KR101889525B1 - Phase change microcapsule for artificial marble and the manufacturing method thereof - Google Patents

Abstract

The present invention relates to phase change microcapsules for artificial marble, which is composed of a core containing a heat storage material and a shell containing an acrylic polymer bonded from a monomer mixture of a methyl methacrylate monomer, an epoxy acrylate-based monomer, and a polyfunctional acrylate-based monomer. The present invention aims to provide the phase change microcapsules for artificial marble, which has increased durability while having a heat storage effect, and a manufacturing method thereof.

Description

TECHNICAL FIELD [0001] The present invention relates to a phase transition microcapsule for artificial marble and a method for manufacturing the same,

The present invention relates to a phase transition microcapsule for artificial marble and a method for producing the same, and more particularly, to a phase transition microcapsule comprising a shell containing an acrylic polymer prepared from a core containing a heat storage material and an epoxy acrylate monomer, .

Energy conservation has become a global issue in recent years due to climate conventions to solve global warming problems. Energy conservation technology such as insulation of buildings using insulation has been widely used for heating and cooling, and has been contributing to energy conservation in many areas. At present, Korea consumes about 20% of the total national energy while the buildings are in use, and developed countries, such as the UK and Japan, which are more developed by heating and cooling, currently use about 26 ~ 28% ~ 40% of the energy is expected to be consumed. Also, in the United Kingdom and the like, development is being continued to improve thermal efficiency of walls and roofs using thermal mass.

In other words, research is needed to generate more thermal efficiency with the same amount of energy, and the use of heat storage material has the advantage of increasing the energy use efficiency by keeping the energy used for indoor heating and cooling for a long time at a constant temperature have. Especially, as the existing Ondol type building is replaced with concrete, the heat storage function of the building wall is lowered, resulting in a significant temperature difference between the floor and the wall, resulting in a decrease in energy efficiency. A material having a heat storage performance capable of being maintained at a high temperature.

Therefore, in order to maximize the energy efficiency, much research has been focused on manufacturing a latent heat storage material using a phase change material (PCM). A latent heat storage method, which is a method of storing heat energy by using latent heat as absorbing and emitting heat by using a phase transition material which is a material that absorbs or emits a large amount of heat while changing phases without changing the temperature at a specific temperature, It is possible to store a larger amount of heat per unit volume or unit weight than by using thermal energy.

Most of the conventional structure of the latent heat storage material is stored and used in a carrier having a certain shape, thereby forming a structure for storing heat. In other words, there may be a regenerator having various shapes and materials depending on the characteristics of the carrier. Recently, the most commonly used ones are those in which a phase transition material is stored in a structure such as a sphere or a square having a diameter of 10 cm or more, It has a structure to avoid. In addition, materials such as hydroxide compounds in the latent heat storage materials are highly corrosive and achieve storage purpose by utilizing metal or resin-based storage carriers resistant to corrosion.

In addition, since the paraffinic phase transition material having a very low unit cost as the above-mentioned latent heat storage material flows out above the melting point, it is encapsulated and used. The encapsulation technique of the phase change material uses microencapsulation with melamine or formaldehyde resin. The melamine resin obtained by the polycondensation of melamine and formaldehyde has excellent characteristics such as mechanical strength and heat resistance. However, in this method, there is a possibility that formaldehyde, which is harmful to the human body, may remain because formaldehyde having a molar number twice or more of the melamine is added to increase the reaction rate of the melamine. In addition, since the process is complicated, the production cost is increased, so that it can not be put to practical use, and its application is limited because of low heat resistance.

The conventional microcapsule is a method in which a core located inside the capsule exerts through the pores of the shell to exert its effect or exerts its effect by breaking the capsule by an external pressure. Since the core-shell structure is not robust, And the like.

In order to solve the above problems, it is an object of the present invention to provide a phase transition microcapsule having a durability with a heat storage effect and a method for manufacturing the same.

In addition, the present invention relates to a method for producing a phase change microcapsule in which a shell of phase-transition microcapsules is formed from a monomer mixture comprising a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer, Phase transition microcapsules of the present invention.

It is another object of the present invention to provide a phase transition microcapsule having high latent heat, which is contained in artificial marble and is excellent in energy efficiency.

The phase transition microcapsules for artificial marble according to the present invention were found to contain a core containing a heat storage material and a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer And a shell comprising the acrylic polymer bonded thereto.

The monomer mixture may comprise 75 to 85% by weight of methyl methacrylate monomer, 10 to 20% by weight of polyfunctional acrylate monomer and 1 to 10% by weight of epoxy acrylate monomer.

The epoxy acrylate-based monomer may be any one or more selected from bisphenol A epoxy acrylate, bisphenol F epoxy acrylate, novolak-epoxy acrylate, cresol-novolak epoxy acrylate, and biphenol epoxy acrylate.

The polyfunctional acrylate monomer may be selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol pentaacrylate, dipentaerythritol pentaacrylate , Dipentaerythritol hexaacrylate, glycerol diacrylate, and ethylene diacrylate.

Wherein the heat storage material is selected from the group consisting of C ₁₀ to C ₃₀ saturated hydrocarbons, C ₆ to C ₃₀ Fatty acids and C ₆ to C ₃₀ Fatty alcohols, and mixtures thereof.

The method for producing phase change microcapsules for artificial marble of the present invention comprises the steps of: a) melting a shell mixture comprising an initiator and a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer;

b) preparing a dispersion phase in which a heat storage material is added to the shell mixture to disperse the mixture;

c) adding the dispersed phase to a continuous phase containing a polymer type surfactant to disperse the emulsion to form an emulsion;

d) suspension polymerization of the emulsion; And

and e) drying the suspension polymer to prepare microcapsules.

In the step c), the polymer type surfactant may be any one or a mixture of two or more selected from polyvinyl alcohol and polyvinyl pyrrolidone.

In the step c), the polymer type surfactant may be contained in an amount of 0.05 to 20% by weight based on the total weight of the continuous phase.

And the suspension may be subjected to suspension polymerization after adjusting the emulsion to pH 2 to 5 in step d).

The artificial marble of the present invention may include the phase transition microcapsules described above.

And 10 to 30% by weight based on the total weight of the artificial marble including the phase transition microcapsules.

The phase change microcapsule according to the present invention is a phase change microcapsule in which the shell of the phase transition microcapsule comprises an acryl-based polymer bonded from a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer so that the surface is smooth, Can be manufactured with excellent spherical shape.

In addition, the phase-transition microcapsule of the present invention has an advantage that the durability can be increased while having a heat storage effect.

In addition, the phase transition microcapsule of the present invention has an advantage of being included in artificial marble and having high latent heat to increase energy efficiency.

1 is a scanning electron microscope (SEM) image of phase-change microcapsules according to an embodiment of the present invention.
2 is a scanning electron microscope (SEM) image of phase-change microcapsules according to a comparative example of the present invention.
3 is a particle size distribution diagram of a phase change microcapsule according to an embodiment of the present invention.
FIG. 4 is a latent heat characteristic measured by differential scanning calorimetry of a phase change microcapsule according to an embodiment of the present invention.

Hereinafter, a phase change microcapsule for artificial marble according to the present invention, a method for producing the same, and artificial marble including phase transition microcapsules will be described in more detail. It should be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

As used herein, the term " acrylate " includes acrylate or methacrylate.

In the present specification, the term "polyfunctional" means a compound having two or more functional groups. For example, the polyfunctional acrylate-based monomer means an acrylate-based monomer having two or more functional groups.

As used herein, "microcapsules" may refer to spherical microcapsules containing one or more laminate coatings and a core that is chemically different from and surrounded by such coatings. The microcapsules can be distinguished from microspheres composed of a spherical homogeneous matrix.

In order to accomplish the above object, the present invention relates to a phase transition microcapsule for artificial marble and a method of manufacturing the same.

Hereinafter, the present invention will be described in detail.

The phase change microcapsule for artificial marble of the present invention comprises a core containing a heat storage material; And a shell comprising an acrylic polymer prepared from a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer.

The phase change microcapsule of the present invention can broaden the application range of the phase change material and increase the durability of the microcapsule. More specifically, a core comprising a heat storage material; And a shell comprising an acryl-based polymer prepared from a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate-based monomer and a polyfunctional acrylate-based monomer, thereby increasing the durability of the microcapsule It is characterized by.

In addition, since the phase-transition microcapsule of the present invention is produced in a spherical shape having a smooth surface according to the above composition, it has a narrow range of phase transition temperature region, and thus it is possible to maximize the heat storage function in a target temperature range.

According to an embodiment of the present invention, the heat storage material may be any one or a mixture of two or more selected from C ₁₀ to C ₃₀ saturated hydrocarbons, C ₆ to C ₃₀ fatty acids and C ₆ to C ₃₀ fatty alcohols. Preferably a C ₁₅ to C ₃₀ saturated hydrocarbon, a C ₁₀ to C ₃₀ fatty acid and a C ₁₀ to C ₃₀ fatty alcohol, or a mixture of two or more thereof. The heat storage material is capable of absorbing or releasing latent heat while changing from a solid phase to a solid phase from a solid phase to a liquid phase or a liquid phase, and thus it is possible to have an excellent energy storage efficiency by storing heat at a remarkably high temperature. In addition, the heat storage material not only can reduce heat loss by cutting off excessive heat or cold, but also can maintain the room temperature constant.

According to an embodiment of the present invention, the heat storage material may have a melting point of 20 to 40 ° C. The microcapsule of the present invention can be prepared by heating at a temperature higher than the melting point of the heat storage material and encapsulating the microcapsule. The heating temperature may be 30 to 60 占 폚. It is preferable to prevent evaporation or pyrolysis of the heat storage material at the heating temperature.

Generally, the microcapsules can improve the latent heat by increasing the content of the heat storage material, but they can not substantially increase the content, and the durability of the shell, which is a wall material of the microcapsule, is decreased.

According to an aspect of the present invention, the monomer mixture for forming the shell of the phase change microcapsule comprises a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer And may include bonded acrylic polymers.

The monomer mixture may be prepared from an acrylic polymer by combining a monomer including a methyl methacrylate monomer, an epoxy acrylate monomer, and a polyfunctional acrylate monomer, thereby making spherical particles having excellent durability and having smooth surfaces. . Accordingly, the content of the heat storage material can be maximized and the latent heat property of the heat storage material can be further improved.

According to one embodiment of the present invention, the monomer mixture may comprise 75 to 85 wt% of methyl methacrylate monomer, 10 to 20 wt% of polyfunctional acrylate monomer, and 1 to 10 wt% of epoxy acrylate monomer. In the above range, a shell having excellent durability that can prevent loss and damage of the heat storage material can be produced, which is preferable.

According to one embodiment of the present invention, the epoxy acrylate monomer is selected from the group consisting of bisphenol A epoxy acrylate, bisphenol F epoxy acrylate, novolac-epoxy acrylate, cresol-novolac epoxy acrylate and biphenol epoxy acrylate One or two or more. When the epoxy acrylate monomer is mixed with the methyl methacrylate monomer and the polyfunctional acrylate monomer, a spherical microcapsule having a smooth surface can be formed.

According to an embodiment of the present invention, the polyfunctional acrylate monomer may be an acrylate monomer having two or more functional groups. Preferably, the functional group may be a double bond, which is an unsaturated bond. Specific examples of the polyfunctional acrylate monomer include trimethylolpropane triacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol pentaacrylate, dipentaerythritol pentaacrylate, Ethylene glycol diacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, erythritol pentaacrylate, dipentaerythritol hexaacrylate, glycerol diacrylate, ethylene diacrylate, and the like. The multifunctional acrylate monomer is preferably mixed with the methyl methacrylate monomer and the epoxy acrylate monomer so that the surface of the shell can form a smooth spherical microcapsule.

According to one embodiment of the present invention, 0.1 to 5 parts by weight of a C ₈ to C ₂₀ alkyl acrylate monomer may be further added to 100 parts by weight of the monomer mixture. The C ₈ to C ₂₀ alkyl acrylate, if further comprise a monomer artificial marble factory or the core in the microcapsule interior by the high-temperature heat flows out through the pores of the shell, it is possible to prevent the shape microcapsules break. Specifically, the C ₈ to C ₂₀ alkyl acrylate-based monomer may exist in a swollen form due to the long chain at the interface between the core and the shell. In addition, the storage material can be selectively absorbed by the lipophilic property, thereby enhancing the stability of the microcapsule. Therefore, the C ₈ -C ₂₀ alkyl acrylate monomer absorbs or protects the interface between the core and the shell so as to prevent the heat storage material from flowing out, thereby preventing the microcapsules from breaking or popping due to expansion of the heat storage material due to high temperature and high pressure So that the durability is improved.

According to one embodiment of the present invention, the C ₈ to C ₂₀ alkyl acrylate monomers include, for example, dodecyl acrylate, isodecyl acrylate, n-undecyl acrylate, tridecyl acrylate, Acrylate, n-octyl methacrylate, n-nonyl acrylate, isobutyl acrylate, isooctyl acrylate, isooctyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, , 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, and the like, or a mixture of two or more thereof.

According to one embodiment of the present invention, the microcapsule may have 60 to 90% by weight of the core and 10 to 40% by weight of the shell. Preferably, the core may be 65 to 85 wt% and the shell may be 15 to 35 wt%, but is not limited thereto. In the above range, it is preferable to have a thin shell so that the durability is excellent, the content of the core including the heat storage material can be maximized, and the latent heat property is further improved.

For example, the microcapsules may have an average particle size of 1 to 10 mu m, although the present invention is not limited thereto according to an embodiment of the present invention. When the average particle size is within the above-mentioned range, the artificial marble has excellent dispersibility upon mixing and is excellent in compatibility with artificial marble. However, the present invention is not limited thereto.

A method for producing phase change microcapsules for artificial marble of the present invention will be described in detail. A) A shell mixture comprising a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer and an initiator ;

b) preparing a dispersion phase in which a heat storage material is added to the shell mixture to disperse the mixture;

c) adding the dispersed phase to a continuous phase containing a polymer type surfactant to disperse the emulsion to form an emulsion;

d) suspension polymerization of the emulsion; And

and e) drying the suspension polymer to prepare microcapsules.

The method for producing a phase-change microcapsule of the present invention is a manufacturing method capable of expanding the application range of the microcapsule phase transition material and increasing the durability of the microcapsule. More specifically, a core comprising a heat storage material; And a shell comprising an acryl-based polymer bonded from a monomer mixture comprising a methyl methacrylate monomer, an epoxy acrylate monomer and a polyfunctional acrylate monomer, thereby increasing the durability of the microcapsule It is characterized by.

According to an embodiment of the present invention, the melting or dispersing temperature may be uniformly melted or dispersed in the steps a) to c), but is not limited thereto.

According to one embodiment of the present invention, the initiator serves to initiate a polymerization reaction, and specific examples thereof include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium persulfate, and hydrogen peroxide; butyl hydroperoxide, cumene hydroperoxide, p-menthol hydroperoxide, di-t-butyl peroxide, t-butyl cumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide Organic peroxides such as peroxide, 3,5,5-trimethylhexanol peroxide, t-butyl peroxyisobutyrate, and diisopropylbenzene hydroperoxide; Nitrogen compounds such as azobisisobutyronitrile, azobisisobutylonitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and azobisisobutyronitrile (methyl butyrate), and the like, But is not limited thereto.

The initiator may be included in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the monomer mixture, but is not limited thereto.

According to an embodiment of the present invention, in the step b), the dispersed phase may be a mixed dispersion of 60 to 90% by weight of a heat storage material and 10 to 40% by weight of a shell mixture. Preferably 65 to 85% by weight of the heat storage material and 15 to 35% by weight of the shell mixture, but is not limited thereto. In the above range, microcapsules having excellent durability and maximizing the content of the core including the heat storage material can be produced even though they have a thin shell.

According to an embodiment of the present invention, the polymer type surfactant in step c) may be any one or a mixture of two or more selected from polyvinyl alcohol and polyvinyl pyrrolidone. When the above-mentioned surfactant is contained in the continuous phase of the present invention, the generation of fine particles is reduced and more uniform particles can be obtained.

According to one embodiment of the present invention, in step c), the polymer type surfactant may be an aqueous solution of a surfactant in an amount of 0.05 to 20% by weight, preferably 1 to 10% by weight. When the above range is satisfied, microcapsules having excellent monodispersibility can be prepared, but the present invention is not limited thereto.

The polymer type surfactant may be included in an amount of 5 to 20 parts by weight based on 100 parts by weight of the dispersed phase, but is not limited thereto. When it is included in the above-mentioned range, it is preferable that the size of the microcapsule is excessively increased or the increase of fine particles is minimized.

According to one embodiment of the present invention, the emulsion may be subjected to suspension polymerization after adjusting the emulsion at a pH of 2 to 5 in the step d). When the suspension polymerization is carried out in the above-mentioned pH range, a film is formed by the ring-opening polymerization of the epoxy group at an initial temperature of low temperature, so that spherical microcapsules having smooth surfaces can be produced. The hardness increases the durability of the shell, .

According to an embodiment of the present invention, the suspension polymerization temperature may be 40 to 80 ° C, and the polymerization reaction time may be 1 to 12 hours, but is not limited thereto. Preferably, the polymerization reaction can be carried out at 50 to 70 DEG C for 3 to 5 hours. In the suspension polymerization in the above-mentioned range, unstable system formation due to a rapid polymerization reaction can be prevented, so that uniform microcapsules can be produced.

According to one embodiment of the present invention, the suspension polymer is not limited to be carried out by a conventional drying method upon drying, but may preferably be spray-dried. During the spray drying, for example, the inlet temperature of the hot stream may be between 100 and 200 ° C and the outlet temperature of the air stream may be between 30 and 90 ° C, preferably between 60 and 80 ° C, It is not. In addition, it is preferable that the microcapsules have excellent solubility and fluidity as compared with other drying methods during the spray drying, so that spherical microcapsules with smooth surfaces can be produced.

The artificial marble of the present invention may include, for example, the phase transition microcapsules described above. The artificial marble of the present invention includes the phase transition microcapsule, so that the latent heat characteristic can be improved and excellent energy storage efficiency can be obtained.

According to an embodiment of the present invention, the phase transition microcapsules may contain 10 to 30% by weight based on the total weight of the total artificial marble. When the microcapsule is included in the above-described range, the microcapsule can have a heat storage performance capable of keeping the room temperature constant even under extreme temperature changes. Further, microcapsules can be uniformly dispersed in the artificial marble, and it is preferable because it does not affect the mechanical properties of the artificial marble.

Hereinafter, the phase transition microcapsules for artificial marble according to the present invention and a method for producing the same will be described in more detail with reference to the following examples. It should be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In addition, the unit of the additives not specifically described in the specification may be% by weight.

[Measurement of physical properties]

1. Latent heat measurement

The latent heat of a microcapsule according to one embodiment was measured with a differential scanning calorimeter (DSC, TA company Q1000).

Measurement conditions: a temperature of 60 DEG C in a nitrogen atmosphere at a heating rate of 5 DEG C / min

2. Observation of morphology.

FE-SEM (MIRA 3 LMH, TESCAN) was measured to observe the morphology of the microcapsule according to one embodiment and is shown in FIG. 1 and FIG. FE-SEM was prepared by coating the synthesized microcapsules on carbon tape and coating with Pt.

Each microcapsule obtained above was mixed and its shape was confirmed. The microcapsules were evaluated qualitatively according to the following criteria.

◎: The surface is smooth and perfectly spherical.

[Delta]: The surface is smooth and completely spherical, but cracks or irregularities are generated partially on the surface.

X: Uneven shape occurred on the surface.

[Example 1]

   (Initiator Vazo 52G (ADVN, Dupont) 0.36 g) was added to 3.6 g of methyl methacrylate (MMA, LG-MMA), 3.6 g of trimethylolpropane triacrylate (TMPTA, KPX) and 1.2 g of epoxy acrylate (Miramer PE210, Miwon specialty Chemical) g, and then sufficiently melted to prepare a shell mixture. The shell mixture was added to 53.2 g of n-octadecane (RT28HC, RUBITHERM) heated to 40 DEG C and melted and 2.8 g of stearyl alcohol (Aecochem) to prepare a dispersed phase. Then, 79.64 ml of a 10 wt% aqueous solution of polyvinyl alcohol (PVA217, KURARAY POVAL) maintained at 40 DEG C was continuously added to the dispersion phase at 2,500 rpm using a homomixer for 2 minutes and emulsified for 10 minutes to obtain a stable o / w emulsion was prepared. Thereafter, the stirring speed was set to 300 rpm, the pH was adjusted to 4 with a 1 wt% aqueous phosphoric acid solution, and suspension polymerization was carried out at 60 ° C for 4 hours to prepare a suspension polymer. After cooling the suspension polymer to room temperature, the suspension polymer was pulverized using a spray dryer (FSD-1.5R) at a feeding rate of 100 ml / min, an atomizer speed of 13,000 rpm, In let temp. 180 캜, Out let temp. Spray-drying was carried out under the condition of 80 캜 to prepare phase change microcapsules.

 [Example 2]

  (MMA), 2.4 g of trimethylolpropane triacrylate (TMPTA) and 0.8 g of epoxy acrylate (Miramer PE210, Miwon Specialty Chemical) and initiator Vazo 52G (ADVN, Dupont ) Was used as the starting material.

 [Example 3]

  In Example 1, 10.0 g of methyl methacrylate (MMA), 4.4 g of trimethylolpropane triacrylate (TMPTA) and 1.8 g of epoxy acrylate (Miramer PE 210, Miwon specialty Chemical) and initiator Vazo 52G (ADVN, Dupont ) Was used as the starting material.

[Example 4]

 Except that n-nonadecane (RT31, RUBITHERM) was used in place of n-octadecane in Example 1.

[Example 5]

Except that the epoxy acrylate was used in place of Miramer PE210 in Example 1 using Miramer PE250.

[Example 6]

Except that polyvinylpyrrolidone was used instead of polyvinyl alcohol in Example 1 above.

[Example 7]

Except that 1 part by weight of n-octyl acrylate was further added to 100 parts by weight of the monomer mixture in Example 1 above.

[Comparative Example 1]

  Except that 20.4 g of methyl methacrylate (MMA), 3.6 g of trimethylolpropane triacrylate (TMPTA) and 0.36 g of initiator Vazo 52G (ADVN, Dupont) were used as the shell mixture in Example 1 above Respectively.

[Comparative Example 2]

  Except that 53.2 g of n-octadecane (RT28HC, RUBITHERM) and 55 g of n-octadecane (RT28HC, RUBITHERM) instead of 2.8 g of stearyl alcohol (AECOCEM) Respectively.

[Comparative Example 3]

  Except that 20.4 g of methyl methacrylate (MMA) and 3.6 g of epoxy acrylate (Miramer PE 210, Miwon Specialty Chemical) and 0.36 g of initiator Vazo 52G (ADVN, Dupont) were used as the shell mixture in Comparative Example 1 .

division Latent heat ΔH
(J / g) Particle size
(탆) Particle shape Example 1 179.4 10.4 ◎ Example 2 202.0 4.3 ◎ Example 3 185.1 6.6 △ Example 4 100.2 9.2 ◎ Example 5 170.7 9.5 ◎ Example 6 180.1 10.1 ◎ Example 7 174.2 9.3 ◎ Comparative Example 1 161.0 8.5 X Comparative Example 2 140.4 7.6 X Comparative Example 3 99.1 7.5 X

As shown in Table 1, it was confirmed that the phase-transition microcapsules of the present invention had excellent latent heat. Further, as shown in FIG. 1, spherical microcapsules having smooth surfaces were produced, and it was confirmed that the content of the heat storage material was maximized to exhibit more excellent latent heat characteristics.

The phase transition microcapsule of the present invention is further characterized in that the monomer mixture of the shell mixture contains 75 to 85% by weight of the methyl methacrylate monomer, 10 to 20% by weight of the polyfunctional acrylate monomer and 1 to 10% by weight of the epoxy acrylate monomer , It was confirmed that the phase transition microcapsule formed a spherical surface with a more smooth surface and improved durability.

In addition, polyvinyl alcohol was excellent as a continuous phase surfactant, but it was confirmed that more uniform particles were obtained when polyvinylpyrrolidone was used.

Further, in the monomer mixture C ₈ to C ₂₀ alkyl acrylate based time to the monomer further comprises hayeoteul manufacturing microcapsules, C ₈ to C ₂₀ alkyl acrylate monomer micro the heat storage material due to expansion caused by high temperature and pressure The capsule was prevented from being damaged, and the microcapsules with better durability could be manufactured.

In Comparative Examples 1 and 2, microcapsules having poor durability were prepared without epoxy acrylate. As a result, as shown in FIG. 2, shrinkage occurred and a rough and uneven shape like a concavo-convex structure was observed on the surface Respectively. In addition, the microcapsules having poor surface are low in the content of the heat storage material, widen the phase transition temperature range, and not only the heat storage effect is lowered, but also non-uniform microcapsules can not uniformly store the artificial marble in the artificial marble.

Further, when the multifunctional acrylate monomer is not contained, as in the case of Comparative Example 3, the weak bond between the methyl methacrylate and the epoxy acrylate monomer is vulnerable to external impact, so that the heat storage material is externally exposed Or is undesirable.

Also, when the shell mixture contains only the epoxy acrylate group, the adhesive strength between the microcapsules is improved by incorporating a large amount of unstable epoxy groups, so that the microcapsules are agglomerated to produce microcapsules having a large particle size. it's difficult. In addition, it may be necessary to add a curing agent according to an excessive amount of epoxy group. If a curing agent is added, heat is generated due to a rapid reaction and thermal decomposition of the heat storage material occurs.

As described above, the phase change microcapsule for artificial marble and the method for manufacturing the same are described in the present invention through specific matters and a limited embodiment. However, the present invention is provided for better understanding of the present invention. The present invention is not limited thereto, and various modifications and changes may be made thereto by those skilled in the art to which the present invention belongs.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (9)

A core comprising a heat storage material and
An acrylic polymer prepared from a monomer mixture consisting of 75 to 85% by weight of a methyl methacrylate monomer, 1 to 10% by weight of an epoxy acrylate monomer and 10 to 20% by weight of a polyfunctional acrylate monomer, Phase transition microcapsules. delete The method according to claim 1,
Wherein the epoxy acrylate monomer is at least one selected from the group consisting of bisphenol A epoxy acrylate, bisphenol F epoxy acrylate, novolac-epoxy acrylate, cresol-novolak epoxy acrylate, and biphenol epoxy acrylate Phase transition microcapsules. The method according to claim 1,
The polyfunctional acrylate monomer may be selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol pentaacrylate, dipentaerythritol pentaacrylate , Dipentaerythritol hexaacrylate, glycerol diacrylate, and ethylene diacrylate. 2. The phase change microcapsule for artificial marble according to claim 1, The method according to claim 1,
Wherein the heat storage material is selected from the group consisting of C ₁₀ to C ₃₀ saturated hydrocarbons, C ₆ to C ₃₀ Fatty acids and C ₆ to C ₃₀ Phase aliphatic microcapsule for artificial marble, which is a mixture of any one or two selected from fatty alcohols. a) melting a shell mixture comprising 75 to 85% by weight of a methyl methacrylate monomer, 1 to 10% by weight of an epoxy acrylate monomer and 10 to 20% by weight of a multifunctional acrylate monomer and an initiator, ;
b) preparing a dispersion phase in which a heat storage material is added to the shell mixture to disperse the mixture;
c) adding the dispersed phase to a continuous phase containing a polymer type surfactant to disperse the emulsion to form an emulsion;
d) suspension polymerization of the emulsion; And
e) drying the suspension polymer to prepare microcapsules;
Wherein the phase transition microcapsules have a thickness of 100 nm or less. The method according to claim 6,
Wherein the surfactant in the step c) is any one or a mixture of two or more selected from polyvinyl alcohol and polyvinylpyrrolidone. The method according to claim 6,
Wherein the polymer type surfactant in step c) is contained in an amount of 0.05 to 20% by weight based on the total weight of the continuous phase of the phase change microcapsules. The method according to claim 6,
Wherein the emulsion is adjusted to a pH of from 2 to 5 and then subjected to suspension polymerization in the step d).

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