WO2015166933A1

WO2015166933A1 - Heat storage material

Info

Publication number: WO2015166933A1
Application number: PCT/JP2015/062760
Authority: WO
Inventors: 仁人吉野; 祐岡　輝明; 上野　和重; 近藤　康雄; 鈴木　智之
Original assignee: 北川工業株式会社
Priority date: 2014-04-28
Filing date: 2015-04-28
Publication date: 2015-11-05

Abstract

Provided is a heat storage material which is capable of more quickly heating an object to be heated by the heat storage material. This heat storage material includes sodium acetate and silicon carbide. The silicon carbide content of the present invention is preferably 50-70 mass% inclusive with respect to the total mass.

Description

Heat storage material

The present invention relates to a heat storage material.

For example, a supercooled liquid such as sodium acetate trihydrate is known as a latent heat storage material capable of arbitrarily releasing solidification heat. The latent heat storage material releases solidification heat by changing the phase from a supercooled state (liquid state) to a solid state (see, for example, Patent Document 1).

JP 2013-231383 A

(Problems to be solved by the invention)
The heat generated from the latent heat storage material can be used, for example, for heating a battery, a radiator or the like when starting an automobile engine. In such an application, it is required to warm an object heated by the heat storage material faster.

This invention was completed based on the above situations, and it aims at providing the thermal storage material which can warm up the target object heated by a thermal storage material more rapidly.

(Means for solving the problem)
As a result of studies to solve the above problems, it has been found that by using silicon carbide together with sodium acetate, it is possible to warm the object faster than when using only sodium acetate.

The present invention is a heat storage material containing sodium acetate and silicon carbide.

According to the present invention, since sodium acetate and silicon carbide are included, the object can be warmed faster than the heat storage material containing only sodium acetate.
In this invention, it is preferable that content of silicon carbide is 50 to 70 mass% of the whole mass.

(The invention's effect)
According to this invention, the target object warmed by the heat storage material can be warmed more quickly.

Diagram showing a water temperature measuring device The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of an Example Graph showing the relationship between time and water temperature when using the heat storage material of the comparative example A diagram schematically showing the water temperature measuring device used in Evaluation Test 2 The perspective view which represented typically the measurement container used by the evaluation test 2 The figure which represented typically the process of nucleating the thermal storage material in a measurement container in the water temperature measuring apparatus of the evaluation test 2. The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of Examples 4-8 The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of Examples 9-13 The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of Examples 14-18 The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of Examples 19-23 The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of Examples 24 and 25 The graph which shows the relationship between time and water temperature at the time of using the thermal storage material of Examples 26-28, Example 18 and Example 23

<Embodiment 1>
The heat storage material of the present invention contains sodium acetate and silicon carbide.
Examples of sodium acetate include sodium acetate trihydrate itself, sodium acetate trihydrate dissolved in water, anhydrous sodium acetate dissolved in water (for example, 70 parts by mass with respect to 100 parts by mass of anhydrous sodium acetate) For example, a sodium acetate aqueous solution obtained by adding water of 100 parts by mass or less, preferably 74.61 parts by mass or more and 95.16 parts by mass or less can be used.

Silicon carbide is added to a liquid material containing sodium acetate. The “liquid substance containing sodium acetate” includes not only a liquid state but also a semi-fluid (gel) state. Specifically, the “liquid material containing sodium acetate” includes sodium acetate trihydrate and anhydrous sodium acetate dissolved in water, liquid sodium acetate trihydrate, and the like.

The silicon carbide content is preferably 30% by mass to 70% by mass with respect to the total mass of the heat storage material. When the content of silicon carbide is within such a range, heat can be efficiently transmitted to the outside from the heat storage material.

The particle size (average particle size) of silicon carbide is not particularly limited as long as the object of the present invention can be achieved. For example, the particle size is preferably 3 μm to 100 μm, more preferably 5 μm to 95 μm, and more preferably 5.5 μm to 90 μm. Is particularly preferred. When the particle size (average particle size) of silicon carbide is in such a range, the aqueous sodium acetate solution and silicon carbide can be mixed, and a heat storage material can be prepared.

The heat storage material of the present invention can be used by being housed in a resin container or the like together with known members that impart physical stimulation or impact to the heat storage material.

<Example>
EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this.
(Sample preparation)
(1) Production of heat storage materials of Examples 1 to 3 Heat storage materials of Examples 1 to 3 were produced by the following procedure using anhydrous sodium acetate, distilled water, and silicon carbide in the amounts shown in Table 1.
Each heat storage material was produced by mixing a sodium acetate aqueous solution obtained by mixing anhydrous sodium acetate and distilled water with silicon carbide in a stainless steel sealed container having a volume of 150 cm ³ . Volume of each heat storage material was 150 cm ^3.

(2) Preparation of compositions of Comparative Examples 1 and 2 Compositions of Comparative Examples 1 and 2 were prepared according to the following procedure.
A composition of Comparative Example 1 was prepared by mixing an aqueous solution of sodium acetate obtained by mixing anhydrous sodium acetate and distilled water with aluminum oxide in a sealed container made of stainless steel having a volume of 150 cm ³ .
A composition of Comparative Example 2 was prepared by mixing an aqueous sodium acetate solution obtained by mixing anhydrous sodium acetate and distilled water and aluminum hydroxide into a stainless steel sealed container having a volume of 150 cm ³ .
The volume of each composition of Comparative Examples 1 and 2 was 150 cm ³ .

(3) Production of blank A sodium acetate aqueous solution not containing silicon carbide, aluminum hydroxide and aluminum oxide was used as a blank. The blank was prepared by mixing anhydrous sodium acetate and distilled water in a stainless steel sealed container having a volume of 150 cm ³ . The volume of the blank was 150 cm ³ .

The materials used in the production of the heat storage materials of Examples 1 to 3, the compositions of Comparative Examples 1 and 2 and the blanks are as follows.
Anhydrous sodium acetate: Special grade reagent Anhydrous sodium acetate: Wako Pure Chemical Industries, Ltd.
Silicon carbide GC # 2500: Showa Denko Co., Ltd. GC # 320: Showa Denko Co., Ltd. NGF180: Taiheiyo Random Co., Ltd. aluminum oxide LS-250: Nippon Light Metal Co., Ltd. Aluminum hydroxide BF083: Nippon Light Metal ( In Table 1, “addition amount (g)” refers to the addition amount (g) of silicon carbide or filler (aluminum oxide, aluminum hydroxide), and “addition amount (mass%)” refers to the heat storage material. It refers to the ratio of silicon carbide or filler to the total mass or the total mass of the composition.
In Table 1, “particle size” refers to the particle size of silicon carbide or the particle size of filler.

(Evaluation Test 1)
Using the water temperature measuring device 10 shown in FIG. 1, the heat release characteristics of the heat storage materials of Examples 1 to 3 and the compositions of Comparative Examples 1 and 2 were evaluated by the following procedure. Specifically, the thermocouple 2 for liquid is attached to the inner wall surface of the heat insulating container 1 containing 250 ml of tap water W, and the heat storage material of the example, the composition of the comparative example, or the sodium acetate aqueous solution is contained. The sealed container 3 was fitted into the groove 1A of the heat insulating container 1. In addition, after fitting the sealed container 3, the opening part of the heat insulation container 1 was closed with the heat insulation cover which is not shown in figure. Thus, the water temperature in the heat insulation container 1 after fitting the sealed container 3 in the heat insulation container 1 was measured by the temperature logger 4 every 240 seconds until 240 seconds later (refer FIG. 1).

The temperature (initial temperature) of tap water before the start of measurement was 17.8 ° C. for all samples. Tables 2 and 3 show the elapsed time (seconds) from the start of measurement, measurement results (temperature ° C), temperature rise per 10 seconds (average value), and FIGS. 2 and 3 show the measurement results. Shown in the graph. The horizontal axis of the graphs shown in FIGS. 2 and 3 indicates the elapsed time (seconds) from the time when the sealed container 3 is fitted into the heat insulating container 1, and the vertical axis of the graph indicates the water temperature (° C.) at that time. In addition, the heat storage material (and composition) in the sealed container 3 is opened immediately before the sealed container 3 is fitted into the heat-insulating container 1, and the anhydrous sodium acetate powder is charged by opening the lid of the sealed container 3. Nucleation begins.

(Results and discussion)
As shown in Table 2 and FIG. 2, in the heat storage materials of Examples 1 to 3, the water temperature rose significantly after 50 seconds after the start of measurement, and the difference of 2 ° C. or more after 240 seconds. was there.
As shown in Table 3 and FIG. 3, in Comparative Example 2, the water temperature is slightly higher than that of the blank from 60 seconds to 230 seconds after the start of measurement, but the water temperature after 240 seconds is almost the same. In Comparative Example 1, the increase in water temperature was smaller than that of the blank until 240 seconds after the start of measurement.

From these results, it was found that the object warmed by the heat storage material can be warmed more quickly according to the present invention.

[Evaluation Test 2]
Using the water temperature measuring device 110 different from the evaluation test 1, the heat dissipation characteristics of the respective heat storage materials of Examples 4 to 28 shown below were evaluated.

(Water temperature measuring device)
FIG. 4 is a diagram schematically illustrating the water temperature measuring device 110 used in the evaluation test 2. As shown in FIG. 4, the water temperature measuring device 110 mainly includes a heat insulating container 11, a thermocouple 12, a measuring container 13, a temperature logger 14, a stirring device 15, and the like.

The heat insulating container 11 is the same type as that used in the water temperature measuring device 10 of the evaluation test 1, and water (tap water) W (300 ml) is placed in the heat insulating container 11. The measurement container 13 includes a cylindrical stainless steel container body 13A that opens upward, and a heat insulating lid 13B that closes the opening of the container body 13A. A heat storage material to be measured is accommodated in the container body 13A of the measurement container 13. The volume of the measurement container 13 (the volume of the container body 13A) is 150 cm ³ .

FIG. 5 is a perspective view schematically showing the measurement container 13 used in the evaluation test 2. FIG. As shown in FIG. 5, a through hole 13 C that is small enough to insert a needle tip is formed in the approximate center of the lid 13 B of the measurement container 13. The through-hole 13C is used to add a nucleating agent (anhydrous sodium acetate powder) to the tip of the needle and put it into the measuring container 13 in order to nucleate the heat storage material in the measuring container 13.

FIG. 6 is a diagram schematically showing a process of nucleating the heat storage material in the measurement container 13 in the water temperature measuring device 110 of the evaluation test 2. As shown in FIG. 6, in the water temperature measuring device 110, the heat storage material is nucleated while the measurement container 13 that stores the heat storage material is placed on the pedestal 16 so as to be immersed in the water W in the heat insulation container 11. Is done. Specifically, the nucleating agent is introduced into the measurement container 13 by inserting the needle tip N with the nucleating agent (anhydrous sodium acetate powder) through the through-hole 13C in the lid 13B of the measurement container 13. , Heat storage material nucleates. After the heat storage material in the measurement container 13 is nucleated, the opening of the heat insulating container 11 is closed with a heat insulating lid 17.

The measurement container 13 is placed on a pedestal 16 installed at the bottom of the measurement container 13 in a state where most of the container body 13A is immersed in the water W. The pedestal 16 is disposed at the bottom of the heat insulating container 11 so as to sink into the water W. The water level in the heat insulating container 11 is set so that the lid 13B of the measurement container 13 does not get wet with the water W.

The thermocouple 12 is the same type as that used in the water temperature measuring device 10 of the evaluation test 1 and is attached to the inner wall surface of the heat insulating container 11. The thermocouple 12 is surrounded by a polypropylene insulating sheet (not shown) so as not to contact the measurement container 13 (container body 13A) in the heat insulating container 11.

The temperature logger 14 is the same type as that used in the water temperature measuring device 10 of the evaluation test 1 and measures the water temperature in the heat insulating container 1 at predetermined intervals based on the detection result of the thermocouple 12. In the evaluation test 2, the water temperature in the heat insulating container 1 is measured every 300 seconds from the start of the test until 300 seconds later.

The heat insulation container 11 is placed on a stirring device (magnetic stirrer) 15 with the measurement container 13 installed inside. A stirrer (stirrer chip) 15A for stirring the water W is placed on the bottom of the heat insulating container 11 so as to be disposed below the pedestal 16, and when the stirrer 15 is activated, the stirrer 15A is moved. Is rotated by receiving the magnetic force, and the water W in the heat insulating container 11 is stirred.

Such a water temperature measuring device 110 has higher measurement accuracy and excellent reproducibility because the heat distribution can be made uniform and the water temperature can be made uniform as compared with the water temperature measuring device 10 of the evaluation test 1.

(Heat dissipation characteristics of heat storage material (containing 30% silicon carbide))
<Production of heat storage material of Example 4>
The container body 13A made of stainless steel measuring container 13 volume is 150 cm ^3, and sodium acetate aqueous solution obtained by mixing anhydrous sodium acetate 102.62g and distilled water 76.34G, silicon carbide (average particle size: 5.5 [mu] m , True specific gravity: 3.22, trade name “GC # 2500” (manufactured by Showa Denko KK) 76.69 g was added and mixed to prepare a heat storage material. A lid 13B is attached to the container main body 13A of the measurement container 13 in a state where the heat storage material is accommodated.

<Production of heat storage material of Example 5>
As silicon carbide, the product name “GCF180” (manufactured by Showa Denko Co., Ltd., average particle size: 90 μm, true specific gravity: 3.21) was used, and was housed in the measurement container 13 in the same manner as in Example 4. A heat storage material in a heated state was produced.

<Production of heat storage material of Example 6>
The measurement container 13 was used in the same manner as in Example 4 except that the trade name “Tera-5” (manufactured by TGM, average particle size: 5.4 μm, true specific gravity: 3.22) was used as silicon carbide. A heat storage material in a state of being housed in the container was produced.

<Production of heat storage material of Example 7>
As silicon carbide, a measurement container was used in the same manner as in Example 4 except that the trade name “GC # 3000”, manufactured by Showa Denko KK, average particle size: 4.0 μm, true specific gravity: 3.22) was used. A heat storage material in a state of being accommodated in 13 was produced.

<Production of heat storage material of Example 8>
As silicon carbide, trade name “GC # 240”, manufactured by Showa Denko KK, average particle size: 57 μm
, True specific gravity: 3.22) A heat storage material in a state of being accommodated in the measurement container 13 was produced in the same manner as in Example 4 except that it was used.

<Production of blank>
An aqueous sodium acetate solution obtained by mixing 117.6 g of anhydrous sodium acetate and 87.4 g of distilled water is placed in a container main body 13A of a stainless steel measurement container 13 having a volume of 150 cm ³ , and a blank (contained in the measurement container 13). In this state, an aqueous solution of sodium acetate) was prepared.

<Evaluation of heat dissipation characteristics (evaluation test 2)>
The heat dissipation characteristics of the heat storage materials of Examples 4 to 8 were evaluated using the water temperature measuring device 110. Specifically, as shown in FIG. 4, 300 ml of water (tap water) W is placed inside the heat insulating container 11 in a state where the thermocouple 12, the stirrer 15 A and the base 16 are set at predetermined positions. . The heat insulating container 11 is placed on the stirring device 15, and the stirrer 15 A rotates by receiving a magnetic action from the stirring device 15, and the water W in the heat insulating container 11 is stirred.

The measurement container 13 containing the heat storage material 12 is placed on a pedestal 16 at the bottom of the heat insulation container 11. Then, as shown in FIGS. 5 and 6, the needle tip N attached with a nucleating agent (anhydrous sodium acetate powder) is inserted into the lid 13 B of the measurement container 13 using the through hole 13 C. Thus, the nucleating agent is charged into the measurement container 13, the heat storage material generates heat (heat radiation), and the test (temperature measurement) is started.

In addition, after the nucleating agent is charged into the measurement container 13, the opening of the heat insulating container 11 is closed by the heat insulating lid 17. After the test (temperature measurement) was started in this way, the water temperature in the heat insulating container 11 was measured by the temperature logger 14 every 10 seconds until 300 seconds later. In addition, the temperature of the water W before a measurement start was 20 degreeC. The test results for the heat storage materials of Examples 4 to 8 are shown in Table 4. FIG. 7 shows a graph of test results for the heat storage materials of Examples 4 to 8. The horizontal axis of the graph shown in FIG. 7 represents elapsed time, and the vertical axis represents the water temperature in the heat insulating container 11.

As shown in Table 4, the heat storage materials of Examples 4 to 8 were compared with the blank not containing silicon carbide (SiC), the release rate (%) (heat release (kcal) / total heat (kcal)). X100) was confirmed to be high. The amount of heat released is determined by the specific heat of water (1 cal / g · ° C.) × rising temperature ΔT (° C.) × the amount of water (g), and the total amount of heat is [the amount of sodium acetate trihydrate (reference value: 264). (J / g)) × sodium acetate trihydrate amount (g)] / 4.186 (J / cal). The same applies to the amount of heat released and the total amount of heat in each example shown below.

Further, as shown in FIG. 7, it was confirmed that the heat storage materials of Examples 4 to 7 efficiently transferred heat to the outside of the measurement container 13 as compared with the blank.

(Heat dissipation characteristics of heat storage material (40% by mass silicon carbide))
<Production of heat storage material of Example 9>
Measured in the same manner as in Example 4 except that the amount of anhydrous sodium acetate was changed to 94.26 g, the amount of distilled water was changed to 70.12 g, and the amount of silicon carbide was changed to 109.58 g. A heat storage material accommodated in the container 13 was produced.

<Production of heat storage material of Examples 10 to 13>
A heat storage material accommodated in the measurement container 13 was produced in the same manner as in Example 9 except that the silicon carbide shown in Table 5 was used.

<Evaluation of heat dissipation characteristics (evaluation test 2)>
The heat storage materials of Examples 10 to 13 were heated by the same method as in Example 4 above, and the water temperature in the heat insulating container 11 was measured by the temperature logger 14 every 10 seconds until 300 seconds later. In addition, the temperature of the water W before a measurement start was 20 degreeC. The test results for the heat storage materials of Examples 10 to 13 are shown in Table 5. In addition, FIG. 8 shows a graph of test results for the heat storage materials of Examples 10 to 13. The horizontal axis of the graph shown in FIG. 8 represents elapsed time, and the vertical axis represents the water temperature in the heat insulating container 11. Table 5 and FIG. 8 also show the measurement results of the blank.

As shown in Table 5, the heat storage materials of Examples 9 to 13 were compared with the blank not containing silicon carbide (SiC), the release ratio (%) (heat release (kcal) / total heat (kcal)). X100) was confirmed to be high.

Further, as shown in FIG. 8, it was confirmed that the heat storage materials of Examples 9 to 12 efficiently transferred heat to the outside of the measurement container 13 as compared with the blank.

(Heat dissipation characteristics of heat storage material (50% by mass silicon carbide))
<Production of heat storage material of Example 14>
Measured in the same manner as in Example 4 except that the amount of anhydrous sodium acetate was changed to 84.60 g, the amount of distilled water was changed to 62.93 g, and the amount of silicon carbide was changed to 147.53 g. A heat storage material accommodated in the container 13 was produced.

<Production of heat storage material of Examples 15 to 18>
A heat storage material accommodated in the measurement container 13 was produced in the same manner as in Example 14 except that the silicon carbide shown in Table 6 was used.

<Evaluation of heat dissipation characteristics (evaluation test 2)>
The heat storage materials of Examples 14 to 18 were heated by the same method as in Example 4 above, and the water temperature in the heat insulating container 11 was measured by the temperature logger 14 every 300 seconds until 300 seconds later. In addition, the temperature of the water W before a measurement start was 20 degreeC. The test results for the heat storage materials of Examples 14 to 18 are shown in Table 6. In addition, FIG. 9 shows a graph of test results for the heat storage materials of Examples 14 to 18. The horizontal axis of the graph shown in FIG. 9 represents elapsed time, and the vertical axis represents the water temperature in the heat insulating container 11. Table 6 and FIG. 9 also show the measurement results of the blank.

As shown in Table 6, the heat storage materials of Examples 14 to 18 were compared with the blank not containing silicon carbide (SiC), the release ratio (%) (heat release (kcal) / total heat (kcal)). X100) was confirmed to be high.

Further, as shown in FIG. 9, it was confirmed that the heat storage materials of Examples 14 to 17 efficiently transferred heat to the outside of the measurement container 13 as compared with the blank.

(Heat dissipation characteristics of heat storage material (60% by mass silicon carbide))
<Production of heat storage material of Example 19>
Measured in the same manner as in Example 4 except that the amount of anhydrous sodium acetate was changed to 73.33 g, the amount of distilled water was changed to 54.55 g, and the amount of silicon carbide was changed to 191.82 g. A heat storage material accommodated in the container 13 was produced.

<Production of heat storage material of Examples 20 to 23>
A heat storage material accommodated in the measurement container 13 was produced in the same manner as in Example 19 except that the silicon carbide shown in Table 7 was used.

<Evaluation of heat dissipation characteristics (evaluation test 2)>
The heat storage materials of Examples 20 to 23 were heated by the same method as in Example 4 above, and then the water temperature in the heat insulating container 11 was measured by the temperature logger 14 every 300 seconds until 300 seconds later. In addition, the temperature of the water W before a measurement start was 20 degreeC. The test results for the heat storage materials of Examples 19 to 23 are shown in Table 7. FIG. 10 shows a graph of the test results for the heat storage materials of Examples 19 to 23. The horizontal axis of the graph shown in FIG. 10 represents elapsed time, and the vertical axis represents the water temperature in the heat insulating container 11. Table 7 and FIG. 10 also show the measurement results of the blank.

As shown in Table 7, the heat storage materials of Examples 19 to 23 were compared with the blank not containing silicon carbide (SiC), the release ratio (%) (heat release (kcal) / total heat (kcal)). X100) was confirmed to be high.

Further, as shown in FIG. 10, it was confirmed that the heat storage materials of Examples 19 to 23 efficiently transferred heat to the outside of the measurement container 13 as compared with the blank.

(Heat dissipation characteristics of heat storage material (70% by mass silicon carbide))
<Production of heat storage material of Example 24>
Measured in the same manner as in Example 5 except that the amount of anhydrous sodium acetate was changed to 60.01 g, the amount of distilled water was changed to 44.64 g, and the amount of silicon carbide was changed to 244.18 g. A heat storage material accommodated in the container 13 was produced.

<Production of heat storage material of Example 25>
A heat storage material accommodated in the measurement container 13 was produced in the same manner as in Example 24 except that the silicon carbide shown in Table 8 was used.

<Production of heat storage materials of Comparative Examples 3 to 5>
Except for replacing the silicon carbide shown in Table 8, an attempt was made to produce a heat storage material in the same manner as in Example 24. However, the silicon carbide aggregated and the heat storage material could not be produced.

<Evaluation of heat dissipation characteristics (evaluation test 2)>
The heat storage materials of Examples 24 and 25 were heated by the same method as in Example 4 above, and then the water temperature in the heat insulating container 11 was measured by the temperature logger 14 every 10 seconds until 300 seconds later. In addition, the temperature of the water W before a measurement start was 20 degreeC. The test results for the heat storage materials of Examples 24 and 25 are shown in Table 8. Moreover, the graph of the test result in the heat storage material of Examples 24 and 25 was shown in FIG. The horizontal axis of the graph shown in FIG. 11 represents elapsed time, and the vertical axis represents the water temperature in the heat insulating container 11. Table 8 and FIG. 11 also show the measurement results of the blank.

As shown in Table 8, the heat storage materials of Examples 24 and 25 were compared with the blank not containing silicon carbide (SiC), the release ratio (%) (heat release amount (kcal) / total heat amount (kcal)). X100) was confirmed to be high.

Further, as shown in FIG. 11, it was confirmed that the heat storage material of Example 25 efficiently transferred heat to the outside of the measurement container 13 as compared with the blank.

(Heat dissipation characteristics of heat storage material (53 to 57 mass% silicon carbide))
<Preparation of heat storage material of Example 26 (55% by mass of silicon carbide)>
Measurement was performed in the same manner as in Example 8 except that the amount of anhydrous sodium acetate was changed to 79.18 g, the amount of distilled water was changed to 58.91 g, and the amount of silicon carbide was changed to 168.78 g. A heat storage material accommodated in the container 13 was produced.

<Preparation of Heat Storage Material of Example 27 (53% by mass of silicon carbide)>
Measured in the same manner as in Example 8 except that the amount of anhydrous sodium acetate was changed to 81.40 g, the amount of distilled water was changed to 60.56 g, and the amount of silicon carbide was changed to 160.09 g. A heat storage material accommodated in the container 13 was produced.

<Production of heat storage material of Example 28 (57% by mass of silicon carbide)>
Measurement was carried out in the same manner as in Example 8 except that the amount of anhydrous sodium acetate was changed to 76.91 g, the amount of distilled water was changed to 57.22 g, and the amount of silicon carbide was changed to 177.79 g. A heat storage material accommodated in the container 13 was produced.

<Evaluation of heat dissipation characteristics (evaluation test 2)>
The heat storage materials of Examples 26 to 28 were heated by the same method as in Example 4 above, and the water temperature in the heat insulating container 11 was measured by the temperature logger 14 every 10 seconds until 300 seconds later. In addition, the temperature of the water W before a measurement start was 20 degreeC. The test results for the heat storage materials of Examples 26 to 28 are shown in Table 9. FIG. 12 shows a graph of test results for the heat storage materials of Examples 26 to 28. The horizontal axis of the graph shown in FIG. 12 represents elapsed time, and the vertical axis represents the water temperature in the heat insulating container 11. Table 9 and FIG. 12 also show the measurement results of the blank. FIG. 12 also shows the results of Example 18 (50% by mass) and Example 23 (60% by mass).

As shown in Table 9, the heat storage materials of Examples 26 to 28 were compared with the blank not containing silicon carbide (SiC), the release rate (%) (heat release (kcal) / total heat (kcal)). X100) was confirmed to be high.

Also, as shown in FIG. 12, it was confirmed that the heat storage materials of Examples 26 and 28 had the same efficiency as that of the blank in extracting heat to the outside of the measurement container 13. In addition, in the heat storage material of Example 18 (50% by mass of silicon carbide) and the heat storage material of Example 27 (53% by mass of silicon carbide), the efficiency of extracting heat to the outside of the measurement container 13 is higher than that of the blank. Was inferior.

That is, when the trade name “GC # 240” is used as silicon carbide, the content of silicon carbide in the heat storage material is 54% by mass or more, preferably 55% by mass or more based on the total mass. .

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) Although the silicon carbide content in the above embodiment is 50% by mass, 60% by mass, and 70% by mass with respect to the total mass, the present invention is not limited to this. The content of silicon carbide may be less than 50% by mass of the total mass, 55% by mass or 65% by mass, or more than 70% by mass.

DESCRIPTION OF SYMBOLS 1 ... Thermal insulation container, 2 ... Thermocouple, 3 ... Sealed container, 4 ... Temperature logger, W ... Tap water, 10 ... Water temperature measuring device, 11 ... Thermal insulation container, 12 ... Thermocouple, 13 ... Measurement container, 13A ... Container body , 13B ... lid, 14 ... temperature logger, 15 ... stirrer, 15A ... stirrer, 16 ... pedestal, 17 ... lid, 110 ... water temperature measuring device, N ... needle tip

Claims

A heat storage material comprising sodium acetate and silicon carbide.
The heat storage material according to claim 1, wherein the content of the silicon carbide is 30% by mass or more and 70% by mass or less of the total mass.