JP2017198369A - Container for heat storage agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent heat storage agent from oozing to the outside of a container.SOLUTION: A container 10 for heat storage agent is configured such that the whole containing a portion to which paraffinic heat storage agent sealed therein adheres is composed of polyamide resin. As the polyamide resin, polyamide containing an aliphatic skeleton is used, without containing filler. Also, the polyamide resin contains, as reductant, halogenated alkyl such as potassium iodide. A pinch-off part formed in the container for heat storage agent derived from blow molding is excellent in impact resistance and strength against tension.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat storage agent container in which a heat storage agent is enclosed.

  When goods such as pharmaceuticals and foods are transported, a heat storage body is placed in a transport container together with the goods, and the goods are kept cold or warm by the heat storage body. The heat storage body includes a heat storage agent and a container that stores the heat storage agent, and cools or keeps the heat using latent heat associated with the phase transition of the heat storage agent (see, for example, Patent Document 1). As the heat storage agent, a material containing paraffin is often used. Moreover, as a container which encloses a thermal storage agent, olefin-type synthetic resins, such as polyethylene, are used from a viewpoint of handleability and cost, and forming a container by blow molding is performed.

Japanese Patent Laid-Open No. 10-160372

  However, if a paraffin-based heat storage agent is used in a container made of an olefin-based synthetic resin, the heat storage agent may bleed (exude). For this reason, the heat storage agent is gelled to reduce the influence even if the heat storage agent bleeds from the container, but the gelled heat storage agent has a low latent heat and a long freezing time. There is. In addition, when a gelled heat storage agent is used, there is a problem that the cost increases and it is difficult to enclose in a container.

  That is, the present invention has been proposed to solve these problems in view of the above-mentioned problems related to the prior art, and an object of the present invention is to provide a heat storage agent container that can prevent bleeding of the heat storage agent.

In order to overcome the above-mentioned problems and achieve the intended purpose, the container for a heat storage agent of the invention according to claim 1 of the present application,
The gist is that the portion in contact with the paraffinic heat storage agent enclosed therein is at least composed of a polyamide resin.
According to the invention which concerns on Claim 1, since the part which contact | connects a thermal storage agent is comprised with the polyamide resin, even if it uses what contains paraffin as a thermal storage agent enclosed inside, a thermal storage agent bleeds outside. Can be prevented. Moreover, durability and impact resistance at low temperatures can be ensured by configuring the heat storage agent container with a polyamide resin.

The invention according to claim 2 is characterized in that the polyamide resin is a polyamide containing an aliphatic skeleton.
According to the invention which concerns on Claim 2, the melting temperature at the time of shaping | molding can be lowered | hung by using the polyamide containing an aliphatic skeleton, and the moldability of the container for thermal storage agents can be improved.

The invention according to claim 3 is characterized in that the polyamide resin does not contain a filler.
According to the invention which concerns on Claim 3, since the filler is not included, durability at the time of low temperature and impact resistance can be improved more.

The invention according to claim 4 is characterized in that the polyamide resin contains an alkyl halide as a reducing agent.
According to the invention which concerns on Claim 4, durability and impact resistance at the time of low temperature can be improved more about the pinch-off part formed at the time of shaping | molding by containing the alkyl halide as a reducing agent.

In the invention which concerns on Claim 5, the said container for thermal storage agents is comprised entirely with the said polyamide resin,
The gist is that the tensile strength measured based on JIS 7161 of the pinch-off portion formed in the heat storage agent container is 5 MPa or more.
According to the invention which concerns on Claim 5, since the tensile strength of the pinch-off part formed at the time of shaping | molding is high, the durability and impact resistance which are required as a whole are securable.

  According to the container for a heat storage agent according to the present invention, bleeding of the heat storage agent enclosed inside can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic perspective view which shows the container for thermal storage agents which concerns on the suitable Example of this invention, (a) shows from the one plate surface side of a box-shaped body, (b) is the other plate surface side of a box-shaped body. Shown from. It is sectional drawing which shows the container for thermal storage agents of an Example, (a) cuts the center part vertically, (b) cuts the side edge part vertically. It is explanatory drawing which shows the state which stacked the container for thermal storage agents of an Example. It is explanatory drawing which shows the manufacture process of the container for thermal storage agents of an Example.

  Next, the heat storage agent container according to the present invention will be described below with reference to the accompanying drawings by way of preferred examples.

  As shown in FIGS. 1 and 2, a heat storage agent container (hereinafter simply referred to as a container) 10 according to an embodiment has a box-like body in which a space 10 a capable of storing a heat storage agent is provided as a main body, The outer shape is formed in a rectangular shape. On the plate surface of the container 10, a convex portion 12 or a concave portion 14 is provided at each corner portion, and two convex portions 12, 12 arranged at one of the diagonals of the plate surface formed in a substantially rectangular shape, And two concave portions 14 and 14 disposed on the other diagonal of the plate surface. Further, in the container 10, the convex portion 12 and the concave portion 14 are arranged so as to be front and back, and corresponding to one plate surface in which the convex portion 12 is arranged at the corner, the same on the other plate surface Concave portions 14 are arranged at the corners. In the embodiment, the plate surface of the container 10 refers to the widest surface of the rectangular box-shaped container 10. The convex portion 12 is formed in a hemispherical shape protruding from the plate surface, and the concave portion 14 is formed to have a smaller diameter than the convex portion 12 or shallower than the height of the convex portion 12. It is formed so as to be accommodated. As shown in FIG. 3, the plurality of containers 10 can be stacked in a state in which the convex portions 14 are accommodated in the concave portions 12 and are prevented from being displaced from each other, and are adjacent when the plurality of containers 10 are stacked. A gap S for air circulation is opened between the containers 10. Further, the container 10 is provided with two reinforcing portions 18 which are indented from both plate surfaces and are joined to each other at the bottoms which are opposed to each other, spaced apart in the longitudinal direction at the center of the container 10 in the short direction. In addition, in the container 10, the pinch-off part P derived from molding exists over the length of the narrowest surface, and in the embodiment, the pinch-off part P exists on each of the upper surface and the lower surface shown in FIG. Yes.

  The container 10 is a molded article made of polyamide resin, and is preferably formed by blow molding from the viewpoint of cost and the like. Examples of the polyamide resin include hexamethylene diamine, decamethylene diamine, dodecamethylene diamine, 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, and 1,3-bis (aminomethyl). Aliphatic, alicyclic and aromatic diamines such as cyclohexane, 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- or p-xylylenediamine, adipic acid, and suberin Polyamides obtained by polycondensation of acids, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid with aliphatic, alicyclic and aromatic dicarboxylic acids; amino such as ε-aminocaproic acid and 11-aminoundecanoic acid Polyamide obtained by condensation of carboxylic acid; ε-caprolac Arm, .omega. obtained from lactams laurolactam and polyamide or copolyamide consisting of these components, mixtures of these polyamides. As the polyamide resin, it is preferable to use a polyamide containing an aliphatic skeleton, and it is even better to use a polyamide composed only of an aliphatic skeleton. Examples of the polyamide composed only of the aliphatic skeleton include nylon 6, nylon 66, nylon 610, nylon 9, nylon 11, nylon 12, nylon 6/66, nylon 66/610, nylon 6/11, and the like. The container 10 is preferably made of a single polyamide resin instead of an alloy resin in which a polyamide resin and polyethylene are mixed.

  Even if the container 10 in which the portion where the heat storage agent is in contact with the polyamide resin is used is used, the heat storage agent can be prevented from bleeding (exuding) to the outside even if a container containing paraffin is used. Further, by constituting the container 10 with a polyamide resin, it is possible to ensure durability and impact resistance at low temperatures below the freezing point such as when the heat storage agent is frozen. Thus, according to the said container 10, since the bleeding of a thermal storage agent can be prevented, it is not necessary to gelatinize a thermal storage agent and it becomes possible to use a liquid thermal storage agent. Since the liquid heat storage agent does not require the addition of a gelling component, the latent heat can be increased, and the gelling step is unnecessary, so that the cost can be suppressed. In addition, since the heat storage body in which the liquid heat storage agent is sealed in the container 10, convection occurs inside the container 10, the freezing time can be shortened compared to a gel in which convection does not occur. When the heat storage agent is liquid, it is easy to enclose it in the container 10. Further, by using a polyamide containing an aliphatic skeleton as the polyamide resin constituting the container 10, it can be melted at a lower temperature at the time of molding than a polyamide containing an aromatic skeleton, and the moldability of the container 10 is improved. And the equipment can be simplified.

  The polyamide resin constituting the container 10 does not contain a filler. That is, the polyamide resin constituting the container 10 is glass fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, Fibrous fillers such as asbestos fibers, stone fiber, metal fibers, or silicates such as talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, alumina silicate, silicon oxide, Metal compounds such as magnesium oxide, alumina, zirconium oxide, titanium oxide and iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, calcium hydroxide and hydroxide Magnesium, hydroxides such as aluminum hydroxide, glass beads, glass flakes, glass powder, does not include ceramic beads, boron nitride, silicon carbide, carbon black and silica, a non-fibrous filler such as graphite. Since the polyamide resin constituting the container 10 does not contain a filler that may become a starting point of breakage when an impact is applied, the strength, durability, and impact resistance can be further improved. In particular, the strength, durability and impact resistance of the container 10 can be further improved at a low temperature in the sub-freezing region where the heat storage agent freezes.

  The polyamide resin constituting the container 10 contains an alkyl halide as a reducing agent. Examples of the alkyl halide include potassium iodide, lithium chloride, lithium bromide, lithium iodide, potassium chloride, potassium bromide, sodium bromide and sodium iodide. Among these, potassium iodide is preferable. Thus, the strength of the pinch-off part P derived from molding can be improved by including the alkyl halide in the polyamide resin constituting the container 10. In particular, the tensile strength, durability, and impact resistance of the pinch-off portion P in the container 10 can be further improved at a low temperature in the sub-freezing region where the heat storage agent freezes. The alkyl halide is added in the range of 0.1 parts by weight to 0.5 parts by weight with respect to 100 parts by weight of the polyamide resin. When the reducing agent is less than 0.1 parts by weight, the effect of improving the strength of the pinch-off part P (see FIG. 1) of the container 10 formed at the time of molding is thin, and when the reducing agent is more than 0.5 parts by weight, The pinch-off part P becomes fragile.

  The polyamide resin constituting the container 10 may contain a copper compound, and long-term heat resistance can be improved by using the copper compound. Copper compounds include cuprous iodide, cupric iodide, cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cupric sulfate, cupric nitrate, phosphorus Copper oxide, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and inorganic copper halides and xylylenediamine, 2-mercaptobenzimidazole, benzimidazole and other complexes Compound etc. are mentioned. Among these, monovalent copper compounds and monovalent copper halide compounds such as cuprous iodide are particularly preferable. The copper compound is preferably in the range of 0.01 to 2 parts by weight and more preferably in the range of 0.015 to 1 part by weight with respect to 100 parts by weight of the polyamide resin. When the addition amount of the copper compound is large, the release of metallic copper is likely to occur when the polyamide resin is melted, and when the addition amount of the copper compound is small, the effect of improving long-term heat resistance cannot be suitably obtained.

  The polyamide resin constituting the container 10 may contain an additive capable of extending the molecular chain of the polyamide resin. Examples of the additive include a silane coupling agent and a titanium coupling agent. In particular, a silane coupling agent is preferable, and among these, an alkoxysilane compound is more preferable. Examples of the alkoxysilane compound include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and N-2- (aminoethyl) -3. -Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-amino Amino group-containing alkoxysilane compounds such as propyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3 -Glycidoxypropyl triethoxy Epoxy group-containing alkoxysilane compounds such as vinyl, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane compounds such as vinyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, Acryloxy group-containing alkoxysilane compounds such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, ureido group-containing alkoxysilane compounds such as 3-ureidopropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane An isocyanate group-containing alkoxysilane compound such as Silane compounds having a glycidoxy group such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylethyldiethoxysilane It may be. The additive preferably has one or more functional groups selected from the group consisting of alkoxy groups, hydroxyl groups, epoxy groups, amino groups, ureido groups, and isocyanate groups, and these functional groups. Thereby, the reactivity with a polyamide resin can be improved. Thus, by including the said additive in the polyamide resin which comprises the container 10, the melt viscosity of the fuse | melted resin can be adjusted appropriately, and the drawdown at the time of blow molding can be prevented.

  The container 10 has a tensile strength measured based on JIS K7161 of the pinch-off part P of 5 MPa or more, more preferably 10 MPa or more, and further preferably 15 MPa or more. If the tensile strength of the pinch-off part P in the container 10 is less than 5 MPa, there is a risk of cracking when the thermal storage agent falls in a frozen state. Thus, since the container 10 has a high tensile strength of the pinch-off portion P that is formed at the time of molding, the strength, durability, and impact resistance required as a whole can be ensured.

  A heat storage agent is configured by enclosing a heat storage agent in the container 10. As the heat storage agent, normal paraffin, a mixture of normal paraffin and aliphatic alcohol can be used. As the normal paraffin, normal paraffin having 10 to 30 carbon atoms is preferable. For example, n-tetradecane, n-ventadecane, n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, n-eicosane, n-icosane. , N-henicosane, n-triacontane and the like, and those having 10 to 30 carbon atoms can be used, and these can be used alone or in combination. Thus, if the normal paraffin having 10 to 30 carbon atoms is used, it is easy to adjust the melting temperature or the solidification temperature. If the normal paraffin having 14 or more carbon atoms is used, the melting temperature is 0 ° C. or higher. The temperature range from near the melting temperature to near room temperature can be set as the control temperature.

  As the aliphatic alcohol, a monohydric alcohol is mainly used. As the aliphatic alcohol, any of linear alcohol, branched alcohol, primary alcohol, secondary alcohol, and tertiary alcohol can be used. Among these, an aliphatic alcohol having 6 to 20 carbon atoms is preferable from the viewpoint of adjusting the melting temperature or the solidification temperature, and a monohydric alcohol having 10 or more carbon atoms and a melting temperature of 0 ° C. or higher is water as a management temperature. This is more preferable because the target article can be kept warm in the temperature range from near the melting temperature to near room temperature. Examples of the monohydric alcohol having 10 or more carbon atoms include 1-decanol, 2-decanol, undecanol, lauryl alcohol, tridecanol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, nonadecanol, aralkyl alcohol, Examples include behenyl alcohol, carnaupyl alcohol, seryl alcohol, elaidino alcohol, 1-menthol and the like.

  As a heat storage agent, not only a gel thing but a liquid thing is also employable. Further, the heat storage agent can be used alone or in combination of two or more materials, and is arbitrarily selected from the relationship between the management temperature of the target article and the melting temperature of the heat storage agent.

  Next, the manufacturing method by the direct blow molding of the container 10 for thermal storage agents which concerns on an Example is demonstrated. The above-described materials such as polyamide resin, reducing agent and additive are mixed and melted, and extruded from the extruder 20 into a cylindrical shape to form a parison 22 (FIG. 4 (a)). Next, after the parison 22 is sandwiched between the molds 24 (FIG. 4B), air is blown into the parison 22, and the parison 22 is pressed against the mold surface of the mold 24 (FIG. 4C). )). Then, the mold 24 is opened, and the molded container 10 is taken out (FIG. 4 (d)). Thus, in the direct blow molding, the portion joined when the upper and lower sides of the parison 22 are sandwiched becomes the pinch-off portion P, and the strength of the pinch-off portion P in the container 10 is relatively inferior.

(test)
Tests were conducted for the presence or absence of bleed, low temperature impact resistance, heat resistance and tensile strength. The containers of the test example and the comparative example are both formed by direct blow molding, and are rectangular hollow box-shaped bodies having a width of 150 mm, a length of 200 mm, and a thickness of 25 mm. In addition, the pinch-off part exists in the container so that it may extend in the left-right direction on the narrowest upper surface and lower surface. In the test example and the comparative example, 350 g of a heat storage agent made of liquid normal paraffin (carbon number 14) is sealed in a 110 g container. Table 1 shows the resins, fillers, and reducing agents used in the test examples and comparative examples. Note that potassium iodide is used as the reducing agent.

  After bleeding the heat storage agent in the container, the bleed was allowed to stand for 168 hours at 80 ° C., and then the oozing of the heat storage agent was evaluated depending on whether the surface of the container was sticky or not. As shown in Table 1, when the evaluator does not feel stickiness of the heat storage agent, it is “◯”, and when the evaluator feels stickiness of the heat storage agent, it is “x”. For impact resistance, a container in which a heat storage agent was frozen by cooling at −25 ° C. for 24 hours was naturally dropped from a height of 30 cm, 60 cm, and 90 cm in a standing position. The impact resistance was tested five times at the same height. As shown in Table 1, the impact resistance is “◯” when there is no crack in the pinch-off part or other parts in all five trials, and there is a crack even in one of the five trials. Was evaluated as “×”. For heat resistance, the container was allowed to stand in an atmosphere of 50 ° C. or 80 ° C. for 24 hours, and then whether or not the container had an abnormality such as deformation or cracking or leakage of the heat storage agent was evaluated. As shown in Table 1, when there was no abnormality, it was set as “◯”, and when there was an abnormality, it was evaluated as “x”. The tensile test was performed at a tensile speed of 2 mm / min based on JIS K7161. The test piece is formed by cutting out the containers of the test example and the comparative example in a U shape centering on the pinch-off part so that the width of the pinch-off part is 25 mm and the length from the pinch-off part to the plate surface side is 25 mm. did. In addition, the tension test is pulling from both sides in a direction orthogonal to the extending direction of the pinch-off part.

  As shown in Table 1, no bleed was observed in a container using nylon 6 or nylon 66, which is a polyamide resin. Moreover, even if it was a polyamide resin, it turned out that the thing which does not contain a filler is excellent in impact resistance. Furthermore, the impact resistance is improved when potassium iodide as a reducing agent is contained in a predetermined range. By containing 0.1 part by weight or more of the reducing agent, the tensile strength can be 10 MPa or more, and when 0.6 part by weight of the reducing agent is contained, impact resistance and tensile strength are lowered. And by containing a reducing agent in a predetermined range and not containing a filler, it is possible to have both impact resistance and a tensile strength of 15 MPa or more. Note that Comparative Example 1 made of polyethylene has difficulty in bleed resistance and heat resistance. Further, Comparative Example 2 composed of nylon 6 and maleic anhydride-modified polyethylene and Comparative Example 3 composed of polyvinyl chloride all have lower impact resistance, heat resistance and tensile strength than the test examples.

(Example of change)
The present invention is not limited to the configuration described above, and can be modified as follows, for example.
(1) In the embodiment, the entire container is made of polyamide resin, but the inner surface of the container in contact with the heat storage agent may be made of polyamide resin and the outside may be covered with another resin.
(2) In the embodiment, the convex portion and the concave portion are provided in the container. However, the shape is not limited to the embodiment, and a circular shape, a triangular shape or a polygonal shape such as a square shape may be appropriately selected. Moreover, you may abbreviate | omit a recessed part or both a convex part and a recessed part.
(3) The plate surface of the container may be provided with a groove shape such as a lattice shape or a circular shape in order to promote air circulation.

  10 container (container for heat storage agent), P pinch-off part

Claims (5)

A container for a heat storage agent, wherein a portion in contact with a paraffin-based heat storage agent enclosed therein is made of at least a polyamide resin.   The heat storage agent container according to claim 1, wherein the polyamide resin is a polyamide containing an aliphatic skeleton.   The heat storage agent container according to claim 1, wherein the polyamide resin does not contain a filler.   The container for a heat storage agent according to any one of claims 1 to 3, wherein the polyamide resin contains an alkyl halide as a reducing agent. The heat storage agent container is entirely composed of the polyamide resin,
The container for heat storage agents as described in any one of Claims 1-4 whose tensile strength measured based on JISK7161 of the pinch-off part formed in the said container for heat storage agents is 5 Mpa or more.

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