JP5584395B2 - Paraffin heat storage material composition - Google Patents

Description

  The present invention relates to a paraffin-based heat storage material composition exhibiting heat storage properties due to latent heat of fusion. More particularly, the present invention relates to a paraffin-based latent heat storage material composition suitable as a heat storage material used for cooling and air-conditioning applications, refrigeration / refrigerated storage containers, cold transport media, freeze prevention and the like.

  In recent years, there has been a demand for effective use of surplus energy for energy saving and effective use of energy. As an effective method, a method of storing heat using latent heat accompanying a phase change of a substance has been used. Compared to the method using only sensible heat without phase change, the method using latent heat can store a large amount of heat energy in a narrow temperature range at a high density, which not only reduces the capacity of the heat storage material, Since a large temperature difference does not occur for a large amount of heat storage, heat loss can be suppressed to a small amount.

These heat storage materials are being used for heat storage type air conditioners, heat storage type building materials, various heat retaining devices and devices, etc., using the amount of heat released during the phase transition from the liquid phase to the solid phase.
Conventionally, a heat storage agent composed of normal paraffin is known as a latent heat storage material composition having a latent heat of fusion accompanying a phase change (Patent Document 1). However, such a latent heat storage agent has a problem that a remarkable supercooling phenomenon occurs due to a decrease in the freezing point with respect to the melting point.

  In general, paraffin is less susceptible to supercooling, and the composition is considered to exhibit a certain melting point and freezing point. However, in practice, the conditions of use (temperature rise, cooling rate) and the paraffin form (bulk, capsule, granular, emulsion) Etc.), even with the same paraffin composition, the actual melting point fluctuates and exhibits a supercooling phenomenon.

Therefore, various methods for suppressing the supercooling phenomenon of the heat storage material have been studied.
For example, Patent Document 2 discloses that an emulsion-type regenerator composed of water, a surfactant, and a saturated hydrocarbon with a phase change has a phase change temperature that is 1 to 30 ° C. higher than the phase change temperature of the saturated hydrocarbon. A method of adding a saturated hydrocarbon as a nucleating agent has been proposed.

Also, a method for preventing supercooling by adding a surfactant to an aliphatic hydrocarbon (Patent Document 3), and an organic compound accompanied by a phase change with an amine derivative, an alcohol derivative or a carboxylic acid derivative of the organic compound as a nucleating agent (Patent Document 4), a method of using a compound having a melting point of 40 ° C. or higher, such as carboxylic acids, alcohols, amides, etc., as an anti-cooling agent for paraffinic hydrocarbons (Patent Document 5), n- A heat storage material (Patent Document 6) obtained by adding a supercooling inhibitor such as glycerin fatty acid ester, diglycerin fatty acid ester, and polyglycerin fatty acid ester to tetradecane has been proposed. However, when these supercooling inhibitors are added to aliphatic hydrocarbons, the materials that come into contact with the heat storage material, such as containers and pipes, may be altered or corroded, or the respective additives may precipitate during long-term use. There is a problem that the supercooling prevention function is not exhibited due to an action such as alteration.
Japanese Patent Laid-Open No. 06-234967 JP 2000-336350 A JP 2003-261866 A JP 09-31451 A JP 09-176623 A JP 09-296163 A

  The present invention has a large amount of latent heat, the supercooling phenomenon is sufficiently suppressed, the temperature difference between the melting point and the freezing point is small, the absorption and release of latent heat can be repeated in a narrow operating temperature range, and the melting and solidification are repeated for a long time. Even if used, the latent heat storage material (PCM), which has no change in quality or separation, has a stable and stable composition, has little effect on containers and pipes in contact, has high accuracy, and requires stable melting and solidification characteristics. It is an object of the present invention to provide a paraffin-based latent heat storage material composition that can be suitably used as a).

The paraffin-based heat storage material composition of the present invention has a latent heat storage material (A) composed of normal paraffin (a) having a melting point in the range of −15 to 10 ° C. and 35 ° C. or higher than the melting point of normal paraffin (a). And a supercooling inhibitor (B) made of normal paraffin (b) having a high melting point.

Such a paraffin-based heat storage material composition of the present invention preferably contains 0.01 to 10 parts by weight of the supercooling suppression material (B) with respect to 100 parts by weight of the latent heat storage material (A).
In the paraffin-based heat storage material composition of the present invention, the content of n-dodecane in normal paraffin (a) is 90% by weight or more, and n-undecane, n-dodecane in normal paraffin (a), and The total content of n-tridecane is preferably 95% by weight or more, and the main component of normal paraffin (b) is preferably n-eicosane or n-pentacosane.

  The paraffin-based heat storage material composition of the present invention has a content of n-tetradecane in normal paraffin (a) of 90% by weight or more, and n-tridecane, n-tetradecane in normal paraffin (a), and The total content of n-pentadecane is preferably 95% by weight or more, and the main component of normal paraffin (b) is preferably n-octacosane.

  According to the present invention, it is suitable as a heat storage material used for cooling / air-conditioning applications, refrigeration / refrigerated storage containers, cold heat transfer media, anti-freezing, etc., has a large amount of latent heat, and a supercooling phenomenon is sufficiently suppressed to have a melting point. It is possible to provide a paraffin-based latent heat storage material composition that has a small freezing point temperature difference and can repeatedly absorb and release latent heat within a narrow operating temperature range.

  The paraffin-based latent heat storage material composition of the present invention has a sufficient amount of heat storage and has good properties of conventional paraffin-based heat storage materials that are not corrosive. As a latent heat storage material (PCM), which has no change in quality or separation even when it is repeated, has a stable and stable composition, has little effect on the containers and pipes in contact with it, and requires high-precision melting-solidification temperature characteristics. It can be used suitably, and has excellent performance as a heat storage material for cooling used particularly in the cooling temperature region (-15 to 10 ° C.).

Hereinafter, the present invention will be specifically described.
The paraffin-based heat storage material composition of the present invention contains a latent heat storage material (A) and a supercooling suppression material (B).

The latent heat storage material (A) is composed of normal paraffin (a) having a melting point in the range of −15 to 10 ° C. Since normal paraffin has a high heat storage density and is chemically stable, it has the property of not deteriorating even when phase changes are repeated, and is suitable as a latent heat storage agent. Since the melting point of the paraffin-based heat storage material composition of the present invention is in the range of −15 to 10 ° C., the paraffin-based heat storage material composition exhibits excellent effects in cooling air conditioning, a freezing / refrigerated storage container, a cold transport medium, freezing prevention and the like.

The supercooling inhibitor (B) is composed of normal paraffin (b) having a melting point 35 ° C. higher than the melting point of normal paraffin (a). The melting point of the normal paraffin (b) is preferably 35 to 130 ° C., more preferably 40 to 110 ° C. higher than the melting point of the normal paraffin (a). The supercooling suppression material (B) comprising the normal paraffin (b) having such a melting point acts as a solidification nucleus in the paraffin-based heat storage material composition, and thereby, the melting-solidification phase of the latent heat storage material (A). The change is smoothly performed near the melting point of normal paraffin (a). When the melting point of normal paraffin (b) is not higher than the melting point of normal paraffin (a) by 35 ° C. or more, the solidification nucleation generating action in the paraffin-based heat storage material composition becomes insufficient and the supercooling suppression effect is reduced. This is not preferable.

  In the present invention, the melting point is the point at which the tangent of the maximum slope of the peak of the temperature-caloric diagram obtained when heated at a rate of temperature increase of 10 ° C./min using a differential scanning calorimeter intersects the baseline. Temperature. Therefore, the melting point of normal paraffin (a) can usually be represented by one point even when it is a composition.

The normal paraffin (a) may be a kind of normal paraffin or a composition of two or more normal paraffins.
When the normal paraffin (a) is a composition of two or more normal paraffins, it is preferably a composition composed of two or more normal paraffins having 11 to 16 carbon atoms.

  That is, as normal paraffin (a), n-undecane (carbon number 11, melting point −25 ° C.), n-dodecane (carbon number 12, melting point −9 ° C.), n-tridecane (carbon number 13, melting point −5 ° C.) ), N-tetradecane (14 carbon atoms, melting point 6 ° C.), n-pentadecane (15 carbon atoms, melting point −9.9 ° C.) and n-hexadecane (16 carbon atoms, melting point 18 ° C.) have a melting point of −15 It is also preferable to use a single material satisfying the range of 10 ° C to 10 ° C, and a composition containing two or more of these, wherein the melting point of the composition satisfies the range of -15 to 10 ° C. It is also preferable. A normal paraffin composition having a large melting point peak and separated into two or more in the measurement with a differential scanning calorimeter is not preferable as the normal paraffin (a) used in the present invention.

  The normal paraffin (b) may be one kind of normal paraffin or a composition of two or more kinds of normal paraffins, and preferably contains one kind of normal paraffin as a main component.

  As the normal paraffin (b), any normal paraffin having a melting point 35 ° C. higher than the melting point of the normal paraffin (a) constituting the latent heat storage material (A) is preferably used, and the carbon number is about 17 to 100. These normal paraffins can be used alone or in combination of two or more. In addition, when demonstrating melting | fusing point of these normal paraffin, n-heptadecane (carbon number 17): 22 degreeC, n-octadecane (carbon number 18): 28 degreeC, n-eicosane (carbon number 20): 37 degreeC, n- Docosane (carbon number 22): 44 ° C, n-pentacosane (carbon number 25): 54 ° C, n-octacosane (carbon number 28): 61 ° C, n-triacontane (carbon number 30): 66 ° C, carbon number 40 Normal paraffin: 82 ° C., normal paraffin having 50 carbon atoms: 92 ° C., normal paraffin having 100 carbon atoms: about 115 ° C.

  Among the normal paraffins (a) described above, normal paraffins (a) mainly composed of n-dodecane or n-tetradecane are particularly preferably used from the viewpoint of availability and accuracy of melting-solidification temperature.

  As the normal paraffin (a) mainly composed of n-dodecane, the n-dodecane content in the normal paraffin (a) is 80% by weight or more, preferably 90% by weight or more. More preferably, the content of n-dodecane in the normal paraffin (a) is 90% by weight or more, and the total content of n-undecane, n-dodecane and n-tridecane in the normal paraffin (a) is Normal paraffin (a) of 95% by weight or more is preferred.

  When the normal paraffin (a) containing n-dodecane as the main component is used as the latent heat storage material (A), the normal paraffin containing n-eicosane or n-pentacosane as the main component is used as the supercooling suppression material (B). It is preferable to use (b). At this time, it is desirable that the content of n-eicosane or n-pentacosane in the normal paraffin (b) is 80% by weight or more, preferably 90% by weight or more, and particularly preferably 95% by weight or more.

  As the normal paraffin (a) mainly composed of n-tetradecane, the n-tetradecane content in the normal paraffin (a) is 80% by weight or more, preferably 90% by weight or more. More preferably, the content of n-tetradecane in the normal paraffin (a) is 90% by weight or more, and the total content of n-tridecane, n-tetradecane and n-pentadecane in the normal paraffin (a) is Normal paraffin (a) of 95% by weight or more is preferred.

  When normal paraffin (a) mainly composed of n-tetradecane is used as the latent heat storage material (A), normal paraffin (b) mainly composed of n-octacosane is used as the supercooling suppression material (B). It is preferable to use it. At this time, the n-octacosane content in the normal paraffin (b) is 80% by weight or more, preferably 90% by weight or more, and particularly preferably 95% by weight or more.

Here, the main component means that the content is 70% by weight or more, preferably 80% by weight or more, particularly preferably 90% by weight or more.
The paraffin-based heat storage material composition of the present invention is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 100 parts by weight of the supercooling suppression material (B) with respect to 100 parts by weight of the latent heat storage material (A). It is preferable to contain 5 parts by weight. When the supercooling suppression material (B) is contained in such an amount, the supercooling suppression effect is sufficiently obtained, and the paraffin-based heat storage material composition sufficiently exhibits the heat storage performance of the latent heat storage material (A). High accuracy and stable melting and solidification characteristics.

  In addition, the paraffin-based heat storage material composition of the present invention desirably contains 90% by weight or more, preferably 95% by weight or more of the latent heat storage material (A) in the composition. The paraffin-based heat storage material composition containing the latent heat storage material (A) at such a ratio is preferable because the latent heat storage material content is large, the heat storage amount is large, and the heat storage performance is excellent.

  The paraffin-based heat storage material composition of the present invention preferably has a latent heat value of 100 J / g or more, more preferably 150 J / g, and even more preferably 200 J / g. If the amount of latent heat is less than 100 J / g, sufficient effects may not be exhibited when used for air conditioning applications, refrigerated / refrigerated storage containers, cold transport media, freeze prevention, and the like.

In addition to normal paraffins (a) and (b), the paraffin-based heat storage material composition of the present invention contains hydrocarbons having other structures, such as isoparaffin, olefin, naphthene, or aromatic components, as long as the object of the present invention is not impaired. It can be included. In addition, the paraffin-based heat storage material composition of the present invention may contain a resin monomer, a polymer material, a surfactant, and the like used when manufacturing an applied product such as a microcapsule. Furthermore, the paraffin-based heat storage material composition of the present invention includes additives that are usually used such as antioxidants and ultraviolet absorbers, specific gravity adjusting agents, colorants such as pigments and dyes, and aromatics, as long as the object of the present invention is not impaired. An additive such as an agent and a gelling agent may be included.

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[Example 1]
Latent heat storage material A containing 2.5% by weight of n-undecane, 95% by weight of n-dodecane and 2.5% by weight of n-tridecane, and normal paraffin (n-pentacosane having 25 carbon atoms) as supercooling suppression material B And 0.5 parts by weight of the supercooling suppression material B was blended with 100 parts by weight of the latent heat storage material A to prepare a heat storage material composition. Here, as the normal paraffins constituting the latent heat storage material A, reagents manufactured by Kanto Chemical Co., Ltd. (deer grade, purity 98% or more) were used. Moreover, as the normal paraffin used as the supercooling suppression material B, the reagent (TCI-GR, purity 98% or more) by Tokyo Chemical Industry was used.

  Table 1 shows the measurement results of the melting point and freezing point, the degree of supercooling, and the latent heat value of the obtained heat storage material composition. Here, the degree of supercooling refers to a value obtained by subtracting the freezing point of the heat storage material composition from the melting point of normal paraffin alone showing the maximum content in the used latent heat storage material A. In addition, when there are a plurality of normal paraffins having the maximum content, it means a value obtained by subtracting the freezing point of the heat storage material composition from the melting point of the normal paraffin having the smallest carbon number.

  The freezing point is the temperature at which the tangent of the maximum slope of the peak of the temperature-caloric diagram obtained when cooling at a rate of temperature decrease of 10 ° C./min using a differential scanning calorimeter intersects the baseline. Say. The freezing point, melting point and latent heat were measured using a DSC220CU differential scanning calorimeter manufactured by Seiko Instruments Inc.

  As the evaluation of the degree of supercooling, the case where the degree of supercooling of the latent heat storage material composition is less than 3 ° C. The case where the latent heat amount was 190 J / g or more was evaluated as ◯, and the case where it was less than 190 J / g was evaluated as x. The evaluation results are shown in Table 1.

[Examples 2 to 12, Comparative Examples 1 to 16]
Example 1 except that the composition ratio of the latent heat storage material A, the type of the supercooling suppression material B, and the blending ratio of the latent heat storage material A and the supercooling suppression material B are as shown in Table 1 or Table 2. A heat storage material composition was prepared in the same manner as described above. Here, as the normal paraffins constituting the latent heat storage material A, a reagent (deer grade, purity 98% or more) manufactured by Kanto Chemical Co., Ltd. was used. In Examples 2 to 12 and Comparative Examples 1 to 7, 10, 15 and 16, normal paraffin reagents shown in Table 1 or Table 2 (Tokyo Chemical Industry Co., Ltd., TCI-GR, purity of 98% or more) In Comparative Examples 11 to 13, paraffin wax manufactured by Nippon Seiwa Co., Ltd. (product name is shown in Table 2), and in Comparative Example 14, microcrystalline wax manufactured by Nippon Seiwa Co., Ltd. (product name) : Hi-MiC-1045) was used as the supercooling suppression material B, respectively.

  The melting point and freezing point, the degree of supercooling, and the latent heat quantity of the obtained heat storage material composition were measured or evaluated in the same manner as in Example 1. The results are shown in Table 1 or Table 2.

  The paraffin-based heat storage material composition of the present invention can be suitably used as a heat storage material used for cooling and air-conditioning applications, refrigerated / refrigerated storage containers, cold heat transfer media, freeze prevention, etc., in particular, high accuracy, stable melting, It can be suitably used as a latent heat storage material (PCM) that requires solidification characteristics.

Claims (4)

A normal paraffin comprising one or more selected from the group consisting of normal paraffins having 11 to 16 carbon atoms, having a melting point in the range of −15 to 10 ° C. and containing 70% by weight or more of n-dodecane or n-tetradecane. A latent heat storage material (A) comprising (a);
Supercooling suppression consisting of normal paraffin (b) consisting of one or more selected from the group consisting of normal paraffins having 17 to 100 carbon atoms and having a melting point 35 ° C. higher than the melting point of normal paraffin (a) Containing material (B) ,
The content of n-dodecane in the normal paraffin (a) is 90% by weight or more, and the total content of n-undecane, n-dodecane and n-tridecane in the normal paraffin (a) is 95% by weight or more. Because
A paraffin-based heat storage material composition, wherein the main component of normal paraffin (b) is n-eicosane or n-pentacosane .   The paraffin-based heat storage material composition according to claim 1, wherein the supercooling suppression material (B) is contained in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the latent heat storage material (A). A normal paraffin comprising one or more selected from the group consisting of normal paraffins having 11 to 16 carbon atoms, having a melting point in the range of −15 to 10 ° C. and containing 70% by weight or more of n-dodecane or n-tetradecane. A latent heat storage material (A) comprising (a);
Supercooling suppression consisting of normal paraffin (b) consisting of one or more selected from the group consisting of normal paraffins having 17 to 100 carbon atoms and having a melting point 35 ° C. higher than the melting point of normal paraffin (a) Containing material (B) ,
The content of n-tetradecane in the normal paraffin (a) is 90% by weight or more, and the total content of n-tridecane, n-tetradecane and n-pentadecane in the normal paraffin (a) is 95% by weight or more. Because
A paraffin-based heat storage material composition, wherein the main component of normal paraffin (b) is n-octacosane . The paraffin-based heat storage material composition according to claim 3 , comprising 0.01 to 10 parts by weight of the supercooling suppression material (B) with respect to 100 parts by weight of the latent heat storage material (A).