JP5502394B2 - Thermal storage composition and thermal storage molded body - Google Patents

Description

  The present invention relates to a heat storage composition and a heat storage molded body having high heat storage properties.

In recent years, a technique for storing thermal energy, that is, a thermal storage technique, has attracted attention as one of the techniques for solving the recent energy problems.
Thermal storage technology is a technology that makes effective use of natural energy, such as solar heat and geothermal heat, and residual heat from air-conditioning equipment.For example, in homes, heat is stored using inexpensive nighttime power and used as a multipurpose heat source. It is used as a technology to reduce power consumption during the day.

  Examples of the heat storage material used in such a heat storage technology include a sensible heat storage material and a latent heat storage material, and in particular, a lot of latent heat storage materials using latent heat due to phase change of substances are employed.

  This latent heat storage material utilizes the property of storing heat (heat storage) when a substance changes phase from solid to liquid, and releasing (dissipating heat) when changing phase from liquid to solid. It uses a liquid change to store and release heat.

In order to effectively use such a latent heat storage material, it is necessary to increase the content of the latent heat storage material per unit volume.
For example, there is a method of using a latent heat storage material by enclosing it in a sealed laminate sheet or plastic case. In such a method, the content of the latent heat storage material per unit volume can be increased.
However, the latent heat storage material may cause a volume change due to a state change accompanying a solid-liquid change, and may apply a load to the sheet or the case. In some cases, the latent heat storage material may be leaked. Furthermore, there is a problem that the latent heat storage material in a liquid state cannot effectively exhibit a heat storage effect, such as being biased toward the bottom.

JP 2006-316194 A (Claims)

In order to solve such a problem, in Patent Document 1, a gelling agent selected from a specific hydrocarbon, a linear low-density polyethylene having a side chain having a length of C ₈ minutes, and a natural fatty acid is used as a main component. It has been proposed to use a gel-like heat storage body.
However, in a high-temperature region where hydrocarbons are in a liquid state, the heat storage body has fluidity, and there is a possibility that hydrocarbons may leak out, which may be difficult to handle and dimensionally stable. there were.

  As a result of intensive investigations to solve the above problems, the present invention provides a heat storage molded body obtained from a heat storage composition obtained by mixing inorganic porous powder having a specific bulk density at a specific ratio, and has excellent heat storage properties. Further, the present inventors have found that the heat storage material is hardly leaked and is excellent in handleability and dimensional stability, and completed the present invention.

That is, the present invention includes the following features.
1. (A) 5-50% by weight of a styrene-butadiene thermoplastic elastomer,
(B) 45 to 90% by weight of aliphatic hydrocarbon as a heat storage material,
(C) 5-30% by weight of an inorganic porous powder having a bulk density of 0.01-0.2 g / cm ³ ,
(D) 0.1 to 2% by weight of inorganic fiber,
The composition (weight ratio) of styrene and butadiene in the (A) styrene-butadiene thermoplastic elastomer is 10:90 to 50:50 .
2. (D) The inorganic fiber has a fiber length of 10 mm or less. The heat storage composition according to 1.
3.1. Or 2. A heat storage molded article obtained from the heat storage composition described in 1.

  The heat storage molded body obtained from the heat storage composition of the present invention has a large amount of latent heat storage material per unit volume and is excellent in heat storage, and the heat storage material is difficult to leak, and is excellent in handleability and dimensional stability. Yes.

  Hereinafter, the present invention will be described in detail together with embodiments thereof.

The heat storage composition of the present invention comprises (A) a thermoplastic elastomer (hereinafter also referred to as “component (A)”) 5 to 50% by weight, (B) an aliphatic hydrocarbon (hereinafter referred to as “component (B)”) as a heat storage material. Also referred to as)) 45 to 90% by weight, (C) inorganic porous powder having a bulk density of 0.01 to 0.2 g / cm ³ (hereinafter also referred to as “component (C)”) 5 to 30% by weight. It is characterized by including.

The heat storage molded body obtained from such a heat storage composition contains a very large amount of the component (B), which is a heat storage material, of 45 to 90% by weight. Leaks or the heat storage molded body itself has a feeling of tack and is poor in handleability.
However, in the present invention, the (B) component, which is a heat storage material, is retained in the heat storage molded body, and the (B) component is contained in a very large amount, particularly by blending the component (C) at a specific ratio. Nevertheless, the component (B) is less likely to leak, the tackiness due to the component (B) can be suppressed, and the handling property and dimensional stability are excellent.

(A) A component is a thermoplastic elastomer and is a component which forms a thermal storage molded object. Examples of the thermoplastic elastomer include styrene-based thermoplastic elastomer, urethane-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, fluororesin-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, and the like. Among these, one kind or two or more kinds can be mixed and used.
In the present invention, it is particularly preferable to use a styrene-based thermoplastic elastomer, and examples thereof include a styrene-butadiene thermoplastic elastomer, a styrene-isoprene thermoplastic elastomer, a styrene-ethylenebutylene thermoplastic elastomer, and a styrene-ethylenepropylene thermoplastic elastomer. Of these, one kind or two or more kinds can be mixed and used.
In the present invention, it is particularly preferable to use a styrene-butadiene thermoplastic elastomer, and the styrene-butadiene thermoplastic elastomer has good compatibility with the component (B) which is a heat storage material, and the component (B) is efficiently contained in the heat storage molded body. It can hold well, is excellent in flexibility with respect to the volume change accompanying the liquid-solid phase change of the component (B), and can suppress the leakage of the component (B). As the styrene-butadiene thermoplastic elastomer, particularly, a composition ratio (weight ratio) of styrene and butadiene is copolymerized at a ratio of 10:90 to 50:50 (preferably 20:80 to 40:60). It is preferable that
(A) Content of a component is 5 to 50 weight% with respect to the thermal storage composition whole quantity, Preferably, it is 10 to 40 weight%. When the amount of the component (A) is too small, it is difficult to form a heat storage molded body. When the amount of the component (A) is too large, the content of the component (B) is reduced and the heat storage performance is inferior.

(B) A component is an aliphatic hydrocarbon and is a component used as a heat storage material.
Examples of the component (B) include dodecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosan, heneicosan, docosan, tetracosan, hexacosan, heptacosan, octacosan, triacontane, paraffin wax, and the like. One type or two or more types can be used in combination.
As content of (B) component, it is 45 to 90 weight% with respect to the thermal storage composition whole quantity, Preferably it is 50 to 85 weight%.
Thus, in this invention, since many (B) components can be included in a composition, the outstanding thermal storage performance can be shown.

The component (C) is an inorganic porous powder having a bulk density of 0.01 to 0.2 g / cm ³ (preferably 0.02 to 0.15 g / cm ³ ).
(C) A component is a component which mainly maintains the shape of a heat storage molded object at the time of heat storage molded object manufacture, after manufacture, and at the time of heat storage molded object processing.
In the previous studies, the present inventors have used a thermoplastic elastomer as the component (A), and in a two-component system using a large amount of the component (B), in particular, the phase of the component (B). It has been confirmed that shape deformation is likely to occur above the change temperature. In the present invention, by including the component (C), the heat storage molded body is less likely to be deformed during the heat storage molded body manufacturing, after the manufacturing, and during the heat storage molded body processing, and the shape of the heat storage molded body is maintained. It is possible to obtain a heat storage molded article having excellent dimensional stability. In addition, due to the synergistic effect of the component (C) and the component (A), the effect of retaining the component (B) can be improved, and the leakage of the component (B) from the heat storage molded product can be suppressed. Therefore, it is possible to obtain a heat storage molded body that is less likely to remain and has excellent handleability.
Such an effect includes the (C) component, so that the (B) component or the (A) component enters the gap in the (C) component or between the (C) components, and the heat is stored while maintaining such a state. Since a molded body can be formed, it is considered that the heat storage molded body is hardly deformed and the component (B) can be prevented from leaking to the outside. In particular, in the present invention, by using the component (C) having a small bulk density, a larger amount of the component (B) and the component (A) can easily enter the gaps between the components (C) or between the components (C), thereby storing heat. While making it difficult to cause deformation of the molded body, it is possible to suppress leakage of the component (B) to the outside .
When the bulk density of the component (C) is greater than 0.2 g / cm ^3, it is difficult for many components (B) and (A) to enter the gaps between the components (C) or between the components (C). The component (B) may leak from the molded body.
In addition, the bulk specific gravity in this invention is a value measured by supplying a lightweight elastic particle to a cylindrical container, and giving a vertical vibration (tapping vibration) until the bulk change of the lightweight elastic particle in a container is complete | finished.
In addition, in the organic porous powder, plasticization by the component (B) may occur, the shape of the powder itself cannot be maintained, and as a result, it becomes difficult to maintain the component (B). There is. Moreover, it is inferior to heat resistance, for example, when producing a thermal storage molded object at high temperature, or when installing in a high temperature location, a malfunction may arise.

Examples of the component (C) include pearlite.
The content of the component (C) is 5% by weight to 30% by weight, more preferably 6% by weight to 20% by weight, and further preferably 7% by weight to 15% by weight with respect to the total amount of the heat storage composition. . When the amount is less than 5% by weight, the formability of the heat storage molded body is poor and the shape of the heat storage molded body cannot be maintained. In addition, the tackiness remains and the handleability is poor. On the other hand, when the content is more than 30% by weight, the content of the component (B) is reduced correspondingly and the heat storage performance is inferior.

In the present invention, it is preferable to further contain 0.1 to 2.0% by weight of (D) inorganic fiber (hereinafter also referred to as “component (D)”).
(D) A component is a component which mainly maintains the shape of a heat storage molded object at the time of heat storage molded object manufacture, after manufacture, and at the time of heat storage molded object processing. Moreover, the effect by above-described (C) component can be heightened by using together with (C) component.
In addition, at a temperature equal to or lower than the phase change temperature of the component (B), it may be difficult to adjust the thickness of the heat storage molded body, but by containing the component (D), the thickness can be easily adjusted, A heat storage molded article excellent in processability and handleability can be obtained.
Furthermore, since (D) component is excellent also in heat resistance, it is suitable, for example, also when manufacturing a thermal storage molded object at high temperature, or when installing in a high temperature location.
Examples of the component (D) include glass fiber, carbon fiber, metal fiber, and the like. Among these, one kind or two or more kinds can be used in combination. In the present invention, glass fiber is particularly preferably used.
The fiber length of the component (D) is 10 mm or less, preferably 6 mm or less.
The content of the component (D) is 0.1 wt% or more and 2 wt% or less, further 0.2 wt% or more and 1.5 wt% or less with respect to the total amount of the heat storage composition. If it is less than 0.1% by weight, improvement in dimensional stability cannot be expected. Moreover, when more than 2 weight%, the workability of a heat storage molded object may be inferior.

  In addition to the above-mentioned components, the heat storage composition of the present invention includes a solvent, a thickener, a plasticizer, a buffering agent, a dispersing agent, a crosslinking agent, an antiseptic, an antifungal agent, an antibacterial agent, and an algae as necessary. An agent, a wetting agent, an antifoaming agent, a leveling agent, a lubricant, a dehydrating agent, an ultraviolet absorber, an antioxidant, a light stabilizer, a fragrance, or other additives may be added.

The heat storage composition of this invention can manufacture a heat storage molded object by a well-known method.
For example, a method of obtaining a heat storage molded body of a panel shape, a sheet shape, or a predetermined mold (formwork method) by pouring a heat storage composition in which various components are mixed into a predetermined mold and forming it.
Examples thereof include a method (rolling method) for obtaining a sheet-like heat storage molded body by rolling a heat storage composition in which various components are mixed using an extrusion molding machine and / or a stretch molding machine.
For example, the formwork method is a method in which a heat storage composition is poured into a predetermined mold and molded to obtain a heat storage molded body, and the heat storage composition is heated in advance so that the heat storage composition is easy to manufacture. You may keep it. Moreover, you may laminate | stack previously the material mentioned later.
The rolling method is a method of rolling using an extrusion molding machine and / or a stretch molding machine, and the thermal storage composition may be preliminarily heated to facilitate rolling so that it can be easily manufactured.

The heat storage composition of the present invention is excellent in moldability, and the heat storage molded body obtained from the heat storage composition has excellent workability such as deformation and cut-out because the heat storage material does not leak out, and handleability Excellent in dimensional stability. The density of the heat storage molded body is not particularly limited, but is preferably 0.8 g / cm ³ or more and 1.0 g / cm ³ or less.

The use for which the heat storage molded body of the present invention is used is not particularly limited. For example, the wall material of a building such as a house, a ceiling material, a material of interior / exterior materials such as a floor material, a floor heating system, a vehicle, etc. Interior products, industrial products such as machinery / equipment, thermoelectric conversion systems, heat transfer media, cooling / heating equipment, refrigeration / freezers, bathtubs / bathrooms, cooler boxes, heat insulation sheets, anti-condensation sheets, electrical products, OA equipment, plants, tanks, It can also be used as a material for clothing, curtains, carpets, bedding, daily necessities, etc.
Since the heat storage body of the present invention is basically a gel-like substance, the shape can be changed in accordance with the intended use, and application to a wide range of uses is possible. Moreover, it is effective not only for temperature control (heat storage effect) but also for parts that require a dew condensation prevention effect and a fog prevention effect.

  For example, glass plate, resin plate or sheet (including film) such as acrylic resin, vinyl resin, PET resin, etc., metal plate or metal foil such as stainless steel, copper, aluminum, iron, true iron, zinc, magnesium, nickel, non-woven fabric , Textile materials such as woven fabric and glass cloth, paper materials such as paper and synthetic paper, wood materials such as wood, particle board and plywood, slate board, gypsum board, ALC board, calcium silicate board, wood wool cement board, ceramic Paper, natural stone board, inorganic board such as inorganic siding board, metal material such as metal siding board, metal film, film molding such as glass fiber, foam fireproof material, flame retardant material, polystyrene foam, rigid polyurethane foam Polyurethane foam, acrylic resin foam, phenolic resin foam, polyethylene tree, etc. It can also be used by laminating foam, foam rubber, glass wool, rock wool, foam ceramic, etc., heating elements, etc., embedded in fibers, etc., or enclosed in a sealed laminate sheet or plastic case. it can.

  Examples and Comparative Examples are shown below to clarify the features of the present invention, but the present invention is not limited to these Examples.

(Examples 1-6, Comparative Examples 1-4)
Using the raw materials shown in Table 1, the heat storage material and the thermoplastic elastomer were melt-heated and mixed at 160 ° C. at the blending ratio shown in Table 2, and then the inorganic porous powder at 120 ° C. using a heating kneader, A slurry in which inorganic fibers were mixed was obtained.
Using this slurry, the following formability test, workability test, and shape stability test were conducted.

(Formability test)
The moldability of the heat storage molded body (thickness: about 5 mm) was evaluated using an extrusion molding machine at 80 ° C., which is a temperature range equal to or higher than the phase change temperature of the heat storage material. The results are shown in Table 2.
(Double-circle): The manufacture of the heat storage molded object of uniform thickness was easy.
○: Production of heat storage molded body was possible.
(Triangle | delta): Although manufacture of the heat storage molded object was possible, the tuck feeling remained in the obtained heat storage molded object.
X: The slurry adhered to the extrusion molding machine, and it was difficult to produce a heat storage molded body.

(Workability test)
Stretch moldability (workability) when adjusting the thickness to 3 mm using a stretch molding machine at a temperature of 25 ° C. in order to adjust the thickness of the heat storage molded body obtained in the moldability test. Evaluated. The results are shown in Table 2.
(Double-circle): It was excellent in the stretch moldability of the heat storage molded object, and thickness adjustment of thickness 3mm was easy.
○: Thickness adjustment of 3 mm was possible by using a stretch molding machine a plurality of times.
Δ: Thickness adjustment was difficult.
X: The thickness could not be adjusted.

(Shape stability test)
After the heat storage molded body obtained by the workability test is molded to 300 × 100 mm, and left for 24 hours in an atmosphere of 10 ° C., and after 24 hours in a 70 ° C. atmosphere, after 30 cycles are repeated The temperature was transferred to an atmosphere of 23 ° C. and a relative humidity of 50% RH, and the shape stability of the heat storage molded body was evaluated. The evaluation is as follows. The results are shown in Table 2.
(Double-circle): The shape change of the heat storage molded object was not seen.
○: Almost no change in shape of the heat storage molded body was observed.
X: The shape of the heat storage molded body was changed, and leakage of the heat storage material was also observed.

Table 2 shows the density, latent heat amount, and phase change temperature of the heat storage molded product obtained in the workability test.
The latent heat amount and phase change temperature were measured by differential scanning calorimetry (DSC measurement) using DSC220CU (manufactured by Seiko Instruments Inc.), with aluminum as a reference, temperature rising temperature 10 ° C / min, -20 to 60 ° C. It is a value measured in the temperature region.

Claims (3)

(A) 5-50% by weight of a styrene-butadiene thermoplastic elastomer,
(B) 45 to 90% by weight of aliphatic hydrocarbon as a heat storage material,
(C) 5-30% by weight of an inorganic porous powder having a bulk density of 0.01-0.2 g / cm ³ ,
(D) 0.1 to 2% by weight of inorganic fiber,
The composition (weight ratio) of styrene and butadiene in the (A) styrene-butadiene thermoplastic elastomer is 10:90 to 50:50 .   (D) The heat storage composition according to claim 1, wherein the inorganic fiber has a fiber length of 10 mm or less. The heat storage molded object obtained from the heat storage composition of Claim 1 or Claim 2.