JP6863481B2 - Chemical heat storage complex, composition for forming chemical heat storage complex, and method for forming chemical heat storage complex - Google Patents

Description

The present invention relates to a chemical heat storage complex containing a resin and a chemical heat storage material.

In recent years, in order to use energy with high efficiency, it has been requested to establish a heat energy storage technology and a heat storage technology using waste heat. Examples of the heat storage method currently in practical use include a method using sensible heat or latent heat using a heat storage medium. However, these methods have a low heat storage amount and require a heat insulating material for heat retention, and are not suitable for long-term heat storage storage. Chemical heat storage is attracting attention as a method for solving these problems.

In chemical heat storage, a chemical heat storage material such as a metal oxide, a salt, or an adsorbent and a reaction medium gas such as water, ammonia, or methanol are reversibly chemically or adsorbed, and the heat absorption reaction is the heat storage or exothermic reaction. It is a heat storage method that dissipates heat. Such chemical heat storage has an advantage that it can store heat stably for a long period of time because it has a large amount of heat storage and does not require heat retention as compared with other heat storage methods such as latent heat and sensible heat. Chemical heat storage materials are used in chemical heat storage systems such as chemical heat pumps, which are required to make effective use of thermal energy. Studies are underway to improve the fuel efficiency of automobiles by using this chemical heat storage system to generate cold heat from exhaust heat of 100 ° C or less emitted from automobiles as an air conditioner system.

The chemical heat storage material is used by being filled in, for example, a heat exchanger. However, when the chemical heat storage material is used as a powder, there is a problem that the volume of the chemical heat storage material expands and contracts in the process of repeating endothermic reaction and exothermic reaction, the chemical heat storage material falls off from the heat exchanger, and the amount of heat storage decreases. was there.

Various studies have been conducted on such problems. For example, a method is disclosed in which a chemically heat storage material is supported on a cage-shaped carbon structure having a large number of pores by bringing a refractory organic compound into contact with a chemical heat storage material and firing it in an inert atmosphere (Patent). Document 1). Further, the chemical heat storage material is decomposed by containing the chemical heat storage material in the dense three-dimensional structure formed by desorbing all the alkoxy groups bonded to silicon by firing the alkoxysilane at 680 ° C. or higher. A method for preventing this is disclosed (Patent Document 2). In addition, a method of preventing leakage of the heat storage material by forming a core-shell structure in which a heat storage material containing a chemical heat storage material is used as a core and polyurethane polyurea having high mechanical strength is used as a shell has been studied (Patent Document 3).
JP-A-2009-256518 Japanese Unexamined Patent Publication No. 2015-098582 Japanese Unexamined Patent Publication No. 2017-137437

However, in the methods of Patent Documents 1 and 2, since the method is to obtain a three-dimensional structure surrounding the heat storage material by firing, the structure becomes hard and brittle and cannot follow the volume expansion of the chemical heat storage material, so that the heat exchanger There is a fact that it is not possible to sufficiently suppress the dropout from. Further, the method of Patent Document 3 has a function of preventing volatilization and exudation in the shell portion, and therefore, there is a problem that the chemical heat storage material and the reaction medium gas cannot sufficiently react.

In view of the above circumstances, an object to be solved by the present invention is to provide a chemical heat storage composite capable of suppressing the heat storage material from falling off from the heat exchanger due to volume expansion or the like and withstanding repeated use. ..

In order to solve the fundamental problem, the idea was to relieve the stress during volume expansion of the chemical heat storage material, and as a result of diligent studies, it was found that the stress can be relieved by supporting the chemical heat storage material on a specific resin. The heading led to the present invention.

That is, the present invention relates to the following items 1 to 6.
Item 1.
A chemical heat storage complex characterized by being a chemical heat storage complex containing an elastomer having a chemically crosslinked structure and a chemical heat storage material.
Item 2.
A chemical heat storage composite containing an elastomer having a chemically crosslinked structure and a chemical heat storage material, which is a chemical heat storage composite having a bulk density of 1.0 to 6.0 g / cm ³ .
Item 3.
Item 1 or 2, wherein the elastomer is at least one resin selected from the group consisting of natural rubber, diene rubber, olefin rubber, silicone resin, polyester resin, epoxy resin and urethane resin. Chemical heat storage complex.
Item 4.
A composition for forming a chemical heat storage complex containing a liquid that is cured by heating and a chemical heat storage material, wherein the liquid that is cured by heating becomes an elastomer when cured. Composition for forming a chemical heat storage complex.
Item 5.
A composition for forming a chemical heat storage complex containing a liquid that is cured by heating and a chemical heat storage material, wherein the liquid that is cured by heating becomes an elastomer when cured and after curing. A composition for forming a chemical heat storage complex, which is prepared so that the chemical heat storage complex has a bulk density of 1.0 to 6.0 g / cm ^3.
Item 6.
Item 4. The composition for forming a chemical heat storage complex according to Item 4 or 5, further comprising a solvent.
Item 7.
Item 4 to any one of Items 4 to 6, wherein the elastomer is at least one resin selected from the group consisting of natural rubber, diene rubber, olefin rubber, silicone resin, polyester resin, epoxy resin and urethane resin. The composition for forming a chemical heat storage complex according to the section.
Item 8.
A step of applying the chemical heat storage complex forming composition according to any one of Items 4 to 7 to the surface of the base material, and a step of heating the base material on which the chemical heat storage complex forming composition is applied to the surface. And, a method of forming a chemical heat storage complex containing.

The chemical heat storage composite of the present invention has an excellent heat storage density per volume, and even if heat absorption and exothermic reactions are repeated, the volume expansion of the chemical heat storage material contained in the composite can be alleviated. Therefore, the chemical heat storage complex of the present invention has an excellent effect of having a high heat storage density and a long life. Further, according to the composition for forming a chemical heat storage complex of the present invention, when a chemical heat storage complex is formed using the composition, a chemical heat storage complex having the above-mentioned excellent effects can be obtained.

The chemical heat storage composite in the present invention is a composite material (sometimes referred to as a heat storage material in the present specification) composed of a resin which is an elastomer having a chemically crosslinked structure and a chemical heat storage material. The chemical heat storage material is dispersed in the resin and is contained therein. Since the resin is an elastomer having a chemically crosslinked structure, the resin has a rubber-like structure and is a stretchable (soft) material. Therefore, by adopting such a structure, the stress at the time of volume expansion and contraction of the chemical heat storage material generated at the time of heat storage and heat dissipation can be relaxed by the resin, and the deterioration of the chemical heat storage material can be prevented. Further, the elastomer having a chemically crosslinked structure has high heat resistance and can maintain a sufficient rubber-like structure even after repeated use, so that the life of the chemical heat storage material can be extended.

Elastomers with a chemically crosslinked structure are known to have high gas permeability, and can react with a reaction medium gas even if a chemical heat storage material is contained in the resin.
It is designed with due consideration of the reaction between the chemical heat storage material and the reaction medium gas, and it is possible to improve the heat storage density because it is not an essential condition for the carrier structure to have voids in order to exert its function. Is. As a result, the above-mentioned excellent effect can be obtained.

Hereinafter, the present invention will be described in detail.
<Explanation of chemical heat storage complex>
In the present invention, the "chemical heat storage complex" refers to a composite of a chemical heat storage material and a resin. It is different from the "chemical heat storage material" described later. The "composition for a chemical heat storage complex" described later is a material used for forming a chemical heat storage complex, and can be formed by a method described later or the like.

<Explanation of elastomer>
The elastomer used in the present invention is characterized by being an elastomer having a chemically crosslinked structure. An elastomer having a chemically crosslinked structure is a soft segment or a soft segment and a hard segment crosslinked by a covalent bond. By having such a chemical crosslinked structure, the stress in the repeated volume change of expansion and contraction required for the chemical heat storage complex is relaxed, and a technical problem in the case where the stress is not relaxed can be solved. The hard segment in the elastomer is not particularly limited, and examples thereof include polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyester, and polyamide. The soft segment is not particularly limited, but for example, polybutadiene, polyisobutylene, polyisobutylene, aliphatic polyester, aliphatic polyether, polydimethylsiloxane, polyvinylidene fluoride, ethylene / propylene / diene rubber, ethylene propylene rubber, acrylic rubber, etc. Fluoro rubber, silicone rubber and the like can be mentioned. Each segment may be one type or a combination of two or more types.
The cross-linking is not particularly limited, and for example, cross-linking with sulfur or a sulfur compound (vulcanization), cross-linking with an epoxy group, cross-linking with isocyanate and alcohol (urethane bond), cross-linking with peroxide, cross-linking by hydrosilylation reaction, dehydration. Examples thereof include cross-linking by condensation. The cross-linking method is not particularly limited, and examples thereof include cross-linking by heating, cross-linking by ultraviolet rays, and cross-linking by radiation. Crosslinking by heating is preferable from the viewpoint of productivity.
The elastomer having a chemically crosslinked structure is not particularly limited, and examples thereof include natural rubber, diene rubber, olefin rubber, silicone resin, polyester resin, epoxy resin, urethane resin, urethane rubber, fluororubber, and silicone rubber. Be done. Rubbers such as natural rubber, diene-based rubber, and olefin-based rubber are not preferable because they require additional labor such as kneading and viscosity adjustment before cross-linking such as vulcanization. Silicone resin, polyester resin, epoxy resin, etc. because it is easy to obtain raw materials, has better workability and durability (heat resistance, light resistance, chemical resistance, etc.), and has the following gas permeability and productivity. Urethane resin is preferable. Even in actual use, a resin having such a suitable chemically crosslinked structure undergoes repeated endothermic reactions and exothermic reactions when installed in a heat exchanger, and the chemical heat storage material falls off from the chemical heat storage composite. Can be suppressed for a longer period of time.

From the viewpoint of gas permeability and productivity, the elastomer having a chemically crosslinked structure preferably has a glass transition temperature of −140 ° C. or higher and 30 ° C. or lower, and an elastic modulus of 0.3 MPa or higher and 500 MPa or lower at 30 ° C. It is preferable that it is in the range of. The values obtained by the following evaluation methods were used for the glass transition temperature and elastic modulus.

<Evaluation of glass transition temperature of elastomer>
The glass transition temperature of the elastomer in the chemical heat storage composite can be measured by a dynamic viscoelasticity measuring device, and the maximum value of the loss tangent (tan δ) obtained by the measurement is defined as the glass transition temperature. The measurement was carried out by measuring the chemical heat storage composite in the form of strips with a dynamic viscoelasticity measuring device under the conditions of a temperature rise temperature of 3 ° C./min and a frequency of 1 Hz. The loss tangent (tan δ) is a value (tan δ = E ″ / E ′) obtained by dividing the loss elastic modulus (E ″) by the storage elastic modulus (E ′).

<Evaluation of elastic modulus of elastomer>
It is difficult to measure only the elastic modulus of the elastomer from the chemical heat storage composite, and it was obtained by curing the liquid that is cured by heating, excluding the chemical heat storage material, in the composition for forming the chemical heat storage composite. The elastic modulus of the elastomer was defined as the elastic modulus of the elastomer in the chemical heat storage composite. The elastic modulus of the elastomer was defined as the storage elastic modulus (E') when the resin was measured with a dynamic viscoelasticity measuring device under the conditions of a temperature of 30 ° C. and a frequency of 1 Hz.

<Explanation of chemical heat storage material>
The chemical heat storage material used in the present invention can reversibly undergo a chemical reaction or an adsorption reaction with a reaction medium gas, and can store heat by an endothermic reaction and dissipate heat by an exothermic reaction. Examples of the chemical heat storage material include metal oxides, hydroxides, salts, and adsorbents.

Specific examples of the reaction medium gas include gases such as water (water vapor), ammonia, hydrogen, carbon dioxide, alcohols, ammonia, primary amines, secondary amines, and tertiary amines. The reaction medium may be used alone or in combination of two or more. Examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, n-butanol, ethylene glycol and the like. Examples of the primary amine include methylamine, ethylamine, propylamine and the like. Examples of the secondary amine include dimethylamine, ethylmethylamine, N-methylpropylamine and the like. Examples of the tertiary amine include trimethylamine, N, N-diethylmethylamine, N, N-dimethylethylamine and the like. For example, water (steam), ammonia, carbon dioxide, methanol, and ethanol are preferable from the viewpoint of excellent stability in repeated heat storage and heat dissipation when the chemical heat storage composite is incorporated into a heat exchanger and used. A suitable reaction medium gas that is less dangerous, easier to handle, and has a relatively large amount of heat taken out is water (water vapor).

Depending on the reaction medium gas, a suitable chemical heat storage material can be appropriately selected. As the chemical heat storage material, any known and commonly used material can be used. In the case of a reaction between a chemical heat storage material and water (water vapor), which is a preferred embodiment, for example, the reaction between the chemical heat storage material and water (water vapor) is a hydration reaction, an adsorption reaction of water molecules, a hydroxylation reaction, or the like. Can be mentioned. An example of the reaction is shown below. In the hydration reaction, heat is generated when hydrating with water (water vapor), and endothermic occurs when dehydrating. In the adsorption reaction of water molecules, heat is generated when the water molecules are adsorbed on the heat storage material, and heat absorption occurs when the water molecules are dehydrated. In the hydroxylation reaction, heat is generated when water (water vapor) and an oxide undergo a hydration reaction to form a hydroxide, and heat is absorbed during a dehydration reaction in which water (water vapor) and an oxide are produced from the hydroxide.

Hydration reaction
CaCl ₂ + nH ₂ O ⇔ CaCl ₂・ nH ₂ O
LiOH + H ₂ O ⇔ LiOH ・ H ₂ O
Ba (OH) ₂ + nH ₂ O ⇔ Ba (OH) ₂・ nH ₂ O

Adsorption and desorption reaction of water molecules
Zeolite + nH ₂ O ⇔ Zeolite ・ nH ₂ O

Hydroxylation reaction
MgO + H ₂ O ⇔ Mg (OH) ₂
CaO + H ₂ O ⇔ Ca (OH) ₂

Examples of the chemical heat storage material capable of forming a hydrate include inorganic salts, organic salts, and hydroxides.
Specific examples of the inorganic salt include halides, sulfates, phosphates, silicates and the like. Examples of the halide include fluoride, chloride, bromide, iodide and the like. Specific examples of the fluoride include lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride and the like. Specific examples of chlorides include lithium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, strontium chloride, barium chloride, iron chloride, zinc chloride, cobalt chloride, nickel chloride, copper chloride, and ammonium chloride. Can be mentioned. Specifically, as the bromide, for example, lithium bromide, sodium bromide, potassium bromide, magnesium bromide, calcium bromide, strontium bromide, barium bromide, iron bromide, zinc bromide, cobalt bromide, odor. Examples include nickel bromide and copper bromide. Specifically, as iodide, for example, lithium iodide, sodium iodide, potassium iodide, magnesium iodide, calcium iodide, strontium iodide, barium iodide, iron iodide, zinc iodide, cobalt iodide, Examples thereof include nickel iodide and copper iodide. These may be combined.

Specifically, as the sulfate, for example, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, strontium sulfate, barium sulfate, ittrium sulfate, lanthanum sulfate, chromium sulfate, manganese sulfate, iron sulfate, cobalt sulfate, sulfate. Examples thereof include nickel, copper sulfate, zinc sulfate, cerium sulfate, lead sulfate, aluminum sulfate, potassium aluminum sulfate, and ammonium aluminum sulfate. These may be combined.

Specific examples of the phosphate include lithium phosphate, sodium phosphate, calcium phosphate, magnesium phosphate and the like. These may be combined.

Specific examples of silicic acid include lithium silicate, sodium silicate, potassium silicate, magnesium silicate, calcium silicate, and aluminum silicate.

Specific examples of the organic salt include carboxylates, sulfonates, phosphonates, phosphinates and the like. These may be combined.

Carboxylic acid is a salt of carboxylic acid and metal, and specific examples of carboxylic acid include citric acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, oleic acid, linoleic acid, linolenic acid, lactic acid, and apple. Acids, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, aconitic acid, pyruvate, acrylic acid, methacryl Acids, polyacrylic acid, polymethacrylic acid and the like can be mentioned, and specific metals include, for example, lithium, sodium, potassium, magnesium, calcium, barium, manganese, iron, cobalt, nickel, copper, zinc and aluminum. Can be mentioned. These may be combined.

The sulfonic acid salt is a salt of a sulfonic acid and a metal, and specific examples of the sulfonic acid include methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, taurine, and fluorosulfonic acid. Specific examples of the metal include lithium, sodium, potassium, magnesium, calcium, barium, manganese, iron, cobalt, nickel, copper, zinc, and aluminum. These may be combined.

The phosphonate is a salt of phosphonic acid and a metal, and specific examples of the phosphonic acid include methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, phenylphosphonic acid, methylenediphosphonic acid, and 1,4-phenylenediphosphonic acid. Examples include acid. Specific examples of the metal include lithium, sodium, potassium, magnesium, calcium, barium, manganese, iron, cobalt, nickel, copper, zinc, and aluminum. These may be combined.

The phosphinate is a salt of phosphinic acid and a metal, and specific examples of the phosphinic acid include phenylphosphinic acid, methylphosphinic acid, ethylphosphinic acid, aminoethylphosphinic acid, and the like. Examples include lithium, sodium, potassium, magnesium, calcium, barium, manganese, iron, cobalt, nickel, copper, zinc, aluminum and the like. These may be combined.

Examples of the hydroxide include lithium hydroxide, strontium hydroxide, barium hydroxide and the like. These may be combined.

Chemical heat storage materials that become oxides by the dehydration reaction and become hydroxides by the hydration reaction include, for example, magnesium oxide, calcium oxide, zinc oxide, nickel oxide, cobalt oxide, iron oxide, copper oxide, strontium oxide, and barium oxide. , Oxide lantern and the like. These may be combined.

Examples of the chemical heat storage material capable of absorbing and desorbing water molecules include zeolite, clay, silica gel, porous carbon, an organic structure, and acrylic fine particles. These may be combined.

<Explanation of chemical heat storage complex>
From the viewpoint of obtaining a high heat storage density, the chemical heat storage composite of the present invention is not substantially hollow (porous) and has substantially no voids derived from other than the chemical heat storage material and the elastomer (confidential). ) Is preferable. In particular, it is desirable that the bulk density of the chemical heat storage complex is at least the true density of the elastomer alone that does not contain voids, and is equal to or lower than the true density when the chemical heat storage material is contained in almost 100%. The bulk density of the chemical heat storage complex is preferably 0.9 to 6.0 g / cm ³ . Further, the heat storage density is determined by the type and weight of the heat storage material contained, and in actual use, a higher heat storage density is required based on the volume. That is, it is more desirable ^{that the bulk density is 1.0 to 6.0 g / cm 3} so that the amount of energy does not decrease even when converted by volume. A high heat storage density can be obtained when the porosity is almost zero, but the state is not limited when air bubbles are unintentionally contained in the curing process. When additives for the purpose of improving thermal conductivity are used, the weight and volume excluding those additives are used for calculation.
The bulk density is the density obtained by dividing the weight of the substance by its volume, and the true density is the density excluding the connected or independent voids contained in the substance. Since the bulk density of the elastomer having a chemically crosslinked structure may be reduced, it is preferable that the foaming agent is not contained in the chemical heat storage complex and the chemical heat storage complex forming-like composition.

<Evaluation of bulk density of chemical heat storage complex>
The bulk density of the chemical heat storage composite is the density obtained by dividing the weight of the substance by its volume as described above, and the value is the true density of the elastomer and the chemical heat storage material and its content. It is also possible to calculate from. It is possible to confirm whether or not there is a gap by comparing the measured value with the calculated value.

<Explanation of manufacturing method>
The method for producing the "chemical heat storage complex" of the present invention will be described below.
The chemical heat storage complex is formed, for example, by applying a composition for forming a chemical heat storage complex to a base material or the like and heating the base material. Since the chemical heat storage material itself or its content causes poor light transmission, the thermosetting system is more advantageous than the photocuring system in preparing the composition of the present invention. The composition for forming a chemical heat storage complex is a composition containing a chemical heat storage material and a liquid that becomes an elastomer by being cured by heating. Those that are liquid at room temperature are preferably used because they are easy to handle.

Any liquid that cures when heated to become an elastomer may be used, but is preferably easily available, has better workability and durability (heat resistance, light resistance, chemical resistance, etc.), and is bulky. From the viewpoint of density and high performance when formed into a chemical heat storage composite, a two-component curable composition containing a silicone resin, a polyester resin, an epoxy resin, or a urethane resin is preferable. As described above, the chemical heat storage composite obtained from such a suitable composition is subjected to repeated endothermic reaction and exothermic reaction when installed in a heat exchanger even in actual use, and is obtained from the chemical heat storage composite. It is possible to prevent the chemical heat storage material from falling off for a longer period of time.
Examples of the liquid that cures by heating to become an elastomer include a combination of a main agent and a cross-linking material or a catalyst, and preferably, for example, a polymerizable double-bond-containing polysiloxane and a double-bonded polymerization catalyst. A combination of a polymer polyol such as a polyester polyol or a polyether polyol and a polyisocyanate, a moisture-curable terminal isocyanate-based urethane prepolymer containing a repeating unit of an ether structure and / or an ester structure, and an epoxy compound. Examples thereof include a two-component curable composition such as a combination with a compound selected from the group consisting of an amine compound, a phenol compound and an acid anhydride.
A one-component curable composition such as a solvent solution of polyamic acid that produces a polyimide resin by heat cross-linking does not exhibit elastomeric properties due to an elastic modulus that is too high due to curing cross-linking, so that the heat storage performance is insufficient in either case. ..
The cross-linking material, catalyst, etc. required for curing may be included in the composition for forming the chemical heat storage complex in advance, or may be added to the composition for forming the chemical heat storage complex at the stage of coating. .. When preparing a two-component curable composition, it is preferable to add a cross-linking material, a catalyst, or the like at the stage of coating from the viewpoint of workability and storage stability.

Examples of the cross-linking material and the catalyst include sulfur, a cross-linking material having an amine group, a catalyst, a cross-linking material having an isocyanate group, and the like, which can be appropriately selected depending on the main agent component.

Examples of the cross-linking material and catalyst having an amine group include aliphatic polyamines, alicyclic polyamines, Mannig bases, amine-epoxy addition products, polyamide polyamines, and liquid aromatic polyamines.

Examples of the cross-linking material having an isocyanate group include tolylene diisocyanate (TDI) such as 2,4-tolylene diisocyanate (2,4-TDI) and 2,6-tolylene diisocyanate (2,6-TDI), 4, Diphenylmethane diisocyanate (MDI) such as 4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylenediocyanate, polymethylenepolyphenylene polyisocyanate, Aromatic polyisocyanates such as xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), trizine diisocyanate (TODI), 1,5-naphthalenediocyanate (NDI), triphenylmethane triisocyanate, polypeptide diphenylmethane diisocyanate, ethylene diisocyanate , Propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornandiisocyanate (NBDI) and other aliphatic polyisocyanates.

Examples of the catalyst that promotes curing and cross-linking include a platinum catalyst and the like. Examples of the platinum catalyst include platinum alone, platinum chloride, platinum chloride acid, platinum chloride salt, platinum chloride, platinum chloride acid or a complex of platinum chloride salt and a vinyl group-containing siloxane.

The content ratio of the elastomer having a chemically crosslinked structure, which is an essential component constituting the chemical heat storage composite, and the chemical heat storage material may be an optimum ratio according to the raw material used, and is particularly limited. However, when the non-volatile content in the liquid component that cures by heating to produce an elastomer, which is the raw material, is used as a reference, the non-volatile component / chemical heat storage material in the liquid component that cures by heating to produce an elastomer is For example, setting 5/95 to 50/50 in terms of mass, especially 10/90 to 35/65, allows appropriate gas permeation even if the volume of the chemical heat storage complex changes due to repeated heat storage and heat dissipation. Therefore, it is preferable because a high heat storage density can be maintained, the deterioration of the chemical heat storage composite due to stress relaxation is small, and the durability can be improved.

A solvent can be added to the composition for forming a chemical heat storage complex, if necessary. As the solvent, at least one of an organic solvent and water can be used. Examples of the organic solvent include hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, cellosolve acetate and butyl cellosolve, and alcohols such as methanol and ethanol. It is preferable not to use an organic solvent or to keep the amount as small as possible even if it is used, in order to eliminate the need for a recovery step and improve the handleability.

A heat conductive filler can be added to the composition for forming a chemical heat storage complex in order to improve the thermal conductivity. Examples of the thermally conductive filler include graphite, silicon carbide, aluminum oxide, magnesium oxide, boron nitride and the like. This may be used alone or in combination of two or more.

Additives for improving the adhesion to the base material can be added to the composition for forming the chemical heat storage complex.

A rheology control agent or the like for improving coatability can be added to the composition for forming a chemical heat storage complex.

In order to enhance the dispersion stability of the chemical heat storage material, the dispersant may be included in the composition for forming the chemical heat storage complex.

The method for preparing the composition for forming a chemical heat storage complex is not particularly limited, and a known method can be used. For example, in addition to a chemical heat storage material and a liquid that cures by heating to produce an elastomer with a chemically crosslinked structure, the optional components are mixed in a kneader (eg, uniaxial extruder, twin screw extruder, planetary mixer, twin shaft). It can be prepared by kneading with a mixer, a high shear type mixer, etc.).
In the composition for forming a chemical heat storage composite, the chemical heat storage composite obtained after curing and cross-linking has as high a heat storage density as possible and the durability of repeated heat storage and heat dissipation over a long period of time when incorporated into a heat exchanger is enhanced. As described above, it is preferable to perform defoaming so as to have substantially no voids (become dense) derived from other than the chemical heat storage material and the elastomer.

<Explanation of usage>
Such a "chemical heat storage complex" of the present invention can be used in applications such as a chemical heat pump by forming a chemical heat storage material on the surface of a base material of a heat exchanger or the like.

<Explanation of chemical heat storage complex formation process>
In the chemical heat storage complex of the present invention, for example, the step of applying the above-mentioned chemical heat storage complex forming composition to the surface of the base material and the base material coated with the chemical heat storage complex forming composition on the surface are heated. It can be formed by going through a process. Specifically, it includes a coating step described as follows and a heating step.

<Applying process>
In the coating step, the above composition for forming a chemical heat storage complex is coated on a substrate. The composition for forming a chemical heat storage complex is preferably liquid at room temperature without a solvent because it has high fluidity and is easy to apply. However, if the composition does not contain a solvent and has a high viscosity at room temperature, heating or the like is performed. It is also possible to apply after increasing the fluidity. The composition for forming a chemical heat storage complex containing a solvent is preferably dried by a known method at the same time as or after coating.
Any method may be used as long as the composition for forming a chemical heat storage complex is applied to the base material. For example, a method of immersing the base material in the composition for forming a chemical heat storage complex by showering or dipping and applying the composition. , Application method using an applicator or the like. The base material to which the composition for forming the chemical heat storage composite is applied is not particularly limited, and examples thereof include aluminum, copper, steel, and stainless steel, which are metal materials used for the heat exchange surface of the heat exchanger.

<Heating process>
In the heating step, the composition for the chemical heat storage complex on the surface of the base material is heated after the coating step. When the composition for a chemical heat storage composite is heated in the heating step, cross-linking proceeds by curing to become an elastomer having a chemically cross-linked structure, and a chemical heat storage composite including a chemical heat storage material is formed. The heating step can be performed by an electric furnace, a heating oven, or the like, but the heating device is not particularly limited. The optimum conditions for heat curing may be selected according to the composition of the composition for forming a chemical heat storage complex to be used. For example, the heating temperature is in the range of room temperature to 300 ° C., and the heating time is 3 minutes to 3 hours. It can be done within the range of.
Although this heating step can be performed in an atmosphere of oxygen gas or air, for example, it is less likely that curing inhibition due to heating will occur if the heating step is performed in an atmosphere of an inert gas such as nitrogen gas or helium gas. The obtained chemical heat storage composite has a higher heat storage density and a high durability of repeated heat storage and heat dissipation for a long period of time when incorporated into a heat exchanger.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following production examples. The reference example shows a method for preparing a resin for determining the elastic modulus of the resin contained in the chemical heat storage complex.

Reference example 1
Weigh 1 g of SYLGARD184 Silicone Elastomer (manufactured by Toray Dow Corning Co., Ltd.) and 0.1 g of SYLGARD184 Curing Agent (manufactured by Toray Dow Corning Co., Ltd.) in a vial, and use Awatori Rentaro (manufactured by Shinky Co., Ltd.). A liquid was obtained by stirring and defoaming. The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated at 200 ° C. for 1 hour in a nitrogen atmosphere to obtain a crosslinked silicone resin elastomer film. ..

Production Example 1 (Chemical heat storage complex of crosslinked silicone resin elastomer)
Calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 1 g, SYLGARD184 Silicone Elastomer (manufactured by Toray Dow Corning Co., Ltd.) 1 g, SYLGARD184 Curing Agent (manufactured by Toray Dow Corning Co., Ltd.) 0.1 g, toluene 1 g vial Weighed into a bottle, stirred and defoamed with Awatori Rentaro (manufactured by Shinky Co., Ltd.) to obtain a paste containing a silicone resin and calcium chloride. The obtained paste was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated at 200 ° C. for 1 hour in a nitrogen atmosphere to obtain a crosslinked silicone resin elastomer and a chemical heat storage material. A film (D1) of a chemical heat storage complex containing the above was obtained.

Reference example 2
Poly (dimethylsiloxane), vinyl terminal (weight average molecular weight 25,000, manufactured by Sigma Aldrich Co., Ltd.) 10 g, methylhydrosiloxane-dimethylsiloxane copolymer, trimethylsiloxy terminal (number average molecular weight 950, manufactured by Sigma Aldrich Co., Ltd.) 0 Weigh 1.5 g and 150 μg of platinum (0) -1,3-divinyltetramethyldisiloxane complex (manufactured by Tokyo Kasei Co., Ltd.) into a vial, and stir and defoam with Awatori Rentaro (manufactured by Shinky Co., Ltd.). And obtained a liquid. The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated at 100 ° C. for 1 hour in a nitrogen atmosphere to obtain a crosslinked silicone resin elastomer film. ..

Production Example 2 (Chemical heat storage complex of silicone resin elastomer)
Poly (dimethylsiloxane), vinyl terminal (weight average molecular weight 25,000, manufactured by Sigma Aldrich Co., Ltd.) 10 g, methylhydrosiloxane-dimethylsiloxane copolymer, trimethylsiloxy terminal (number average molecular weight 950, manufactured by Sigma Aldrich Co., Ltd.) 0 Weigh .5 g, platinum (0) -1,3-divinyltetramethyldisiloxane complex (manufactured by Tokyo Kasei Co., Ltd.) 150 μg, and calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 10 g into a vial. A liquid was obtained by stirring and defoaming with Neritaro (manufactured by Shinky Co., Ltd.). The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated at 100 ° C. for 1 hour in a nitrogen atmosphere to obtain a crosslinked silicone resin elastomer and a chemical heat storage material. A film (D2) of a chemical heat storage complex containing the above was obtained.

Reference example 3
Weigh 5 g of Pandex GW-1340 (manufactured by DIC Corporation) and 0.3 g of Burnock DN-902S (manufactured by DIC Corporation) into a vial, and stir and remove with Awatori Rentaro (manufactured by Shinky Co., Ltd.). Foamed to obtain liquid. The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated in air at 80 ° C. for 1 hour to obtain a film of a crosslinked urethane resin elastomer.

Production Example 3 (Chemical heat storage complex of crosslinked urethane resin elastomer)
Weigh 5 g of Pandex GW-1340 (manufactured by DIC Co., Ltd.), 0.3 g of Barnock DN-902S (manufactured by DIC Co., Ltd.), and 5 g of calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) in a vial. A liquid was obtained by stirring and defoaming with Tori Rentaro (manufactured by Shinky Co., Ltd.). The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated at 80 ° C. for 1 hour in a nitrogen atmosphere to obtain a crosslinked urethane resin elastomer and a chemical heat storage material. A film (D3) of a chemical heat storage complex containing the above was obtained.

Reference example 4
Weigh 4 g of Dick Dry LX-627M (manufactured by DIC Corporation) and 1 g of KW-40 (manufactured by DIC Corporation) into a vial, and stir and defoam with Awatori Rentaro (manufactured by Shinky Co., Ltd.). Obtained liquid. The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated in air at 50 ° C. for 3 days to obtain a film of a crosslinked polyester resin elastomer.

Production Example 4 (Chemical heat storage complex of crosslinked polyester resin elastomer)
Weigh 4 g of Dick Dry LX-627M (manufactured by DIC Corporation), 1 g of KW-40 (manufactured by DIC Corporation), and 5 g of calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) in a vial, and weigh Awatori Rentaro. A liquid was obtained by stirring and defoaming with (manufactured by Shinky Corporation). The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated at 50 ° C. for 3 days in a nitrogen atmosphere to obtain a crosslinked polyester resin elastomer and a chemical heat storage material. A film (D4) of a chemical heat storage complex containing the above was obtained.

Reference example 5
Weigh 2.84 g of EPICLON EXA-4850-150 (manufactured by DIC Corporation) and 0.16 g of triethylenetetramine (manufactured by Tokyo Kasei Co., Ltd.) in a vial, and use Awatori Rentaro (manufactured by Shinky Co., Ltd.). A liquid was obtained by stirring and defoaming. The obtained liquid was applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate was heated in air at 80 ° C. for 3 hours and 150 ° C. for 2 hours to obtain a crosslinked epoxy resin elastomer. A membrane was obtained.

Production Example 5 (Chemical heat storage complex of crosslinked epoxy resin elastomer)
EPICLON EXA-4850-150 (manufactured by DIC Co., Ltd.) 2.84 g, triethylenetetramine (manufactured by Tokyo Kasei Co., Ltd.) 0.16 g, calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 3 g, toluene 1 g vial Weighed into a bottle, stirred with Awatori Rentaro (manufactured by Shinky Co., Ltd.), and defoamed to obtain a liquid. The obtained liquid is applied onto a stainless steel (SUS304) plate (7 cm × 3 cm) using an applicator, and the applied plate is heated at 80 ° C. for 3 hours and 150 ° C. for 2 hours in a nitrogen atmosphere to obtain a crosslinked epoxy resin elastomer. A film (D5) of a chemical heat storage composite containing the chemical heat storage material and the chemical heat storage material was obtained.

Comparative reference example 1
1 g of U-varnish-A (manufactured by Ube Industries, Ltd.) is applied onto a stainless steel (SUS304) plate (7 cm x 3 cm) using an applicator, and the applied plate is heated in air at 200 ° C. for 3 hours to obtain polyimide. A resin film was obtained.

Comparative Production Example 1 (Chemical heat storage complex of polyimide resin)
Apply 2 g of U-Wanis-A (manufactured by Ube Industries, Ltd.) and 0.1 g of calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) on a stainless steel (SUS304) plate (7 cm x 3 cm) using an applicator. The coated plate was heated at 200 ° C. for 3 hours in a nitrogen atmosphere to obtain a film (C1) of a chemical heat storage composite containing a polyimide resin and a chemical heat storage material.

[Measurement of glass transition temperature]
The glass transition temperature was measured for the films obtained in Production Examples 1, 2, 3, 4, 5 and Comparative Production Example 1. The glass transition temperature was measured using RSA III manufactured by TA Instruments Co., Ltd. The sample was cut into strips having a width of 0.5 cm and a length of 4 cm, and the thickness was measured using a micrometer (PMU150-25MX manufactured by Mitutoyo Co., Ltd.). This was used as a test piece for measurement. This test piece was attached to a jig for a tensile test and measured under the conditions of a temperature of −50 to 100 ° C. and a frequency of 1 Hz. If there is a glass transition temperature on the lower temperature side than this condition, remeasure it under the same conditions in the range of -140 to 0 ° C, and if there is a glass transition temperature on the higher temperature side, it is in the range of 50 ° C to 300 ° C. Measured under the same conditions. The temperature of the maximum value of the loss tangent (tan δ) obtained by the measurement was defined as the glass transition temperature.

[Measurement of elastic modulus]
The elastic modulus was measured for the films obtained in Reference Examples 1, 2, 3, 4, 5 and Comparative Reference Example 1. The elastic modulus was measured using RSA III manufactured by TA Instruments Co., Ltd. The sample was cut into strips having a width of 0.5 cm and a length of 4 cm, and the thickness was measured using a micrometer (PMU150-25MX manufactured by Mitutoyo Co., Ltd.). This was used as a test piece for measurement. This test piece was attached to a jig for a tensile test and measured under the conditions of a temperature of 30 ° C. and a frequency of 1 Hz. The storage elastic modulus (E') obtained at that time was taken as the elastic modulus. The results are shown in Table 1.

[Measurement of bulk density]
The bulk density was measured for the films obtained in Reference Examples 1, 2, 3, 4, 5 and Comparative Reference Example 1. The bulk density was measured by the bulk volume and weight of the test piece. The external dimensions of the chemical heat storage composite of about 20 mm in length × about 20 mm in width, which was left to stand for 1 hour or more in an environment with a temperature of 23 ° C and a dew point of -15 ° C or less, were measured with a caliper with an accuracy of 0.1 mm, and the thickness was measured with a micrometer (micrometer). The bulk volume was determined by measuring with an accuracy of 0.001 mm using a PMU150-25MX manufactured by Mitutoyo Co., Ltd. Then, the weight (g) of the test piece was precisely weighed. The weight of the test piece obtained as described above was divided by the bulk volume of the test piece and converted into units. Five test pieces were prepared, and the average value of the three results excluding the highest and lowest bulk densities obtained is shown in Table 1 as the measured value.

[Evaluation of heat storage performance]
Approximately 10 mg of the film of the chemical heat storage complex obtained in Production Examples 1, 2, 3, 4, 5 and Comparative Production Example 1 was cut out from the SUS304 plate, and TG-DTA measurement (TG-DTA2020SA Bruker AX) was performed using this. The heat storage performance of the chemical heat storage complex was evaluated by S. Co., Ltd.

For evaluation, the temperature was raised to 200 ° C. at 10 ° C./min while flowing nitrogen gas (200 ml / min), held at 200 ° C. for 30 minutes, and subsequently cooled to 80 ° C. at 10 ° C./min. The mixture was held at 80 ° C. for 10 minutes, and then the mixture was switched to a nitrogen mixed gas (200 ml / min) having a partial pressure of water vapor of 5.6 kPa while maintaining the temperature, and the mixed gas containing water vapor was circulated for 30 minutes. The calorific value was evaluated from the DTA area while adsorbing water vapor for 30 minutes, and this was used as an index for evaluating the heat storage performance. The calorific value was calculated by correcting the obtained DTA area with the heat of fusion of In, Sn, and Pb, and the calorific value per 1 kg of the chemical heat storage material was calculated. If the calorific value at this time is 100 kJ / kg or more, it is judged that the chemical heat storage complex has the heat storage performance, and if it is less than 100 kJ / kg, it is judged that the chemical heat storage complex does not have the heat storage performance. The results are shown in Table 1.

As is clear from Table 1, Production Examples 1 to 5, which are chemical heat storage composites containing an elastomer having a chemically crosslinked structure, store heat as compared with Comparative Production Example 1 containing a polyimide resin having no elastomeric properties. It is shown that the performance is high, which means that a chemical heat storage composite composed of an elastomer having a chemically crosslinked structure and a chemical heat storage material shown in Production Examples 1 to 5 can be suitably used as a heat storage material.

Since the chemical heat storage composites of the above-mentioned Examples are all produced using a composition having better processability, it is easy without requiring a special time-consuming step before crosslinking. It was a chemical heat storage composite that had durability (heat resistance, light resistance, chemical resistance, etc.), gas permeability, and productivity. Further, even in actual use, when it was installed in the heat exchanger, the endothermic reaction and the exothermic reaction were repeated, and the chemical heat storage material could be suppressed from falling off from the chemical heat storage composite for a longer period of time.

Since the chemical heat storage composite of the present invention is a chemical heat storage composite containing an elastomer having a chemically crosslinked structure and a chemical heat storage material, the reaction medium gas is absorbed by the chemical heat storage material in the matrix resin. The stress due to the volume change due to desorption can be greatly relaxed, voids are less likely to occur in the composite shown on the left, and the durability of repeated heat storage and heat dissipation is excellent while maintaining a high heat storage density. When used in combination with a heat exchanger, such a chemical heat storage complex of the present invention can be used in a factory exhaust heat utilization system, a vehicle exhaust heat utilization system, a residential heat utilization system (for example, an air conditioning system), or the like. Can be suitably used for.

Claims (5)

A composition for forming a chemical heat storage complex containing a liquid that is cured by heating and a chemical heat storage material, wherein the liquid that is cured by heating becomes an elastomer when cured. Composition for forming a chemical heat storage complex. A composition for forming a chemical heat storage complex containing a liquid that is cured by heating and a chemical heat storage material, wherein the liquid that is cured by heating becomes an elastomer when cured and after curing. A composition for forming a chemical heat storage complex, which is prepared so that the chemical heat storage complex has a bulk density of 0.9 to 6.0 g / cm ^3. The composition for forming a chemical heat storage complex according to claim 1 or 2, further comprising a solvent. Any of claims 1 to 3, wherein the elastomer is at least one resin selected from the group consisting of natural rubber, diene rubber, olefin rubber, silicone resin, polyester resin, epoxy resin and urethane resin. The composition for forming a chemical heat storage complex according to item 1. The step of applying the chemical heat storage complex forming composition according to any one of claims 1 to 4 to the surface of the base material, and heating the base material on which the chemical heat storage complex forming composition is applied to the surface. Steps and methods of forming chemical heat storage complexes, including.