JPH1060423A - Production of heat-accumulation agent and heat-accumulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a safe heat-accumulation agent free from the leakage of oily substance caused by the deterioration with time by polymerizing a monomer component in a heat-accumulating oily substance thereby including the oily substance in the polymer in a specific state. SOLUTION: A monomer component is polymerized in a heat-accumulating oily substance (preferably pentadecane as a paraffin) preferably in the presence of an oil-soluble radical polymerization initiator to obtain a polymer containing the oily substance to lower the fluidity of the oily substance even in a state liquefied by phase change. The polymer preferably has a crosslinked structure. The crosslinking of the polymer is preferably carried out e.g. by the polymerization of (A) a monomer having one polymerizable unsaturated group and (B) a crosslinking monomer having two or more polymerizable unsaturated groups. The component A is preferably a 1-30C alkyl (meth)acrylamide, etc., and the component B is preferably divinylbenzene, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heat storage agent utilizing latent heat due to a phase change, and a method for manufacturing a heat storage material using the same, which is suitably used for cooling and heating of a building air conditioner or the like.

[0002]

2. Description of the Related Art Conventionally, when heat is used as energy for home or industrial use, the heat source and the place where the heat is used are different, and when heat is generated and when it is used. In some cases, it has been proposed to use a medium for transporting or temporarily storing heat, a so-called heat storage.

[0003] As such a heat storage element, those using sensible heat utilizing the heat capacity of the heat storage element and latent heat due to a phase change of the heat storage element are known. Latent heat is a phenomenon in which heat is stored at the time of a phase change from a solid to a liquid and heat is released at the time of a phase change from a liquid to a solid.

Water, stone blocks, and heat storage materials using sensible heat
Various metals are known, but those using sensible heat have the disadvantage that the heat capacity is low and the heat storage density is low, so the heat storage tank needs to be large, and the temperature range of heat when extracting heat is low. Because of the large size, there is an inconvenience that the temperature of the heat source and the destination of the heat may be limited.

On the other hand, hydrocarbons such as inorganic hydrate salts and paraffin have been proposed as heat storage bodies utilizing latent heat.
However, the disadvantage of inorganic hydrates is that, in general, supercooling is large, and in practice, even when the temperature is below the melting point, freezing may be inhibited, and a serious obstacle such as a significant decrease in the heat density to be radiated may be caused. It has been known.

On the other hand, hydrocarbons such as paraffin are
The adverse effect of supercooling is less than that of inorganic hydrate salts, and
Latent heat is as large as about 40-60 cal / g and about 2-96
Since each of them has a melting point over a wide temperature range of ° C., it has an advantage that it can select one having optimum properties according to the application.

However, even with such a hydrocarbon such as paraffin, if exposed to a high temperature for a long period of time, there is a problem that its physical properties are deteriorated and the adverse effects due to supercooling are increased.

In order to avoid such a problem, it has been proposed to add a nucleating agent such as zeolite powder to the above-mentioned hydrocarbon such as paraffin to prevent supercooling. The nucleating agent imparts the sufficient effect of the nucleating agent to the hydrocarbon by separating the nucleating agent from the liquid hydrocarbon with a specific gravity difference during use, particularly while the hydrocarbon is in a liquid state. There is a problem that it becomes impossible.

Further, when such a hydrocarbon such as paraffin is used as a heat storage agent for latent heat storage, since the heat storage agent is used in large quantities indoors, fire fighting against the use of a flammable heat storage agent is required. In order to comply with regulations such as the law, there is a problem that a measure is required to prevent leakage from the container to the outside due to flow during liquefaction.

In order to avoid the above-mentioned problems, JP-A-6-58686 discloses that a coagulant such as gelatin or hydroxystearic acid is added to a paraffin-based heat storage agent to form a jelly-like material. A latent heat storage device using a heat transfer medium having a capsule filled with the paraffin-based heat storage agent that has been gelled is disclosed.

In order to avoid the above-mentioned problems, Japanese Unexamined Patent Publication (Kokai) No. 56-103273 discloses an amide, ester and amine salt of N-acyl amino acid with 12-acyl amino acid.
At least one selected from hydroxystearic acid
There is disclosed a heat storage material comprising paraffin, which contains a kind of compound as a gelling agent and has low fluidity during liquefaction.

In Japanese Patent Application Laid-Open No. 4-85387,
Paraffins as a heat storage component and a binder component made of a hydrocarbon-based organic polymer such as a polyolefin-based polymer are mixed with each other by mechanical means. A material is disclosed.

[0013] The mixing by the above-mentioned mechanical means means that the remaining components are at least swelled and preferably dissolved in a melt of at least one component in both the paraffins and the hydrocarbon-based organic polymer, or at a high temperature. Means an operation of stirring, mixing and kneading in a state where any components to be mixed can be fluidly deformed by an external force.

[0014]

However, in the above-mentioned paraffinic heat storage agent gelled by the method described in the above-mentioned prior art JP-A-6-58686, freezing and thawing when storing and releasing heat are performed. Is repeated, the gelation collapses,
When the contained paraffin-based heat storage agent is fluidized and the capsule breaks, the above-mentioned paraffin-based heat storage agent easily flows out, thereby causing a problem that the risk of fire and the like increases.

In addition, the conventional Japanese Patent Application Laid-Open No. Sho 56-10327
In the heat storage material obtained by the method described in Japanese Patent Publication No. 3 (1999), the gel collapses by freezing and thawing several times when storing heat, and the paraffin contained therein fluidizes and leaks to the outside. There is a problem of increasing.

Further, as described in the above-mentioned JP-A-4-85387, it is difficult to use paraffin at a high content in the method of compounding a polymer and paraffin by mechanical means. However, even if a high content rate can be achieved, the paraffin exudes during freezing and thawing during storage of heat, resulting in an increase in leakage and a problem of increasing the risk.

In each of the above publications, since the heat storage material is a gel-like molded product or a molded product in which the heat storage material is mixed with a binder component, the heat storage material has a complicated shape that can increase the contact surface area with the medium. In a container, for example, a thin tube,
In a donut-shaped or coil-shaped container, there is a problem that it takes time to fill the heat storage body which is a formed body, and it is difficult to fill the formed body without any gap in the container. There is a problem that the heat efficiency is also reduced due to the reduction.

In addition, the above-mentioned conventional Japanese Patent Application Laid-Open No. 56-1032
With the heat storage material obtained by the method described in Japanese Patent No. 73, when filling in a container, it is necessary to melt the heat storage material in order to make it into a liquid state and perform the filling operation at a high temperature. It cannot be practically filled in containers with low heat resistance such as vinyl chloride, and is used only for containers made of high heat-resistant but expensive resin materials or containers made of corrosion-resistant but expensive stainless steel. The inconvenience has also arisen.

[0019]

According to a first aspect of the present invention, there is provided a method for producing a heat storage agent, comprising the steps of polymerizing a monomer component in an oily substance having a heat storage property. The present invention is characterized in that the oily substance is retained in a polymer obtained by polymerizing the monomer component so that the fluidity of the oily substance which is liquefied by the phase change is reduced.

According to the method of the first aspect, a polymer obtained by polymerizing a monomer component is formed in an oily substance, whereby the oily substance liquefied by phase change in the polymer. The oily substance can be gelled or solid by holding the oily substance so that the fluidity of the oily substance decreases. Therefore, in the above method, it is possible to obtain a heat storage agent in which leakage such as oozing of an oily substance upon repeated freezing and thawing when storing and releasing heat is reduced.

According to a second aspect of the present invention, in the method for producing a heat storage agent according to the first aspect, the polymer obtained by polymerizing the monomer component has a crosslinked structure. It is characterized by.

According to a third aspect of the present invention, there is provided a method for producing a heat storage agent, wherein the monomer component comprises at least two polymerizable unsaturated groups in a molecule. It is characterized in that a cross-linked structure is formed by the cross-linkable monomer by including the cross-linkable monomer having the above and copolymerizing the monomer component.

According to a fourth aspect of the present invention, in the method for producing a heat storage agent, the monomer component is a reactive monomer having a functional group for crosslinking. A polymer obtained by copolymerizing the above monomer component in an oily substance, in a state containing the above oily substance, a crosslinker is used to crosslink functional groups to form a crosslinked structure. .

According to the above-mentioned method, since the polymer has a cross-linked structure, the heat storage agent holding the oily substance can further reduce the leakage such as seepage of the oily substance. It can be.

According to a fifth aspect of the present invention, there is provided a method for producing a heat storage agent, comprising the step of combining the functional group of the reactive monomer with the functional group of the crosslinking agent. Is selected from the group consisting of a carboxyl group, a hydroxyl group, a mercapto group, an amino group and an amide group, and at least one functional group selected from the group consisting of an isocyanate group, an epoxy group and a carboxylic anhydride group. It is characterized in that it is a combination with at least one functional group.

According to the method of the fifth aspect, the combination of the functional group of the reactive monomer and the functional group of the crosslinking agent is selected from the above combinations, so that the unreacted functional group remains. A polymer with a reduced amount can be obtained. Therefore, by allowing the polymer to retain an oily substance, it is possible to obtain a heat storage agent that does not impair the heat storage characteristics of the oily substance.

According to a sixth aspect of the present invention, there is provided the method for producing a heat storage agent according to the fourth aspect, wherein the reactive monomer has a hydroxyl group and has at least two crosslinking agents. It is characterized by having an isocyanate group.

According to the method of the sixth aspect, a polymer having a reduced residual amount of unreacted functional groups can be obtained, so that a heat storage agent which does not hinder the heat storage characteristics of an oily substance can be obtained. Can be. Further, according to the above method, the oily substance can be gelled at a low temperature. For this reason, it is possible to hold the oily substance in a gel state without using a heat-resistant container, and to obtain a heat storage agent having excellent long-term stability.

[0029] The method for producing a heat storage agent according to claim 7 of the present invention is the method for producing a heat storage agent according to any one of claims 1 to 6, wherein the monomer component has a solubility parameter of 9 or less. It is characterized by containing 50% by weight or more of a monomer.

According to the method of claim 7, the monomer component contains a monomer having a solubility parameter of 9 or less by 50% by weight or more, so that the oily substance is liquefied. It is also possible to stably obtain a heat storage agent that stably holds.

A method for producing a heat storage material according to claim 8 of the present invention uses the method for producing a heat storage agent according to any one of claims 1 to 7, and fills the container in a liquid state, and then fills the container. It is characterized by being cured within.

According to the above-mentioned method, it is easy to make the mixture of the oily substance and, for example, the monomer component or the polymer before crosslinking into a liquid state at a relatively low temperature near normal temperature. Because it is possible, the oily substance and the monomer component or the polymer before cross-linking can be easily filled in a container.

Subsequently, the resulting heat storage agent is obtained by polymerizing or crosslinking the monomer component or the polymer before crosslinking at a relatively low temperature near room temperature in the container.
The oily substance can be densely filled in the container while being held in the polymer.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. The method for producing a heat storage agent of the present invention, in an oily substance having heat storage properties, preferably in the presence of an oil-soluble radical polymerization initiator, polymerizing the monomer component,
In this method, the oily substance is retained in a polymer obtained by polymerizing the monomer component so that the fluidity of the oily substance that liquefies due to a phase change is reduced. Further, it is preferable to select a combination in which the polymer obtained from the above monomer component and the oily substance are basically compatible with each other (ones having similar polarities).

In the heat storage agent, the polymer obtained by polymerizing the monomer component preferably has a crosslinked structure in order to more stably maintain the state in which the oily substance is retained. In order to impart such a crosslinked structure to the polymer, at least two polymerizable unsaturated groups are contained in the monomer component in the molecule.
It is preferable to include a crosslinkable monomer having at least one or a reactive monomer having a functional group for crosslinking.

When the monomer component contains a reactive monomer, a polymer obtained by copolymerizing the above-mentioned monomer component in an oily substance is mixed with the above-mentioned functional group by a crosslinking agent while containing the above-mentioned oily substance. A polymer having a crosslinked structure is obtained by crosslinking between the two.

As the above-mentioned oily substance having heat storage properties,
At room temperature (25 ° C.) and normal pressure (1 atm), it is oily and does not inhibit the polymerization of the monomer components or the crosslinking of the polymer. There is no particular limitation as long as it can store and release heat energy such as chemical reaction heat storage, but since it has a high heat storage density and can store and dissipate heat near a certain temperature,
It is preferable to use a substance having latent heat storage utilizing heat of phase change or phase transition as heat storage.

Examples of such an oily substance capable of storing latent heat include hydrocarbon compounds such as alcohols, esters, ethers, and paraffin. Among them, paraffin is preferable, and pentadecane is particularly preferable as paraffin.

This is because paraffin readily dissolves the monomer component and the polymer, and does not react with the polyfunctional compound at the time of polymerization of the monomer component or crosslinking of the polymer. Inhibition is avoided, and furthermore, a heat storage agent that can be easily obtained and can be used in a wide temperature range can be easily and stably produced. .

The reason why the heat storage agent can be easily and stably produced is that paraffins having different structures have a wide melting point temperature range and paraffins having various melting points can be selected. Because.

Specific examples of the above-mentioned hydrocarbon compound include middle-grade paraffin which is liquid at room temperature, such as C ₁₄ -C ₁₆ paraffin, C ₁₅ -C ₁₆ paraffin, pentadecane, C ₁₄ paraffin and C ₁₆ paraffin, or room temperature. And a higher alcohol which is a solid such as 1-decanol.

Examples of the oil-soluble radical polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide and cumene hydroperoxide; 2,2'-azobisisobutyronitrile;
An azo compound such as 2,2'-azobisdimethylvaleronitrile can be exemplified.

The above oil-soluble radical polymerization initiator can be generally used in a range of 0.1 to 5% by weight based on the monomer component. The polymerization temperature is a temperature at which the used oily substance can maintain a liquid state depending on the melting point of the oily substance, the type of the monomer component, and the type of the polymerization initiator.
The temperature can be appropriately selected within the range of 0 ° C, but more preferably 0 to 80 ° C.

The monomer components include a monomer (a) having one polymerizable unsaturated group in the molecule as a main component and at least two polymerizable unsaturated groups in the molecule. And a monomer component containing the crosslinkable monomer (b).

The above monomer (a) and crosslinkable monomer (b)
Is added to monomer (a) 9
6 to 99.999% by weight, crosslinkable monomer (b) 0.00
It is preferably 1 to 4% by weight (however, the total of the monomer (a) and the crosslinkable monomer (b) is 100% by weight).

The monomer (a) is preferably a monomer having a solubility parameter (SP value) of 9 or less. The solubility parameter (SP value) is generally used as a scale representing the polarity of a compound.
The value derived by substituting Hoy's cohesive energy constant into the formula for l is applied, and the unit is represented by (cal / cm ³ ) ^1/2 .

When a monomer having a solubility parameter (SP value) of more than 9 is used as a main component in the monomer component, the polymer obtained from the monomer component is converted from an oily substance into a gel or solid. It can not be made into a shape, or it can contain only a very small amount of oily substance,
The property of retaining the oily substance in the obtained heat storage agent cannot be secured.

The monomer (a) having a solubility parameter (SP value) of 9 or less and having at least one polymerizable unsaturated group in the molecule includes an unsaturated carboxylic acid ester and a hydrocarbon group. (Meth) acrylamide, α-
Olefins, alicyclic vinyl compounds, allyl ethers having an aliphatic hydrocarbon group, vinyl esters having an aliphatic hydrocarbon group, vinyl ethers having an aliphatic hydrocarbon group, aromatic vinyl compounds and the like can be mentioned. One or two or more monomers can be used.

As the unsaturated carboxylic acid ester, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, iso-butyl (meth) acrylate, t-
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, octylphenyl (meth) acrylate, nonylphenyl ( (Meth) acrylate, dinonylphenyl (meth) acrylate, cyclohexyl (meth) acrylate, menthyl (meth) acrylate, isobonyl (meth) acrylate, dibutyl (meth) acrylate, dibutyl maleate, didodecyl maleate, dodecyl rotonate, Dodecyl itaconate and the like.

The (meth) acrylamide having a hydrocarbon group includes (di) butyl (meth) acrylamide,
(Di) dodecyl (meth) acrylamide, (di) stearyl (meth) acrylamide, (di) butylphenyl (meth) acrylamide, (di) octylphenyl (meth) acrylamide and the like.

As the α-olefin, 1-hexene,
Examples thereof include 1-octene, isooctene, 1-nonene, 1-decene, and the like. Examples of the alicyclic vinyl compound include vinylcyclohexane and the like. Examples of the allyl ether having an aliphatic hydrocarbon group include dodecyl allyl ether.

Examples of the vinyl ester having an aliphatic hydrocarbon group include vinyl caproate, vinyl laurate, vinyl palmitate, vinyl stearylate and the like.
Examples of the vinyl ether having an aliphatic hydrocarbon group include butyl vinyl ether and dodecyl vinyl ether. Examples of the aromatic vinyl compound include styrene, t-butylstyrene, octylstyrene, and the like.

Among these, as a monomer which gives the obtained polymer a more excellent property of lowering the fluidity of the liquefied oily substance and keeping the oily substance in a gel or solid state, Is at least one of 1 to 3 carbon atoms
Having 0 aliphatic hydrocarbon groups and alkyl (meth)
A simple compound containing as a main component at least one unsaturated compound selected from the group consisting of acrylate, alkylaryl (meth) acrylate, alkyl (meth) acrylamide, alkylaryl (meth) acrylamide, fatty acid vinyl ester, alkylstyrene and α-olefin. The monomer (a) is particularly preferred.

The crosslinkable monomer (b) is a monomer having at least two polymerizable unsaturated monomers in the molecule, for example, ethylene glycol di (meth) acrylate, diethylene glycol Di (meth) acrylate, polyethylene glycol di (meth) acrylate, polyethylene glycol-polypropylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) ) Acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, N, N'-methylenebisacrylamide, N, N'-propylenebisacrylamide, glycerin tri (meth) acryle , Trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, alkylene oxide adducts of polyhydric alcohols (eg, glycerin, trimethylolpropanetetramethylolmethane) with (meth) acrylic acid The resulting polyfunctional (meta)
Acrylate and divinylbenzene are preferred, and one or more of these crosslinkable monomers can be used.

Further, as another monomer component different from the above-mentioned monomer component, a functional group containing the above-mentioned monomer (a) as a main component and chemically bonding to a crosslinking agent described later. ,
And those containing a reactive monomer (c) having one polymerizable unsaturated group.

The above monomer (a) and the reactive monomer (c)
Is added to monomer (a) 9
0 to 99.995% by weight, reactive monomer (c) 0.00
It is preferably 5 to 10% by weight (provided that the total of the monomer (a) and the reactive monomer (c) is 100% by weight).

As such a reactive monomer (c),
Any compound having a condensable functional group (X) that condenses with a condensable functional group (Y) of a cross-linking agent described below to form a chemical bond may be used. Examples of such a condensable functional group (X) include a carboxyl group, a hydroxyl group, a mercapto group, a nitrile group, an amino group, an amide group, an isocyanate group, an epoxy group, and a polymerizable unsaturated group of an acid anhydride. .

Examples of the reactive monomer (c) include a vinyl monomer having a carboxyl group, a vinyl monomer having a hydroxyl group, a vinyl monomer having a mercapto group, and a nitrile group. Vinyl monomer, vinyl monomer having an amino group, vinyl monomer having an amide group, vinyl monomer having an isocyanate group, vinyl monomer having an epoxy group, Examples thereof include acid anhydrides having a saturated group, and one or more of these monomers can be used.

Examples of the vinyl monomer having a carboxyl group include (meth) acrylic acid, fumaric acid, and itaconic acid. Examples of the vinyl monomer having a hydroxyl group include hydroxyethyl (meth) acrylate,
Examples thereof include polyethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, glycerin (meth) acrylate, trimethylolpropane (meth) acrylate, and hydroxystyrene.

The vinyl monomers having a mercapto group include vinyl mercaptan and mercaptoethyl (meth)
Acrylate and the like. Examples of the vinyl monomer having a nitrile group include (meth) acrylonitrile. As a vinyl monomer having an amino group,
Aminoethyl (meth) acrylate, vinylpyridine and the like can be mentioned.

Examples of the vinyl monomer having an amide group include (meth) acrylamide. Examples of the vinyl monomer having an isocyanate group include vinyl isocyanate. Examples of the vinyl monomer having an epoxy group include glycidyl (meth) acrylate. Examples of the acid anhydride having a polymerizable unsaturated group include maleic anhydride.

The crosslinking agent has at least two condensable functional groups (Y) in the molecule, and is appropriately selected according to the condensable functional groups (X) contained in the polymer.
Examples of such a crosslinking agent include a condensable functional group (X)
When the compound is a carboxyl group, a mercapto group, a nitrile group, or an epoxy group, a phenol resin such as dimethylol phenol or polymethylol phenol, which can be condensed.

As another example of the crosslinking agent, when the condensable functional group (X) is a carboxyl group or a hydroxyl group, an amino compound such as melamine, benzoguanamine or urea which can be condensed with formaldehyde or alcohol is used. An addition-condensed amino resin may be used.

Further examples of the crosslinking agent include hexamethylenediamine, diethylenetriamine and tetraethylenepentamine which can be condensed when the condensable functional group (X) is a carboxyl group, an isocyanate group or an epoxy group. And polyvalent amino compounds.

As still another example of the crosslinking agent, the condensable functional group (X) may be a carboxyl group, a hydroxyl group,
Hexamethylene diisocyanate, isophorone diisocyanate, p which can be condensed when it is a mercapto group, isocyanate group, amide group, amino group, epoxy group
Phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate,
Examples thereof include 1,5-naphthalenediisocyanate and isocyanate compounds such as blocked isocyanate obtained by condensing these isocyanates with methanol, phenol, or the like.

Further examples of the above-mentioned crosslinking agent include malonic acid, succinic acid, adipic acid, phthalic acid, terephthalic acid and the like, which are condensable when the condensable functional group (X) is an isocyanate group or an epoxy group. And polycarboxylic acids such as acids.

Further examples of the crosslinking agent include phthalic anhydride and pyromellitic anhydride, which can be condensed when the condensable functional group (X) is a hydroxyl group, an isocyanate group or an epoxy group. Acid anhydrides such as benzophenonetetracarboxylic acid anhydride are exemplified.

Further examples of the crosslinking agent include aldehyde compounds such as glyoxal and terephthalaldehyde which can be condensed when the condensable functional group (X) is a hydroxyl group, a mercapto group, an amino group or an amide group. Is mentioned.

Further examples of the crosslinking agent include ethylene glycol, diethylene glycol, propylene glycol and hexanediol which can be condensed when the condensable functional group (X) is a hydroxyl group, an isocyanate group or an epoxy group. And other polyhydric alcohols.

As still another example of the crosslinking agent, the condensable functional group (X) may be a carboxyl group, a hydroxyl group,
Epoxy compounds such as toluene glycidyl ether, hexamethylene glycidyl ether, bisphenol A diglycidyl ether, and polypropylene glycol diglycidyl ether, which can be condensed when they are a mercapto group or an isocyanate group, are exemplified.

The combination of each compound as such a crosslinking agent is appropriately determined depending on the type of the condensable functional group (X) contained in the polymer, and one or more of these compounds are used.

Among these, the combination of the condensable functional group (X), which is particularly preferable, and the condensable functional group (Y) of the crosslinking agent is
At least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group, a mercapto group, an amino group and an amide group, and at least one functional group selected from the group consisting of an isocyanate group, an epoxy group, and a carboxylic anhydride group; It is a combination of

By selecting the condensable functional group (X) and the condensable functional group (Y) of the crosslinking agent from the above combinations, it is possible to obtain a polymer in which the residual amount of the unreacted functional groups is reduced. it can. Therefore, by allowing the polymer to hold the oily substance, a heat storage agent that does not hinder the heat storage characteristics of the oily substance can be obtained. And especially, the combination in which the condensable functional group (X) is a hydroxyl group and the condensable functional group (Y) of the crosslinking agent is an isocyanate group, that is, the reactive monomer has a hydroxyl group, By selecting a combination in which the crosslinking agent has at least two isocyanate groups in the molecule, it becomes possible to gel the oily substance at a low temperature. For this reason, the oily substance can be held in a gel state without being a heat-resistant container,
A heat storage agent having excellent long-term stability can be obtained.

The ratio of the crosslinking agent used to the polymer to be crosslinked is determined by the number of moles of the condensable functional group (X), which is a constituent unit of the polymer, and the condensable functional group (Y) of the crosslinking agent.
And the number of moles of the condensable functional group (Y) is 0.1 to 10 per mole of the condensable functional group (X).
Is preferably within the range.

When the number of moles of the condensable functional group (Y) is less than 0.1 with respect to 1 mole of the condensable functional group (X), the crosslinked polymer cannot be sufficiently crosslinked and has low strength. It is not preferable because only the above may be obtained. On the other hand, if it exceeds 10, undesirably, a crosslinked polymer having excellent properties such as retaining a large amount of oily substances may not be formed.

In order to obtain an effective heat storage agent by using such a crosslinking agent, a polymer obtained by polymerizing a monomer component before crosslinking is prepared by:
After mixing with the cross-linking agent, before the cross-linking reaction proceeds, for example, the mixture is poured into a container, the oily substance can be maintained in a liquid state by melting, and the cross-linking reaction is performed at a temperature of 0 to 80 ° C. And harden it. Further, if necessary, the reaction rate can be increased by selecting and using a catalyst that promotes various polymerization reactions and crosslinking reactions.

Further, in order to prevent the above-mentioned condensable functional group (X) and condensable functional group (Y) from remaining unreacted after the cross-linking reaction, the condensable functional group (X) and the condensable functional group (Y) are each added within a range not hindering the cross-linking reaction. A compound having a reactive group capable of polycondensation with the functional group (X) or the condensable functional group (Y) may be added in advance or after the crosslinking reaction. For example, when the condensable functional group (X) or the condensable functional group (Y) is a polyvalent isocyanate, a long-chain carboxylic acid or the like can be used as the compound. It is not preferable that the functional groups (X) and (Y) remain unreacted, since the heat storage properties of the oily substance may be impaired.

In the present invention, the solubility parameter (SP
The amount of the monomer (a) having a value of 9 or less in the monomer component is 50% by weight or more, more preferably 70% by weight or more, based on the entire monomer component. When the amount of the monomer (a) is less than 50% by weight, the content of the oily substance that can be retained in the obtained heat storage agent may be significantly reduced, which is not desirable.

In the present invention, 50% by weight of a monomer (a) having a solubility parameter (SP value) of 9 or less is contained in the monomer component.
Although it is necessary to contain the above, 50%
A solubility parameter (SP value) of less than 9% by weight
A monomer having one polymerizable unsaturated group in a molecule exceeding the above, and containing another monomer different from the crosslinkable monomer (b) and the reactive monomer (c). You may.

Examples of such a monomer include methoxypolyethylene glycol (meth) acrylate and phenoxypolyethylene glycol (meth) acrylate.

In the method for producing a heat storage agent of the present invention, the oil-soluble radical polymerization initiation is carried out in a state in which the oily substance and the monomer component are mutually dissolved and mixed and suspended in an aqueous solvent. A method of suspension polymerization in the presence of an agent (suspension polymerization in water) can also be used.

As described above, when, for example, suspension polymerization is used in an aqueous solvent such as water, the suspension polymerization is carried out by dispersing the monomer component in a water-based medium such as water with a protective colloid agent or a surfactant. Is dissolved in, for example, an aqueous surfactant solution in the form of suspended particles, and polymerized using, for example, an oil-soluble radical polymerization initiator. In addition, if necessary, the monomer component may be dissolved in a water-insoluble organic solvent in advance, and then the solution may be subjected to suspension polymerization in an aqueous solvent.

Examples of the protective colloid agent include polyvinyl alcohol, hydroxyethyl cellulose, gelatin, and the like. Examples of the surfactant include sodium alkyl sulfonate, sodium alkyl benzene sulfonate, polyoxyethylene alkyl ether, and fatty acid. Soaps and the like can be mentioned.

In the method for producing a heat storage agent of the present invention, it is possible to further add an additive. Examples of the additives include metal powder (iron, copper, etc.), metal fiber, metal oxide, carbon, carbon fiber, and the like for improving heat transfer.
In addition, sand, clay, stone, metal powder (lead, iron, etc.) for adjusting the specific gravity may be used.

Other additives include water for imparting flame retardancy, water gel, metal powder, inorganic compounds (such as calcium carbonate), and flame retardants (bromine-based, chlorine-based, phosphorus-based, etc.). Note that the flame retardancy includes a reduction in flammability, prevention of fire spread, extinction of a flash point by steam, an effect of reducing the amount of combustion heat, and the like.

Examples of other additives include metal powder and high-molecular paraffin (wax) for preventing supercooling, and waxes for adjusting the freezing point. Antioxidants (phenol-based, thio-based, phosphorus-based, etc.) for preventing deterioration are included.
Further, as other additives, a coloring agent, a pigment, an antistatic agent, and a bactericide can be added as necessary.

As another additive, an inclusion compound for adjusting the latent heat of the oily substance may be added to the oily substance. As the clathrate compound, C ₄ H ₈ .O.
17H ₂ O, (CH ₃ ) ₃ N · 10.25H ₂ O, (C
_{4 H 9) 4 NCHO 2 ·} 32H 2 O, (C 4 H 9) 4 N
CH ₃ CO ₂ .32H ₂ O and the like can be mentioned.

The amount of such an additive is, for example, when calcium carbonate is used as an additive in order to reduce flammability, calcium carbonate is added in an amount of 10 to 10 with respect to the total amount of the oily substance and the polymer. It is preferable to add 40% by weight.

If the amount of calcium carbonate is less than 10% by weight, the effect of reducing the calorific value of the fuel and the effect of preventing the spread of fire are not sufficient. On the other hand, if the addition amount of calcium carbonate exceeds 40% by weight, the content of the oily substance is relatively decreased, and the heat storage amount is undesirably decreased.

When each of such additives is added to the heat storage agent of the present invention, the freezing / freezing of the oily substance for heat storage / radiation is performed.
Even if the dissolution is repeated, the fluidity of the oily substance held in the polymer can be reduced to maintain the oily substance in a gel state or a solid state more stably than before. For this reason, for example, even when a substance having a large specific gravity difference of 1 or more with an oily substance, such as a metal powder, is used as an additive, the additive can be kept in a uniform state in the heat storage agent. Thus, the effects of the above additives can be more effectively exerted.

Further, even when the compatibility between the additive and the oily substance is inferior, such as when the difference in the numerical value of the solubility parameter between the additive and the oily substance is two or more apart,
Due to the crosslinked structure of the polymer in the heat storage agent of the present invention, the additive and the oily substance are held in the crosslinked structure, and the additive and the oily substance can be prevented from being separated from each other, and the additive can be avoided. Can be more effectively exerted.

In the method for producing a heat storage material of the present invention, a method is used in which a monomer component or a polymer before crosslinking is filled in a liquid state in a container and cured in the container using the above-described method for producing a heat storage agent. It is.

That is, as a method for producing the heat storage material, an oily substance and a monomer component containing a crosslinkable monomer are charged into a container in a liquid state, and the monomer is contained in the oily substance. A method in which the components are subjected to bulk crosslinking polymerization in the presence of an oil-soluble radical polymerization initiator and cured (casting polymerization),
A mixture obtained by mixing a monomer component containing a reactive monomer in an oily substance in the presence of an oil-soluble radical polymerization initiator in the presence of an oil-soluble radical polymerization initiator, and a crosslinking agent, is mixed with the above functional group. Before the cross-linking by the group and the cross-linking agent is completed, there is a method in which the mixture is charged into a container in a liquid state and filled, and the cross-linking is completed in the container and cured (cast polymerization).

According to the above methods and, the oily substance and the monomer component or the polymer before cross-linking can be easily brought into a liquid state at around normal temperature.
The oily substance and the monomer component or the polymer before cross-linking can be easily filled densely in a container. Subsequently, by polymerizing or cross-linking the monomer component or the polymer before cross-linking at about room temperature in the container, a cross-linked polymer obtained by polymerizing and curing the monomer component is converted into an oily substance. The container can be densely filled while being held.

Therefore, in the above method, the time and effort for filling the polymer holding the oily substance into the container becomes simpler than before, while the oily substance having heat storage property held by the polymer is placed in the container. Since it is possible to fill more densely and more, it is possible to obtain a heat storage material in which the thermal efficiency of the oily substance is improved compared to the conventional one.

The shape of the above-mentioned container is not particularly limited. However, when the container is used for air conditioning in a building, the contact surface area with the medium for transferring heat in the heat storage tank should be increased. Therefore, those having a hollow portion such as a bent tube shape, a coil shape, a spherical shape, and a cylindrical shape are preferable, and a plate shape is preferable when used for floor heating.

The material of the above-mentioned container is such that it does not corrode with a medium for transferring heat, an oily substance or a polymer, and has a long-term immersion in an aqueous medium for many years. The material is not particularly limited as long as it has durability over time such as water resistance, but polyvinyl chloride or the like which is inexpensive and excellent in moldability is preferable.

[0098]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to each embodiment, but the present invention is not limited to the following embodiments.

Example 1 First, a container composed of a polyvinyl chloride transparent cylindrical pipe having a diameter of 4 cm and a height of 25 cm, to which a lid made of polyvinyl chloride was fused, was prepared. Next, dodecyl acrylate (SP
Value: 7.9) 39 g and ethylene glycol dimethacrylate 0.8 g, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile 0.2 g as a polymerization initiator, and pentadecane 160 as an oily substance
g were mixed so as to be uniform with each other to prepare a mixed solution.

Thereafter, the mixed solution was filled in the container, and nitrogen was sufficiently introduced into the mixed solution through a gas inlet tube mounted on the upper portion of the container to convert oxygen in the mixed solution into nitrogen. Replaced.

Next, the mixed solution was polymerized and crosslinked by allowing the container to stand in a constant temperature bath maintained at 40 ° C. for 8 hours while maintaining the nitrogen atmosphere, thereby holding pentadecane in a gel state. After visually confirming the formation of the polymer, the gas introduction pipe was removed to remove the polymer.
(1) and a heat storage material (1) using the same.

Example 2 6 g of gelatin was dissolved in 594 g of water and charged in a 1-liter flask equipped with a thermometer, a stirrer, a gas inlet tube, and a reflux condenser. And heated to 80 ° C. under a nitrogen stream.

Thereafter, 39 g of dodecyl acrylate and 0.8 g of ethylene glycol dimethacrylate as monomer components, 0.2 g of benzoyl peroxide as a polymerization initiator, and pentadecane 1 as an oily substance
A mixed solution obtained by mixing 60 g with each other to be uniform,
The suspension polymerization reaction was carried out for 2 hours under a nitrogen stream while mixing at 400 rpm in the flask at a time.

Thereafter, the inside of the flask was further heated to 90 ° C., and maintained for 2 hours to complete the polymerization, thereby forming a polymer in which pentadecane was held in a gel state. After polymerization is complete,
After obtaining a granular (average particle size: 0.3 mm) product from the contents in the flask by vacuum filtration as the heat storage agent (2) of the second embodiment, the above product is transferred to the container described in the first embodiment. By filling the inside, the heat storage material (2) of Example 2 was obtained.

Example 3 A 500 equipped with a thermometer, a stirrer, a gas inlet tube, two dropping funnels and a reflux condenser was used.
A milliliter flask was charged with 10 g of pentadecane as an oily substance, the atmosphere in the flask was replaced with nitrogen under stirring, and the flask was heated to 65 ° C. under a nitrogen stream.

Next, 2-ethylhexyl acrylate (SP value:
7.8) 38 g and hydroxyethyl acrylate 2
g, and a solution composed of 40 g of pentadecane as an oily substance, and 0.1 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile as a polymerization initiator, and an oily substance in a further dropping funnel. And a solution comprising 10 g of pentadecane as a diluent was charged.

Subsequently, the solution and the solution were simultaneously dropped into the flask over 1 hour to carry out a polymerization reaction. Thereafter, the temperature in the flask was further raised to 80 ° C.
The polymerization was completed by maintaining for a time to obtain a polymer before crosslinking.

After cooling, a solution composed of 2.3 g of toluene diisocyanate as a cross-linking agent, 0.1 g of dibutyltin dilaurate, 100 g of an oily substance and 100 g of pentadecane as a diluent was added to the flask and mixed. Immediately, the contents in the flask were filled in the container described in Example 1 and allowed to stand at room temperature for 4 hours, followed by crosslinking to form a gel containing pentadecane. Thermal storage agent of the third embodiment (3)
And a heat storage material (3) using the same.

Example 4 First, 39 g of dodecyl acrylate (SP value: 7.9) as a monomer component and 0.8 g of ethylene glycol dimethacrylate, and 2,2′-azobis (2,2) as a polymerization initiator A paraffin wax having a melting point of 50 ° C. as an oily substance (product name 120, manufactured by Nippon Wax Co., Ltd.) previously melted at 60 ° C. with a mixed solution consisting of 0.2 g of 4-dimethylvalerovaleronitrile)
160 g, and mixed so as to be uniform with each other to prepare a mixed solution. Thereafter, the mixed solution was mixed with the mixture of Example 1
Was filled into a container made of a polyvinyl chloride transparent cylindrical pipe prepared in the same manner as in Example 1.

Then, while keeping the container at 60 ° C. in a thermostat, nitrogen was sufficiently introduced into the mixed solution through a gas inlet tube mounted on the upper portion of the container to replace oxygen in the mixed solution with nitrogen. did. Further, the container was allowed to stand at 60 ° C. for 8 hours while maintaining a nitrogen atmosphere, so that the mixed solution was polymerized and crosslinked to form a polymer in which paraffin wax was held in a gel state. By removing the gas introduction pipe, a heat storage agent (4) and a heat storage material (4) using the same were obtained.

Next, comparative examples for illustrating the features of the present invention will be described below. Comparative Example 1 160 g of pentadecane was charged into the flask described in Example 2, and the temperature was raised to 90 ° C. while stirring under a nitrogen stream. 40 g of 12-hydroxystearic acid as a gelling agent was added to the flask, and 3 g
After stirring at 00 rpm for 5 minutes, the mixture was filled in the container described in Example 1 and allowed to cool to room temperature to obtain a comparative heat storage agent (1) and a comparative heat storage material (1) using the same.

Comparative Example 2 160 g of pentadecane was charged into the flask described in Example 2, and the temperature was raised to 140 ° C. while stirring under a nitrogen stream. In this flask, 40 g of an amino acid-based oil gelling agent (GP-1 manufactured by Ajinomoto Co., Inc.) was added, and the mixture was stirred at 300 rpm for 5 minutes. Then, the mixture was filled into the container described in Example 1 and cooled to room temperature. After cooling, a comparative heat storage agent (2) and a comparative heat storage material (2) using the same were obtained.

Comparative Example 3 26 parts of uncrosslinked high-density polyethylene (density: 0.945, MI: 0.4) and 100 parts of pentadecane were kneaded and mixed with two rolls whose temperature was adjusted to 130 ° C. And a uniform composition.

Then, the above composition was formed into pellets having an average particle diameter of about 3 mm, 126 parts of the pellets, 2.4 parts of vinyltrimethoxysilane, and 0.1 part of dicumyl peroxide.
18 parts were preliminarily mixed in a closed container, and this mixture was extruded with an extruder adjusted to a cylinder temperature of 200 ° C., filled in the container described in Example 1, and then immersed in 70 ° C. hot water for 24 hours to crosslink. Thus, a comparative heat storage agent (3) and a comparative heat storage material (3) using the same were obtained.

Next, the above Examples 1 to 4 and Comparative Example 1
Heat storage agents (1) to (4), heat storage materials (1) to (4), comparative heat storage agents (1) to (3), and comparative heat storage materials (1) to (3) obtained by the methods of (1) to (3). Was measured for changes in physical properties over time.

That is, the heat storage materials (1) to (3) and the comparative heat storage materials (1) to (3) were respectively charged into a thermostat.
After repeating the freeze-thawing of pentadecane as an oily substance 20 times according to a time program of 2 ° C. × 8 hours and 30 ° C. × 8 hours as a set, liquid pentadecane is removed from each gel or solid heat storage agent. The presence or absence of separation was visually confirmed. The heat storage agent (4) was also charged into the thermostat in the same manner as described above, and 40 ° C. × 8 hours and 60 ° C. × 8 hours were added for 1 hour.
After repeating the freeze-thawing of paraffin wax as an oily substance 20 times by a set time program, the presence or absence of separation of liquid paraffin wax from the gel or solid heat storage agent (4) was visually confirmed. .

As a result, in the heat storage materials (1) to (3), no separation of pentadecane liquefied by the phase change was observed in the heat storage materials (1) to (3).
In the heat storage material (4), the separation of the liquefied paraffin wax was not observed in the heat storage agent (4), but in the comparative heat storage materials (1) to (3), the comparative heat storage agents (1) to (3) were used.
Since the separation of liquefied pentadecane in (3) was observed, the heat storage agent according to the present invention is a comparative heat storage agent (1)
It was found to be superior in stability over time as compared with (3).

Further, in the comparative heat storage materials (2) and (3), the comparative heat storage materials (1) and (2), which have been melted to have a high temperature, are filled in the container. , The deformation of the container was observed, and it was found that it was inappropriate to use a thermoplastic synthetic resin such as polyvinyl chloride as the material of the container.

Therefore, the method for producing a heat storage agent of the present invention reduces the fluidity of a flammable oily substance even if the flammable oily substance is liquefied by a phase change due to the heat storage, thereby reducing the fluidity of the oily substance to a gel form. Alternatively, it can be stably held in a solid state to prevent leakage from the container, and also to avoid leakage of oily substances from the container even under normal use conditions where freezing and melting are repeated for heat release and heat storage. Is excellent in stability over time, so that ignited oily substances are prevented from igniting, etc., and safety is high, and a heat storage agent whose safety is stable over time can be produced reliably and easily. It is.

In the method for producing a heat storage material according to the present invention, the heat storage material is prepared by mixing a monomer component which is in a liquid state at normal temperature or a polymer before crosslinking in a container at 40 ° C. By polymerizing or crosslinking at around room temperature, the oily substance can be obtained in a gel or solid state in the container.

Therefore, in the above method, the heat storage agent can be densely filled in the container, and a synthetic resin such as polyvinyl chloride having excellent water resistance but poor heat resistance is used as the material of the container. Even, the heat storage agent in the container, densely, easily, and can be stably filled, as in the past, high heat resistance but expensive resin material, or corrosion resistant but expensive Since the inconvenience of using only expensive containers made of stainless steel or the like can be avoided, the heat storage material can be manufactured stably at low cost.

Furthermore, in the above method, even if the container is formed into a complicated shape, for example, a thin tube, a donut or a coil, in order to increase the contact surface area with the heat transfer medium, the container is kept at a relatively low temperature. By filling the monomer component or the polymer before cross-linking into a container in a liquid state and polymerizing or cross-linking, the heat storage agent can be densely and easily filled in the container, and the heat transfer efficiency is improved. The improved heat storage material can be manufactured stably and easily.

[0123]

According to the method for producing a heat storage agent according to claim 1 of the present invention, as described above, a monomer component is polymerized in an oily substance having heat storage properties, and the monomer component is polymerized. This is a method of retaining the oily substance in the resulting polymer such that the fluidity of the oily substance liquefied by the phase change is reduced.

[0124] Therefore, the above-mentioned method holds the oily substance in a polymer obtained by polymerizing the monomer component in the presence of the oily substance such that the fluidity of the oily substance liquefied by the phase change is reduced. By doing so, leakage such as seepage of the oily substance can be avoided.

In addition, in the above method, by retaining the oily substance in the polymer, deterioration over time such as leakage of the oily substance during repeated freezing and thawing when storing and releasing heat is suppressed. Therefore, it is possible to stably obtain a highly safe heat storage agent in which ignition of the oily substance is suppressed.

According to the method for producing a heat storage agent according to claim 2 of the present invention, as described above, in the method for producing a heat storage agent according to claim 1, the polymer obtained by polymerizing the monomer component is: This is a method having a crosslinked structure.

According to the method for producing a heat storage agent according to claim 3 of the present invention, as described above, in the method for producing a heat storage agent according to claim 2, the monomer component contains a polymerizable unsaturated group as a molecule. This is a method of forming a crosslinked structure with the crosslinkable monomer by including at least two crosslinkable monomers therein and copolymerizing the above monomer components.

In the method for producing a heat storage agent according to claim 4 of the present invention, in the method for producing a heat storage agent according to claim 2, the monomer component is a reactive monomer having a functional group for crosslinking. And forming a crosslinked structure by crosslinking a polymer obtained by copolymerizing the monomer component in an oily substance with a crosslinking agent in a state containing the oily substance.

Therefore, in the method according to any one of claims 2 to 4, since the heat storage agent has a crosslinked structure, the heat storage agent holding the oily substance can be further stabilized, and the leakage of the oily substance can be further reduced. Can be reduced, degradation is suppressed,
Further, there is an effect that a heat storage agent with high safety can be obtained.

According to the method for producing a heat storage agent according to claim 5 of the present invention, as described above, in the method for producing a heat storage agent according to claim 4, the functional group of the reactive monomer and the crosslinking agent have A combination with a functional group includes a carboxyl group, a hydroxyl group, a mercapto group, an amino group and an amide group, and at least one functional group selected from the group consisting of an isocyanate group, an epoxy group and a carboxylic anhydride group. The method is a combination with at least one functional group selected from the group consisting of:

Therefore, in the above method, the remaining amount of the unreacted functional group was reduced by selecting the combination of the functional group of the reactive monomer and the functional group of the crosslinking agent from the above combinations. A polymer can be obtained. Therefore, by holding the oily substance in the polymer, it is possible to form an oily gel body that does not inhibit the heat storage characteristics of the oily substance.

According to the method for producing a heat storage agent according to claim 6 of the present invention, as described above, in the method for producing a heat storage agent according to claim 4, the reactive monomer has a hydroxyl group and a crosslinking agent. Has at least two isocyanate groups.

Therefore, according to the above method, a polymer having a reduced residual amount of unreacted functional groups can be obtained.
A heat storage agent that does not hinder the heat storage characteristics of the oily substance can be obtained. Further, according to the above method, the oily substance can be gelled at a low temperature. Therefore, it is possible to keep the oily substance in a gel state without using a heat-resistant container, and to obtain a heat storage agent having excellent long-term stability.

According to the method for producing a heat storage agent according to claim 7 of the present invention, as described above, in the method for producing a heat storage agent according to any one of claims 1 to 6, the monomer component has This is a method in which a monomer having a parameter of 9 or less contains 50% by weight or more.

Therefore, in the above method, the monomer component is
By containing 50% by weight or more of a monomer having a solubility parameter of 9 or less, it is possible to stably obtain a heat storage agent that stably holds an oily substance even when it is in a liquid state. .

The method for producing a heat storage material according to claim 8 of the present invention uses the method for producing a heat storage agent according to any one of claims 1 to 7 in a liquid state in a container. This is a method of filling and curing in a container.

Therefore, in the above method, the heat storage agent is converted into an oily substance by polymerizing or crosslinking a monomer component or a polymer before crosslinking in the container in a liquid state. The container can be densely filled while being held.

From the above, according to the above method, in addition to the effects of the manufacturing method according to the first to seventh aspects, the oily substance having heat storage properties held in the heat storage agent can be filled more in the container. There is an effect that a heat storage material with improved thermal efficiency due to the substance can be stably obtained.

In addition, in the above method, a liquid state, for example, a monomer component or a polymer before cross-linking is polymerized or cross-linked, for example, at around normal temperature and cured in a container, thereby curing the container to be used. Thus, the necessity of considering heat resistance and the like is reduced, so that an inexpensive material that does not particularly consider heat resistance and the like can be used for the container.

Claims (8)

[Claims] 1. An oily substance having heat storage properties, in which a monomer component is polymerized, and a polymer obtained by polymerizing the monomer component reduces the fluidity of the oily substance which is liquefied by phase change. A method for producing a heat storage agent, wherein the oily substance is retained. 2. A polymer obtained by polymerizing a monomer component,
The method for producing a heat storage agent according to claim 1, having a crosslinked structure. 3. The monomer component contains a crosslinkable monomer having at least two polymerizable unsaturated groups in a molecule, and the monomer component is copolymerized to form the crosslinkable monomer. The method for producing a heat storage agent according to claim 2, wherein a crosslinked structure is formed by the monomer. 4. The monomer component contains a reactive monomer having a functional group for crosslinking, and a polymer obtained by copolymerizing the monomer component in an oily substance,
The method for producing a heat storage agent according to claim 2, wherein a cross-linking structure is formed by cross-linking the functional groups with a cross-linking agent while the oil-based substance is contained. 5. A combination of the functional group of the reactive monomer and the functional group of the crosslinking agent, wherein at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group, a mercapto group, an amino group and an amide group. The method for producing a heat storage agent according to claim 4, wherein the combination is a combination of a group and at least one functional group selected from the group consisting of an isocyanate group, an epoxy group, and a carboxylic anhydride group. 6. The method according to claim 4, wherein the reactive monomer has a hydroxyl group and the crosslinking agent has at least two isocyanate groups. 7. The method according to claim 1, wherein the monomer component contains at least 50% by weight of a monomer having a solubility parameter of 9 or less. . 8. A method for producing a heat storage material, comprising using the method for producing a heat storage agent according to any one of claims 1 to 7, filling the liquid state in a container, and curing the material in the container. .