KR20080052202A - Manufacturing method of phase change material - Google Patents

Abstract

A method for preparing a phase change material is provided to produce the phase change material that is applicable to a cold chain system of agricultural crops and shows thermally insulating characteristics at the temperature ranging from 0 to 15 °C. A method for preparing a phase change material includes a step of reacting an emulsion colloid with a pretreated polymer to obtain a slurry in a microcapsule form. The emulsion colloid is obtained by adding sodium acrylate, a nucleator, and water to an aqueous SMA solution, and then emulsifying the admixture at 3,000-10,000 rpm. The pretreated polymer is obtained by reacting a melanin resin or gelatin with water. The nucleator is at least any one selected from C14H30 and C18H38.

Description

Manufacturing method of phase change material

Figure 1 is a photograph of the phase change material (K1) in the slurry form prepared in Examples 1-1 to 1-3.

Figure 2 is a photograph of the phase change material (K2) of the slurry form prepared in Examples 2-1 to 2-3.

3 is a photograph of a phase change material (K3) in the form of a slurry prepared in Examples 3-1 to 3-3.

Figure 4a is a graph showing the melting point and latent heat (melting point and latent heat) of the phase change material prepared in Example 4, Figure 4b is a graph showing the freezing point and latent heat (freezing point and latent heat).

Figure 5a is a graph showing the melting point and the latent heat of the phase change material prepared in Example 5, Figure 5b is a graph showing the freezing point and latent heat.

Figure 6a is a graph showing the melting point and the latent heat of the phase change material prepared in Example 6, Figure 6b is a graph showing the freezing point and latent heat.

The present invention relates to a method for producing a phase change material.

Phase change material (PCM) is a material that can store cold and warm heat by using latent heat during phase change.

Generally, the most widely used heat storage material is water, and water is easily available when the latent heat obtained during phase change is available.

Water has a low procurement cost and is easily available, and it has excellent properties as a phase change material because it is not toxic and explosive. However, in the case of hot water that stores heat when water is phase-changing, it may cause corrosion of the storage pipe due to heat, and ice that stores cold heat is difficult to flow when filling or transporting, and a lot of facilities are needed for reuse. The disadvantage is that the cost must be invested. In addition, since ice for storing cold heat is generated below freezing point, it is necessary to increase production cost and production time.

While water has a large latent heat energy, there is a problem in that the supercooling phenomenon is large when the phase change and the change of the wave is severe. Therefore, as a solution to this problem, a new phase change material with convenience, simplicity, and economy in production, distribution, and recovery is required for the ease of handling as well as the development of a new regenerative heat storage material for efficient cooling and heating.

 Due to the improvement of the standard of living and the westernization of the diet, the low temperature distribution of fast food, meat, seafood, fresh vegetables and fruits is increasing day by day.

Since foods, especially foods that must be kept at low temperatures, require refrigeration vehicles, refrigeration, cold storage warehouses, and small packaging refrigeration boxes, the industry related to such cold chain systems is also continuing to grow.

However, unlike the outward growth of the retail industry, the cold chain system is still in the introductory stage and focused on showcases, commercial freezers and courier-type ice packs that can be found at the cold storage and consumer stages of production.

In the case of agricultural products that are most sensitive to low temperature distribution, even if they are left at room temperature after harvesting or pre-cooled and stored, temperature fluctuations during distribution are severe and the initial quality is generally 20-20% after one day. There is a lot of freshness and nutrients are lost due to distribution. In addition, low-temperature distribution of agricultural products, mainly vegetables and fruits, requires more advanced technology to set and maintain the temperature more precisely than freezing distribution mainly applied to aquatic products and some livestock products. There is a problem of quality deterioration due to difficulty in maintaining a constant temperature in the course of several logistics steps from production to consumption.

In terms of production conditions, it is often uneconomical to operate pre-cooling facilities immediately in various places due to the small quantity production of various types of products. It is difficult to afford.

The above-mentioned phase change materials are suitable for phase change temperature, high latent heat density and high thermal shear thermal properties, smooth phase equilibrium, low gas pressure and small volumetric expansion physical properties, and high microcrystalline growth rate without supercooling. Molecular properties, chemical stability without deformation during long-term periodic freezing and thawing, chemical properties without toxicity, stability with storage container materials, and no risk of fire, electrochemically stable and low corrosive corrosion characteristics, It must be easy and affordable.

Meanwhile, phase change materials are classified into organic and inorganic materials or mixed forms thereof according to constituent materials. The types and characteristics of organic phase change materials which are widely known at present are shown in Tables 1 and 2 below. Types and characteristics are shown in Table 3 below.

Table 1. Types and Characteristics of Paraffinic Phase Change Materials

Kinds Melting point [℃] Heat of fusion [kJ / kg] Thermal Conductivity [W / (m · k)] Solid (Liquid) Density [x10 ² kg / m ³ ] Solid (Liquid) Specific heat [kJ / (kgK)] solid (liquid) Temperature Conductivity [mm ² / S] Solid (Liquid) C ₃₀ H ₆₂ 65.4 251 - 0.78 to 0.81 - - C ₂₈ H ₅₈ 61.4 164 - 0.81 (0.78) - - C ₂₇ H ₅₆ 59.5 159 - (078) - - C ₂₆ H ₅₄ 56.3 162 - 0.80 (0.78) - - C ₂₄ H ₅₀ 50.6 162 0.37 0.80 (0.78) 1.8 (2.3) 0.27 C ₂₂ H ₄₆ 44.0 157 - 0.79 - - C ₂₁ H ₄₄ 40.5 161 - 0.79 - - C ₂₀ H ₄₂ 36.4 247 0.37 (0.15) 0.83 (0.78) 1.9 (2.3) 0.22 (0.084) C ₁₉ H ₄₀ 32.1 171 - 0.78 - - C ₁₈ H ₃₈ 28.2 243 (0.15) 0.85 (0.78) 1.8 (2.3) (0.087) C ₁₆ H ₃₄ 18.2 229 (0.16) 0.83 (0.78) 1.8 (2.2) (0.093) C ₁₄ H ₃₀ 5.9 229 (0.14) 0.81 (0.77) 1.8 (2.1) (0.087) C ₁₂ H ₂₆ -9.6 210 - - 1.8 (2.1) -

Table 2. Types and Characteristics of Phase Changes in Organic Matter

Kinds Melting point [℃] Heat of fusion [kJ / kg] Thermal Conductivity [W / (m · k)] Solid (Liquid) Density [x10 ² kg / m ³ ] Solid (Liquid) Specific Heat [kJ / (kgK)] Solid (Liquid) pentaerythritol 188 285 0.221 [470K] - 2.77 [480K] polyethylen 120 to 140 - 0.46 to 0.53 0.94-0.97 1.89 Acet amide 82.3 214 (0.25) 1.16 (1.00) - Propyl amide 81.3 168 - 1.0 (0.93) - naphthalene 78.2 148 0.35 (0.13) 1.03 (0.97) 1.4 (1.6) Stearic acid 71 203 0.33 (0.16) 0.94 2.0 (2.3) poly glycol E6000 66 190 0.36 1.20 (1.08) - Wax (commercially available) 64 174 0.35 (0.17) 0.88 (2.1) 3-heptadecanone 48 218 - - - Cyanamide 44.0 208.41 0.33 (0.21) 1.28 1.6 (2.1) d-lactic acid 26 184 - - - Glycerol 18.2 200.62 - - - Acetic acid 16.6 192.09 (0.17) (0.15) - Ethylenediamine 11.1 375.77 - - - poly glycol E400 8.3 276.35 - - -

Table 3. Types and Characteristics of Inorganic Phase Change Materials

Kinds Melting point [℃] Heat of fusion [kJ / kg] Thermal Conductivity [W / (m · k)] Solid (Liquid) Density [x10 ² kg / m ³ ] Solid (Liquid) Specific heat [kJ / (kgK)] solid (liquid) Temperature Conductivity [mm ² / S] Solid (Liquid) MgCl ₂ · 6H ₂ O 116-118 172 2.1 (1.08) 1.57 (1.50) 2.1 (2.8) 0.64 (0.26) _{Al 2 (SO 4) 3 ·} 10H 2 O 112 182 - - - - NH ₄ Al (SO ₄ ) _{2 12} H ₂ O 93.5 269 - 1.64 1.8 (3.1) - KAl (SO ₄ ) _{2 12} H ₂ O 92.5 238 - 1.76 (1.68) 1.6 (2.8) - Mg (SO ₃ ) ₂ .6H ₂ O 89 160 1.6 1.64 - - SrBr ₂ 8H ₂ O 89 - - 2.39 - - Sr (OH) _{2 8} H ₂ O 88 343 1.8 (0.862) 1.90 1.8 0.53 Ba (OH) ₂ 9H ₂ O 78 266 1.3 (0.657) 2.18 1.5 (2.0) 0.40 Al (NO ₃ ) ₂ 6H ₂ O 73.5 155 - - - - Fe (NO ₃ ) ₂ · 6H ₂ O 60.5 - - 1.62 - - _{NaCH 2 S 2 O 2 · 5H} 2 O 58 264 - 1.48 - - Ni (NO ₃ ) ₂ · 6H ₂ O 56.7 - - 2.05 1.6 _{Na 2 S 2 O 2 · 5H} 2 O 48 197 1.73 (1.67) 1.5 (2.0) 0.46 (0.15) ZnSO ₄ · 7H ₂ O 38.9 - 1.2 (0.598) - 1.3 - CaBr ₂ · 6H ₂ O 38.2 115 - 2.30 - - Zn (NO ₃ ) ₂ · 6H ₂ O 36 147 - 1.92 (1.83) 1.6 (2.1) 0.33 (0.12) Na ₂ HPO _{4 12} H ₂ O 35 281 1.0 (0.477) 1.52 (1.44) 1.7 (1.9) 0.20 (0.17) Na ₂ CO ₃ · 10H ₂ O 32.5-34.5 247 0.514 (0.476) 1.44 1.9 - Na ₂ SO ₄ · 10H ₂ O 32.4 251 - 1.46 (1.33) 1.9 (2.9) (0.13) NiNO ₂ · 3H ₂ O 30 255 1.6 1.55 (1.45) 2.1 0.49 CaCl ₂ · 6H ₂ O 29.9 192 1.1 (0.54) 1.71 (1.62) 1.5 (2.1) 1.43 (0.16) CaCO ₂ · 10H ₂ O - - - - - - FeBr ₃ · 6H ₂ O 27 - - - - -

The present invention provides a phase change material for providing a phase change material capable of maintaining a low temperature in a certain temperature range for the development of a multipurpose low energy low temperature system that can implement both pre-cooling, storage and transportation functions in a mountain area and delivery function in a consumption area. It is intended to indicate a method of making a substance.

The object of the present invention is to provide a method for producing a phase change material that can be applied to the low temperature distribution of agricultural products, which must be maintained at a low temperature in a certain temperature range, unlike fish and livestock products.

An object of the present invention is to provide a method for producing a phase change material having a cold temperature characteristic at a low temperature of less than 15 ℃ more preferably 0 ~ 15 ℃.

The present invention aims to provide a phase change material which is prepared by the above-mentioned method and has a cold temperature characteristic at a low temperature of preferably 15 ° C. or lower, preferably 0 ° C. to 15 ° C.

The present invention for achieving the above-mentioned object is to prepare a phase change material in the form of a microcapsule slurry consisting of internal and external materials using an In-Situ polymerization method.

The method for preparing a phase change material in the form of a microcapsule of the present invention includes (1) obtaining an emulsified colloid obtained through an emulsification process as an internal material and (2) a polymer pretreated with an external material, and (3) the above (1) and (2) A phase change material in the form of a microcapsule slurry can be prepared by reacting an emulsion colloid obtained in the above-mentioned and a pretreated polymer. That is, if the present invention is more simply shown, a phase change material in the form of a microcapsule slurry may be prepared by reacting an emulsified colloid and a pretreated polymer.

Hereinafter, the present invention will be described in detail by dividing the emulsified colloid into a step, obtaining a pretreated polymer, and reacting the emulsified colloid with a pretreated polymer.

1. Steps to Get Emulsified Colloid

In the present invention, the emulsified colloid may be obtained by adding and emulsifying a phase change material, a nucleating agent, and water to an aqueous solution of stearyl methacrylate (SMA).

As the phase change material, sodium polyacrylate (sodium polyacrylate), C _{12 ~} C ₃₀ may be used any one or more of the paraffin-based material selected from.

The phase change material may use 0.1 to 90% of the total weight of the phase change material.

The nucleating agent may be any one or more selected from C ₁₂ to C ₃₀ paraffinic material, preferably C ₁₄ H ₃₀ , C ₁₈ H ₃₈ .

The nucleating agent may be used 4.5 to 30% of the total weight of the phase change material.

In the case of using a paraffinic material having at least one selected from C ₁₂ to C _{30 as} the phase change material, if C ₁₄ H ₃₀ is used as the phase change material, a nucleating agent may use C ₁₈ H ₃₈ , and a phase change material. If C ₁₈ H ₃₈ is used, the nucleating agent should be C ₁₄ H ₃₀ .

In the above-described SMA aqueous solution, a phase change material, a nucleating agent, and water may be added and emulsified at 3000 to 10,000 rpm to obtain an emulsified colloid. At this time, the emulsified colloid may be obtained by emulsifying at room temperature for 5 to 15 minutes, preferably 7 to 12 minutes.

An example of the method of obtaining an emulsion colloid can be shown to the following (A)-(C).

(A) The SMA powder is dissolved in water at a temperature of 90 ° C. or higher, for example, 90 to 100 ° C., and then cooled at room temperature to obtain an aqueous SMA solution, for example, an 0.1-5 wt% SMA aqueous solution. Sodium polyacrylate, a nucleating agent and water are added to the SMA aqueous solution, and it can be obtained by emulsifying at 3000 to 10000 rpm for 5 to 15 minutes at room temperature, preferably 7 to 12 minutes.

At this time, sodium polyacrylate may be added 0.12% to 0.14% of the total weight of the slurry, which is a phase change material, and nucleating agent is added to 3.5 to 10.5% of C ₁₄ H ₃₀ or C ₁₈ H ₃₈ , based on the total weight of the slurry, which is a phase change material. It is possible to use it by adding the remainder of water.

(B) The SMA powder is dissolved in water at a temperature of 90 ° C. or higher, for example, 90 to 100 ° C., and then cooled at room temperature to obtain an SMA aqueous solution, for example, 0.1 to 5 wt% SMA aqueous solution. It can be obtained by adding a phase change material, a nucleating agent and water to the SMA aqueous solution and emulsifying at 3000 to 10000 rpm for 5 to 15 minutes, preferably 7 to 12 minutes at room temperature.

At this time, C ₁₄ H ₃₀ may be added as a phase change material to 60 to 65% of the total weight of the slurry, and nucleating agent C ₁₈ H ₃₈ may be added at 4.9% to 6.3% to the total weight of the slurry as the phase change material. It can be used by adding the remainder water.

(C) The SMA powder is dissolved in water at a temperature of 90 ° C. or higher, for example, 90-100 ° C., and then cooled at room temperature to obtain an SMA aqueous solution, for example, 0.1-5 wt% SMA aqueous solution. It can be obtained by adding a phase change material, a nucleating agent and water to the SMA aqueous solution and emulsifying at 3000 to 10000 rpm at room temperature for 5 to 15 minutes, preferably 7 to 12 minutes at room temperature.

At this time, C ₁₄ H ₃₀ can be added 40 to 50% of the total weight of the slurry as a phase change material, and nucleating agent C ₁₈ H ₃₈ can be added to 18.9% to 20.3% of the total weight of the slurry as a phase change material. It can be used by adding the remainder water.

2. Obtaining Pretreated Polymer

When the polymer and water are mixed at a weight ratio of 1: 9 to 9: 1 and reacted while stirring, a semitransparent liquid pretreated polymer can be obtained.

In the polymer, melamine resin or gelatin may be used.

In the above, the polymer and water are reacted with stirring at 500 to 1000 rpm for 10 to 20 minutes at a temperature of 50 to 70 ° C. to obtain a semi-transparent liquid pretreated polymer.

3. Reaction step of emulsion colloid and pretreated polymer

The phase change material in the form of a microcapsule slurry may be prepared by reacting the emulsion colloid obtained in step 1 with the pretreated polymer obtained in step 2.

The sodium acrylate or paraffinic material used to obtain the emulsified colloid is used as a microcapsule internal material in the phase change material in the form of a microcapsule slurry, and the pretreated polymer is used as the microcapsule external material.

The emulsion colloid and the pretreated polymer may be polymerized at 50 to 70 ° C. at 500 to 700 rpm for 2 to 4 hours to prepare a microcapsule slurry.

When the emulsion colloid and the pretreated polymer are reacted, the pretreated polymer may be added to the emulsion colloid to react.

In the present invention, after the emulsion colloid and the pretreated polymer are reacted to obtain a phase change material in the form of a microcapsule slurry, spray drying may be further performed on the microcapsule slurry to prepare a phase change material in powder form.

On the other hand, the present invention includes a phase change material obtained by the above method.

The phase change material of the present invention includes the phase change material of the microcapsule slurry and / or the phase change material in the form of a powder spray dried on the microcapsule slurry.

The phase change material of the present invention may maintain the set temperature of the agricultural products at 15 ℃ or less, preferably the set temperature of the agricultural products 0 ~ 15 ℃ during agricultural products distribution.

For example, sodium polyacrylate may be used as a phase change material, and a phase change material (K1) containing C ₁₄ H ₃₀ as a nucleating agent may maintain a set temperature of 0 to 5 ° C. suitable for agricultural distribution. . In the above sodium polyacrylate may be used 0.1 to 0.20% of the total weight of the phase change material slurry.

For example, sodium polyacrylate is used as a phase change material, and C ₁₄ H ₃₀ , Phase change material (K2) containing any one or more selected from C ₁₈ H ₃₈ may maintain a set temperature 5 ~ 10 ℃ suitable for agricultural products distribution. Sodium polyacrylate may be used 20 to 30% relative to the total weight of the phase change material slurry.

For example, sodium polyacrylate is used as a phase change material, and C ₁₄ H ₃₀ , Phase change material (K3) containing any one or more selected from C ₁₈ H ₃₈ may maintain a set temperature 10 ~ 15 ℃ suitable for agricultural products distribution. Sodium polyacrylate may be used 10 to 20% relative to the total weight of the phase change material slurry.

Hereinafter, the content of the present invention will be described in detail through examples and test examples. However, these are intended to explain the present invention in more detail, and the scope of the present invention is not limited thereto.

Example 1-1 Preparation of Slurry Phase Change Material K1-1

The pretreated polymer was added to the emulsion colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K1-1).

In the emulsified colloid is dissolved SMA powder in water of 90 ℃ and then cooled at room temperature to obtain a 5wt% SMA aqueous solution, sodium polyacrylate as a phase change material in the SMA aqueous solution is 0.1% of the total weight of the phase change material slurry, As a nucleating agent, C ₁₄ H ₃₀ was obtained by adding 10% of the total weight of the phase change slurry and the remainder of water to emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin water at a weight ratio of 5: 5 and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K1-1) prepared above is shown in FIG. 1.

<Example 1-2> Preparation of slurry phase change material K1-2

The pretreated polymer was added to the emulsion colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K1-2).

In the emulsified colloid is dissolved SMA powder in water of 90 ℃ and then cooled at room temperature to obtain a 5wt% SMA aqueous solution, sodium polyacrylate as a phase change material in the SMA aqueous solution 0.15% of the total weight of the phase change material slurry, As a nucleating agent, C ₁₄ H ₃₀ was obtained by adding 10% of the total weight of the phase change slurry and the remainder of water to emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin water at a weight ratio of 5: 5 and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K1-2) prepared above is shown in FIG. 1.

Example 1-3 Preparation of Slurry Phase Change Material K1-3

The pretreated polymer was added to the emulsified colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K1-3).

In the emulsified colloid is dissolved SMA powder in water of 90 ℃ and then cooled at room temperature to obtain a 5wt% SMA aqueous solution, sodium polyacrylate as a phase change material in the SMA aqueous solution 0.20% of the total weight of the phase change material slurry, As a nucleating agent, C ₁₄ H ₃₀ was obtained by adding 10% of the total weight of the phase change slurry and the remainder of water to emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin water at a weight ratio of 5: 5 and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K1-3) prepared above is shown in FIG. 1.

Example 2-1 Preparation of Slurry Phase Change Material K2-1

The pretreated polymer was added to the emulsion colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K2-1).

In the emulsified colloid is dissolved SMA powder in water of 90 ℃ and then cooled at room temperature to obtain a 5wt% SMA aqueous solution, 20% of the total weight of the phase change material slurry of sodium polyacrylate as a phase change material in the SMA solution As a nucleating agent, C ₁₈ H ₃₈ was obtained by adding 7% of the total weight of the phase change slurry and the remainder of water to emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin water at a weight ratio of 5: 5 and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K2-1) prepared above is shown in FIG. 2.

Example 2-2 Preparation of Slurry Phase Change Material K2-2

The pretreated polymer was added to the emulsion colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K2-2).

In the emulsified colloid, the SMA powder is dissolved in water at 90 ° C., and then cooled at room temperature to obtain a 5 wt% SMA aqueous solution. Sodium polyacrylate is 25% of the total weight of the phase change material slurry as a phase change material in the SMA aqueous solution. As a nucleating agent, C ₁₈ H ₃₈ was obtained by adding 7% of the total weight of the phase change slurry and the remainder of water to emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin water at a weight ratio of 5: 5 and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K2-2) prepared above is shown in FIG. 2.

Example 2-3 Preparation of Slurry Phase Change Material K2-3

The pretreated polymer was added to the emulsified colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K2-3).

In the emulsified colloid is dissolved SMA powder in water of 90 ℃ and then cooled at room temperature to obtain a 5wt% SMA aqueous solution, sodium polyacrylate as a phase change material in the SMA aqueous solution 30% of the total weight of the phase change material slurry, As a nucleating agent, C ₁₈ H ₃₈ was obtained by adding 7% of the total weight of the phase change slurry and the remainder of water to emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin in a weight ratio of 5: 5, and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K2-3) prepared above is shown in FIG. 2.

Example 3-1 Preparation of Slurry Phase Change Material K3-1

The pretreated polymer was added to the emulsion colloid and polymerized at 600 rpm for 3 hours at 60 ° C. to prepare a microcapsule slurry phase change material (K3-1).

In the emulsified colloid is dissolved SMA powder in water of 90 ℃ and then cooled at room temperature to obtain a 5wt% SMA aqueous solution, sodium polyacrylate as a phase change material in the SMA aqueous solution 10% of the total weight of the phase change material slurry, As the nucleating agent, C ₁₄ H ₃₀ and C ₁₈ H ₃₈ are used, wherein the nucleating agent C ₁₄ H ₃₀ is 2.5% of the total weight of the phase change material slurry, C ₁₈ H ₃₈ is 2.5% of the total weight of the phase change material slurry and Water was added and obtained by emulsification at 5000 rpm for 10 minutes at room temperature.

The pretreated polymer was mixed with melamine resin water at a weight ratio of 5: 5 and reacted with stirring at 500 rpm for 10 minutes at a temperature of 60 ° C. to obtain a translucent liquid pretreated polymer.

The microcapsule slurry phase change material (K3-1) prepared above is shown in FIG. 3.

Example 3-2 Preparation of Slurry Phase Change Material K3-2

Sodium polyacrylate was prepared in the same manner as in Example 3-1, except that 15% of the total weight of the phase change material slurry was prepared.

Example 3-3 Preparation of Slurry Phase Change Material K3-3

Sodium polyacrylate was prepared in the same manner as in Example 3-1, except that 20% of the total weight of the phase change material slurry was prepared.

Example 4 Preparation of Powder Phase Change Material (I)

The pretreated polymer was added to the emulsified colloid and polymerized at 600 rpm for 3 hours to obtain a microcapsule slurry, and then spray dried to prepare a phase change material in powder form.

The emulsion colloid and the pretreated polymer were used in Example 1-1.

Example 5 Preparation of Powder Phase Change Material (II)

The pretreated polymer was added to the emulsion colloid and polymerized at 600 rpm for 3 hours to obtain a microcapsule slurry, and then spray dried to prepare a phase change material in powder form.

The emulsion colloid and the pretreated polymer were used in Example 2-1.

Example 6 Preparation of Powder Phase Change Material (III)

The pretreated polymer was added to the emulsified colloid and polymerized at 600 rpm for 3 hours to obtain a microcapsule slurry, and then spray dried to prepare a phase change material in powder form.

Emulsified colloids and pretreated polymers were those obtained in Example 3-1.

<Test Example 1>

Thermal properties of each of the phase change materials prepared in Examples 1-1 to 3-3 were measured and the results are shown in Table 4 below.

Table 4. Properties of Thermal Properties of Phase Change Materials

In Table 4, the phase change temperature was measured using a 0.3 mmΨcopper-constantan thermocouple for temperature measurement and a multipoint Hydra data acquisition (2625A, Fluke, USA).

* In Table 4, latent heat measurement was performed using UNIX DSC 7 (PERKIN ELMER, USA), which is a DSC (Differential Scanning Calorimeter).

<Test Example 2>

K1 phase change material (K1-1, K1-2, K1-3) of Example 1-1 to Example 1-3, K2 phase change material (K2- of Example 2-1 to 2-3) 1, K2-2, K2-3), and the K3 phase change materials (K3-1, K3-2, K3-3) of Examples 3-1 to 3-3 with styrofoam, ice box After filling by the same container, the cold storage characteristics of each container filled with each phase change material at the cooling temperature of 7 ℃, 13 ℃, 17 ℃, was measured.

As a result, the Styrofoam container filled with K 1 phase change material retained the cooling characteristics at 7 ℃, 13 ℃, and 17 ℃ for 42 ~ 55 hours, and the K2 phase change materials and K3 phase change materials maintained the cooling characteristics for 12 ~ 155 hours (See Tables 5, 6 and 7).

In case of ice box container, K1 phase change material was kept cold for 66 ~ 68 hours at 7 ℃, 13 ℃ and 17 ℃, and K2 and K3 phase change materials were kept cold at 5 ℃, 12 ℃ and 17 ℃ for 12-18 hours. Properties were maintained (see Tables 5, 6 and 7).

Table 5.Cold retention time (K1) of phase change material (PCM)

Table 6. Cold retention time (K2) of phase change material (PCM)

Table 7.Cold Hold Time (K3) of Phase Change Materials (PCM)

From the results of Tables 5 to 7, it can be seen that the phase change materials (K1, K2, K3) prepared according to the present invention exhibit cold storage characteristics at a cooling temperature of 7 to 17 ℃.

<Test Example 3>

Melting point and latent heat and freezing point and latent heat were respectively measured using DSC for each of the powdered phase change materials prepared in Examples 4 to 6. The results are shown in FIGS. 4A to 6B.

Figure 4a is a graph showing the melting point and latent heat (melting point and latent heat) of the phase change material prepared in Example 4, Figure 4b is a graph showing the freezing point and latent heat (freezing point and latent heat).

Figure 5a is a graph showing the melting point and the latent heat of the phase change material prepared in Example 5, Figure 5b is a graph showing the freezing point and latent heat.

Figure 6a is a graph showing the melting point and the latent heat of the phase change material prepared in Example 6, Figure 6b is a graph showing the freezing point and latent heat.

Figure 4a Figure 5a, Figure 6a is a melting point of the phase change material (PCM), the phase change material (K ₁ ) prepared in Example 4, the phase change material (K ₂ ) prepared in Example 5, prepared in Example 6 The melting point of a phase change material (K ₃ ), which holds cold energy (latent heat) and shows the time when it is completely released. This can be judged as possible.

A phase change material prepared from Figure 4b, Figure 5b, Figure 6b is a phase change material manufactured by the freezing point of the PCM, Example 4 (K _1), Example 5 a phase change material (K _2), Example 6 prepared in The freezing point of (K ₃ ) is the temperature at which the latent heat (thermal energy) is completely discharged, and the temperature can be charged again.The temperature indicated at each peak is the cooling energy required for the cold storage. The supercooling phenomenon occurs, rather the state is not suitable for the agricultural distribution temperature respectively. Therefore, it is a graph showing the freezing point temperature in each PCM.

In addition, the various graph peaks indicate the number of substances mixed in the preparation of the phase change material in the present invention. The melting point and the freezing point of the mixed materials are obtained to obtain the temperature required for each agricultural product distribution temperature. will be.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. It will be appreciated that it can be changed.

As shown in the results of the test example, the phase change material prepared by the present invention has excellent thermal properties, and it can be seen that it exhibits cold storage at an air cooling temperature of 5 to 17 ° C.

Phase change material prepared by the present invention can provide a phase change material that can be applied to the low temperature distribution of agricultural products and livestock products and agricultural products that should be maintained at a low temperature, preferably lower than 15 ℃, preferably 0 ~ 15 ℃ .

Claims (11)

A process for producing a phase change material, characterized in that to obtain a slurry in the form of microcapsules by reacting an emulsion colloid and a pretreated polymer. The method of claim 1, wherein the emulsion colloid is obtained by adding sodium acrylate, a nucleating agent, and water to an aqueous SMA solution and emulsifying at 3000 to 10,000 rpm. The method for preparing a phase change material according to claim 1, wherein the emulsified colloid is obtained by adding paraffinic material, nucleating agent and water selected from C ₁₂ to C ₃₀ to SMA aqueous solution and emulsifying at 3000 to 10000 rpm. . The method of claim 1, wherein the emulsified colloid is obtained by adding at least one substance, nucleating agent, and water of C ₁₄ H ₃₀ , C ₁₈ H _{38 to an} aqueous SMA solution and emulsifying at 3000 to 10,000 rpm. The method of claim 1, wherein the pretreated polymer is obtained by reacting melanin resin or gelatin with water. The method of claim 1, wherein the reaction of the emulsified colloid and the pretreated polymer is polymerized at 500 to 700 rpm for 2 to 4 hours at 50 to 70 ° C. The method of claim 1, wherein the microcapsules-type slurry is further spray dried to obtain a phase change material in powder form. The method for preparing a phase change material according to any one of claims 2, 3 and 4, wherein the nucleating agent is at least one selected from C ₁₄ H ₃₀ and C ₁₈ H ₃₈ . A phase change that is prepared by the method of claim 1, but maintains a set temperature of 0 to 5 ° C. suitable for agricultural distribution, including sodium polyacrylate as a phase change material and C ₁₄ H ₃₀ as a nucleating agent. matter. Prepared by the method of claim 1, wherein sodium polyacrylate is used as a phase change material, C ₁₄ H ₃₀ , A phase change material that maintains a set temperature of 5 to 10 ° C. suitable for distribution of agricultural products, including at least one selected from C ₁₈ H ₃₈ . Prepared by the method of claim 1, wherein sodium polyacrylate is used as a phase change material, C ₁₄ H ₃₀ , C ₁₈ H _38, including at least one selected from the phase change material to maintain the setup temperature 10~15 ℃ suitable to produce distribution.

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