less, 20 or less, or 18 or less. The fewer the carbon atoms in fatty acid F, the lower the cohesive force of the metal soap, making it easier to maintain the particle size of the metal soap. Therefore, the upper limit of the number of carbon atoms in fatty acid F is preferably 18 or less, more preferably 16 or less, and even more preferably 14 or less.

[0040] Fatty acid F is preferably one or more selected from the group consisting of caprylic acid (n-octanoic acid), capric acid (n-decanoic acid), lauric acid (n-dodecanoic acid), myristic acid (n-tetradecanoic acid), palmitic acid (n-hexadecanoic acid), and stearic acid (n-octadecanoic acid), more preferably one or more selected from the group consisting of lauric acid, myristic acid, palmitic acid, and stearic acid, and even more preferably lauric acid. This configuration has the advantage that the metal soap has suitable crystallinity.

[0041] The metal soap is preferably one or more selected from the group consisting of strontium dicaprylate, strontium dicaprate, strontium dilaurate, strontium dimyristate, strontium dipalmitate, and strontium distearate, more preferably one or more selected from the group consisting of strontium dilaurate, strontium dimyristate, strontium dipalmitate, and strontium distearate, and even more preferably strontium dilaurate. This configuration has the advantage that the metal soap has suitable crystallinity.

[0042] In one embodiment of the present invention, the content of the metal soap in 100% by weight of the composition is not particularly limited, but is preferably 0.01% by weight to 0.10% by weight, more preferably 0.03% by weight to 0.07% by weight, and even more preferably 0.03% by weight to 0.05% by weight. This configuration has the advantage of enabling the metal soap to be well dispersed in the composition.

[0043] The metal soap may be a substance obtained by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid. In this specification, "water-soluble" means that the substance has a solubility of 0.01 g / ml or more in water at 25°C. Strontium salts are water-soluble. Therefore, in an aqueous solution containing a strontium salt, the strontium salt may ionize, and strontium ions may be present in the aqueous solution. In an aqueous solution containing a water-soluble metal salt of a fatty acid, the metal salt may ionize, and anions of the fatty acid (anions derived from the fatty acid) may be present in the aqueous solution. Therefore, by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid, for example by mixing them, strontium ions and anions derived from the fatty acid may ionically bond in the resulting mixture, producing a metal soap. In other words, by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid, it is highly likely that a metal soap is produced in the resulting mixture. Therefore, it can be assumed that a metal soap is present in the mixture obtained by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid. On the other hand, in an aqueous solution containing a metal salt of a fatty acid that is not water-soluble (i.e., poorly water-soluble), the metal salt cannot ionize, and therefore no anion of the fatty acid can be present in the aqueous solution. Furthermore, since fatty acids with 8 or more carbon atoms are themselves poorly water-soluble, in an aqueous solution containing a fatty acid with 8 or more carbon atoms, the fatty acid cannot ionize, and therefore no anion of the fatty acid can be present in the aqueous solution. In this specification, when a substance is "poorly water-soluble," it is meant that the substance has a "solubility in water at 25°C of less than 0.01 g / ml." Therefore, when (i) (ia) an aqueous solution containing a water-insoluble metal salt of a fatty acid or (ib) an aqueous solution containing a fatty acid having 8 or more carbon atoms is mixed with (ii) an aqueous solution containing a strontium salt, it is highly likely that no metal soap will be produced in the resulting mixture.Therefore, it can be considered that no metal soap is present in (i) a mixture obtained by mixing (ia) an aqueous solution containing a water-insoluble metal salt of a fatty acid, or (ib) an aqueous solution containing a fatty acid having 8 or more carbon atoms with (ii) an aqueous solution containing a strontium salt.

[0044] Examples of strontium salts include inorganic salts, such as strontium chloride, strontium chloride hexahydrate, strontium hydroxide octahydrate, etc. As the strontium salt, one of the above-mentioned compounds may be used alone, or two or more of them may be used in combination.

[0045] The strontium salt is preferably at least one selected from the group consisting of strontium chloride and strontium chloride hexahydrate, as this can prevent or reduce corrosion of production equipment and the like.

[0046] Examples of the water-soluble metal salt of a fatty acid include alkali metal salts and alkaline earth metal salts. As the water-soluble metal salt of a fatty acid, one of the above-mentioned compounds may be used alone, or two or more of them may be used in combination.

[0047] In order to produce a homogeneous metal soap, the water-soluble metal salt of a fatty acid is preferably one or more selected from the group consisting of alkali metal salts and alkaline earth metal salts, more preferably one or more selected from the group consisting of alkali metal salts, and even more preferably one or more selected from the group consisting of sodium salts and potassium salts.

[0048] A preferred example of the fatty acid in the "water-soluble metal salt of a fatty acid" is the above-mentioned fatty acid F. Therefore, preferred embodiments of fatty acid F are also preferred for the fatty acid in the "water-soluble metal salt of a fatty acid".

[0049] The water-soluble metal salt of a fatty acid is preferably one or more selected from the group consisting of sodium caprylate, sodium caprate, sodium laurate, sodium myristate, sodium palmitate, sodium stearate, potassium caprylate, potassium caprate, potassium laurate, potassium myristate, potassium palmitate, and potassium stearate. This configuration has the advantage of enabling the production of a homogeneous metal soap.

[0050] When the metal soap contained in the present composition is a substance obtained by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid, the concentration of the strontium salt in the aqueous solution containing the strontium salt and the amount of the aqueous solution used, and the concentration of the metal salt in the aqueous solution containing the water-soluble metal salt of a fatty acid and the amount of the aqueous solution used are not particularly limited, but it is preferable that the amount of metal soap in the resulting mixture (composition) is an amount that falls within the preferred range of the metal soap content in the composition described above. In other words, by adjusting the concentration of the strontium salt in the aqueous solution containing the strontium salt and the amount of the aqueous solution used, and the concentration of the metal salt in the aqueous solution containing the water-soluble metal salt of a fatty acid and the amount of the aqueous solution used, respectively, the content of the metal soap in the resulting mixture (composition) can be adjusted to a desired range.

[0051] The volume average particle size of the metal soap in the composition is not particularly limited, but is preferably 0.01 μm to 500.00 μm, more preferably 0.10 μm to 100.00 μm, and even more preferably 0.10 μm to 10.00 μm. This configuration has the advantage of enabling good nucleation by the metal soap as a crystal nucleating agent, thereby enabling the formation of a favorable dispersion state of the metal soap in the composition. The volume average particle size of the metal soap in the composition can be measured using a particle size distribution analyzer that utilizes laser diffraction and / or dynamic light scattering.

[0052] (2-3. Inorganic Salt S) In addition to calcium chloride hexahydrate and a metal soap, the present composition preferably further contains one or more inorganic salts selected from the group consisting of bromide salts and chloride salts. In this specification, "one or more inorganic salts selected from the group consisting of bromide salts and chloride salts" may be referred to as "inorganic salt S."

[0053] The inorganic salt S may have (i) the function of adjusting the melting temperature and / or solidification temperature of the composition, and / or (ii) the function of preventing supercooling of the composition. A "substance capable of adjusting the melting temperature and / or solidification temperature of the composition" may be referred to as a "melting point adjuster" or a "freezing point depressant." A "substance capable of preventing supercooling of the composition" may be referred to as a "supercooling prevention agent," "supercooling suppression agent," "crystal nucleating agent," "nucleating agent," or "nucleating agent." In other words, the inorganic salt S may be referred to as a "melting point adjuster" or a "freezing point depressant," and / or a "supercooling prevention agent," "supercooling suppression agent," "crystal nucleating agent," "nucleating agent," or "nucleating agent."

[0054] In this specification, the above-mentioned calcium chloride hexahydrate and strontium salts, as well as the cellulose derivatives, benzoates, and main agent precursors described below, are not included in the inorganic salts S. For example, calcium chloride hexahydrate, strontium salts strontium bromide and strontium chloride, and main agent precursors calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate are not considered to be inorganic salts S. Therefore, the amounts of calcium chloride hexahydrate, strontium salts strontium bromide and strontium chloride, and main agent precursors calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate used are not included in the total amount of inorganic salts S used.

[0055] The bromide salt is preferably a water-soluble inorganic salt, such as a metal bromide or ammonium bromide.

[0056] Examples of metal bromides include lithium bromide, sodium bromide, potassium bromide, calcium bromide, magnesium bromide, iron bromide, zinc bromide, barium bromide, etc. As the bromide salt, one of the above-mentioned compounds may be used alone, or two or more of them may be used in combination.

[0057] Among the bromide salts described above, sodium bromide, potassium bromide, ammonium bromide, etc., when used in small amounts, can adjust the melting temperature and / or solidification temperature of the resulting composition to a desired temperature (for example, 15° C. to 30° C.) Therefore, the bromide salt preferably includes one or more selected from the group consisting of sodium bromide, potassium bromide, and ammonium bromide, more preferably one or more selected from the group consisting of sodium bromide, potassium bromide, and ammonium bromide, and even more preferably sodium bromide and potassium bromide.

[0058] The chloride salt is preferably a water-soluble inorganic salt, such as a metal chloride or ammonium chloride. Examples of the metal chloride include lithium chloride, sodium chloride, potassium chloride, magnesium chloride, iron chloride, zinc chloride, aluminum chloride, barium chloride, and cobalt chloride. As the chloride salt, one of the above-mentioned compounds may be used alone, or two or more may be used in combination.

[0059] The chloride salt preferably comprises sodium chloride, more preferably sodium chloride, due to its ready availability and general use as a melting point adjuster.

[0060] Of the inorganic salts S described above, sodium bromide, potassium bromide, calcium bromide, ammonium bromide, iron bromide, zinc bromide, barium bromide, sodium chloride, potassium chloride, magnesium chloride, iron chloride, zinc chloride, and cobalt chloride can function as melting point adjusters. Furthermore, of the inorganic salts S described above, sodium chloride and barium chloride can function as supercooling inhibitors. That is, sodium chloride can function as both a "melting point adjuster" and a "supercooling inhibitor."

[0061] By using a small amount of the inorganic salt S, the melting temperature and / or solidification temperature of the resulting composition can be adjusted to a desired temperature (for example, 15°C to 30°C). Therefore, the inorganic salt S is preferably one or more selected from the group consisting of sodium bromide, potassium bromide, potassium chloride and sodium chloride, and more preferably one or more selected from the group consisting of potassium bromide and potassium chloride.

[0062] The total content of inorganic salt S in the composition is not particularly limited and can be appropriately selected depending on the content of calcium chloride hexahydrate in the composition. The composition preferably contains 1.0 wt % to 45.0 wt % of inorganic salt S in total, based on 100 wt % of the composition, more preferably 2.0 wt % to 40.0 wt %, even more preferably 3.0 wt % to 35.0 wt %, and particularly preferably 5.0 wt % to 30.0 wt %. This configuration offers the following advantages: (i) when the resulting composition is used in building materials such as wall, floor, ceiling, and roofing materials, the temperature of the space near the building material or the space covered by the building material can be maintained at an appropriate temperature (e.g., 15°C to 30°C) with high precision; and (ii) the resulting composition can stably maintain the temperature of an item subject to temperature control at around 15°C to 30°C.

[0063] The present composition may further contain a melting point adjuster other than the inorganic salt S that can function as a melting point adjuster (hereinafter, sometimes referred to as "other melting point adjuster"). Examples of other melting point adjusters include (i) ammonium salts other than ammonium bromide and ammonium chloride, (ii) metal halides other than metal bromides and metal chlorides, (iii) metal non-halides, and (iv) urea.

[0064] In order to achieve excellent handling properties, a small environmental impact, and a low odor, the content of the ammonium salt contained in the composition is preferably low. The content of the ammonium salt contained in the composition is preferably 1.00 wt% or less, more preferably 0.50 wt% or less, even more preferably 0.10 wt% or less, even more preferably 0.01 wt% or less, and particularly preferably 0.00 wt%, relative to 100 wt% of the total weight of the composition.

[0065] (2-4. Lower Alcohols) In addition to calcium chloride hexahydrate and a metal soap, the present composition preferably further contains a lower alcohol. The lower alcohol may have the function of adjusting the melting temperature and / or freezing temperature of the composition. In other words, the lower alcohol can be said to be a "melting point adjuster" or a "freezing point depressant."

[0066] Examples of the lower alcohols include alcohols having 5 or less carbon atoms. Specific examples of the lower alcohols include methanol, ethanol, 2-propanol, ethylene glycol, glycerol, etc. Among these, ethanol is particularly preferred as the lower alcohol.

[0067] The content of the lower alcohol in the composition is not particularly limited and can be appropriately determined depending on the amount of calcium chloride hexahydrate in the composition. The composition preferably contains 0.50 wt % to 5.00 wt %, and more preferably 1.00 wt % to 3.00 wt %, of the lower alcohol relative to 100 wt % of the composition. This composition has the advantage of easily adjusting the melting temperature.

[0068] (2-5. Cellulose Derivative) In addition to calcium chloride hexahydrate and a metal soap, the present composition preferably further contains a cellulose derivative. The cellulose derivative may have the function of increasing the viscosity of the composition and / or the function of making the composition gel-like. A "substance capable of increasing the viscosity of the composition" or a "substance capable of making the composition gel-like" may be referred to as a "thickener" or a "gelling agent," respectively. In other words, a cellulose derivative can be said to be a "thickener" or a "gelling agent."

[0069] The present composition containing a cellulose derivative has the advantage that the composition is in a gel state at temperatures above the melting point. Cellulose derivatives are thermosetting thickeners. Therefore, the present composition containing a cellulose derivative has the advantage that the composition can be produced efficiently and stably.

[0070] Examples of cellulose derivatives include carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, etc. The cellulose derivative preferably includes hydroxyethyl cellulose, and more preferably is hydroxyethyl cellulose, because (i) it is nonionic and does not affect inorganic ions dissolved in the composition, and (ii) it can turn an aqueous solution with a high ion concentration into a gel.

[0071] In the composition, depending on the concentration of the inorganic salt contained (here, "inorganic salt" is not limited to the inorganic salt S described above, but also includes other inorganic salts), precipitation of the inorganic salt may occur over time due to temperature changes. When the composition contains a cellulose derivative, the cellulose derivative not only (i) can make the composition gel-like, but also (ii) can efficiently disperse the inorganic salt ions dissolved in the composition. As a result, the cellulose derivative can suppress the precipitation of the inorganic salt in the composition.

[0072] The cellulose derivative in the composition does not affect the melting and / or solidification behavior of the composition, and allows the composition to maintain a high latent heat of fusion. Furthermore, when the composition contains a cellulose derivative, the composition has the advantage of remaining in a gel state even after undergoing a cycle test or a thermal stability test at the environmental temperature where the composition is expected to be used. Furthermore, when the composition contains a cellulose derivative, the composition remains in a gel state even in a molten state, allowing the composition to maintain a constant shape. As a result, even when the composition is in a molten state, there is no risk of environmental pollution, and environmental impact can be reduced.

[0073] The content of the cellulose derivative in the composition is not particularly limited and can be appropriately set depending on the amount of calcium chloride hexahydrate in the composition. The composition preferably contains 0.3 wt% to 7.0 wt%, more preferably 0.5 wt% to 6.0 wt%, and even more preferably 1.0 wt% to 5.0 wt%, of the cellulose derivative, relative to 100 wt% of the composition. This configuration has the advantages of (i) preventing aggregation and precipitation of salts (both inorganic and organic salts) dissolved in the composition, (ii) providing good handleability for the composition, and (iii) maintaining a gel state in a temperature environment above the melting temperature of the composition.

[0074] The present composition may further contain a thickener other than a cellulose derivative. Examples of thickeners other than a cellulose derivative include water-absorbent resins, gelatin, agar, xanthan gum, gum arabic, guar gum, carrageenan, konjac, etc. Examples of water-absorbent resins include starch-based resins, acrylate-based resins, and poval-based resins. Examples of silica include fumed silica, precipitated silica, and silica gel.

[0075] The calcium chloride hexahydrate and inorganic salts contained in the composition are often dissolved in the composition in an ionic state, and therefore, as a thickener other than a cellulose derivative, a nonionic thickener is preferred, and guar gum and / or dextrin are more preferred, as they do not affect the inorganic ions dissolved in the composition.

[0076] The total content of thickeners in the composition (the total content of the cellulose derivative and the thickener other than the cellulose derivative) is not particularly limited and can be appropriately set depending on the amount of calcium chloride hexahydrate in the composition. The total content of thickeners in the composition is preferably 1 to 10 parts by weight, more preferably 2 to 6 parts by weight, per 100 parts by weight of calcium chloride hexahydrate. This configuration has the advantages of (i) preventing aggregation and precipitation of salts dissolved in the composition, (ii) providing good handleability for the composition, and (iii) maintaining a gel state in a temperature environment above the melting temperature of the composition.

[0077] (2-6. Benzoate) The present composition may further contain a benzoate. The benzoate may have the function of preventing supercooling of the composition. Therefore, the benzoate may be referred to as a "supercooling inhibitor," "supercooling suppressant," "crystal nucleating agent," "nucleating agent," or "nucleating agent." The benzoate may also have the function of preventing spoilage of the composition. Therefore, the benzoate may also be referred to as a "preservative."

[0078] Examples of the benzoate include (i) metal salts of benzoic acid such as sodium benzoate, potassium benzoate, lithium benzoate, and calcium benzoate, and (ii) ammonium benzoate. As the benzoate, one of the above-mentioned compounds may be used alone, or two or more may be used in combination.

[0079] Because of their high water solubility and the ability to reduce the degree of supercooling of the composition, the benzoate preferably includes one or more selected from the group consisting of metal salts of benzoic acid and ammonium benzoate, more preferably one or more selected from the group consisting of metal salts of benzoic acid and ammonium benzoate, even more preferably one or more selected from the group consisting of sodium benzoate, potassium benzoate and ammonium benzoate, and particularly preferably sodium benzoate.

[0080] The content of the benzoate in the present composition is not particularly limited.

[0081] (2-7. Organic Solvent) In order to further enhance the flame retardancy of the composition, it is preferable that the content of organic solvents that are volatile at room temperature (e.g., 15°C to 30°C) in the composition (e.g., monocyclic aromatic compounds, more specifically, benzene, toluene, xylene, ethylenebenzene, cumene, paracymene, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, etc.) is small. Specifically, the content of organic solvents that are volatile at room temperature (e.g., monocyclic aromatic compounds) per 100 parts by weight of the total weight of the composition is preferably 50.0 parts by weight or less, 10.0 parts by weight or less, 5.0 parts by weight or less, 1.0 parts by weight or less, 0.5 parts by weight or less, or 0.1 parts by weight or less (the lower limit is 0.0 parts by weight). The total content of one or more compounds selected from the group consisting of benzyl, toluene, xylene, ethylenebenzene, cumene, paracymene, dimethyl phthalate, diethyl phthalate, and dipropyl phthalate per 100 parts by weight of the total weight of the composition is preferably 50.0 parts by weight or less, 10.0 parts by weight or less, 5.0 parts by weight or less, 1.0 parts by weight or less, 0.5 parts by weight or less, or 0.1 parts by weight or less (the lower limit is 0.0 part by weight).

[0082] (2-8. Other Components) The composition may contain other components as needed, as long as the effects of one embodiment of the present invention are not impaired. Examples of other components include solvents, alcohols other than lower alcohols, preservatives, fragrances, colorants, antifoaming agents, flame retardants, light resistance stabilizers, UV absorbers, storage stabilizers, foam regulators, lubricants, antifungal agents, antibacterial agents, high molecular weight polymers, other organic compounds, and other inorganic compounds.

[0083] The solvent is preferably water in order to further increase the flame retardancy of the composition.

[0084] Examples of alcohols other than the lower alcohols include higher alcohols (e.g., alcohols having 6 or more carbon atoms, such as capryl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, and linoleyl alcohol). Higher alcohols can have the function of adjusting the melting temperature and / or solidification temperature of the composition.

[0085] (2-9. Physical Properties) The physical properties of the present composition will now be described.

[0086] (Melting Temperature) The melting temperature of the present composition is not particularly limited. The present composition preferably has a melting temperature of 15°C to 30°C, more preferably 17°C to 28°C, and even more preferably 18°C ​​to 25°C. This configuration has the following advantages: (i) by suitably applying the obtained composition to a home, the latent heat of the composition can be utilized to easily create a comfortable living environment, and (ii) the obtained composition can stably maintain the temperature of an item subject to temperature management at around 15°C to 30°C. A method for measuring the melting temperature of the composition will be described in detail in the Examples below. The "melting temperature" is sometimes also referred to as the "melting point."

[0087] (Freezing Temperature) The freezing temperature of the present composition is not particularly limited. The present composition preferably has a freezing temperature of 15°C to 30°C, more preferably 17°C to 28°C, and even more preferably 20°C to 25°C. This configuration has the following advantages: (i) by suitably applying the obtained composition to a home, the latent heat of the composition can be utilized to easily create a comfortable living environment, and (ii) the obtained composition can stably maintain the temperature of an item subject to temperature control at around 15°C to 30°C. The "freezing temperature" is sometimes referred to as the "freezing point." The "melting temperature" and "freezing temperature" are sometimes collectively referred to as the "phase change temperature" or "phase transition temperature."

[0088] (2-10. Uses) The present composition can be suitably used as a latent heat storage material that utilizes (i) the absorption of thermal energy during the phase transition of the composition from a solidified state (solid) to a molten state (liquid or gel state), and (ii) the release of thermal energy during the phase transition of the composition from a molten state (liquid or gel state) to a solidified state (solid). The "molten state" can also be referred to as a "melted state."

[0089] For example, the present composition can maintain, for example, a room temperature at a desired temperature below the ambient temperature, even in a high-temperature environment (e.g., summer), by absorbing thermal energy during the phase transition from the solidified state to the molten state. Furthermore, the present composition can maintain, for example, a room temperature at a desired temperature above the ambient temperature, even in a low-temperature environment (e.g., winter), by releasing thermal energy during the phase transition from the molten state to the solidified state. In other words, the inorganic latent heat storage material composition according to one embodiment of the present invention can maintain, for example, a room temperature at a desired temperature (e.g., 15°C to 30°C), even in both high-temperature and low-temperature environments.

[0090] The inorganic latent heat storage material composition according to one embodiment of the present invention can be suitably used in various applications requiring heat storage performance, such as building materials such as wall materials, floor materials, ceiling materials, roofing materials, etc. Furthermore, the inorganic latent heat storage material composition according to one embodiment of the present invention can be suitably used in applications for constant temperature transportation of items requiring temperature control, such as reactive substances (e.g., adhesives), precision instruments, semiconductors, pharmaceuticals, investigational drugs, and specimens.

[0091] [3. Manufacturing method of inorganic latent heat storage material composition] The manufacturing method (preparation method) of the present composition is not particularly limited. The present composition can be prepared using any technique known in the technical field of inorganic latent heat storage material compositions. The present composition can be prepared, for example, by mixing the above-mentioned components.

[0092] A method for producing an inorganic latent heat storage material composition according to one embodiment of the present invention will be described below, but the description in [2. Inorganic latent heat storage material composition] will be used as appropriate for matters other than those detailed below. In this specification, the "method for producing an inorganic latent heat storage material composition" will sometimes be referred to as the "production method," and the "method for producing an inorganic latent heat storage material composition according to one embodiment of the present invention" will sometimes be referred to as the "present production method." Furthermore, in [2. Inorganic latent heat storage material composition], each aspect described as the "content" of a certain substance (component) can be used as the "usage amount," "blended amount," or "added amount" of a certain substance (component) in the method for producing the composition.

[0093] Calcium chloride hexahydrate is commercially available. Meanwhile, calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate are also commercially available. In this production method, only calcium chloride hexahydrate, the main component, may be used. Alternatively, in this production method, part or all of the main component calcium chloride hexahydrate may be replaced with one or more components selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate. Calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate all (i) form hydrates (or hydrates with higher hydration numbers) upon contact with water, and (ii) generate heat upon hydrate formation, i.e., exhibit a positive heat of solution. Calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate can all form calcium chloride hexahydrate, the main component, upon contact with water. Even when part or all of calcium chloride hexahydrate is replaced with one or more selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate, the present composition containing calcium chloride hexahydrate can be obtained. Therefore, calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate can all be referred to as "main agent precursors." Hereinafter, "calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate" may be collectively referred to as "main agent precursors."

[0094] Since the inorganic latent heat storage material composition can be efficiently provided, the method for producing an inorganic latent heat storage material composition according to one embodiment of the present invention preferably includes any one of the following mixing steps (A) to (C): a mixing step (A) of mixing calcium chloride hexahydrate with a metal soap comprising strontium ions and an anion derived from a fatty acid; a mixing step (B) of mixing a dispersion containing a metal soap comprising strontium ions and an anion derived from a fatty acid with one or more members selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate; or a mixing step (C) of mixing a metal soap comprising strontium ions and an anion derived from a fatty acid with water and one or more members selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0095] In the present production method, the device used to mix the components is not particularly limited, and known devices such as mixers such as intensive mixers, stirrers, and shakers can be used as appropriate.

[0096] (3-1. Mixing Step (A)) In the mixing step (A), at least calcium chloride hexahydrate and a metal soap are mixed. In the mixing step (A), water, an inorganic salt S, and / or a cellulose derivative may be further mixed as desired. In the mixing step (A), the method and timing of mixing the water, the inorganic salt S, and / or the cellulose derivative are not particularly limited. For example, calcium chloride hexahydrate and the inorganic salt S are mixed in advance to prepare a mixture. Then, the mixture may be mixed with a metal soap. Furthermore, the obtained mixture may be mixed with a cellulose derivative.

[0097] (3-2. Mixing Step (B)) In the mixing step (B), a dispersion containing a metal soap composed of strontium ions and anions derived from a fatty acid is mixed with one or more main agent precursors.

[0098] When the mixing step (B) is carried out, a dispersion preparation step of preparing a dispersion containing a metal soap may be further carried out before the mixing step (B). In other words, the present production method further includes a dispersion preparation step of preparing a dispersion containing a metal soap before the mixing step (B), and in the mixing step (B), the dispersion prepared in the dispersion preparation step may be mixed with one or more selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0099] (Dispersion Preparation Step) The dispersion preparation step is not particularly limited as long as it can obtain a dispersion in which the metal soap is dispersed in a solvent (for example, water). The solvent is preferably water, and the dispersion is preferably an aqueous dispersion.

[0100] The dispersion preparation step may be, for example, a step of mixing water and a metal soap.

[0101] As described above, a mixture (dispersion) containing a metal soap can be prepared by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid. To react an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid, the aqueous solution containing the strontium salt and the aqueous solution containing the water-soluble metal salt of a fatty acid can be brought into contact with each other, for example, by simply mixing them. Therefore, the dispersion preparation step may be a step of mixing an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of a fatty acid. Since a dispersion in which the metal soap is uniformly or substantially uniformly dispersed in a solvent can be obtained, the dispersion preparation step is preferably a step of preparing a dispersion containing the metal soap by reacting an aqueous solution containing a strontium salt with an aqueous solution containing the water-soluble metal salt of a fatty acid.

[0102] In the mixing step (B), one or more main component precursors selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate are used in place of calcium chloride hexahydrate, which is the main component. As described above, the main component precursor reacts with water to form calcium chloride hexahydrate, which is the main component. Therefore, the mixing step (B) can also be said to be a step of preparing a mixture containing calcium chloride hexahydrate and a metal soap, i.e., an inorganic latent heat storage material composition.

[0103] In the mixing step (B), the total amount of calcium chloride anhydrous, calcium chloride dihydrate, and calcium chloride tetrahydrate used can be appropriately determined so that the content of calcium chloride hexahydrate in the final composition is the desired amount.

[0104] The base precursor generates heat upon hydration and exhibits a positive heat of dissolution. In order to make the most of the heat generated by hydration of the base precursor, it is preferable that the base precursor to be mixed with the aqueous solution is a solid, rather than a solution state obtained by premixing with water. That is, the mixing step (B) is preferably a step of mixing a dispersion containing a metal soap with one or more solid compounds selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0105] In the mixing step (B), optionally, water, an inorganic salt S, and / or a cellulose derivative may be further mixed in. In the mixing step (B), the method and timing of mixing the water, the inorganic salt S, and / or the cellulose derivative are not particularly limited.

[0106] A case where an inorganic salt S is further mixed in the mixing step (B) (hereinafter also referred to as "case A") will be described. In case A, the mixing step (B) may be (i) a step of mixing a dispersion of a metal soap, an inorganic salt S, and one or more main component precursors, or (ii) a step of mixing a dispersion in which the inorganic salt S is dissolved and the metal soap is dispersed with one or more main component precursors. From the viewpoint of enhancing uniform solubility, in case A, the mixing step (B) is preferably a step of mixing a dispersion in which the inorganic salt S is dissolved and the metal soap is dispersed with one or more main component precursors.

[0107] In the dispersion preparation step in Case A, a dispersion in which the inorganic salt S is dissolved and the metal soap is dispersed is prepared. In the dispersion preparation step in Case A, for example, (i) water, the metal soap, and the inorganic salt S may be mixed to prepare a dispersion in which the inorganic salt S is dissolved and the metal soap is dispersed, (ii) an aqueous solution containing a strontium salt and the inorganic salt S may be reacted with an aqueous solution containing a water-soluble metal salt of a fatty acid to prepare a dispersion in which the inorganic salt S is dissolved and the metal soap, or (iii) an aqueous solution containing a strontium salt may be reacted with an aqueous solution containing a water-soluble metal salt of a fatty acid and the inorganic salt S to prepare a dispersion in which the inorganic salt S is dissolved and the metal soap. From the viewpoint of further enhancing uniform solubility, the dispersion preparation step in Case A is preferably a step of preparing a dispersion in which the inorganic salt S is dissolved and the metal soap by reacting an aqueous solution containing a strontium salt and the inorganic salt S with an aqueous solution containing a water-soluble metal salt of a fatty acid.

[0108] When a cellulose derivative is further mixed in the mixing step (B), the mixing step (B) may be (i) a step of mixing a dispersion of a metal soap, a cellulose derivative, and one or more types of main component precursors, or (ii) a step of mixing a dispersion in which the cellulose derivative and the metal soap are dispersed, with one or more types of main component precursors.

[0109] (3-3. Mixing Step (C)) In the mixing step (C), a solid metal soap, water, and one or more main agent precursors are mixed together.

[0110] In the mixing step (C), one or more main component precursors selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate are used in place of calcium chloride hexahydrate, which is the main component. As described above, the main component precursor reacts with water to form calcium chloride hexahydrate, which is the main component. Therefore, the mixing step (C) can also be said to be a step of preparing a mixture containing calcium chloride hexahydrate and a metal soap, i.e., an inorganic latent heat storage material composition.

[0111] In the mixing step (C), the total amount of calcium chloride anhydrous, calcium chloride dihydrate, and calcium chloride tetrahydrate used can be appropriately determined so that the content of calcium chloride hexahydrate in the final composition is a desired amount.

[0112] The base precursor generates heat upon hydration and exhibits a positive heat of dissolution. In order to make the most of the heat generated by hydration of the base precursor, it is preferable that the base precursor to be mixed with the aqueous solution is in the form of a solid, rather than in the form of a solution previously mixed with water. That is, the mixing step (C) is preferably a step of mixing a solid metal soap, water, and one or more solid compounds selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0113] In the mixing step (C), optionally, water, an inorganic salt S, and / or a cellulose derivative may be further mixed in. In the mixing step (C), the method and timing of mixing the water, the inorganic salt S, and / or the cellulose derivative are not particularly limited.

[0114] When an inorganic salt S is further mixed in the mixing step (C), the mixing step (C) may be (i) a step of mixing a metal soap, an inorganic salt S, water, and one or more solid compounds selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate, or (ii) a step of mixing a metal soap, an aqueous solution containing the inorganic salt S, and one or more solid compounds selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0115] When a cellulose derivative is further mixed in the mixing step (C), the mixing step (C) may be (i) a step of mixing a metal soap, a cellulose derivative, water, and one or more solid compounds selected from the group consisting of calcium chloride dihydrate and calcium chloride tetrahydrate, or (ii) a step of mixing a metal soap, a dispersion in which the cellulose derivative is dispersed, and one or more solid compounds selected from the group consisting of calcium chloride dihydrate and calcium chloride tetrahydrate.

[0116] In any of the mixing steps (A), (B) and (C), an inorganic salt S and / or a cellulose derivative may be further mixed with the mixture (composition) obtained by the mixing step.

[0117] In any of the mixing steps (A), (B), and (C), it is preferable to stir the mixture obtained by the mixing step. Alternatively, one component may be stirred while the other component is being added to the component being stirred. The device used for stirring is not particularly limited, and known devices can be used as appropriate. The stirring conditions are also not particularly limited.

[0118] In any of the mixing steps (A), (B), and (C), the mixture obtained by the mixing step may be heated to improve production efficiency. The heating device used is not particularly limited, and any known device can be used as appropriate. For example, the heating may be performed using a heating means provided in the device used to stir the mixture. The heating temperature of the mixture is not particularly limited. When a base precursor is used in the mixing steps (B) and (C), the temperature of the mixture may increase due to the reaction between water and the base precursor in the mixture obtained in the mixing step. Therefore, in the mixing steps (B) and (C), the same advantages as when the mixture is heated can be obtained without using a separate heating means.

[0119] 4. Heat Storage Material The heat storage material according to one embodiment of the present invention may be any material as long as it contains (includes) the inorganic latent heat storage material composition described above, and other configurations, materials, and the like are not limited thereto.

[0120] The heat storage material according to one embodiment of the present invention can be used as a latent heat storage material by (i) absorbing thermal energy while the inorganic latent heat storage material composition forming the heat storage material undergoes a phase transition (in other words, melting) from a solidified state (solid) to a molten state (liquid or gel state), and (ii) absorbing thermal energy while the inorganic latent heat storage material composition forming the heat storage material undergoes a phase transition (in other words, solidifying) from a molten state (liquid or gel state) to a solidified state (solid).

[0121] For example, a heat storage material according to one embodiment of the present invention may be a container, a bag, or the like filled with the inorganic latent heat storage material composition described above.

[0122] From the viewpoint of preventing liquid leakage due to rust and corrosion caused by the inorganic latent heat storage material composition, the container or bag is preferably formed mainly from a resin (e.g., a synthetic resin.) In other words, the heat storage material according to one embodiment of the present invention contains the inorganic latent heat storage material composition according to one embodiment of the present invention described above and a resin.

[0123] Examples of the resin include polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate, polystyrene, nylon, and polyester.

[0124] These materials may be used alone, or in order to improve heat resistance and barrier properties, two or more of these materials may be used in combination (for example, a multi-layer structure may be used).From the standpoints of handling and cost, it is preferable to use containers or bags made of polyethylene.

[0125] The shape of the container or bag is not particularly limited, but from the viewpoint of efficiently exchanging heat between the inorganic latent heat storage material composition and the item to be temperature controlled or the space around it via the container or bag, a shape that is thin and can ensure a large surface area is preferred. The heat storage material can be formed by filling the container or bag with the inorganic latent heat storage material composition.

[0126] A more specific example of the container or bag is the container or bag disclosed in Japanese Patent Application Laid-Open No. 2015-78307, which is incorporated herein by reference.

[0127] The melting temperature, freezing temperature, supercooling temperature and Δsupercooling of the heat storage material according to one embodiment of the present invention can be considered to be the same as the melting temperature, freezing temperature, supercooling temperature and Δsupercooling of the inorganic latent heat storage material composition contained in the heat storage material, respectively.

[0128] Next, the "transport container" will be explained.

[0129] 5. Transport Container The transport container according to one embodiment of the present invention may be any container that includes (is equipped with) the heat storage material according to one embodiment of the present invention described above, and other specific configurations, materials, and the like are not particularly limited.

[0130] An example of a transport container according to one embodiment of the present invention is shown in Fig. 1. Reference numeral 201 in Fig. 1 is a perspective view that schematically shows a heat storage material 10 according to one embodiment of the present invention, and reference numeral 202 in Fig. 1 is an exploded perspective view that schematically shows a transport container 1 according to one embodiment of the present invention.

[0131] 1 , the opening of the heat storage material 10 of this embodiment is closed by a heat storage material lid 11. The heat storage material 10 is filled with an inorganic latent heat storage material composition 20 according to one embodiment of the present invention through the opening, and the heat storage material 10 can be used by being stored or placed in an insulated container 40. In other words, the transport container according to one embodiment of the present invention includes the heat storage material and the insulated container according to one embodiment of the present invention described above.

[0132] The materials for the heat storage material 10 and the heat storage material lid 11 are not particularly limited, and conventionally known materials can be used as appropriate.

[0133] The heat-insulating container 40 is configured to have heat insulation properties by using, for example, a box body 41 and a lid 42 that fits into an opening 410 of the box body.

[0134] The material for the insulated container 40 is not particularly limited as long as it has insulating properties. However, foamed plastic is preferred because it is lightweight, inexpensive, and can prevent condensation. Vacuum insulation material is also preferred because it has very high insulating properties, a long temperature retention time, and can prevent condensation. Examples of foamed plastic include foamed polyurethane, polystyrene, polyethylene, polypropylene, AS resin, and ABS resin. Examples of vacuum insulation material include those with a core made of silica powder, glass wool, or glass fiber. Furthermore, the insulated container 40 may be constructed using a combination of foamed plastic and vacuum insulation material. In this case, a highly insulating container 40 can be obtained by (i) covering the exterior or interior surfaces of the foamed plastic box 41 and lid 42 with vacuum insulation material, or (ii) embedding vacuum insulation material within the walls of the foamed plastic box 41 and lid 42.

[0135] 2 is a perspective view showing the inside of the transport container 1, and 302 is a cross-sectional view showing the inside of the transport container 1 taken along line AA of 301 in FIG.

[0136] As shown in 202 in Fig. 1 , the insulated container 40 includes a box body 41 and a lid 42, and the transport container 1 according to one embodiment of the present invention includes the insulated container 40, the heat storage material 10, and a spacer 6. In other words, the transport container according to one embodiment of the present invention includes the heat storage material, the insulated container, and the spacer according to one embodiment of the present invention described above. As shown in Figs. 1 and 2 , the transport container 1 according to one embodiment of the present invention may also include spacers 6 to (1) fill the spaces between the surface of the lid 42 covering the space within the box body, the side surface 412 of the box body, and the bottom surface 411 of the box body and the heat storage material 10 when storing or placing the heat storage material 10 inside the transport container 1, and (2) ensure space 5 for storing an item subject to temperature control, as shown in 302 in Fig. 2 .

[0137] 1 and 2, the transport container 1 is provided with 10 heat storage materials 10, but the number of heat storage materials provided in the transport container 1 is not particularly limited as long as it is one or more. From the viewpoint of storing or transporting items subject to temperature control for a long period of time and / or stably at a controlled temperature, the number of heat storage materials 10 provided 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 heat storage materials 10 provided in the transport container 1 may be selected appropriately depending on the size of the heat storage material 10, the storage or transport time of the items subject to temperature control, the outside air temperature during storage or transport of the items subject to temperature control, etc.

[0138] The material of the spacer 6 is not particularly limited, but examples thereof include polyurethane, polystyrene, polyethylene, polypropylene, AS resin, ABS resin, and foamed plastics obtained by foaming these resins.

[0139] In one embodiment of the present invention, a pair of spacers 6 are arranged facing each other inside the insulated container 40. By providing the spacers 6, the transport container 1 according to one embodiment of the present invention determines the position of the heat storage material 10, making it possible to easily pack the heat storage material 10. The size and number of the spacers 6 provided in the transport container 1 are not particularly limited and may be set appropriately depending on the sizes of the transport container 1, the heat storage material 10, and the item to be temperature controlled, etc.

[0140] 1 and 2, the transport container 1 has one space 5 for accommodating an item subject to temperature control, but the number of spaces 5 provided in the transport container 1 is not particularly limited as long as it is one or more, and the transport container 1 may have a plurality of spaces 5. For example, the space 5 may be divided and used by disposing a heat storage material 10 and / or a spacer 6 in one space 5.

[0141] The transport container according to one embodiment of the present invention allows items requiring temperature control (items subject to temperature control) to be stored or transported for long periods of time while being maintained at an appropriate controlled temperature, regardless of the outside air temperature. Furthermore, since the transport container according to one embodiment of the present invention includes a heat storage material containing the inorganic latent heat storage material composition, the appropriate controlled temperature can be stably achieved.

[0142] Among items subject to temperature control, a controlled temperature of 15°C to 30°C may be required for storage or transportation of reactive substances such as adhesives, precision instruments, semiconductors, pharmaceuticals, investigational drugs, and specimens. The controlled temperature in the transport container according to one embodiment of the present invention is not particularly limited, but is preferably within the range of 15°C to 30°C, for example. In other words, the transport container according to one embodiment of the present invention is preferably capable of maintaining the temperature-controlled items within the range of 15°C to 30°C for an extended period of time. For this reason, the transport container according to one embodiment of the present invention can also be referred to as an "insulated container." Examples of uses for a transport container that stores or transports items at a temperature maintained between 15°C and 30°C include the storage and / or transportation of temperature-controlled items such as reactive substances such as adhesives, precision instruments, semiconductors, pharmaceuticals, investigational drugs, and specimens.

[0143] As a more specific configuration of the heat-insulating container, the configuration disclosed in Japanese Patent Application Laid-Open No. 2015-78307 can be used. This document is incorporated herein by reference.

[0144] That is, one embodiment of the present invention includes the following configuration.

[0145] [1] An inorganic latent heat storage material composition comprising calcium chloride hexahydrate and a metal soap comprising strontium ions and anions derived from a fatty acid.

[0146] [2] The inorganic latent heat storage material composition according to [1], further comprising one or more inorganic salts selected from the group consisting of bromide salts and chloride salts.

[0147] [3] The inorganic latent heat storage material composition according to [1] or [2], further comprising a lower alcohol.

[0148] [4] The inorganic latent heat storage material composition according to any one of [1] to [3], wherein the fatty acid is at least one selected from the group consisting of lauric acid, myristic acid, palmitic acid, and stearic acid.

[0149] [5] The inorganic latent heat storage material composition according to any one of [1] to [4], wherein the content of the metal soap is 0.01 wt% to 0.10 wt% in 100 wt% of the inorganic latent heat storage material composition.

[0150] [6] The inorganic latent heat storage material composition according to any one of [1] to [5], wherein the metal soap is obtained by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of the fatty acid.

[0151] [7] The inorganic latent heat storage material composition according to [6], wherein the metal salt is at least one selected from the group consisting of sodium salts and potassium salts.

[0152] [8] The inorganic latent heat storage material composition according to any one of [1] to [7], further comprising a cellulose derivative.

[0153] [9] A heat storage material comprising the inorganic latent heat storage material composition according to any one of [1] to [8].

[0154]

[10] A transport container comprising the heat storage material according to [9].

[0155]

[11] A method for producing an inorganic latent heat storage material composition, comprising any one of the following mixing steps (A) to (C): a mixing step (A) of mixing calcium chloride hexahydrate with a metal soap comprising strontium ions and an anion derived from a fatty acid; a mixing step (B) of mixing a dispersion containing a metal soap comprising strontium ions and an anion derived from a fatty acid with one or more members selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate; or a mixing step (C) of mixing a metal soap comprising strontium ions and an anion derived from a fatty acid with water and one or more members selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0156]

[12] The method for producing an inorganic latent heat storage material composition according to

[11] , further comprising, before the mixing step (B), a dispersion preparation step of preparing a dispersion containing the metal soap by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of the fatty acid, and in the mixing step (B), the dispersion prepared in the dispersion preparation step is mixed with one or more selected from the group consisting of calcium chloride anhydrate, calcium chloride dihydrate, and calcium chloride tetrahydrate.

[0157] Hereinafter, one embodiment of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0158] (Measurement and Evaluation Methods) The measurement and evaluation methods used in the examples and comparative examples are as follows.

[0159] (Melting Temperature) The inorganic latent heat storage material compositions obtained in the Examples and Comparative Examples were filled into polypropylene cryovials with a volume of 2 ml together with a thermocouple. The cryovials were left for a certain period of time in an environment of 5°C or less, and the temperature of the composition in the cryovials was reduced to 5°C or less, and the composition was solidified. The cryovials were placed in an ultra-low temperature thermostatic bath (Cryoporter (registered trademark) CS-75CP, manufactured by Synix Corporation). The temperature of the thermostatic bath was then increased from 5°C to 50°C at a rate of 1.0°C / min. During this period, the temperature of the composition in the thermostatic bath was monitored with a thermocouple during the temperature increase process of the thermostatic bath, and the obtained results (temperature) were plotted against time to obtain a graph. In the obtained graph, the temperature of the composition changed in the following order (1) to (3) compared to the temperature of the thermostatic bath, which was increasing at a constant rate: (1) From 5°C to a certain temperature (temperature T １ (2) the temperature T １ to a certain temperature (temperature T ２ (3) The composition hardly changes due to the latent heat until the temperature T ２ The temperature T １ and temperature T ２ The midpoint temperature was calculated as the melting temperature of the composition.

[0160] (Supercooling temperature and solidification temperature) The inorganic latent heat storage material compositions obtained in the examples and comparative examples were filled into the cryovials with a volume of 2 ml, together with a thermocouple. The cryovials were left in an environment of 50°C or higher for a certain period of time, and the temperature of the composition in the cryovials was raised to 50°C or higher, and the composition was melted. The cryovials were then left standing in the ultra-low temperature thermostatic bath. Next, the temperature of the thermostatic bath was lowered from 50°C to 5°C at a rate of 1.0°C / min. During this period, the temperature of the composition in the thermostatic bath was monitored with a thermocouple as the temperature of the thermostatic bath was lowered, and the obtained results (temperature) were plotted against time to obtain a graph. In the obtained graph, the temperature of the composition changed in the following order (1) to (3), compared to the temperature of the thermostatic bath, which was lowered at a constant rate: (1) From 50°C to a certain temperature (temperature T ４(2) The temperature T ４ to a certain temperature (temperature T ５ After a slight rise to temperature T ５ to a certain temperature (temperature T ６ (3) The composition hardly changes due to the latent heat until the temperature T ６ The temperature T ４ is the supercooling temperature of the composition, and temperature T ５ was the solidification temperature of the composition. ４ (supercooling temperature) and temperature T ５ The difference (temperature difference) between the solidification temperature and the temperature at which the composition was cooled was calculated as Δ supercooling (°C).

[0161] Note that there were also compositions in which the above (2) and (3) were not observed. This means that the composition did not solidify while the temperature of the thermostatic bath was lowered from 50°C to 5°C at a temperature drop rate of 1.0°C / min. For such compositions, "-" is entered in the columns for solidification temperature, supercooling temperature, and Δ supercooling in Table 2.

[0162] (Evaluation of Initial Δ Supercooling) Based on the initial Δ supercooling value (°C) (after production, before use (solidification)), the degree of initial Δ supercooling was evaluated according to the following criteria: 2 (Excellent): Δ supercooling less than 2.5°C 1 (Good): Δ supercooling 2.5°C or more and less than 5.0°C 0 (Poor): Δ supercooling 5°C or more, or the composition did not solidify while the temperature of the thermostatic bath was lowered from 50°C to 5°C in the above-mentioned measurement method.

[0163] (Cycle Test) In order to evaluate the degree of Δ supercooling of the composition after repeated use, a cycle test was performed by the following methods (1) to (6): (1) The composition was filled into the cryovial together with a thermocouple; (2) The cryovial was left for a certain period of time in an environment of 5°C or less, and the temperature of the composition in the cryovial was reduced to 5°C or less; (3) The cryovial was left standing in the ultra-low temperature constant temperature bath; (4) The temperature of the constant temperature bath was then increased from 5°C to 50°C at a heating rate of 1.0°C / min; (5) The temperature of the constant temperature bath was then decreased from 50°C to 5°C at a cooling rate of 1.0°C / min; (6) The operations (4) and (5) (collectively referred to as a temperature change cycle) were performed a total of 20 times.

[0164] (Evaluation of Δ supercooling after cycle test) During the final (20th) temperature cycle in the cycle test, the temperature of the composition in the thermostatic chamber was monitored with a thermocouple, and the obtained results (temperature) were plotted against time to obtain a graph. Next, from the obtained graph, the melting temperature, solidification temperature, and supercooling temperature of the composition were calculated using the method described above. Furthermore, Δ supercooling was calculated, and the degree of Δ supercooling after the cycle test was evaluated using the same criteria as described above (evaluation of initial Δ supercooling).

[0165] (Thermal Stability Test) In order to evaluate the degree of thermal stability of the composition, i.e., the degree of Δ supercooling of the composition after the thermal stability test, the thermal stability test was performed by the following methods (1) to (5): (1) The composition was filled into the cryovial together with a thermocouple; (2) The cryovial was left in an environment of 50°C or higher, and the temperature of the composition in the cryovial was left to stand for 24 hours at 50°C; (3) The cryovial was left in an environment of 5°C or lower for a certain period of time, and the temperature of the composition in the cryovial was reduced to 5°C or lower; (4) The cryovial was left to stand in the ultra-low temperature constant temperature bath; (5) Next, the temperature of the constant temperature bath was increased from 5°C to 50°C at a heating rate of 1.0°C / min; (6) Next, the temperature of the constant temperature bath was decreased from 50°C to 5°C at a cooling rate of 1.0°C / min.

[0166] (Evaluation of Δ supercooling after thermal stability test) In the process (5) and (6) of the thermal stability test, the temperature of the composition in the thermostatic chamber was monitored by a thermocouple, and the obtained results (temperature) were plotted against time to obtain a graph.Then, from the obtained graph, the melting temperature, solidification temperature, and supercooling temperature of the composition were calculated by the above-mentioned method.Furthermore, Δ supercooling was calculated, and the degree of Δ supercooling after the thermal stability test was evaluated according to the same criteria as those described above (evaluation of initial Δ supercooling).

[0167] Examples and comparative examples will be described below.

[0168] Example 1 Calcium chloride hexahydrate was obtained by mixing water with calcium chloride dihydrate, a main agent precursor, with the amount of water adjusted so that the total amount of water mixed with calcium chloride dihydrate reacted with the total amount of calcium chloride dihydrate to form calcium chloride hexahydrate.

[0169] Next, 97.04 parts by weight of the obtained calcium chloride hexahydrate and 2.91 parts by weight of potassium bromide were added to a BeMixer (manufactured by Yasuda Finetech Co., Ltd.), and the mixture was stirred until all of the raw materials in the BeMixer were completely dissolved and a colorless, transparent mixture was obtained.

[0170] Next, 0.05 parts by weight of strontium dilaurate, a metal soap, was further added to the resulting mixture, and the resulting mixture was stirred in a BeMixer for 10 minutes. This procedure yielded a composition. Table 1 lists the content of each component in the composition in weight percent. In Table 1, the number of carbon atoms contained in each fatty acid and water-soluble metal salt of a fatty acid is listed after the carbon atom symbol C. For example, lauric acid has 12 carbon atoms, so it is listed as "lauric acid C12." The melting temperature, solidification temperature, and supercooling temperature of the resulting composition were calculated using the above-described method, initially, after the cycle test, and after the thermal stability test. Furthermore, the degree of Δsupercooling of the composition was evaluated initially, after the cycle test, and after the thermal stability test. The results are shown in Tables 2 and 3.

[0171] Examples 2 to 4, Comparative Examples 1 to 10 Compositions of Examples 2 to 4 and Comparative Examples 1 to 10 were produced by the same method as in Example 1, except that the type and amount of each component was changed to obtain compositions with the compositions shown in Table 1. In Table 1, the content of each component in the composition is shown in weight percent. As in Example 1, the melting temperature, solidification temperature, and supercooling temperature of the resulting compositions were calculated using the methods described above, initially, after the cycle test, and after the thermal stability test. Furthermore, the degree of Δsupercooling of the compositions was evaluated initially, after the cycle test, and after the thermal stability test. The results are shown in Tables 2 and 3.

[0172] Example 5 (Aqueous Solution Preparation Step) 31.93 parts by weight of water, 0.3 parts by weight of potassium bromide, and 0.1 parts by weight of strontium chloride hexahydrate were added to a BeMixer (manufactured by Yasuda Finetech Co., Ltd.) and stirred until all of the ingredients in the BeMixer were completely dissolved in the water and a colorless, transparent aqueous solution was obtained. Then, 1.0 parts by weight of a 5% (w / w) aqueous solution of potassium laurate was added to the resulting aqueous solution, and the resulting mixture was stirred in the BeMixer for 10 minutes. This operation yielded a dispersion containing strontium dilaurate as a metal soap.

[0173] (Step of Adding Main Agent Precursor) 67.1 parts by weight of calcium chloride dihydrate was added as a main agent precursor to the obtained aqueous solution, and the obtained mixture was stirred.

[0174] (Cellulose Derivative Addition Step) 1.0 part by weight of hydroxyethyl cellulose as a cellulose derivative was added to the resulting mixture, and the temperature of the resulting mixture was raised to 50°C. The mixture was stirred for 60 minutes while maintaining the temperature at 50°C, yielding a gel-like composition. Table 1 shows the content of each component in the composition in weight percent. The melting temperature, solidification temperature, and supercooling temperature of the resulting composition were calculated using the above-described methods, initially, after the cycle test, and after the thermal stability test. Furthermore, the degree of Δsupercooling of the composition was evaluated initially, after the cycle test, and after the thermal stability test. The results are shown in Tables 2 and 3.

[0175] Examples 6 to 11 The compositions of Examples 6 to 11 were produced using the same method as Example 5, except that the type and amount of each component were changed to obtain compositions with the compositions shown in Table 1. In Table 1, the content of each component in the composition is shown in weight percent. The composition of Example 6 contained strontium dimyristate as the metallic soap, and the composition of Example 7 contained strontium distearate as the metallic soap. The melting temperature, solidification temperature, and supercooling temperature of the resulting compositions were calculated using the methods described above, initially, after the cycle test, and after the thermal stability test. Furthermore, the degree of Δsupercooling of the compositions was evaluated initially, after the cycle test, and after the thermal stability test. The results are shown in Tables 2 and 3.

[0176] In Examples 5-11, calcium chloride dihydrate was used as the base precursor rather than the base (calcium chloride hexahydrate). All of the calcium chloride dihydrate in the mixture reacted with all of the water in the mixture to form calcium chloride hexahydrate. The amount of calcium chloride hexahydrate contained in the composition was calculated and is shown in the "Calcium Chloride Hexahydrate" column of Table 1.

[0177] According to one embodiment of the present invention, it is possible to provide an inorganic latent heat storage material composition having high thermal stability. The inorganic latent heat storage material composition according to one embodiment of the present invention can be suitably used as a heat storage material, for example, (i) in wall materials, floor materials, ceiling materials, roof materials, and underlayment materials for floor mats, and (ii) in applications for constant-temperature transportation of items that require temperature management.

Claims

1. Calcium chloride hexahydrate and A metal soap consisting of strontium ions and anions derived from fatty acids, An inorganic latent heat storage material composition containing a melting point modifier.

2. The inorganic latent heat storage material composition according to Claim 1, wherein the melting point adjusting agent comprises one or more inorganic salts selected from the group consisting of bromide salts and chloride salts.

3. The inorganic latent heat storage material composition according to Claim 1, wherein the melting point adjusting agent comprises lower alcohols having 5 or fewer carbon atoms.

4. The inorganic latent heat storage material composition according to claim 2, wherein the melting point adjusting agent further comprises lower alcohols having 5 or fewer carbon atoms.

5. The inorganic latent heat storage material composition according to claim 1, wherein the fatty acid is one or more selected from the group consisting of lauric acid, myristic acid, palmitic acid, and stearic acid.

6. The inorganic latent heat storage material composition according to claim 1, wherein the content of the metal soap in 100% by weight of the inorganic latent heat storage material composition is 0.01% by weight to 0.10% by weight.

7. The inorganic latent heat storage material composition according to claim 1, wherein the metal soap is obtained by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of the fatty acid.

8. The inorganic latent heat storage material composition according to claim 7, wherein the metal salt is one or more selected from the group consisting of sodium salts and potassium salts.

9. Furthermore, the inorganic latent heat storage material composition according to claim 1, further comprising a cellulose derivative.

10. A heat storage material comprising the inorganic latent heat storage material composition according to any one of claims 1 to 9.

11. A transport container comprising the heat storage material described in claim 10.

12. A method for producing an inorganic latent heat storage material composition, comprising any one of the following mixing steps (A) to (C): A mixing step (A) involves mixing calcium chloride hexahydrate with a metal soap consisting of strontium ions and anions derived from fatty acids; A mixing step (B) of mixing a dispersion containing a metal soap consisting of strontium ions and anions derived from fatty acids with one or more selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate; or A mixing step (C) involves mixing a metal soap consisting of strontium ions and anions derived from fatty acids with water and one or more substances selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate.

13. Prior to the mixing step (B), the method further includes a dispersion preparation step of preparing a dispersion containing the metal soap by reacting an aqueous solution containing a strontium salt with an aqueous solution containing a water-soluble metal salt of the fatty acid. The method for producing an inorganic latent heat storage material composition according to claim 12, wherein the mixing step (B) involves mixing the dispersion prepared in the dispersion preparation step with one or more selected from the group consisting of anhydrous calcium chloride, calcium chloride dihydrate, and calcium chloride tetrahydrate.

14. A method for producing an inorganic latent heat storage material composition according to claim 12 or 13, wherein a melting point adjusting agent is further mixed in the mixing steps (A) to (C).

15. The method for producing an inorganic latent heat storage material composition according to claim 12 or 13, wherein in the mixing steps (A) to (C), one or more inorganic salts selected from the group consisting of bromide salts and chloride salts are further mixed.

16. The method for producing an inorganic latent heat storage material composition according to claim 12 or 13, wherein in the mixing steps (A) to (C), lower alcohols having 5 or fewer carbon atoms are further mixed.