JP2008308607A - Method for manufacturing heat storage material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an inorganic matter-deposited heat storage material simply and inexpensively, without discharging a harmful matter, that permits controlling a temperature rise upon setting a hydraulic composition and being uniformly mixed with the hydraulic composition. <P>SOLUTION: This inorganic matter-deposited heat storage material of an average particle diameter of 5-100 μm, in which a water-insoluble inorganic fine particle is melt fixed on a surface of a latent heat storage material, is manufactured by way of mixing the latent heat storage material containing at least a ester-structural compound of a melting point of 40-80°C with the water-insoluble inorganic fine particle, at a temperature higher than a melting temperature of the latent heat storage material in presence of water. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a heat storage material used for a heat storage structure such as a house, and a hydraulic composition containing the heat storage material obtained by the production method.

  2. Description of the Related Art As a heat storage material used when cooling or heating a substance or a space, a heat storage material that stores heat using latent heat accompanying a phase change of the substance is widely used. Among them, a material obtained by granulating a latent heat substance that causes phase change and stores heat has an advantage that it is easy to handle and can be dispersed more uniformly even if blended into a molded body or the like.

Conventionally, as a method for producing this type of particulate latent heat storage material, for example, Patent Document 1 discloses a method of preparing an O / W emulsion by dispersing paraffin, which is a latent heat storage material, in water together with an appropriate emulsifier. A method of preparing a liquid by heating it above the melting point and impregnating it with heated porous inorganic substance spheres, and a method of preparing by adsorbing and fixing inorganic ultrafine powder on the surface of paraffin beads are mentioned. Yes. Further, Patent Document 2 includes a microencapsulation method such as a composite emulsion method and an in situ polymerization method.
Patent 2740873 JP 2002-114553 A

  However, the O / W emulsion and the microcapsule type heat storage material often use an organic material such as paraffin as the heat storage material, and the emulsifier and the encapsulated material (shell material) often use an organic compound. . The particle density of the heat storage material composed of these components is lighter than water, and particles tend to float at the time of molding, become non-uniformly dispersed, and the particles tend to localize. As a result, the strength of the cured molded body tends to decrease and the physical properties vary. In these production methods, for example, the type and concentration of the emulsifier, the temperature of the emulsified liquid during emulsification, the emulsification ratio (volume ratio of the aqueous phase to the oil phase), an atomizer called an emulsifier and a disperser Therefore, it is necessary to set conditions such as the operating conditions (the number of revolutions and the processing time), and it is technically difficult to stably manufacture these methods, which is not preferable because the manufacturing cost increases. Furthermore, since the microencapsulation consists of a core and a shell, the encapsulation process is generally complicated, and depending on the process, harmful substances (formalin, etc.) may remain and be released from the molded body. The above problems are also a concern.

  In view of the above problems, the present invention can produce a heat storage material having a substantially uniform particle size in a simple and inexpensive manner, and can suppress an increase in temperature when the hydraulic composition is cured, and is uniformly blended in the hydraulic composition. It is an object of the present invention to provide a production method capable of obtaining a heat storage material that is capable of producing no harmful substances.

  In the present invention, the latent heat storage material containing at least a compound having an ester structure with a melting point of 40 to 80 ° C. and the hardly water-soluble inorganic fine particles are mixed with water at a temperature equal to or higher than the melting point or the solid phase transition temperature of the latent heat storage material. It is related with the manufacturing method of the heat storage material which consists of particle | grains with an average particle diameter of 5-100 micrometers which has the process of adhering to the surface of the said latent-heat thermal storage substance, and making the said water hardly soluble inorganic fine particle adhere.

  Moreover, this invention relates to the hydraulic composition containing the thermal storage material manufactured by the manufacturing method of the said invention and hydraulic powder.

  The heat storage material in the present invention has, for example, a latent heat storage material having a melting point or solid phase transition temperature of 30 to 90 ° C., and the latent heat storage material contains at least a compound having an ester structure with a melting point of 40 to 80 ° C. To a solution in which the core material that is essential to be dissolved is added, a solution in which poorly water-soluble inorganic fine particles and water are well dispersed at a temperature equal to or higher than the melting point or solid phase transition temperature of the latent heat storage material is added, and a rapid shear force is added. In addition, the particles are obtained by carrying out a dispersion treatment accompanied with water and, at the same time, coating the surface of the heat storage material by fusing and fixing water-insoluble inorganic fine particles to the surface of the particles.

  According to the present invention, a heat storage material having a substantially uniform particle size can be produced easily and inexpensively, and the temperature rise during curing of the hydraulic composition can be suppressed, and can be uniformly blended in the hydraulic composition. There is provided a production method capable of obtaining a heat storage material that is not released.

More specifically, according to the present invention, the following effects can be obtained.
(1) By using a heat storage material to which poorly water-soluble inorganic fine particles are attached, it is possible to suppress the hydration heat generation of cement paste, mortar, concrete, etc., which are hydraulic compositions, and to affect the setting delay compared to organic ones. Less is. For example, if a heat storage material is added about 6% with respect to cement, the temperature rise at the time of hardening can be reduced about 7 to 9%. Moreover, since it is not necessary to use a toxic substance as a raw material, a molded body in which no toxic substance is released from the heat storage material can be obtained.
(2) By using poorly water-soluble inorganic fine particles, heat storage material particles having a particle size of about 10 μm and heavier than substantially uniform water can be produced. This heat storage material is considered to contribute to the improvement of the stability in the molded body, and this enables the heat storage material to be dispersed more uniformly in the hydraulic composition, so that the surface of the cured body is also less damaged than the plain. it can.
(3) By using a latent heat storage material containing at least a compound having an ester structure with a melting point of 40 to 80 ° C. as the heat storage material of the heat storage material, it is possible to easily stabilize the dispersion of a hydrocarbon compound having a low polarity. Thereby, it becomes possible to provide a latent heat storage material with high applicability to the hydraulic composition at low cost.

  The latent heat storage material used in the method for manufacturing a heat storage material of the present invention contains at least a compound having an ester structure with a melting point of 40 to 80 ° C. (hereinafter referred to as an ester compound).

  The latent heat storage material used in the present invention preferably has a melting point or solid phase transition temperature of 30 to 90 ° C. The latent heat storage material is preferably a lipophilic material. The melting point or solid phase transition temperature can be measured by the method described in Examples. In the case of using a plurality of ester compounds as the latent heat storage material, or in the case of a mixture using both ester compounds and non-ester components, the solid phase transition temperature is used. When the latent heat storage material changes from the solid phase to the liquid phase at the melting point or the solid phase transition temperature, the temperature rise of the molded body can be suppressed. Here, the solid phase transition temperature in the present invention refers to the value of the top peak of the melting temperature by DSC measurement described in Examples.

  By using the ester compound as a latent heat storage material, particles having a substantially uniform particle size distribution can be obtained without causing coalescence of particles during the production of the particles. Moreover, the hydrocarbon compound mentioned later can be stably contained with an ester compound. The ester compound is preferably a lipophilic substance. Moreover, melting | fusing point of an ester compound is 40-80 degreeC. The heat of fusion of the ester compound is preferably 60 J / g or more, and more preferably 80 J / g or more. The latent heat storage material according to the present invention preferably has a heat of fusion of 60 J / g or more, and more preferably 80 J / g or more. The amount of heat of fusion can be measured by the method described in the Examples. Examples of the ester compound include esters of a monohydric alcohol having 1 to 18 carbon atoms and a monovalent carboxylic acid having 12 to 28 carbon atoms. Specifically, myristyl myristate, palmityl myristate, stearyl myristate, and palmitic acid. Examples include palmitic acid palmitate, myristyl palmitate, stearyl palmitate, myristyl stearate, palmityl stearate, stearyl stearate, and the like. These may be used alone or in combination of two or more. The content of the ester compound in the latent heat storage material is preferably 5 to 100% by weight, more preferably 10 to 100% by weight.

  The latent heat storage material can also contain components other than the ester compound (hereinafter referred to as non-ester components). The non-ester component is preferably a lipophilic substance, preferably has a melting point or solid phase transition temperature of 30 to 90 ° C, more preferably 40 to 80 ° C. Further, those having a heat of fusion of 60 J / g or more are preferred, and those having a heat of fusion of 80 J / g or more are more preferred. The non-ester component is preferably a hydrocarbon compound because it has a large latent heat and is highly stable even in a strong alkali such as cement slurry. Examples of the hydrocarbon compound include linear or branched hydrocarbon compounds having 17 to 30 carbon atoms, such as heptadecane, octadecane, nonadecane, eicosan, heneicosan, docosan, tetracosan, pentacosan, triacontane, pentatriacontane and the like. It is done. These may be used alone or in combination of two or more. Further, the content of the non-ester component in the latent heat storage material is preferably 0 to 95% by weight, more preferably 0 to 90% by weight. When a hydrocarbon compound is used as the non-ester component, the weight ratio of hydrocarbon compound / ester compound is preferably 0/100 to 95/5, more preferably 0/100 to 90/10.

  In addition, for both the ester compound and the non-ester component, the lipophilic substance means one having a solubility in water of 3% by weight or less.

  Examples of the compound constituting the poorly water-soluble inorganic fine particles used in the present invention include tricalcium phosphate, hydroxyapatite, basic magnesium carbonate, magnesium oxide, titanium oxide, kaolin, etc. Among these, adhesion to latent heat storage materials From the above viewpoint, particles containing one or more compounds selected from tricalcium phosphate, hydroxyapatite, and basic magnesium carbonate are preferable. These may be used alone or in combination of two or more. The particles may be either particles of the inorganic compound itself (primary particles) or secondary particles in which they are aggregated. Here, poorly water-soluble means that the solubility in water at 20 ° C. is 1% by weight or less.

  The average particle diameter of the water-insoluble inorganic fine particles is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm. This average particle diameter can be measured by the method of an Example. The heat storage material produced in the present invention has a structure in which poorly water-soluble inorganic fine particles are adhered to a latent heat storage material. By mixing in the presence of water at a temperature equal to or higher than the melting point or solid phase transition temperature of the latent heat storage material, the latent heat storage material liquefies, and poorly water-soluble inorganic fine particles come into contact with and adhere to the interface. And if it returns to normal temperature, a latent heat storage material solidifies and a latent heat storage material and water hardly soluble inorganic fine particles adhere firmly. And it is thought that it is the structure where the poorly water-soluble inorganic fine particle is arrange | positioned on the outer side, and contributes to the improvement in the stability in a molded object at the time of adding the said thermal storage material to a hydraulic composition.

  In the production method of the present invention, the hardly water-soluble inorganic fine particles are used in a ratio of 6 to 100 parts by weight, and further 10 to 50 parts by weight with respect to 100 parts by weight of the latent heat storage material from the viewpoint of stability in the molded body. It is preferable.

  In the production method of the present invention, there are few restrictions other than the temperature condition when mixing the latent heat storage material and the poorly water-soluble inorganic fine particles, and problems such as the operating conditions of the atomization apparatus in the conventional method are solved.

  In the production method of the present invention, the latent heat storage material and the poorly water-soluble inorganic fine particles are mixed in the presence of water at a temperature equal to or higher than the melting point or solid phase transition temperature of the latent heat storage material. Specifically, the latent heat storage material as a core is heated to a temperature equal to or higher than its melting point or solid phase transition temperature to be liquefied (melted), and hot water containing sparingly water-soluble inorganic fine particles is added to the suspension dispersion. To prepare. By liquefying the latent heat storage material, the particle size can be controlled and the adhesion of inorganic fine particles to the latent heat storage material can be strengthened. This suspension dispersion is quickly subjected to a dispersion treatment using a strong shearing disperser to prepare an O / W type suspension dispersion preferably having a particle size of 8 to 50 μm, more preferably 9 to 40 μm. At that time, inorganic fine particles are adhered to the particle surface of the latent heat storage material in a molten state, and the temperature of the dispersion subjected to the dispersion treatment is lowered below the melting point (or solid phase transition temperature) of the latent heat storage material. The inorganic fine particles can be fused and fixed to the particle surface, and a wall film of the inorganic fine particles is formed. This makes it possible to produce an inorganic substance-type heat storage material without uniting the individual particles, and to obtain a dispersion of suspended particles (heat storage material) heavier than water. That is, from this manufacturing method, the inorganic material-attached heat storage material is obtained as a slurry dispersed in water. Of course, water can be removed from the water-dispersed slurry to obtain a powdered inorganic material-attached heat storage material.

  The mixing of the latent heat storage material and the poorly water-soluble inorganic fine particles in the presence of water is preferably performed using a dispersion treatment with a shearing force, particularly using a strong shearing disperser. The strong shearing disperser here has a mechanism capable of acting a strong shearing force on the dispersion, and examples thereof include a homomixer, a homogenizer, and a colloid mill. The mixing condition is preferably a condition that enables obtaining a dispersion particle size of about 10 μm, but is appropriately adjusted because it varies depending on conditions such as the amount of the dispersion, the composition, the processing temperature, and the processing time. For example, in order to reduce the average particle size, methods such as increasing the shearing force of stirring and raising the temperature can be mentioned. In particular, the inorganic material-attached heat storage material obtained by the present invention has an average particle diameter of 5 to 100 μm, preferably 5 to 70 μm, more preferably 7 to 50 μm. Therefore, the above-mentioned conditions are adjusted to be in this range. It is preferable to do. This average particle diameter can be measured by the method of an Example.

  According to the present invention, heat storage with an average particle size of 5 to 100 μm having a uniform particle size distribution in which hardly water-soluble inorganic fine particles adhere to the surface of a latent heat storage material containing at least a compound having an ester structure with a melting point of 40 to 80 ° C. A material is obtained.

  In the heat storage material produced in the present invention, by using inorganic fine particles as particles to be adhered to the surface of the latent heat storage material, the specific gravity of the inorganic material-attached heat storage material becomes heavier than water, and when added to the hydraulic composition, Material separation due to specific gravity difference from the base material (hydraulic composition) is improved. Furthermore, the physical property fall of a hardening molded object can be suppressed by disperse | distributing uniformly also in the hardening molded object of a hydraulic composition. In addition, the suppression of the heat of hydration of the hydraulic composition, which is also a function as a heat storage material, can be dispersed more uniformly in the formed body by atomizing, and the effect is enhanced. For this reason, it is suitable as an inorganic substance adhesion type heat storage material for hydraulic compositions.

  The hydraulic composition which is the subject of the present invention contains hydraulic powder and water. Cement or gypsum can be used as the hydraulic powder. Examples of cement include Portland cement such as ordinary, early strength, moderate heat, and low heat cement, and mixed cement such as blast furnace, silica, and fly ash cement. These may be used alone or in combination. It is sufficient that the gypsum has a level of purity that can be used as a gypsum board raw material. The gypsum used may be either α-type hemihydrate gypsum, β-type hemihydrate gypsum, or a mixture thereof, and can be used in any blending ratio.

  Moreover, a hydraulic composition may contain various materials used when manufacturing a normal concrete structure and board-shaped building materials, such as a dispersing agent, a retarder, AE agent, an antifoamer, and a reinforcing fiber material. Is possible. Although the hydraulic composition depends on the application, the ratio of water / hydraulic powder [weight percentage (% by weight) of water and hydraulic powder in the hydraulic composition, usually abbreviated as W / P. When the powder is cement, it is abbreviated as W / C. ] Is preferably 23 to 100% by weight, more preferably 30 to 70% by weight. Note that P of the W / P includes the amount of the heat storage material according to the present invention. Moreover, the quantity of the kneading water for hydraulic composition preparation containing a mixture etc. can be used as the quantity of W (after-mentioned Test example 1 etc.).

  The kneading machine for the composition of the hydraulic composition is not particularly limited. However, in the case of a concrete composition, a tilted barrel mixer, a uniaxial or biaxial forced kneader mixer, a bread mixer, etc. An Eirich mixer or the like can be used. There is no particular limitation on the timing of addition of the inorganic material-based heat storage material of the present invention. Further, the inorganic material adhesion type heat storage material of the present invention is 1-30 parts by weight with respect to 100 parts by weight of the hydraulic powder from the viewpoint of the strength and heat storage performance of the molded body, although depending on the use of the hydraulic composition. It is preferably used in a proportion of 5 to 20 parts by weight.

  The hydraulic composition containing the inorganic material-attached heat storage material of the present invention can be applied to, for example, a molding method and a curing method used for manufacturing a molded body such as a normal concrete structure or a board-shaped building material.

[Example 1]
In a beaker, measure 104.3 g of myristyl myristate (Exepar MY-M, Kao Corp., melting point: 45.0 ° C.) 104.3 g and heat and melt it. 31.3 g of tricalcium phosphate (manufactured by Taihei Chemical Industry) A dispersion at 65 ° C. dispersed in 664.3 g of water was added, and the obtained mixed solution was quickly used at 10,000 rpm for 3 minutes using a strong shear disperser (“TK homomixer M type” manufactured by Tokushu Kika Kogyo Co., Ltd.). A suspension dispersion was obtained. The suspension dispersion was cooled to room temperature while stirring gently with a stirrer, then filtered through a wire mesh with an opening of 300 μm and left to stand for a while. Thereafter, 434 g of the supernatant liquid was removed from the suspended dispersion particles settled at the bottom to obtain 334 g of a suspension dispersion concentrated to a solid content of 39% (weight basis, hereinafter the same unless otherwise specified).

  In addition, the electron micrograph of the inorganic substance adhesion type heat storage material obtained in Example 1 is shown in FIG. 1, and the particle size distribution is shown in FIG. The electron micrograph shown in FIG. 1 was taken using a Hitachi ultra-high performance field emission scanning electron microscope “S-4800” manufactured by Hitachi High-Technologies Corporation (magnification is × 3K). Was confirmed to be coated with an inorganic substance. Furthermore, since the particle size distribution in FIG. 3 shows almost normal distribution at one peak, it was confirmed that there was no aggregation between particles.

[Example 2]
In the same operation as in Example 1, instead of myristyl myristate, stearyl stearate (Exepar SS, melting point 62.6 ° C., manufactured by Kao Corporation) was changed to 337 g of a suspension dispersion concentrated to a solid content of 39%. Got.

Example 3
In the same operation as in Example 1, instead of 104.3 g of myristyl myristate, 52.2 g of myristyl myristate and paraffin wax 115 (manufactured by Nippon Seiwa Co., Ltd., melting point 51.0 ° C.) 52.2 g were changed to a solid. Thus, 330 g of a suspension dispersion concentrated to 39% was obtained. In addition, the electron micrograph (conditions are the same as Example 1) of the inorganic substance adhesion type heat storage material obtained in Example 3 is shown in FIG. 2, and the particle size distribution pattern is shown in FIG. This confirmed that the particles were coated with an inorganic substance.

Example 4
In the same manner as in Example 1, instead of 104.3 g of myristyl myristate, 10.4 g of myristyl myristate and 93.9 g of paraffin wax 115 were obtained, and 313 g of a suspension dispersion concentrated to a solid content of 39% was obtained. .

Example 5
In the same manner as in Example 1, instead of 104.3 g of myristyl myristate, stearyl stearate was changed to 10.4 g and paraffin wax 115 93.9 g to obtain 320 g of a suspension dispersion concentrated to a solid content of 39%. .

[Comparative Example 1]
In the same manner as in Example 1, instead of myristyl myristate, paraffin wax 115 (manufactured by Nippon Seiwa Co., Ltd., melting point 51.0 ° C.) was used. While the suspension dispersion was lightly stirred with a stirrer and cooled to room temperature, a lump (aggregate) of paraffin wax of about 1 to 15 mm floated at the interface. Thereafter, the suspension dispersion was filtered through a wire mesh having an opening of 300 μm, but a large amount of aggregates remained on the wire mesh.

[Comparative Example 2]
The operation was changed to cetyl alcohol (Kao Co., Ltd., Calcoal 6098, melting point 51.2 ° C.) by the same operation as in Example 1. While the suspension dispersion was lightly stirred with a stirrer, a cecil alcohol mass (aggregate) of about 1 to 5 mm floated on the interface while cooling to room temperature. Thereafter, the suspension dispersion was filtered through a wire mesh having an opening of 300 μm, but a large amount of aggregates remained on the wire mesh.

[Comparative Example 3]
By the same operation as Example 1, it changed to myristic acid (the Kao Co., Ltd. make, Lunac MY-98, melting | fusing point 56.6 degreeC). The dispersion was subjected to a dispersion treatment at 10,000 rpm for 3 minutes using a strong shear disperser (“TK homomixer M type” manufactured by Tokushu Kika Kogyo Co., Ltd.). The whole became a white gel and no longer showed a dispersed state.

[Comparative Example 4]
The operation was changed to butyl stearate (manufactured by Kao Corporation, Exepearl BS, melting point 38 ° C.) by the same operation as in Example 1. While the suspension dispersion was lightly stirred with a stirrer and cooled to room temperature, a lump of butyl stearate (aggregate) of about 1 to 5 mm floated at the interface. Thereafter, the suspension dispersion was filtered through a wire mesh having an opening of 300 μm, but a large amount of aggregates remained on the wire mesh.

[Comparative Example 5]
In a beaker, 104.3 g of methyl stearate (manufactured by Kao Corporation, Exepearl MS, melting point 28 ° C.) is weighed and melted, and in this, 31.3 g of tricalcium phosphate (manufactured by Taihei Chemical Industry), 664.3 g of water. Add a dispersion at 65 ° C. mixed with, and quickly disperse the obtained dispersion at 10,000 rpm for 3 minutes using a powerful shearing disperser (“TK homomixer M type” manufactured by Tokushu Kika Kogyo Co., Ltd.). did. Thereafter, the suspension dispersion was cooled to room temperature while gently stirring with a stirrer. During cooling, a lump (aggregate) of about 1 to 5 mm of methyl stearate floated at the interface. Thereafter, the suspension dispersion was filtered through a wire mesh having an opening of 300 μm, but a large amount of aggregates remained on the wire mesh.

<Evaluation of particle properties and dispersion characteristics>
The dispersion characteristics (dispersion stability, particle properties) of the suspension dispersions containing the inorganic material-attached heat storage material obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated by the following methods. Further, the characteristic values of each substance and the characteristics of the suspension dispersion were also measured by the following method. The results are shown in Table 1.

(1-1) Melting point, solid phase transition temperature and heat of fusion The melting point, solid phase transition temperature and heat of fusion of the latent heat storage material were determined by differential scanning calorimetry of “Pyris 6 DSC” type manufactured by Perkin Elmer. The solid phase transition temperature is the top peak value of the melting temperature. The measurement conditions were Heat 1st at 3 ° C./min to -10 ° C. to 100 ° C., Cool 3 ° C./min to 100 ° C. to −30 ° C., Heat 2nd 3 ° C./min to −30 The heating was repeated from 100 ° C. to 100, and the value of Heat 2nd was adopted.

(1-2) Average particle diameter The average particle diameter is the particle diameter of the particles contained in the suspension dispersion using “Laser diffraction / scattering particle size distribution analyzer LA-300” manufactured by Horiba, Ltd. (Volume basis, median diameter) was measured. At that time, the particle size of the hardly water-soluble inorganic fine particles was measured by dispersing in water by ultrasonic treatment for 2 minutes, and the particle size of the suspended particles in the suspension dispersion (inorganic-attached heat storage material) was 300 μm. Measurements were made on a wire mesh product.

(1-3) Aggregate amount The aggregate amount was obtained by filtering the suspension dispersion after cooling through a wire mesh having a mesh size of 300 μm and measuring the dry weight of the wire mesh residue by the following equation.
Aggregate amount (% by weight) = Dry weight (g) of wire mesh residue with mesh opening of 300 μm ÷ {Latent heat storage material (g) + Slightly water-soluble inorganic fine particles (g)} × 100

  The dispersion stability of the suspension dispersion can be evaluated from the average particle diameter and the amount of aggregates of the suspension dispersion. When the average particle size is 100 μm or less and the aggregate amount is 10% or less, the dispersion stability has no practical problem.

  In the table, the amount of the slightly water-soluble inorganic fine particles added is 100 parts by weight of the latent heat storage material (hereinafter the same).

  From the results shown in Table 1 and FIGS. 1 and 2, it is difficult to encapsulate even in the production method of the present invention because paraffinic materials generally used as latent heat storage materials have almost no polarity from the examples and comparative examples. . However, in the present invention, a substance having an ester structure with a melting point of 40 ° C. or higher has a small amount of aggregates and has a particle size of about 10 μm. Therefore, it may be a latent heat storage material suitable for the production of the present invention. I understood. Furthermore, from Examples and Comparative Example 1, by using a substance having an ester structure with a melting point of 40 ° C. or more as an essential component, stable dispersed particles can be produced even when other heat storage materials such as paraffin are used in combination. I understood. Moreover, when these were observed with an electron micrograph, the particle shape of Example 1 was almost a sphere, and the paraffin combination system of Example 3 was slightly deformed, but fine inorganic fine particles uniformly adhered to both particle surfaces. However, it is shown that it is well coated. Furthermore, from the particle size distributions of Examples 1 and 3 in FIG. 3, both of them show a normal distribution with one peak, which indicates that there is no coalescence between the particles.

Example 6
In the same operation as in Example 1, instead of tricalcium phosphate, hydroxyapatite (manufactured by Taihei Chemical Sangyo Co., Ltd., quasi-drug material standard, average particle size 4.7 μm) was changed to a solid content of 39%. 337 g of a turbid dispersion was obtained.

Example 7
In the same manner as in Example 1, instead of tricalcium phosphate, basic magnesium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., first grade reagent, average particle size 12.1 μm) was changed to a solid content of 39%. 338 g of the resulting suspension dispersion was obtained.

Example 8
In the same manner as in Example 1, instead of tricalcium phosphate, magnesium oxide (Kanto Chemical Co., Ltd., first grade reagent, average particle size 3.3 μm) was changed to a suspension dispersion concentrated to a solid content of 39%. 288 g of liquid was obtained.

Example 9
In the same manner as in Example 1, instead of tricalcium phosphate, titanium oxide (made by Wako Pure Chemical Industries, Ltd., special grade reagent, rutile type, average particle size 0.2 μm) was changed to a solid content of 39%. 263 g of the resulting suspension dispersion was obtained.

[Example 10]
In the same manner as in Example 1, instead of tricalcium phosphate, kaolin (made by Kishida Chemical Co., Ltd., reagent, 300 mesh, average particle size 6 μm) was changed to 211 g of a suspension dispersion concentrated to a solid content of 39%. Got.

<Evaluation of particle properties and dispersion characteristics>
About the suspension dispersion liquid containing the inorganic substance adhesion type heat storage material obtained in Examples 6 to 10, the dispersion characteristics, the characteristic values of each substance, and the like were evaluated in the same manner as in Example 1 and the like. The results are shown in Table 2. For reference, the results of Example 1 are also shown in Table 2.

  From the results of Table 2, from Examples 1 and 6 to 10, the hardly water-soluble inorganic fine particles having a particle diameter of 10 μm or less are useful as the hardly water-soluble inorganic fine particles suitable for the production of the present invention. It was found that tricalcium phosphate, hydroxyapatite, basic magnesium carbonate, and the like are effective when pursuing high productivity and high productivity (reducing the amount of unnecessary aggregates and increasing the yield).

<Test example>
[1] Production of heat storage material for comparison [Comparative Production Example 1]
In a beaker, 75.0 g of paraffin wax 115 (manufactured by Nippon Seiwa Co., Ltd., melting point 51.0 ° C.) and 12.0 g of sorbitan monostearate (Kao Co., Ltd. Rheodor SP-S10V) were weighed and melted. In addition, 8.0 g of polyoxyethylene sorbitan monostearate (manufactured by Kao Corporation, Rhedol TW-S120) and 5.0 g of polyoxyethylene lauryl ether (manufactured by Kao Corporation, Emulgen 120) were dispersed in 400 g of water. A dispersion at ℃ was added, and the resulting mixture was quickly subjected to a dispersion treatment at 6000 rpm for 3 minutes using a strong shear disperser ("TK homomixer M type" manufactured by Tokushu Kika Kogyo Co., Ltd.) A liquid was obtained. The suspension dispersion was cooled to room temperature with light stirring with a stirrer, and then filtered through a wire mesh having an opening of 300 μm to obtain an emulsion having a solid content of 20.8% and an average particle size of 4.9 μm.

[Comparative Production Example 2]
13. 138.9 g of paraffin wax 115 (manufactured by Nippon Seiwa Co., Ltd., melting point 51.0 ° C.) was weighed and melted in a beaker, and styrene-maleic anhydride copolymer (manufactured by BASF, solid content 30%) was added therein. Add 5g and 10% aqueous solution of PVA (Nippon Gosei Chemical Co., Ltd., Gohsenol GL-05) at 55.6g in 287g of water and add 70 ° C dispersion. Dispersion treatment was performed at 6000 rpm for 3 minutes using “TK homomixer M type” manufactured by Kogyo Co., Ltd. to obtain a suspension dispersion. The suspension dispersion was cooled to room temperature with light stirring with a stirrer, and then filtered through a wire mesh having an opening of 300 μm to obtain an emulsion having a solid content of 28.5% and an average particle size of 11.9 μm.

[Comparative Production Example 3]
As another latent heat storage material, an emulsion with a solid content of 40% is prepared from a commercially available paraffin wax emulsion (manufactured by Nippon Seiwa Co., Ltd., EMUSTAR-1015, melting point 47 ° C., anionic, average particle size 0.32 μm). did.

[Comparative Production Example 4]
As another latent heat storage material, an emulsion having a solid content of 42% is prepared from a commercially available polyethylene wax emulsion (manufactured by Nippon Seiwa Co., Ltd., EMUSTAR-5555, melting point 55 ° C., anionic, average particle size 0.56 μm). did.

[Test Example 1]
278 g of water containing 7 g (solid form) of cement admixture (manufactured by Kao Co., Ltd., Mighty 3000S) was added to 208 g of 39% suspension dispersion of the inorganic substance-type heat storage material obtained in Example 1, and the prepared kneaded water was added. Got ready. 486 g of the prepared kneaded water [heat storage material (solid content) 81.1 g, water 404.9 g (including 7 g of admixture)] was added to 1000 g of cement (ordinary Portland cement, manufactured by Taiheiyo Cement Co., Ltd.) and quickly added to the kneader. A stir-mixed cement paste was prepared. The cement paste was quickly packed into the cone, and the flow immediately after the adjustment and 20 minutes after the adjustment was measured [this was taken as a dispersibility test (details will be described later). ]. Further, the same procedure as described above was used except that the prepared kneading water was changed to 381.1 g [heat storage material (solid content) 81.1 g, water 300 g (including 7 g of admixture)]. A cement paste was prepared, and a simple adiabatic temperature rise test during curing (details will be described later) was performed to obtain the maximum exothermic temperature. These results are shown in Table 3.

[Test Examples 2 to 4]
Instead of the inorganic material adhesion type heat storage material obtained in Example 1, the heat storage materials of Examples 2, 3, and 5 were used. Other test operations were the same as in Test Example 1, and the results are shown in Table 3.

[Comparative Test Example 1]
Add 375 g of water containing 7 g of cement admixture (manufactured by Kao Corporation, Mighty 3000S) to 1000 g of cement, and quickly stir with a kneader to prepare a cement paste. went. A cement paste was prepared in the same manner as in the dispersibility test except that the water was changed to 300 g containing an admixture by the same operation as described above, and a simple adiabatic temperature rise test was conducted in the same manner as in Test Example 1. The exothermic temperature was determined. These results are shown in Table 3. The maximum exothermic temperature shown in Comparative Test Example 1 is used as a plane (reference) in the simple adiabatic temperature rise test.

[Comparative Test Example 2]
89.4 g of water containing 7 g (solid form) of cement admixture (manufactured by Kao Corporation, Mighty 3000S) is added to 400 g of the paraffin wax emulsion (emulsion having a solid content of 20.8%) obtained in Comparative Production Example 1. In addition, 489.4 g of prepared and kneaded water [83.2 g of paraffin wax emulsion (solid content), 406.2 g of water (including 7 g of admixture)] was prepared. The prepared kneading water was added to 1000 g of cement, and quickly mixed with a kneader to prepare a cement paste. The dispersibility test was conducted in the same manner as in Test Example 1. The results are shown in Table 3.

[Comparative Test Example 3]
233.1 g of paraffin wax emulsion obtained in Comparative Production Example 2 (emulsion having a solid content of 28.5%) and 7 g of cement admixture (manufactured by Kao Corporation, Mighty 3000S) 231. 17.8 g of prepared and kneaded water 467.8 g [paraffin wax emulsion (solid content) 67.5 g, water 400.3 g (including 7 g of admixture)] was prepared. The prepared kneading water was added to 1000 g of cement, and quickly mixed with a kneader to prepare a cement paste. The dispersibility test was conducted in the same manner as in Test Example 1. The results are shown in Table 3.

[Comparative Test Example 4]
Paraffin wax emulsion obtained in Comparative Production Example 3 (manufactured by Nippon Seiwa Co., Ltd., 40% solid emulsion prepared from EMUSTAR-1015), 156 g, cement admixture (Kao Co., Ltd., Mighty 3000S) 305 g of water containing 7 g (solid) was added to prepare 461 g of prepared kneaded water [62.5 g of paraffin wax emulsion (solid content), 398.5 g of water (including 7 g of admixture)]. The prepared kneading water was added to 1000 g of cement, and quickly mixed with a kneader to prepare a cement paste. The dispersibility test was conducted in the same manner as in Test Example 1. The cement paste was prepared in the same manner as in the dispersibility test, except that the prepared kneading water was changed to 362.5 g (paraffin wax emulsion (solid content) 62.5 g, water 300 g (including 7 g of admixture)). In the same manner as in Test Example 1, a simple adiabatic temperature rise test was performed. These results are shown in Table 3.

[Comparative Test Example 5]
149 g of the polyethylene wax emulsion obtained in Comparative Production Example 4 (manufactured by Nippon Seiwa Co., Ltd., 42% solid emulsion prepared from EMUSTAR-5555) and cement admixture (manufactured by Kao Corporation, Mighty 3000S) 312 g of water containing 7 g (solid) was added to prepare 461 g of prepared kneaded water [62.5 g of polyethylene wax emulsion (solid content), 398.5 g of water (including 7 g of admixture)]. The prepared kneading water was added to 1000 g of cement, and quickly mixed with a kneader to prepare a cement paste. The dispersibility test was conducted in the same manner as in Test Example 1. The results are shown in Table 3.

[2] Dispersibility test of cement paste and simple adiabatic temperature rise test For the cement pastes obtained in Test Examples 1 to 4 and Comparative Test Examples 1 to 5, a dispersibility test and a simple adiabatic temperature rise test were conducted by the following methods. It was. The results are shown in Table 3.

(2-1) Dispersibility test The dispersibility test was performed by using a “DALTON universal mixing stirrer 5dm-03-γ” manufactured by Dalton Co., Ltd. as a kneading machine, kneading at a low speed of 60 seconds after adding each material, and then scraping. After stirring at a low speed of 60 seconds, the paste was poured into a paste cone (bottom inner diameter φ85 mm × upper inner diameter φ76 mm × height 40 mm), the cone was quickly lifted, and the initial flow spread was measured. Further, the flow after 20 minutes was measured by the same operation after stirring the cement paste of the above production method for 20 minutes and stirring at a low speed of 10 seconds before measurement.

(2-2) Simple adiabatic temperature rise test The simple adiabatic temperature rise test measures 1150 g of cement paste prepared for this test in a 500 ml container in a heat-insulated box subjected to heat insulation treatment with foamed urethane. It was embedded in a heat insulation box, and the exothermic temperature at the time of hardening of the cement paste was recorded. The temperature tracking information was obtained from the thermocouple inserted into the paste by “Technology Seven Co., Ltd.” “PC data acquisition system soft thermo E830” to obtain the maximum temperature due to hydration heat generation. The test environment was a constant temperature room at 20 ° C. and 60% RH.

  In the table, in the cement paste for the dispersibility test, W / P includes the amount of water in the heat storage material suspension dispersion as W, and P represents the amount of the heat storage material in the heat storage material suspension dispersion (solid Min)). Moreover, in the cement paste for a simple adiabatic temperature rise test, W / C is calculated including the amount of water of the heat storage material suspension dispersion as W.

  From the results of Table 3, from Comparative Test Examples 2 to 5, the emulsion of paraffin and polyethylene wax, which is a general latent heat storage material, shows almost no initial flow of the cement paste, or the flow retention after 20 minutes. The suitability to cement etc. deteriorated remarkably. On the other hand, from Test Examples 1 to 4, when the inorganic material-attached heat storage material by the water-insoluble inorganic fine particles of the present invention was added, the initial flow value of the cement paste decreased to 25 to 30% with respect to the plain, but after 20 minutes Since the retention of the flow value is almost flat, it can be seen that this material is excellent in applicability to cement. Moreover, also in the simple heat insulation temperature rise test, the maximum exothermic temperature can be suppressed 5-8 degreeC with respect to a plane, and the performance is demonstrated as a heat storage material. Since Comparative Test Examples 2, 3, and 5 have a strong curing delay and cannot be appropriately evaluated for suppression of temperature rise during curing, the results of a simple adiabatic temperature rise test were not shown.

2 is a scanning electron microscope (SEM) photograph showing the surface state of the inorganic material-attached heat storage material of the present invention obtained in Example 1. FIG. It is a scanning electron microscope (SEM) photograph which shows the surface state of the inorganic substance adhesion type heat storage material of this invention obtained in Example 3. FIG. It is a particle size distribution pattern of the inorganic substance adhesion type heat storage material of the present invention obtained in Examples 1 and 3.

Claims (4)

A latent heat storage material containing at least a compound having an ester structure with a melting point of 40 to 80 ° C. and a hardly water-soluble inorganic fine particle are mixed in the presence of water at a temperature equal to or higher than the melting point or solid phase transition temperature of the latent heat storage material. The manufacturing method of the heat storage material which consists of a particle | grain with an average particle diameter of 5-100 micrometers which has the process of making the said water hardly soluble inorganic fine particle adhere to the surface of the said latent heat storage material. The manufacturing method of the heat storage material of Claim 1 whose melting | fusing point or solid-phase transition temperature of the said latent heat storage material is 30-90 degreeC. The method for producing a heat storage material according to claim 1 or 2, wherein the poorly water-soluble inorganic fine particles are particles containing one or more compounds selected from tricalcium phosphate, hydroxyapatite, and basic magnesium carbonate. The hydraulic composition containing the thermal storage material manufactured by the manufacturing method of any one of Claims 1-3, and hydraulic powder.