JP2010155932A - Heat storage elastomer molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat storage elastomer molded body which brings about little permanent elongation and which is rich in rubber elasticity, which scarcely develops change in hardness even when used in high temperature surroundings, and further which hardly causes leakage of a heat storage material even when exposed to high temperature surroundings for a long period of time, and which is excellent in heat resistance. <P>SOLUTION: The heat storage elastomer molded body is formed by dispersing 25-150 pts.wt. of microcapsule particles for the heat storage material, each composed of a capsule wall and the heat storage material contained therein in 100 pts.wt. of a liquid silicone prepolymer, and solidifying the dispersion, wherein the capsule wall comprises polymerizable monomers including a cross-linking polymerizable monomer and the content of the cross-linking polymerizable monomer is 10-100 wt.% of the total amount of the polymerizable monomers. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat storage elastomer molded body containing microcapsule particles for a heat storage material, and more particularly to a heat storage elastomer molded body having excellent heat resistance even when exposed to a high temperature environment for a long time.

  In recent years, it has been required to save energy by effectively using thermal energy. As an effective method, a method that uses the property of a heat storage material that stores heat when a phase changes from a solid to a liquid (heat storage) and releases heat (dissipates heat) when the phase changes from a liquid to a solid is used. ing.

  In order to increase the heat exchange efficiency of the heat storage material, a method of encapsulating the heat storage material has been proposed. Microencapsulation makes it easy to handle the heat storage material because the appearance can be kept constant regardless of the phase state of the heat storage material when the heat storage material is repeatedly melted (liquid) and solidified (solid). Can be used in a wide range of applications.

  Until now, molded products containing microencapsulated heat storage materials (microcapsule particles for heat storage materials) in rubber materials have been used as interior materials for buildings such as walls, ceilings, and floors of houses, It has been widely used in applications in which the heat stored in the air-conditioning equipment and natural energy is gradually released in advance, and the room temperature is comfortably maintained even when the outside air temperature fluctuates.

  Newly, rubber molded bodies containing microcapsule particles for heat storage materials are beginning to be studied for application to automobile engine peripheral members. Conventionally, when an automobile engine is temporarily stopped and then restarted, it takes a lot of energy and time to warm up the engine. This problem is particularly serious in cold regions and cold seasons.

  Therefore, by using the microcapsule particle-containing rubber molded body for heat storage material as the engine peripheral member, when the engine is started, the heat received from the high temperature environment is stored, and even if the engine is temporarily stopped, By dissipating the stored heat, energy and time required for starting the engine can be saved.

  The performance required for rubber molded bodies containing microcapsule particles for heat storage materials used as engine peripheral members is that the heat storage material is enclosed by a strong capsule wall, and the heat storage material is unlikely to leak in a high-temperature environment, and vibration associated with engine startup On the other hand, performances such as little change in hardness are required even when used in a high temperature environment without losing rubber elasticity.

  Note that “leakage of heat storage material” here means that the capsule wall is destroyed and the heat storage material leaks to the outside, or the compatibility between the heat storage material and the resin constituting the capsule wall is too high. It refers to a problem that occurs when it is no longer possible to maintain the state in which the heat storage material is suitably contained, such as when the heat storage material oozes out from the outside.

  Patent Document 1 discloses a heat storage rubber material in which a microcapsule containing a heat storage material is kneaded into rubber. Thermosetting urea formalin resin or melamine formalin resin is used as the film of the microcapsule, and silicon rubber (Si) is described as an example of a rubber raw material.

  In patent document 2, the thermal storage laminated body which consists of a thermal storage layer containing a specific thermal storage microcapsule is disclosed. It is described that the capsule wall of the microcapsule is preferably composed of a crosslinkable monomer, and a two-component type organic binder using a crosslinking reaction between a hydroxyl group and an isocyanate group is preferable as a material constituting the heat storage layer. ing.

  However, in Patent Documents 1 and 2, the usage is considered only for the interior materials for buildings, etc., and the engine peripheral member of the automobile is not considered as the usage, and the high temperature state lasts for a long time. When exposed to the environment, it is difficult to cause leakage of the heat storage material, and it has not been examined whether it has excellent heat resistance.

JP 2003-261716 A JP 2006-150953 A

  The object of the present invention is low in permanent elongation, rich in rubber elasticity, little change in hardness even when used in a high temperature environment, and even when exposed to a high temperature environment for a long time, it is difficult for the heat storage material to leak, An object of the present invention is to provide a heat storage elastomer molded body having excellent heat resistance.

  As a result of diligent investigations to achieve the above object, the inventors of the present invention have proposed microcapsule particles for a heat storage material in which a capsule wall is composed of a polymerizable monomer containing a crosslinkable polymerizable monomer at a specific ratio. By using a specific amount of the microcapsule particles for heat storage material dispersed in a liquid silicone prepolymer and solidifying it, the permanent elongation is small and the rubber elasticity is high, and there is little change in hardness even when used in a high temperature environment. Furthermore, even when exposed to a high temperature environment for a long time, the present inventors have found that a heat storage elastomer molded body that hardly causes leakage of the heat storage material can be obtained, and has completed the present invention based on these findings.

That is, the heat storage elastomer molded body of the present invention is obtained by dispersing 25 to 150 parts by weight of microcapsule particles for a heat storage material composed of a capsule wall and a heat storage material contained in the capsule wall in 100 parts by weight of a liquid silicone prepolymer. It is a heat storage elastomer molded body that is made into,
The capsule wall is composed of a polymerizable monomer containing a crosslinkable polymerizable monomer, and the component ratio of the crosslinkable polymerizable monomer is 10 to 100% by weight of the total amount of the polymerizable monomer. It is.

  In the heat storage elastomer molded article, the heat storage material is preferably a multi-branched compound having a number average molecular weight (Mn) of 1,000 to 100,000.

  In the heat storage elastomer molded body, the heat storage material microcapsule particles preferably have a volume average particle size of 3 to 100 μm and an average circularity of 0.94 to 1.

  In the heat storage elastomer molded article, the heat storage material preferably has a melting point of 5 to 150 ° C.

  According to the heat storage elastomer molded body of the present invention as described above, the permanent elongation is small and rich in rubber elasticity, there is little change in hardness even when used in a high temperature environment, and even if it is exposed to a high temperature environment for a long time. Thus, a heat storage elastomer molded body that is less likely to cause leakage of the heat storage material and has excellent heat resistance is provided.

The heat storage elastomer molded body of the present invention is obtained by dispersing 25 to 150 parts by weight of microcapsule particles for heat storage material consisting of a capsule wall and a heat storage material contained in the capsule wall in 100 parts by weight of a liquid silicone prepolymer and solidifying it. Is a heat storage elastomer molded body,
The capsule wall is composed of a polymerizable monomer containing a crosslinkable polymerizable monomer, and the component ratio of the crosslinkable polymerizable monomer is 10 to 100% by weight of the total amount of the polymerizable monomer. It is characterized by being.

  Hereinafter, the heat storage elastomer molding of the present invention will be described. The microcapsule particles for a heat storage material constituting the heat storage elastomer molded body are obtained by mixing a polymerizable monomer composition containing a crosslinkable polymerizable monomer and a heat storage material in an aqueous medium containing a dispersion stabilizer. After suspending, it is polymerized, followed by separation / washing, filtration, dehydration and drying, thereby obtaining capsule walls made of a crosslinkable resin and particles made of a heat storage material contained therein.

(1) Preparation Step of Polymerizable Monomer Composition First, a polymerizable monomer containing a crosslinkable polymerizable monomer serving as a capsule wall in a specific ratio and a heat storage material are heated in a thermostatic bath and dissolved. Then, using a stirrer such as a bead mill, the mixture is stirred, mixed, and uniformly dispersed to prepare a polymerizable monomer composition.

  In the present invention, the set temperature when the polymerizable monomer and the heat storage material, which are constituent components of the capsule wall, are heated in a thermostatic chamber varies depending on the component of the polymerizable monomer and the type of the heat storage material. However, it is preferable to set to 20-60 degreeC, and it is more preferable to set to 25-50 degreeC.

In the present invention, a polymerizable monomer containing a “crosslinkable polymerizable monomer” is used as the polymerizable monomer constituting the capsule wall.
Here, the “crosslinkable polymerizable monomer” refers to a crosslinkable polymerizable monomer having two or more polymerizable functional groups in the molecule.
The polymerizable functional group is preferably a carbon-carbon unsaturated double bond (—C═C—).

  Examples of such “crosslinkable polymerizable monomers” include vinyl-based crosslinkable polymerizable monomers such as divinylbenzene, divinylbiphenyl, and divinylnaphthalene; diallyl phthalate, triallyl isocyanurate, and the like. Allyl crosslinkable polymerizable monomer; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) And (meth) acrylic crosslinkable polymerizable monomers such as acrylate, 1,3-butylene glycol di (meth) acrylate, and trimethylolpropane tri (meth) acrylate;

These crosslinkable polymerizable monomers can be used alone or in combination of two or more.
Among these, since a suitable capsule wall can be easily obtained, a (meth) acrylic crosslinkable polymerizable monomer and a vinylic crosslinkable polymerizable monomer are preferably used. A crosslinkable polymerizable monomer is more preferably used, and ethylene glycol dimethacrylate is particularly preferably used.

  In the present invention, the component ratio of the crosslinkable polymerizable monomer is 10 to 100% by weight, preferably 30 to 100% by weight, and preferably 50 to 100% by weight based on the total amount of the polymerizable monomer. It is more preferable.

  When the component ratio of the crosslinkable polymerizable monomer is less than the above lower limit, the component ratio of the polymerizable monomer having a crosslinkable component is too small, so that sufficient strength as a capsule wall is obtained. In other words, the capsule wall is easily destroyed, which may cause the heat storage material to leak.

In the present invention, a “monofunctional polymerizable monomer” can be used in combination with a “crosslinkable polymerizable monomer” as the polymerizable monomer constituting the capsule wall.
Here, the “monofunctional polymerizable monomer” refers to a polymerizable monomer having one polymerizable functional group in the molecule.
The polymerizable functional group is preferably a carbon-carbon unsaturated double bond (—C═C—).

  Examples of such “monofunctional polymerizable monomers” include monovinyl aromatic monofunctional polymerizable monomers such as styrene, vinyltoluene, and α-methylstyrene; (meth) acrylic acid, ( (Meth) such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and dimethylaminoethyl (meth) acrylate And acrylic monofunctional polymerizable monomers; olefin monofunctional polymerizable monomers such as ethylene, propylene, and butylene; and the like.

These monofunctional polymerizable monomers can be used alone or in combination of two or more.
Among these, since a suitable capsule wall is easily obtained, monovinyl aromatic monofunctional polymerizable monomers and (meth) acrylic monofunctional polymerizable monomers are preferably used. Styrene is particularly preferably used.

  In the present invention, the component ratio of the monofunctional polymerizable monomer is preferably 90% by weight or less, more preferably 70% by weight or less, and more preferably 50% by weight or less of the total amount of the polymerizable monomers. More preferably it is.

In the present invention, it is preferable to use a “multi-branched compound” having a specific molecular weight as the heat storage material.
Here, the “multi-branched compound” refers to a polymer compound (polymer) having two or more branched chains in the molecule.

  Examples of such “multi-branched compounds” include “multi-branched chain-containing α-olefin polymers” and “trifunctional or higher polyfunctional fatty acid ester compounds”. "Polymer" is preferably used.

  “Multi-branched chain-containing α-olefin polymer” is a carbon-carbon unsaturated double bond (—C═C—) having an α-position (terminal) and an α-olefin having 10 or more carbon atoms as a raw material. Is a polymer.

Examples of the “α-olefin” include 1-decene (C ₁₀ ), 1-undecene (C ₁₁ ), 1-dodecene (C ₁₂ ), 1-tridecene (C ₁₃ ), 1-tetradecene (C ₁₄ ). 1-pentadecene (C ₁₅ ), 1-hexadecene (C ₁₆ ), 1-heptadecene (C ₁₇ ), 1-octadecene (C ₁₈ ), 1-nonadecene (C ₁₉ ), 1-eicosene (C ₂₀ ), 1 - heneicosene _(C 21), 1-docosene _(C 22), 1-tricosene _(C 23), 1-tetracosene _(C 24), 1-pentacosene _{(C 25),} and 1-hexacosenoic _{(C 26)} or the like can be mentioned It is done.
These “α-olefins” can be used alone or in combination of two or more.

Among these, since it is easy to obtain a heat storage material (multi-branched compound) having a desired molecular weight, an α-olefin having 10 to 30 carbon atoms is preferably used, and an α-olefin having 14 to 28 carbon atoms is more preferable. An α-olefin having 18 to 26 carbon atoms is preferably used, and 1-docosene (C ₂₂ ) and 1-tetracocene (C ₂₄ ) are particularly preferably used.

The “multi-branched chain-containing α-olefin polymer” can be obtained by subjecting the above-mentioned “α-olefin” to a polymerization reaction in the presence of a catalyst.
As the catalyst used in the polymerization reaction of “α-olefin”, a “metallocene compound” is preferably used because a heat storage material (multi-branched compound) having a desired molecular weight can be easily obtained.

Examples of the “metallocene compound” include dimethylsilylene bis (2-methyl-4,5-benzoindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2 -Methyl-4-naphthylindenyl) zirconium dichloride, dimethylsilylenebis (2-methylindenyl) zirconium dichloride, ethylenebis (2-methylindenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1 '-Dimethylsilylene) bis (3-trimethylsilylmethyl-indenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-trimethylsilylmethyl-indenyl) (indenyl) Zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (indenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3- n-butyl-indenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) (n-butyl-indenyl) (indenyl) zirconium dichloride, (1,2′-dimethylsilylene) ( 2,1′-dimethylsilylene) bis (indenyl) zirconium dichloride, 1,1′-dimethylsilylenebis [2-ethyl-4- (2-fluoro-4-biphenylyl) -4H-azurenyl] zirconium dichloride, and dimethylsilylene (Cyclopentadienyl) (2,4-dimethyl-4H- 1-azurenyl) zirconium dichloride compounds such as zirconium dichloride; and zirconium compounds such as compounds in which the dichloride of these zirconium dichloride compounds is substituted with dimethyl or dibenzyl; and titanium compounds in which the zirconium of these zirconium compounds is substituted with titanium; Can be mentioned.
These “metallocene compounds” can be used alone or in combination of two or more.

  The above-mentioned “trifunctional or higher polyfunctional fatty acid ester compound” uses “higher fatty acid” and “polyhydric alcohol” as raw materials, and the dehydration condensation occurs between the carboxyl group of “higher fatty acid” and the hydroxyl group of “polyhydric alcohol”. An ester compound having three or more ester bonds in the molecule.

  Here, “higher fatty acid” means a fatty acid having 12 or more carbon atoms, and is roughly classified into linear saturated higher fatty acid, linear unsaturated higher fatty acid, branched saturated higher fatty acid, and branched unsaturated higher fatty acid. Of these, linear saturated higher fatty acids are preferably used.

Examples of the “linear saturated higher fatty acid” include lauric acid (C ₁₂ ), myristic acid (C ₁₄ ), palmitic acid (C ₁₆ ), stearic acid (C ₁₈ ), arachidic acid (C ₂₀ ), behenic acid ( C ₂₂ ), lignoceric acid (C ₂₄ ), serotic acid (C ₂₆ ), montanic acid (C ₂₈ ), melicic acid (C ₃₀ ) and the like.

  These “linear saturated higher fatty acids” can be used alone or in combination of two or more.

Among these, since a heat storage material having a desired molecular weight is easily obtained, a linear saturated higher fatty acid having 12 to 28 carbon atoms is preferably used, and a linear saturated higher fatty acid having 14 to 26 carbon atoms is more preferable. Straight chain saturated higher fatty acids having 16 to 24 carbon atoms are more preferably used, and stearic acid (C ₁₈ ), arachidic acid (C ₂₀ ), and behenic acid (C ₂₂ ) are particularly preferably used. .

  Here, “polyhydric alcohol” refers to a trihydric or higher alcohol having three or more hydroxyl groups in the molecule.

  Examples of the trihydric alcohol include glycerin, trimethylolpropane, 1,2,4-butanetriol, and 1,2,6-hexanetriol.

  Examples of the tetrahydric alcohol include diglycerin, pentaerythritol, ditrimethylolpropane, and tetrahydroxycyclohexane.

  Examples of the pentahydric alcohol include triglycerin, xylitol, arabitol, and pentahydroxybenzene.

  Examples of the hexavalent alcohol include dipentaerythritol, tetraglycerin, sorbitol, and mannitol.

  Examples of the 7-valent alcohol include pentaglycerin and the like.

  Examples of the octahydric alcohol include sucrose, hexaglycerin, and tripentaerythritol.

  These “polyhydric alcohols” can be used alone or in combination of two or more.

  Among these, since it is easy to obtain a heat storage material having a desired molecular weight, a polyhydric alcohol having a valence of 4 or more is preferably used, and a polyhydric alcohol having a valence of 6 or more is more preferably used. Among them, dipentaerythritol, And hexaglycerin are particularly preferably used.

  In the present invention, the number average molecular weight (Mn) of the “multi-branched compound” used as the heat storage material is preferably 1,000 to 100,000, more preferably 5,000 to 50,000. More preferably, it is 3,000-35,000.

  When the number average molecular weight (Mn) of the multi-branched compound is less than the above lower limit, the compatibility between the crosslinkable polymerizable monomer forming the capsule wall and the heat storage material becomes too high, particularly at high temperatures. If exposed to the environment for a long time, leakage of the heat storage material may easily occur. On the other hand, when the number average molecular weight (Mn) of the multi-branched compound exceeds the upper limit, the compatibility between the polymerizable monomer and the heat storage material is lowered in the preparation process of the polymerizable monomer composition. For this reason, the capsule wall cannot be suitably formed, and the heat storage material may easily leak.

  The weight average molecular weight (Mw) of the multi-branched compound is preferably 1,500 to 200,000, more preferably 10,000 to 100,000, and 20,000 to 50,000. More preferably it is.

  When the weight average molecular weight (Mw) of the multi-branched compound is less than the lower limit, the compatibility between the crosslinkable polymerizable monomer forming the capsule wall and the heat storage material becomes too high. If exposed to the environment for a long time, leakage of the heat storage material may easily occur. On the other hand, when the weight average molecular weight (Mw) of the multi-branched compound exceeds the upper limit, the compatibility between the polymerizable monomer and the heat storage material is lowered in the preparation process of the polymerizable monomer composition. For this reason, the capsule wall cannot be suitably formed, and the heat storage material may easily leak.

  Moreover, it is preferable that the molecular weight distribution (Mw / Mn) which is a ratio of the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the said multibranched compound is 1-3, and is 1-2. Is more preferable, and it is still more preferable that it is 1-2.

  When the molecular weight distribution (Mw / Mn) of the hyperbranched compound exceeds the above upper limit, the low molecular weight component of the heat storage material is likely to exude from the capsule wall to the outside, and the heat storage material is suitably included. It can be difficult to maintain.

  In addition, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the hyperbranched compound are values determined by gel permeation chromatography (GPC) method using a GPC measuring device and converted to polystyrene. For example, it can measure using the Tosoh GPC measuring apparatus (brand name: HLC-8220GPC).

In the present invention, the melting point (Tm) of the heat storage material (phase transition temperature of the heat storage material) is preferably 5 to 150 ° C, more preferably 10 to 120 ° C, and more preferably 20 to 80 ° C. Further preferred.
Here, the “melting point (Tm)” refers to a value defined as the temperature at the top of a peak in a DSC curve by a differential scanning calorimeter (DSC).

  In addition, melting | fusing point (Tm) of a thermal storage material is a value measured using a differential scanning calorimeter, for example, measured using the differential scanning calorimeter (model name: DSC 6200) by Seiko Instruments Inc. can do.

  When the melting point (Tm) of the heat storage material (phase transition temperature of the heat storage material) is less than the lower limit, it may be difficult to obtain an endothermic reaction effect associated with the phase transition of the heat storage material. On the other hand, when the melting point (Tm) of the heat storage material (phase transition temperature of the heat storage material) exceeds the upper limit, it may be difficult to obtain the effect of the exothermic reaction accompanying the phase transition of the heat storage material.

In the present invention, the content of the heat storage material is preferably 30 to 100 parts by weight, more preferably 40 to 90 parts by weight, more preferably 50 to 50 parts by weight with respect to 100 parts by weight of the crosslinkable resin that becomes the capsule wall. More preferably, it is 80 parts by weight.
The “crosslinkable resin” refers to a polymer obtained by polymerizing a polymerizable monomer containing a crosslinkable polymerizable monomer constituting the capsule wall.

  When content of the said heat storage material is less than the said minimum, the function as a heat storage material cannot fully be exhibited, and heat storage performance may be inferior. On the other hand, when the content of the heat storage material exceeds the upper limit, the heat storage material becomes difficult to dissolve in the polymerizable monomer in the preparation step of the polymerizable monomer composition, and the capsule wall is suitably formed. It may not be possible to cause leakage of the heat storage material.

(2) Step of obtaining a suspension (droplet forming step)
(1) The polymerizable monomer composition obtained by the preparation step of the polymerizable monomer composition is suspended in an aqueous dispersion medium and suspended (polymerizable monomer composition dispersion). Get.
Here, “suspension” means forming droplets of the polymerizable monomer composition in an aqueous dispersion medium.

  Dispersion treatment for droplet formation is, for example, an in-line type emulsifying disperser (manufactured by Ebara Manufacturing Co., Ltd., trade name: Ebara Milder MDN303V), a high-speed emulsifying / dispersing machine (trade name: TK Homomixer MARK II type) and the like capable of strong stirring.

  As the aqueous dispersion medium, water alone may be used, but a solvent that is soluble in water, such as lower alcohol and lower ketone, may be used in combination.

  In droplet formation, it is preferable to use a dispersion stabilizer in an aqueous dispersion medium in order to control the particle size of the microcapsule particles for heat storage material and improve the circularity.

Examples of the dispersion stabilizer include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate and magnesium carbonate; phosphates such as calcium phosphate; metals such as aluminum oxide and titanium oxide. Oxides and metal compounds such as metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and ferric hydroxide; water-soluble polymer compounds such as polyvinyl alcohol, methyl cellulose, and gelatin; anionic surfactants , Organic polymer compounds such as nonionic surfactants and amphoteric surfactants;
Among these, metal compounds, particularly poorly water-soluble metal hydroxides are preferred, and magnesium hydroxide is most preferred.

  The amount of the dispersion stabilizer added is preferably 0.1 to 20 parts by weight and more preferably 0.2 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

Examples of the polymerization initiator include inorganic persulfates such as potassium persulfate and ammonium persulfate; 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-methyl-N— (2-hydroxyethyl) propionamide, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2,4-dimethylvaleronitrile), and 2,2′-azobisisobuty Azo compounds such as nitrile; di-t-butyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy Pivalate, diisopropyl peroxydicarbonate, di-t-butylperoxyisophthalate, and t-butylperoxyisobutyl Organic peroxides rate and the like; and the like.
Among these, an organic peroxide is preferably used.

  When the polymerization initiator is added, the polymerizable monomer composition may be added to the aqueous dispersion medium containing the dispersion stabilizer and then added at the stage before droplet formation. May be added directly to the functional monomer composition.

  The addition amount of the polymerization initiator is preferably 0.1 to 20 parts by weight, more preferably 0.3 to 15 parts by weight with respect to 100 parts by weight of the polymerizable monomer, and 1.0 More preferably, it is 10 weight part.

(3) Polymerization step The suspension obtained in the step (2) of obtaining a suspension (droplet formation step) is heated to perform a polymerization reaction to obtain an aqueous dispersion of microcapsule particles for a heat storage material. .

Although superposition | polymerization temperature is not specifically limited, It is preferable that it is 50-100 degreeC, and it is more preferable that it is 60-95 degreeC.
The time required for the polymerization varies depending on the components of the polymerizable monomer and the kind of the polymerization initiator, but is preferably 1 to 20 hours, and more preferably 2 to 15 hours.

  In order to perform polymerization in a state where the droplets of the polymerizable monomer composition are stably dispersed, the dispersion by stirring is continued in this step, following the step (2) for obtaining a suspension (droplet formation step). The polymerization reaction may be allowed to proceed while performing the treatment.

(4) Separation / washing, filtration, dehydration, and drying step (3) A series of operations such as separation / washing, filtration, and dehydration of the aqueous dispersion of microcapsule particles for heat storage material obtained by the polymerization step is required. Accordingly, the process is repeated several times, and the obtained solid content is dried to obtain microcapsule particles for a heat storage material.

  First, in order to remove the dispersion stabilizer remaining in the aqueous dispersion of the microcapsule particles for the heat storage material, it is preferable to perform washing by adding an acid or an alkali to the aqueous dispersion of the microcapsule particles for the heat storage material. .

  When the used dispersion stabilizer is an acid-soluble compound, an acid is added to the aqueous dispersion of the microcapsule particles for heat storage material, while the used dispersion stabilizer is an alkali-soluble compound. In this case, an alkali is added to the aqueous dispersion of the microcapsule particles for the heat storage material.

When an acid-soluble compound is used as the dispersion stabilizer, it is preferable to adjust the pH to 6.5 or less by adding an acid to the aqueous dispersion of the microcapsule particles for the heat storage material. More preferably, the pH is adjusted to 6.0 or lower.
As the acid to be added, inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid, and organic acids such as formic acid and acetic acid can be used, but the removal efficiency of the dispersion stabilizer is large and the burden on the production equipment is small. Therefore, sulfuric acid is particularly preferable.

(Microcapsule particles for heat storage materials)
Hereinafter, the particle size characteristics of the microcapsule particles for a heat storage material obtained by the above-described suspension polymerization method will be described.

  In this invention, it is preferable that the volume average particle diameter (Dv) of the microcapsule particle for heat storage materials is 3-100 micrometers, It is more preferable that it is 5-50 micrometers, It is still more preferable that it is 10-30 micrometers.

  When the volume average particle diameter (Dv) of the microcapsule particles for heat storage material is less than the lower limit, not only is it difficult to produce by suspension polymerization, but the heat storage persistence is poor due to an increase in surface area. There is a case. On the other hand, when the volume average particle diameter (Dv) of the microcapsule particles for the heat storage material exceeds the upper limit, the capsule wall becomes relatively thin, so that the capsule wall is likely to be damaged, and the heat storage material is leaked. It may be likely to occur.

  The particle size distribution (Dv / Dn), which is the ratio of the volume average particle size (Dv) and the number average particle size (Dn), of the microcapsule particles for heat storage material is preferably 1.0 to 1.3, It is more preferable that it is 1.0-1.25.

  When the particle size distribution (Dv / Dn) of the microcapsule particles for the heat storage material exceeds the upper limit, the proportion of the small particle size increases and the heat storage persistence may deteriorate as described above. .

  In addition, the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the microcapsule particles for the heat storage material are values measured using a particle size measuring machine, for example, particles manufactured by Beckman Coulter, Inc. It can be measured using a diameter measuring machine (trade name: Multisizer).

  The average circularity of the microcapsule particles for a heat storage material is 0.94 to 1, preferably 0.96 to 1, and more preferably 0.97 to 1.

Here, “circularity” is defined as a value obtained by dividing the circumference of a circle having the same projected area as the particle image by the circumference of the projected image of the particle. Further, the average circularity in the present invention is used as a simple method for quantitatively expressing the shape of the particles, and is an index indicating the degree of unevenness of the microcapsule particles for the heat storage material, and the average circularity is the heat storage The value is 1 when the microcapsule particles for material are completely spherical, and the value becomes smaller as the surface shape of the microcapsule particles for heat storage material becomes more complicated. For the average circularity, the circularity (Ci) of each particle measured for particles having an equivalent circle diameter of 0.4 μm or more was determined for each of n particles from the following calculation formula 1, and then the average circularity was calculated from the following calculation formula 2. The degree (Ca) is obtained.
Formula 1:
Circularity (Ci) = perimeter of circle equal to projected area of particle / perimeter of projected particle image

In the above calculation formula 2, fi is the frequency of particles having a circularity (Ci).
The circularity and the average circularity can be measured using, for example, a flow type particle image analyzer “FPIA-2000”, “FPIA-2100”, “FPIA-3000” manufactured by Sysmex Corporation.

In the present invention, the latent heat amount (Q) of the microcapsule particles for a heat storage material is preferably 10 J / g or more, and more preferably 15 J / g or more.
The latent heat (Q) of the microcapsule particles for heat storage material is a value measured using a differential scanning calorimeter, for example, a differential scanning calorimeter (model name: DSC 6200) manufactured by Seiko Instruments Inc. ).

  When the amount of latent heat (Q) of the microcapsule particles for heat storage material is less than the lower limit, the function as the heat storage material cannot be sufficiently exhibited, and the heat storage performance may be inferior.

  The microcapsule particles for a heat storage material obtained by the above method are dispersed in a liquid silicone prepolymer, introduced into a desired mold (molding machine), heated and solidified to form a heat storage elastomer molded body and can do.

(5) Step of obtaining a liquid silicone prepolymer dispersion containing microcapsule particles for heat storage material (4) A specific amount of microcapsule particles for heat storage material obtained by the above separation / washing, filtration, dehydration and drying steps is liquid In addition to the silicone prepolymer, the mixture is stirred and dispersed uniformly to obtain a liquid silicone prepolymer dispersion containing microcapsule particles for a heat storage material.

  When dispersing the microcapsule particles for heat storage material in the liquid silicone prepolymer, in order to prevent air bubbles from being mixed during stirring and degrading the performance of the heat storage elastomer molded body, stirring is performed while defoaming. Preferably it is done. Examples of the apparatus capable of stirring while degassing include a planetary stirring / defoaming apparatus.

  In the present invention, by selecting “liquid silicone prepolymer” as a medium for dispersing the microcapsule particles for the heat storage material, the shear load applied to the capsule wall at the time of stirring can be reduced, so that the capsule wall is destroyed. Without causing the heat storage material to leak to the outside, it is possible to uniformly disperse the capsule particles in which the heat storage material is suitably contained in the dispersion medium.

  Here, the “liquid silicone prepolymer” is an organosilicon compound having a crosslinkable functional group at the terminal of the base polymer having a siloxane bond as a repeating unit, and is a liquid having a low viscosity in a room temperature environment (23 ° C.). What is in state.

Examples of the crosslinkable functional group possessed by the “liquid silicone prepolymer” include a hydroxysilyl functional group (Si—OH), an alkoxysilyl functional group (Si—OR), a hydrosilyl functional group (Si—H), and a vinylsilyl functional group ( Si—CH═CH ₂ ) and the like.

  In these liquid silicone prepolymers having a crosslinkable functional group, the crosslinkable functional group is the starting point of the reaction, and in the presence of a catalyst, a “condensation reaction” or “addition reaction” is initiated, and crosslinking (curing) proceeds. Thus, a silicone polymer (heat storage elastomer) rich in rubber elasticity is formed.

  As described above, “liquid silicone prepolymers” are roughly classified into “condensation reaction type” and “addition reaction type” due to the difference in curing reaction mechanism, and further, “one liquid type” and “two liquid type”, respectively. And classified.

  Here, the “condensation reaction type” refers to a reaction type in which condensation products such as water, alcohol, and hydrogen are generated at the time of curing, and a reaction mechanism represented by the following formulas 1 to 3 is representatively exemplified. .

  The “addition reaction type” is characterized by using a platinum-based catalyst and means a reaction type in which no by-product such as a condensation product is produced at the time of curing. The reaction mechanism represented by the following formula 4 is Representative examples.

  In the “condensation reaction type”, since a desorption component such as a condensation product is by-produced, this may cause foaming, and it may take a long time to complete crosslinking (curing). On the other hand, the “addition reaction type” is preferably employed from the viewpoint of production efficiency because the elimination component is not generated as a by-product, and the crosslinking (curing) can be completed in a short time.

  As the “liquid silicone prepolymer” used in the present invention, from the viewpoint of obtaining a desired heat storage elastomer, there are two such as “two-liquid condensation reaction type liquid silicone prepolymer” and “two-liquid addition reaction type liquid silicone prepolymer”. It is preferably selected from the group consisting of a liquid reaction type liquid silicone prepolymer, and among them, a “two-component addition reaction type liquid silicone prepolymer” is more preferably employed.

  Here, “two-component type” refers to a type that supplies raw materials separately into a main agent (base polymer) and a curing agent (catalyst, etc.), and “one-component type” refers to a main agent (base polymer). And a curing agent (catalyst) from the beginning. Among these supply types, “two-component type” is preferably employed from the viewpoint of easy reaction control.

  In the present invention, “EG-6301”, “SE-1740” and the like manufactured by Toray Dow Corning are listed as commercially available products of “two-component addition reaction type silicone prepolymer” preferably used as a dispersion medium. .

  The viscosity of the “liquid silicone prepolymer” is preferably 10,000 cp or less, more preferably 3,000 cp or less, and still more preferably 2,000 cp or less.

  When the viscosity of the liquid silicone prepolymer exceeds the above upper limit, the shear load applied to the capsule wall during stirring cannot be reduced, the capsule wall is easily destroyed, and the heat storage material leaks to the outside. In some cases, it takes a lot of energy and time to uniformly disperse the capsule particles in the dispersion medium.

  In the present invention, the content of the microcapsule particles for the heat storage material is 25 to 150 parts by weight, preferably 40 to 120 parts by weight, and more preferably 45 to 100 parts by weight with respect to 100 parts by weight of the liquid silicone prepolymer. Parts by weight.

  When the content of the microcapsule particles for the heat storage material is less than the lower limit, the performance as the heat storage material may not be sufficiently exhibited, and the latent heat amount may not be sufficiently obtained. On the other hand, if the content of the microcapsule particles for the heat storage material exceeds the upper limit, the permanent elongation increases, and it may be difficult to impart rubber elasticity to the heat storage elastomer.

(Heat storage elastomer molding)
The liquid silicone prepolymer dispersion containing the microcapsule particles for heat storage material obtained in (4) above is poured so that no bubbles enter a predetermined mold, and is heated under heat using a desktop hot press machine or the like. A heat storage elastomer molding is obtained by pressure molding.

  The heat storage elastomer molded body obtained in the present invention has a small permanent elongation and rich rubber elasticity, has little hardness change even when used in a high temperature environment, and even if it is exposed to a high temperature environment for a long time, the heat storage material It is a heat storage elastomer molded product that is less likely to leak and has excellent heat resistance.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited only to these examples. Parts and% are based on weight unless otherwise specified.
The test methods performed in the examples and comparative examples are as follows.

(1) Heat storage material (1-1) Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn)
A measurement sample (heat storage material) is dissolved in tetrahydrofuran to obtain a 0.2 wt% solution, and then filtered through a 0.45 μm membrane filter. Under the following measurement conditions, the weight average molecular weight (Mw) of the heat storage material, The number average molecular weight (Mn) was measured, and the molecular weight distribution (Mw / Mn) was calculated.
<Measurement conditions>
GPC measuring device: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: 2 Shodex GPC KF-402HQ (Showa Denko)
Eluent: Tetrahydrofuran (THF)
Elution rate: 0.3 ml / min Detector: RI (polarity (+))
Column temperature: 40 ° C
Injection volume: 20 μl

(1-2) Melting point (Tm)
A measurement sample (heat storage material) is weighed in an amount of 6 to 8 mg in a sample holder, and 10 ° C. from −20 ° C. to 100 ° C. using a differential scanning calorimeter (Seiko Instruments, model name: DSC 6200). Measurement was performed under the condition of increasing the temperature at 1 min / min to obtain a DSC curve. The top of the peak of the DSC curve was determined as the melting point (Tm).

(2) Microcapsule particles for heat storage material (2-1) Volume average particle size (Dv), number average particle size (Dn), and particle size distribution (Dv / Dn)
About 0.1 g of microcapsule particles for heat storage material are weighed, taken into a beaker, 0.1 ml of alkylbenzene sulfonic acid aqueous solution (manufactured by Fuji Film Co., Ltd., trade name: Drywell) is added as a dispersant, and a dedicated electrolyte (Beckman 10-30 ml of a product manufactured by Coulter Co., Ltd. (trade name: Isoton II-PC) was added, and after dispersing with an ultrasonic disperser for 20 W for 3 minutes, a particle size measuring device (Beckman Coulter, product name: Multisizer) was used. The volume average particle diameter (Dv) and the number average particle diameter of the microcapsule particles for the heat storage material (100 μm, medium; isoton II-PC, number of measured particles; 100,000) Dn) was measured and the particle size distribution (Dv / Dn) was calculated.

(2-2) Average circularity Into a container, 10 ml of ion-exchanged water is put in advance, 0.02 g of a surfactant (alkyl benzene sulfonic acid) as a dispersant is added thereto, and microcapsule particles for heat storage material 0. 02 g was added, and the dispersion treatment was performed at 60 W for 3 minutes using an ultrasonic disperser.
The microcapsule particle concentration for the heat storage material at the time of measurement is adjusted to 3,000 to 10,000 particles / μl, and the microcapsule particles for the heat storage material having an equivalent circle diameter of 0.4 μm or more is 1,000 to 10,000. Each was measured using a flow type particle image analyzer (trade name: FPIA-2100, manufactured by Simex Corporation). The average circularity was determined from the measured value.
The circularity is shown in the following calculation formula 1, and the average circularity is the number average.
Formula 1:
(Circularity) = (Perimeter of circle equal to projected area of particle) / (Perimeter of particle projection image)

(2-3) latent heat (J / g)
A precisely weighed measurement sample (microcapsule particles for a heat storage material) was introduced into a differential scanning calorimeter (manufactured by Seiko Instruments Inc., model name: DSC 6200), and the heating rate was 10 ° C./min, and the temperature range was 0 ° C. Measurements were made at -100 ° C to obtain a DSC curve.
The integrated value of the difference between the obtained DSC curve and the baseline is defined as the latent heat quantity (Q), and the latent heat quantity (Q) is divided by the weight of the accurately measured measurement sample, and converted into a latent heat quantity per unit weight. Asked.

(2-4) Heat resistance (100 ° C., 100 hr)
10 g of a measurement sample (microcapsule particles for heat storage material) was put in a sealable container and sealed, and then the container was submerged in a constant temperature water bath maintained at a temperature of 100 ° C. After 100 hours, the container was taken out from the thermostatic water tank, and the measurement sample (microcapsule particles for heat storage material) in the container was randomly collected and used with a scanning electron microscope (trade name: S-4700, manufactured by HITACHI). The surface of the microcapsule particles for heat storage material was photographed at a magnification of 2,000 times.
First, photographic images were cut out from the photographed enlarged photograph of the surface of the heat storage material microcapsule particles so that about 50 to 100 heat storage material microcapsule particles were observed, and the total number of particles was counted.
Next, the number of particles exuding the heat storage material from the capsule wall to the outside out of the particles photographed in the cut-out photographic image is counted, and the ratio (number%) of the exuded particles in the total number of particles is obtained. It was.

(3) Thermal storage elastomer molded body (3-1) Permanent elongation rate The produced 4.0 mm thick thermal storage elastomer molded body is punched with No. 3 type dumbbell defined in JIS K6301 standard, and used as an evaluation sheet. The permanent elongation was determined by the following procedure.
Two standard lines are drawn on the surface of the evaluation sheet so as to have a width of 2 cm, and based on the above JIS K6301, using a tensile tester, the direction perpendicular to the two standard lines is the tensile direction, In a room temperature environment (23 ° C.), a tensile speed: 100 mm / min, until the degree of elongation reaches 50%, and while maintaining this tension state, in a high temperature environment (100 ° C.) for 100 hours in an oven After that, the tensile state of the evaluation sheet was released, and it was left in a room temperature environment (23 ° C.) for 1 hour.
And the length between the two marked lines after tension | tensile_strength was measured, and the permanent elongation rate was computed by the following formula 3.

(3-2) Initial Shore A Hardness and Durability Shore A Hardness The produced 4.0 mm-thick heat storage elastomer molded body is punched with a No. 3 type dumbbell defined in JIS K6301 standard, and used as an evaluation sheet. The initial shore A hardness and the durable shore A hardness were determined by the following procedure.
<Initial Shore A hardness>
The evaluation sheet was obtained by measuring the initial Shore A hardness using a micro rubber hardness meter (trade name: MD-1capa, manufactured by Kobunshi Keiki Co., Ltd.) at room temperature (23 ° C.).
<Durable Shore A Hardness>
The evaluation sheet was left in an oven for 100 hours in a high temperature environment (100 ° C.) and then left in a room temperature environment (23 ° C.) for 12 hours, and the durability Shore A hardness was set in the same manner as the initial Shore A hardness. Determined by measurement.

(3-3) latent heat (kJ / kg)
From the surface of the produced 4.0 mm-thick heat storage elastomer molding, 5 to 10 mg of a sample was cut out and precisely weighed so as to have a thickness of about 1 mm.
The precisely weighed sample was introduced into a differential scanning calorimeter (manufactured by Seiko Instruments Inc., model name: DSC 6200) with the smooth surface facing down, and the temperature rising rate: 10 ° C./min, temperature range: Measurement was performed at 0 ° C. to 110 ° C. to obtain a DSC curve.
Using the integrated value of the difference between the obtained DSC curve and the baseline as the latent heat quantity (Q), the latent heat quantity (Q) is divided by the weight of the accurately weighed sample, and converted to the latent heat quantity per unit weight. It was.

(3-4) Heat resistance (100 ° C., 100 hr)
The produced 4.0 mm-thick heat storage elastomer molding was punched with a No. 3 dumbbell defined in the JIS K6301 standard to make a sheet for evaluation, and a heat resistance test was performed according to the following procedure.
After being left in an oven for 100 hours in a high temperature environment of 100 ° C., it was left in a room temperature environment (23 ° C.) for 6 hours and evaluated as follows.
Two standard lines are drawn on the surface of the evaluation sheet so as to have a width of 2 cm, and based on the above JIS K6301, using a tensile tester, the direction perpendicular to the two standard lines is the tensile direction, Under a room temperature environment (23 ° C.), pulling was performed under the condition of a tensile rate of 100 mm / min to break the evaluation sheet, and the fracture surface was magnified by a factor of 2,000 using the scanning electron microscope. A photograph of the fracture surface of the evaluation sheet was taken.
First, photographic images were cut out from the photographed enlarged photograph of the fracture surface of the evaluation sheet so that about 50 to 100 microcapsule particles for heat storage material were observed, and the total number of particles was counted.
Next, the number of particles exuding the heat storage material from the capsule wall to the outside out of the particles photographed in the cut-out photographic image is counted, and the ratio (number%) of the exuded particles in the total number of particles is obtained. It was.

(Production Example 1: Production example of heat storage material)
<Manufacture of catalyst (metallocene compound)>(1,2'-dimethylsilylene)(2,1'-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride Under a nitrogen stream, in a 200 mL Schlenk bottle, (1 , 2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (indene) 2.5 g (7.2 mmol) and 100 mL of diethyl ether were added, and the mixture was cooled to −78 ° C., and n-butyllithium ( n-BuLi) in hexane (concentration 1.6 mol / L) 9.0 mL (14.8 mmol) was added, and the mixture was returned to room temperature and stirred for 12 hours.

  The solvent was distilled off from the resulting solution, and the remaining solid was washed with 20 mL of hexane and then dried under reduced pressure to obtain (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (indene). Was obtained quantitatively as a white solid.

  Next, the obtained lithium salt (6.97 mmol) of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (indene) was dissolved in 50 mL of tetrahydrofuran (THF) in a Schlenk bottle. Then, 2.1 mL (14.2 mmol) of iodomethyltrimethylsilane was slowly added dropwise at room temperature and stirred for 12 hours.

  After stirring, the solvent was distilled off and 50 mL of diethyl ether was added. Further, a saturated aqueous solution of ammonium chloride was added thereto, washed, the aqueous phase was separated, the organic phase was dried, the solvent was removed, and (1,2'-dimethylsilylene) (2,1'-dimethyl) Silylene) bis (3-trimethylsilylmethylindene) 3.04 g (5.9 mmol) was obtained (yield 84%).

  The above-obtained (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (3-trimethylsilylmethylindene) (3.04 g, 5.9 mmol) and diethyl ether (50 mL) were mixed with Schlenk in a nitrogen stream. The solution was put in a bottle, cooled to −78 ° C., 7.4 mL (11.8 mmol) of a hexane solution (1.6 mol / l) of n-butyllithium (n-BuLi) was added, and the temperature was returned to room temperature. Stir for hours.

From the stirred solution, the solvent was distilled off, and the remaining solid was washed with 40 mL of hexane to obtain 3.06 g of a lithium salt diethyl ether adduct. When ¹ H-NMR of the diethyl ether adduct of this lithium salt was determined, the following results were obtained.

¹ H-NMR (90 MHz, THF-d8): δ 0.04 (s, —SiMe ₃ , 18H), 0.48 (s, —Me ₂ Si—, 12H), 1.10 (t, —CH ₃ , _{6H), 2.59 (s, -CH} 2 -, 4H), 3.38 (q, -CH 2 -, 4H), 6.2-7.7 (m, Ar-H, 8H)

  Under a nitrogen stream, 3.06 g of the lithium ether diethyl ether adduct obtained above was suspended in 50 mL of toluene, cooled to −78 ° C., and 1.2 g of zirconium tetrachloride previously cooled to −78 ° C. ( (5.1 mmol) in toluene (20 mL) was added dropwise, and the mixture was returned to room temperature and stirred for 6 hours.

After distilling off the solvent of the obtained solution, the remaining solid was recrystallized with dichloromethane, and the metallocene compound (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (3-trimethyl) was obtained. 0.9 g (1.33 mmol) of yellow microcrystals of (rylmethylindenyl) zirconium dichloride were obtained (yield 26%). When ¹ H-NMR of this yellow fine crystal was determined, the following result was obtained.

¹ H-NMR (90 MHz, CDCl ₃ ): δ 0.0 (s, -SiMe _3- , 18H), 1.02, 1.12 (s, -Me ₃ Si-, 12H), 2.51 (dd, _{-CH 2 -, 4H), 7.1-7.6} (m, Ar-H, 8H)

<Production of multi-branched chain-containing α-olefin polymer>
(Preparation of α-olefin)
An α-olefin (made by Idemitsu Kosan Co., Ltd., trade name: Linearlen 2024) was distilled under reduced pressure (0.13 to 1.8 kPa) at a distillation temperature of 140 to 230 ° C. to give 1-docosene (C ₂₂ ): 63. A fraction of an α-olefin mixture of 5% by weight, 1-tetracosene (C ₂₄ ): 36.5% by weight was obtained.
The obtained α-olefin mixture fraction was introduced into a heat-dried 5 L Schlenk bottle and dehydrated with dry nitrogen and activated alumina for 8 hours to prepare an α-olefin.

(Polymerization of α-olefin)
The α-olefin 5L prepared above was put into a heat-dried 10 L autoclave and heated to 90 ° C., then 15 mmol of triisobutylaluminum, the catalyst (1,2′-dimethylsilylene) prepared above (2 , 1′-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride 25 μmol of toluene slurry (20 μmol / mL, 1.25 mL) and dimethylanilinium tetrakispentafluorophenylborate 100 μmol of toluene slurry (20 μmol / mL, 5 mL) was added, 0.1 MPa of hydrogen was introduced, and the polymerization reaction was continued for 6 hours while maintaining the temperature at 90 ° C.
After the completion of the polymerization reaction, the reaction product was precipitated with acetone, and then dried under heating and reduced pressure to obtain a multi-branched chain-containing α-olefin polymer, which was designated as heat storage material A of Production Example 1.

Example 1
50 parts of styrene as a monofunctional polymerizable monomer, 50 parts of ethylene glycol dimethacrylate as a crosslinkable polymerizable monomer, and a multi-branched chain-containing α-olefin polymer produced in Production Example 1 as a heat storage material A thermal storage material A 50 parts was heated to 65 ° C. in a thermostatic bath and dissolved to prepare a polymerizable monomer composition.

  On the other hand, at room temperature, a magnesium hydroxide aqueous solution in which 9.8 parts of magnesium chloride was dissolved in 250 parts of ion-exchanged water, an aqueous solution of sodium hydroxide in which 6.9 parts of sodium hydroxide were dissolved in 50 parts of ion-exchanged water, While stirring, the mixture was gradually added to prepare a magnesium hydroxide colloid dispersion (slightly water-soluble metal hydroxide colloid dispersion).

The polymerizable monomer composition was charged into the magnesium hydroxide colloid dispersion obtained as described above at room temperature and stirred until the droplets were stabilized.
To this, 5 parts of t-butylperoxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perbutyl O) is added as a polymerization initiator, and an in-line type emulsifying disperser (trade name, manufactured by Ebara Corporation) is added. Using an Ebara Milder MDN303V), high shear stirring is performed for 20 minutes at a rotation speed of 15,000 rpm to form droplets of the polymerizable monomer composition, and the droplets of the polymerizable monomer composition are dispersed. Suspension (polymerizable monomer composition dispersion) was obtained.

The suspension (polymerizable monomer composition dispersion) obtained as described above was put into a reactor equipped with a stirring blade, and the temperature was raised and polymerization was performed while maintaining the temperature at 80 ° C. Reaction was performed.
When the polymerization conversion rate reached 80%, the temperature was further increased, and the polymerization reaction was continued for 4 hours while maintaining the temperature at 90 ° C. Thereafter, the reactor was cooled to room temperature to obtain an aqueous dispersion of microcapsule particles for a heat storage material.

The aqueous dispersion of microcapsule particles for heat storage material obtained as described above is dropped with sulfuric acid while stirring at room temperature, and acid cleaning is performed until the pH is 6.0 or less, and the surface of microcapsule particles for heat storage material The magnesium hydroxide adhering to was dissolved.
The aqueous dispersion of the microcapsule particles for heat storage material after acid cleaning is separated by filtration, and 500 parts of ion-exchanged water is newly added to the obtained solid, and is re-slurried. Dehydration) was repeated several times to obtain a solid content again.

  The solid content obtained above was put in a container of a vacuum dryer and vacuum-dried at 40 ° C. for 24 hours to obtain microcapsule particles for a heat storage material of Example 1.

  As a liquid silicone prepolymer, 50 parts of the microcapsule particles for heat storage material obtained as described above are added to 100 parts of a two-component addition reaction type silicone prepolymer (trade name: EG-6301, manufactured by Toray Dow Corning Co., Ltd.). A liquid silicone prepolymer dispersion containing microcapsule particles for heat storage material, which is defoamed while being stirred and uniformly dispersed at room temperature using an agitating / defoaming device (trade name: MAZERUSSTAR, manufactured by Kurabo Industries) Got.

  The liquid silicone prepolymer dispersion containing the microcapsule particles for heat storage material obtained as described above was poured into a predetermined mold (length: 100 mm, width: 100 mm, thickness: 4 mm) so that no bubbles would enter, and the tabletop Using a hot press machine (made by Shinto Kogyo Co., Ltd., trade name: tabletop CYPT), hot pressing was performed at 120 ° C. for 2 hours with a pressurizing force of 1 kN, pressure forming, and sheet-like heat storage of Example 1 A flexible elastomer molded body was prepared and subjected to a test.

(Example 2)
In Example 1, the type of the liquid silicone prepolymer was changed from “EG-6301” to “SE-1740” (trade name, manufactured by Toray Dow Corning Co., Ltd., two-component addition type liquid silicone prepolymer). Except for the above, a sheet-like heat storage elastomer molded body of Example 2 was produced in the same manner as Example 1, and subjected to the test.

(Example 3)
In Example 1, except that the addition amount of the microcapsule particles for the heat storage material was changed from 50 parts to 35 parts, the sheet-like heat storage elastomer molded body of Example 3 was produced in the same manner as Example 1, It used for the test.

Example 4
In Example 1, the addition amount of the monofunctional polymerizable monomer was changed from 50 parts to 75 parts, and the addition amount of the crosslinkable polymerizable monomer was changed from 50 parts to 25 parts. In the same manner as in Example 1, the sheet-like heat storage elastomer molded body of Example 4 was produced and used for the test.

(Example 5)
In Example 1, the kind of heat storage material is changed from the heat storage material A which is a multi-branched chain-containing α-olefin polymer to hexaglycerin octabehenate which is a trifunctional or higher polyfunctional fatty acid ester compound (trade name, manufactured by NOF Corporation). : A sheet-like heat storage elastomer molded article of Example 5 was produced in the same manner as in Example 1 except that it was changed to WEP7) and subjected to the test.

(Comparative Example 1)
In Example 1, except that the addition amount of the monofunctional polymerizable monomer was changed from 50 parts to 92 parts, and the addition amount of the crosslinkable polymerizable monomer was changed from 50 parts to 8 parts, In the same manner as in Example 1, a sheet-like heat storage elastomer molded body of Comparative Example 1 was produced and used for the test.

(Comparative Example 2)
In Example 1, except that the addition amount of the microcapsule particles for the heat storage material was changed from 50 parts to 200 parts, a sheet-like heat storage elastomer molded body of Comparative Example 2 was produced in the same manner as Example 1, It used for the test.

(Comparative Example 3)
In Example 1, a sheet-like heat storage elastomer molded body of Comparative Example 3 was used in the same manner as in Example 1 except that the two-component reactive polyurethane produced in the following production example was used instead of using the liquid silicone prepolymer. Was prepared and used for testing.

<Production example of two-component reactive polyurethane>
Plaxel 230CP, which is a bifunctional polyester polyol compound as a polyol component (trade name, manufactured by Daicel Chemical Industries, Ltd., poly ε-caprolactone polyol obtained using neopentyl glycol (NPG) as a ring-opening polymerization initiator, number average molecular weight: 3 , 000) 59.81 parts, and 4,4′-diphenylmethane diisocyanate (MDI) 40.19 parts as a polyisocyanate component were added and reacted at 80 ° C. for 3 hours while blowing nitrogen gas to obtain a liquid NCO group. A terminal pseudo-prepolymer was prepared.

  To a liquid NCO group-terminated pseudoprepolymer heated to 80 ° C., Plaxel 220 (trade name, manufactured by Daicel Chemical Industries, Ltd., 1,4-butanediol (1,4- BD) as a initiator and a compound obtained by ring-opening addition of ε-caprolactone using a catalyst, number average molecular weight: 2,000) 16.70 parts, trimethylolpropane (TMP) 5.70 parts as a crosslinking agent, As a chain extender, 5.20 parts of 1,4-butanediol (1,4-BD) and 50 parts of microcapsule particles for a heat storage material are added, and a planetary stirring and defoaming device (manufactured by Kurabo Industries, trade name: The liquid NCO-terminated pseudoprepolymer containing microcapsule particles for a heat storage material is degassed while being stirred at room temperature and uniformly dispersed using -A dispersion was obtained.

  The liquid NCO group-terminal pseudo-prepolymer dispersion containing the microcapsule particles for heat storage material obtained as described above is prevented from entering bubbles in a predetermined mold (vertical: 100 mm, horizontal: 100 mm, thickness: 4 mm). Using a tabletop hot press machine (trade name: tabletop CYPT, manufactured by Shinto Kogyo Co., Ltd.), hot pressing was carried out at 150 ° C. for 1 hour with a pressure of 1 kN, and cured to obtain a sheet of Comparative Example 3 A heat storage elastomer molding was produced and subjected to the test.

(result)
Tables 1 and 2 show the test results of the heat-storing material microcapsule particles and the heat-storing elastomer molded body produced in each example and comparative example, respectively.
The notes in Table 2 are as follows.
* 1: Although described in the item column of the liquid silicone prepolymer for convenience, it is a two-component reactive polyurethane.

(Summary of results)
From the test results described in Tables 1 and 2, the following can be understood.
The heat storage elastomer molded article of Comparative Example 1 is due to the fact that the component ratio of the crosslinkable polymerizable monomer in the total amount of the polymerizable monomer constituting the capsule wall was less than the range specified in the present invention. However, it was confirmed that leakage of the heat storage material occurred in a high temperature environment, and the heat storage elastomer molded body was inferior in heat resistance.

  In the heat storage elastomer molded body of Comparative Example 2, the amount of the microcapsule particles for heat storage material added to the liquid silicone prepolymer exceeded the range specified in the present invention, and the evaluation sheet was in the middle of tensioning. It was a heat storage elastomer molded body that was not able to measure the permanent elongation rate due to breakage and was inferior in rubber elasticity.

  The heat storage elastomer molded body of Comparative Example 3 is a heat storage elastomer having a large change in hardness with respect to environmental fluctuations and inferior rubber elasticity due to the absence of a liquid silicone prepolymer as a medium for dispersing microcapsule particles for heat storage materials. It was a molded body.

  On the other hand, the heat storage elastomer moldings of Examples 1 to 5 are included in the component ratio of the crosslinkable polymerizable monomer in the total amount of the polymerizable monomer constituting the capsule wall, and in the liquid silicone prepolymer. Due to the amount of the microcapsule particles for the heat storage material to be added within the range specified in the present invention, the permanent elongation is small, the rubber elasticity is high, the hardness change is small even when used in a high temperature environment, and the high temperature Even if it was exposed to the environment for a long time, the heat storage material was hardly leaked, and it was a heat storage elastomer molded body excellent in heat resistance.

Claims (4)

A heat storage elastomer molded body in which 25 to 150 parts by weight of microcapsule particles for heat storage material composed of a capsule wall and a heat storage material contained therein are dispersed in 100 parts by weight of a liquid silicone prepolymer and solidified. ,
The capsule wall is composed of a polymerizable monomer containing a crosslinkable polymerizable monomer, and the component ratio of the crosslinkable polymerizable monomer is 10 to 100% by weight of the total amount of the polymerizable monomer. A heat storage elastomer molded body characterized by being.   The heat storage elastomer molded article according to claim 1, wherein the heat storage material is a multi-branched compound having a number average molecular weight (Mn) of 1,000 to 100,000.   The heat storage elastomer molded article according to claim 1 or 2, wherein the microcapsule particles for heat storage material have a volume average particle diameter of 3 to 100 µm and an average circularity of 0.94 to 1.   4. The heat storage elastomer molded article according to claim 1, wherein the heat storage material has a melting point of 5 to 150 ° C. 5.