TWI770907B - Thermal storage composition - Google Patents

Abstract

A thermal storage composition, comprising a chemical thermal storage material, a thermoplastic resin and at least one selected from the group consisting of titanium dioxide, silicon dioxide, an alumina-silicate fiber and an E glass fiber; wherein the thermoplastic resin has a viscometric average molecular weight of 10 thousand to 200 thousand and a kinetic viscosity at 200°C of 3 thousand to 300 thousand mm² /s; a platy chemical thermal storing body comprising a substrate and the chemical thermal storage composition supported on the substrate; and a chemical thermal storage system comprising the platy chemical thermal storing body.

Description

Thermal storage material composition

The present invention relates to a heat storage material composition having excellent kneadability and formability, and a high filling density of a chemical heat storage material, a plate-shaped chemical heat storage body, a chemical heat storage structure, and a chemical heat storage system having excellent durability.

As one of the thermal storage technologies, chemical thermal storage has been known. Chemical heat storage is a process in which the working medium of gas such as water reacts with chemical heat storage materials, and the heat absorption or heat generated at this time is utilized. Compared with latent heat storage materials, sensible heat storage materials, etc., chemical heat storage materials are said to have higher heat storage per unit mass.

Patent Document 1 discloses a composition for forming a heat storage layer characterized by containing 100 parts by mass of a heat storage material, 0.01 to 100 parts by mass of micronized cellulose fibers, and 0.01 to 100 parts by mass of a water-soluble polymer. Patent Document 2 discloses a chemical heat storage complex comprising an elastomer having a chemically crosslinked structure and a chemical heat storage material. Patent Document 3 discloses a chemical heat storage material containing a Group 2 element compound and a polysiloxane polymer.

Patent Document 4 discloses a resin composition comprising a chemical heat storage material composite and a resin characterized by adhering to the surfaces of chemical heat storage material particles (A) particles (B) having different compositions from the particles. When the resin composition is used in the form of a molded body or a paint, handleability can be improved. [Prior Art Literature] [Patent Literature]

[Patent Document 1] WO2018/105617A [Patent Document 2] WO2019/123914A [Patent Document 3] Japanese Patent Laid-Open No. 2015-98582 [Patent Document 4] Japanese Patent Application Laid-Open No. 2018-59016

[The problem to be solved by the invention]

Once the paste of chemical heat storage material such as calcium sulfate is applied and pressed into shape, water is separated and the chemical heat storage material is solidified, and sometimes a good plate-shaped molded body cannot be obtained. If a paste containing a mixture of a chemical heat storage material and an inorganic filler such as titanium dioxide is used, separation of water does not occur, and a favorable plate-shaped molded body can be obtained. However, in order to maintain good kneadability and formability, it is necessary to add a large amount of inorganic fillers. As a result, the packing density of the chemical heat storage material decreases (refer to Comparative Example 7), and the amount of heat that can be stored decreases.

An object of the present invention is to provide a heat storage material composition having excellent kneadability and formability, and a high filling density of the chemical heat storage material, a plate-shaped chemical heat storage body, a chemical heat storage structure, and a chemical heat storage system having excellent durability. [means to solve the problem]

As a result of examination to solve the above-mentioned problems, the present invention including the following aspects has been completed.

[1] A heat storage material composition comprising a chemical heat storage material, a thermoplastic resin having a viscosity average molecular weight of 10,000 to 200,000 and a dynamic viscosity at 200° C. of 3,000 to 300,000 mm ² /s, and a thermoplastic resin selected from the group consisting of titanium dioxide, At least one of the group consisting of silica, aluminum silicate fiber and E glass fiber.

[2] The thermal storage material composition according to [1], wherein the thermoplastic resin has a viscosity-average molecular weight of 30,000 to 100,000, and a kinetic viscosity at 200°C of 3,000 to 250,000 mm ² /s.

[3] The thermal storage material composition according to [1] or [2], wherein the chemical thermal storage material is selected from hydroxides or oxides of magnesium, hydroxides or oxides of strontium, and hydroxides or oxides of barium , calcium hydroxide or oxide, and at least one of the group consisting of calcium sulfate.

[4] The thermal storage material composition according to any one of [1] to [3], wherein the lower limit of the dynamic viscosity of the thermoplastic resin at 200°C is 3 thousand mm ² /s, and the upper limit of the dynamic viscosity at 200°C is 300,000 mm ² /s. [5] The thermal storage material composition according to any one of [1] to [4], wherein the penetration of the thermoplastic resin is 40 to 450 within 5 seconds at 25° C., under a load of 200 gf. [6] The thermal storage material composition according to any one of [1] to [5], wherein the thermoplastic resin is an olefin-based polymer. [7] The thermal storage material composition according to any one of [1] to [5], wherein the thermoplastic resin is polyisobutylene or an isoprene-isobutylene copolymer.

[8] A plate-shaped chemical heat storage body comprising a substrate and the thermal storage material composition according to any one of [1] to [7] supported on the substrate. [9] The plate-shaped chemical heat storage body according to [8], wherein the substrate is made of at least one selected from the group consisting of stainless steel, aluminum, aluminum alloy, copper, and copper alloy. [10] The plate-shaped chemical heat storage body according to [8] or [9], wherein the plate thickness is 0.3 mm or more and 2 mm or less.

[11] A chemical heat storage structure comprising at least one plate-shaped chemical heat storage body according to any one of [8] to [10].

[12] A chemical heat storage system comprising the plate-shaped chemical heat storage body of any one of [8] to [10] or the chemical heat storage structure of [11]. [Effect of invention]

The heat storage material composition of the present invention is excellent in kneadability and formability, and the chemical heat storage material has a high packing density. Even if a chemical heat storage material with low purity or strong expansion is used, the heat storage material composition of the present invention is still excellent in kneadability and formability, and the packing density of the chemical heat storage material is high. The plate-shaped chemical heat storage body of the present invention has excellent shape retention and rapid thermal response. The plate-shaped chemical heat storage body of the present invention has high efficiency of endothermic reaction and exothermic reaction because gas such as water vapor easily penetrates into the deep inside, and the heat storage per unit weight is high. In the plate-shaped chemical heat storage body of the present invention, even if there is a volume change accompanying the dehydration/hydration reaction of the heat storage material, the substrate formed by the mesh will absorb it to prevent cracking and pulverization, so it can maintain the heat storage/release for a long period of time. high performance.

The thermal storage material composition of the present invention includes a chemical thermal storage material, a thermoplastic resin, and an inorganic filler.

The lower limit of the viscosity-average molecular weight of the thermoplastic resin included in the thermal storage material composition of the present invention is usually 10,000, preferably 20,000, and more preferably 30,000; the upper limit of the viscosity-average molecular weight is usually 200,000, preferably 15 10,000, preferably 100,000, and still more preferably 80,000.

The lower limit of the dynamic viscosity of the thermoplastic resin contained in the thermal storage material composition of the present invention at 200°C is usually 3 thousand mm ² /s, preferably 5 thousand mm ² /s, more preferably 10 thousand mm ² /s; the upper limit of the dynamic viscosity at 200°C is usually 300,000 mm ² /s, preferably 250,000 mm ² /s, more preferably 200,000 mm ² /s.

The thermoplastic resin contained in the thermal storage material composition of the present invention has a penetration at 25°C under a load of 200 gf and within 5 seconds, usually 40-450, preferably 100-300, more preferably 150-200. In addition, the measurement of penetration was performed based on JISK2207 (1996). In addition, the penetration degree is expressed as 1 when the needle penetrates vertically into the sample with a length of 0.1 mm.

Specific examples of thermoplastic resins include diene-based polymers, polysiloxanes, polyamides, polyesters, polycarbonates, polyurethanes, polyphenylene ethers, polyphenylene sulfides, and polyether amides. Imine, polyether ether ketone, polyether ketone, polyimide, polyarylate; fluoropolymers such as polyvinylidene fluoride, polytetrafluoroethylene, etc.; polyvinyl alcohol, modified polyvinyl alcohol, polyether , polyethylene glycol, polyethylene oxide, acrylic resin, hydroxyl-containing acrylic resin, butyral resin, styrene butadiene rubber, nitrile rubber; polypropylene, polyethylene, polybutylene, polyisobutylene, isoprene- Olefin-based polymers such as isobutylene copolymers, hydrogenated isoprene-isobutylene copolymers, etc.; C4 petroleum resins, C5 petroleum resins, C5-C9 petroleum resins, C9 petroleum resins and their hydrides and other petroleum resins (hydrocarbon resins) ). Among these, an olefin-based polymer is preferable, and a polyisobutylene and an isoprene-isobutylene copolymer are more preferable.

The amount of the thermoplastic resin is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 20 parts by mass or less, and still more preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the chemical heat storage material.

As the chemical heat storage material included in the heat storage material composition of the present invention, a hydroxide or oxide selected from the group consisting of magnesium hydroxide or oxide, strontium hydroxide or oxide, barium hydroxide or oxide, and calcium hydroxide are used Or at least one of the group consisting of oxides and calcium sulfate.

Magnesium hydroxide or oxide is a chemical heat storage material that uses heat storage when magnesium hydroxide is dehydrated to change to magnesium oxide, and heat is released when magnesium oxide is hydrated and changed to magnesium hydroxide. The heat storage working temperature of magnesium hydroxide or oxide is about 350℃.

The hydroxide or oxide of strontium is a chemical heat storage material for heat storage when strontium hydroxide is dehydrated to change to strontium oxide, and strontium oxide is hydrated and changed to strontium hydroxide to release heat.

Barium hydroxide or oxide is a chemical heat storage material that uses heat storage when barium hydroxide is dehydrated and changed to barium oxide, and heat is released when barium oxide is hydrated and changed to barium hydroxide.

Calcium hydroxide or oxide is a chemical heat storage material that uses heat storage when calcium hydroxide is dehydrated and changed to calcium oxide, and heat is released when calcium oxide is hydrated and changed to calcium hydroxide. The working temperature of heat storage using calcium hydroxide or oxide is about 500 ℃.

Calcium sulfate is a chemical heat storage material that releases heat when calcium sulfate 0.5 hydrate is dehydrated to change to anhydrous calcium sulfate, and anhydrous calcium sulfate is hydrated to change to calcium sulfate 0.5 hydrate. The working temperature of heat storage using calcium sulfate is about 90 ℃.

The inorganic filler contained in the thermal storage material composition of the present invention is at least one selected from the group consisting of titanium dioxide, silicon dioxide, aluminum silicate fiber, and E glass fiber. Titanium dioxide and silicon dioxide are preferably in powder form.

The amount of the inorganic filler is preferably not less than 1 part by mass and not more than 55 parts by mass, more preferably not less than 8 parts by mass but not more than 50 parts by mass, and more preferably not less than 10 parts by mass and not more than 45 parts by mass, relative to 100 parts by mass of the chemical heat storage material. the following.

The thermal storage material composition of the present invention may further contain thermal conductivity imparting material, reinforcing fiber, silica sol, silicate, phosphate, cement, etc. in addition to chemical thermal storage material, inorganic filler and thermoplastic resin. additive.

As the thermal conductivity imparting material, fused silica, alumina, boron nitride, aluminum nitride, silicon nitride, magnesium carbonate, carbon nanotubes, boron nitride nanotubes, beryllium oxide, and the like can be mentioned. Examples of the reinforcing fibers include carbon fibers, aramid fibers, polyolefin fibers, vinylon fibers, and steel fibers.

As other additives, zeolite, activated clay, sepiolite, bentonite, palygorskite, hydrotalcite, zinc oxide, iron oxide, barium sulfate, calcium carbonate, talc, aluminum hydroxide, antimony oxide, graphite, Ferrite etc. Among these, the thermal storage material composition supported on the substrate can be preferably used as a porous additive.

The heat storage material composition of the present invention can be formed into a honeycomb shape, a plate shape, a corrugated shape, or the like by a conventional molding method.

The plate-shaped chemical heat storage body 1 of the present invention includes a substrate 3 and the heat storage material composition 2 of the present invention supported thereon.

The substrate 3 used in the present invention is preferably a mesh. The mesh can be any of those formed by braided wires, those formed by connecting wires, those formed by making cuts in a plate and extending them (porous metal), and those formed by perforating a plate (perforated metal). The material of the substrate is not particularly limited, but it is preferably a metal material, more preferably a metal material with high thermal conductivity, and more preferably stainless steel, aluminum, aluminum alloy, copper, or copper alloy.

The pore size of the mesh is not particularly limited, but it is preferably 10 μm or more, more preferably 100 μm or more, from the viewpoints that the heat storage material composition is difficult to peel off from the substrate, and the viewpoint of improving the thermal conductivity between the heat storage material composition and the substrate. Still more preferably, it is 1 mm or more and 5 mm or less. The net can be a flat net with a flat main surface, a tumor-like net with a tumor-like undulating part on the main surface, a corrugated net with a wave-like undulation on the main surface, and a rib-shaped net with a protruding part relative to the main surface. Because the heat storage material composition penetrates deep into the mesh to achieve the anchoring effect, the flat mesh can also show its sufficient strength. Tumor-like mesh, corrugated mesh or rib-like mesh can be expected to further improve the anchoring effect.

In the plate-shaped chemical heat storage body of the present invention, the heat storage material composition is carried by the substrate, more specifically the outer surface of the mesh constituting the substrate, and in the mesh. The supporting system can be formed by applying the slurry or paste of the thermal storage material composition to the substrate and drying it, by pressing the powder of the thermal storage material composition together with the substrate, or by other supporting methods. Do it.

The plate-shaped chemical heat storage body of the present invention preferably has a plate thickness t of not less than 0.3 mm and not more than 2 mm, more preferably not less than 0.5 mm and not more than 1 mm. The entire surface of the plate-shaped chemical heat storage body of the present invention may be covered with the heat storage material composition, or may have a portion where a part of the substrate is exposed. The main surface of the plate-shaped chemical heat storage body of the present invention may be a smooth surface or a rough surface. In the case of a rough surface, since a gap is slightly formed when the plate-shaped chemical heat storage body of the present invention is laminated, water, which is the working medium of the chemical heat storage material, tends to penetrate deep. From such a viewpoint, the surface roughness of the main surface is preferably several μm to several hundreds of μm.

The plate-shaped chemical heat storage body of the present invention can be cut into a sheet shape, bent into a cylindrical shape, made into a box shape, or embossed into a corrugated shape according to the purpose (for example, the shape shown in FIG. 2 and FIG. 3 , etc. ). Moreover, a plurality of sheets of the plate-shaped chemical heat storage body of the present invention may be laminated, or may be laminated with other plate-shaped objects.

The chemical heat storage structure of the present invention includes at least one plate-shaped chemical heat storage body of the present invention. Fig. 6 shows a chemical heat storage structure 4 formed by laminating a plurality of sheets of the plate-shaped chemical heat storage body 1a of the present invention. When there is a gap between the adjacent plate-shaped chemical heat storage bodies 1a, the water vapor as the working medium can easily pass through the gap. The chemical heat storage structure 4 has a high packing density of the chemical heat storage material per unit volume, can exhibit higher heat storage/release performance, and can maintain its shape stably for a long period of time.

FIG. 7 shows a chemical heat storage structure 5 in which the plate-shaped chemical heat storage body 1a of the present invention and other plate-shaped objects 3 are alternately laminated. The other plate-like objects 3 are not particularly limited, and may be, for example, a substrate 3-a or the like made of a metallic mesh that does not support the thermal storage material composition. The chemical heat storage structure 5 has the plate-like body 3 acting as a spacer, and expands the flow path of the plate-like chemical heat storage body 1, so that the water vapor, which is a working medium, flows easily, and the dehydration/hydration reaction is promoted.

Fig. 8 shows a structure in which a plate-shaped chemical heat storage body 1c formed by alternately forming protruding portions and flat portions at predetermined intervals, as shown in Fig. 3, is laminated. FIG. 9 shows a corrugated structure in which the plate-shaped chemical heat storage body 1a and the plate-shaped chemical heat storage body 1b are alternately laminated as shown in FIG. 2 . The lamination height h at this time is not particularly limited, but it can be preferably set to 2 mm or more and 4 mm or less.

In the chemical heat storage structure of the present invention, since the base plate functions as an aggregate, it is possible to maintain high strength and shape retention for a long period of time. In addition, as long as it is a form which can exhibit the effect in this invention, it is not limited to the above, and may be formed in other shapes. [Example]

Embodiments of the present invention are shown below to further illustrate the present invention. In addition, these are only examples for description, and this invention is not limited by these at all.

[Example 1] 85 parts by mass of calcium sulfate dihydrate (CaSO ₄ 2H ₂ O) powder, 15 parts by mass of titanium oxide powder, and 8.5 parts by mass of polyisobutylene having a viscosity average molecular weight of 30,000 and a dynamic viscosity of 10,000 mm ² /s were added The mixture was mixed and kneaded with a kneader while adding water to obtain a paste-like chemical heat storage material composition with a moisture content of about 40%. The kneadability was A (excellent). Using a pair of rolling rolls, a porous metal substrate made of SUS430 with a width of 500mm (metal mesh plate, P ₁ =4.5mm, P ₂ =3.0mm) was used to fill the gap between the lath meshes In this way, the paste-like chemical heat storage material composition is applied and formed. The coating formability was A (excellent). Next, it was cut into a length of 500 mm with a cutter, and dried at 120° C. for 2 hours. Then, it was cut into small pieces of 50×50 mm to obtain a plate-shaped chemical heat storage body with a thickness of 0.7 mm. The packing density of anhydrite (CaSO ₄ ) in the plate-shaped chemical heat storage body was 0.79 g/cm ³ . The evaluation results are shown in Table 1.

[Examples 2 to 6 and Comparative Examples 1 to 7] Except having changed to the mixing ratio shown in the table|surface, it carried out the same method as Example 1, and obtained the paste chemical heat storage material composition and the plate-shaped chemical heat storage body. The evaluation results are shown in Table 1.

The evaluation of the pasty chemical heat storage material composition was performed according to the following criteria. (Kneading) A: The paste is blended. Because the paste is soft, it can be kneaded without applying strong force. B: The paste is blended, but the paste is slightly hard. It is necessary to apply a little force for mixing. C: The paste is not blended, and the paste is hard. It is necessary to apply strong force for mixing. D: The paste is not blended at all. It is necessary to mix with very strong force. If you try to blend the paste, it will become a paste.

(coating formability) A: No coating spots, and no peeling from the fine screen. Or, the elongation of the fine metal mesh plate before and after coating and forming is less than 5%. B: Slight coating spots, or a little peeling from the fine mesh plate. Or, the elongation of the fine metal mesh plate before and after coating and forming is more than 5% and less than 10%. C: When pressure is applied during coating, water is separated, the composition becomes hard, and coating molding becomes difficult. Or, the elongation of the fine metal mesh plate before and after coating and forming is more than 10% and less than 20%. D: The composition does not spread, and cannot be coated and molded. Or, the elongation of the fine metal mesh plate before and after coating and forming exceeds 20%.

1a, 1b, 1c: Plate-like chemical regenerators 2: Thermal storage material composition 3: Substrate 3-a: Metal mesh substrate 3-b: Porous Metal Substrate 4,5: Chemical heat storage structure h: Lamination height t: plate thickness

Fig. 1 is a diagram showing an example of the plate-shaped chemical heat storage body of the present invention. [ Fig. 2 ] A diagram showing an example of the plate-shaped chemical heat storage body of the present invention. [ Fig. 3] Fig. 3 is a diagram showing an example of the plate-shaped chemical heat storage body of the present invention. [ Fig. 4] Fig. 4 is a diagram showing an example of a substrate used in the plate-shaped chemical heat storage body of the present invention. [ Fig. 5] Fig. 5 is a diagram showing an example of a substrate used in the plate-shaped chemical heat storage body of the present invention. [ Fig. 6] Fig. 6 is a diagram showing an example of the chemical heat storage structure of the present invention. [ Fig. 7] Fig. 7 is a diagram showing an example of the chemical heat storage structure of the present invention. [ Fig. 8] Fig. 8 is a diagram showing an example of the chemical heat storage structure of the present invention. [ Fig. 9] Fig. 9 is a diagram showing an example of the chemical heat storage structure of the present invention.

1a: Plate-shaped chemical regenerator

2: Thermal storage material composition

3: Substrate

t: plate thickness

Claims (12)

A heat storage material composition comprising: a chemical heat storage material, a thermoplastic resin having a viscosity average molecular weight of 10,000 to 200,000, and a dynamic viscosity at 200° C. of 3,000 to 300,000 mm ² /s, and a thermoplastic resin selected from titanium dioxide, titanium dioxide At least one of the group consisting of silicon oxide, aluminum silicate fiber, and E glass fiber, and the amount of the thermoplastic resin is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the chemical heat storage material. The heat storage material composition of claim 1, wherein the viscosity-average molecular weight of the thermoplastic resin is 30,000-100,000, and the dynamic viscosity at 200°C is 3,000-250,000 mm ² /s. The heat storage material composition according to claim 1 or 2, wherein the chemical heat storage material is selected from hydroxide or oxide of magnesium, hydroxide or oxide of strontium, hydroxide or oxide of barium, and hydroxide of calcium compound or oxide, and at least one of the group consisting of calcium sulfate. The thermal storage material composition of claim 1 or 2, wherein the lower limit of the dynamic viscosity of the thermoplastic resin at 200°C is 3,000 mm ² /s, and the upper limit of the dynamic viscosity at 200° C. is 300,000 mm ² /s. The heat storage material composition of claim 1 or 2, wherein the penetration of the thermoplastic resin is 40-450 within 5 seconds at 25°C, under a load of 200gf. The heat storage material composition according to claim 1 or 2, wherein the thermoplastic resin is an olefin-based polymer. The heat storage material composition according to claim 1 or 2, wherein the thermoplastic resin is polyisobutylene, or isoprene-isobutylene copolymer. A plate-shaped chemical heat storage body comprising a base plate and the heat storage material composition according to any one of claims 1 to 7 carried by the base plate. The plate-shaped chemical heat storage body according to claim 8, wherein the substrate is made of at least one selected from the group consisting of stainless steel, aluminum, aluminum alloy, copper, and copper alloy. As in claim 8 or 9, the plate-shaped chemical heat storage body has a thickness of not less than 0.3 mm and not more than 2 mm. A chemical heat storage structure having at least one of the plate-shaped chemical heat storage bodies of claim 8 or 9. A chemical heat storage system comprising the plate-shaped chemical heat storage body of any one of claims 8 to 10 or the chemical heat storage structure of claim 11.

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