Thermal container

Abstract

The present invention provides a cold storage container (70) comprising: a storage space (71); and a wall (72) having an inner surface surrounding the storage space (71), wherein the wall (72) has a greater thermal conductivity in a surface direction orthogonal to the thickness direction along the inner surface than in a thickness direction orthogonal to the inner surface.

Description

Technical Field

[0001] This invention relates to insulated containers. Background Technology

[0002] In the prior art, a thermally conductive inner container is known as an insulated container, as described in Patent Document 1. This inner container is made of metal such as aluminum, aluminum alloy, or copper, and is used to house the target object, and is arranged inside the container together with the heat storage element.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-10523 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The inner container of Patent Document 1, which has high thermal conductivity, is cooled by a heat storage element, maintaining the internal space at a predetermined temperature (e.g., 2°C to 8°C). However, in inner containers with high thermal conductivity, external heat is also transferred, offsetting the cooling effect based on the heat storage element, resulting in a shorter cooling time. Conversely, when the thermal conductivity of the inner container decreases, the heat storage element melts unevenly, leading to temperature unevenness as the cooling time progresses, and the temperature inside the inner container becomes uneven.

[0008] This invention was made to solve such a problem, and its purpose is to provide an insulated container that can achieve temperature uniformity and long-term heat preservation in the storage space.

[0009] Methods for solving problems

[0010] The first aspect of the present invention provides a heat-insulating container, which includes a storage space and a wall having an inner surface surrounding the storage space, wherein the wall has a greater thermal conductivity in a surface direction orthogonal to the thickness direction and along the inner surface than in a thickness direction orthogonal to the inner surface.

[0011] Based on this structure, since the wall has a high thermal conductivity in the planar direction, temperature unevenness in the planar direction can be reduced in the heat storage components of the wall and cooling wall. Furthermore, since the wall has a low thermal conductivity in the thickness direction, heat conduction from the outside of the insulation container to the storage space can be suppressed. Therefore, temperature uniformity and extended insulation time within the storage space can be achieved.

[0012] In the second aspect of the present invention, the heat-insulating container, in the first aspect, has a first wall with a thermal conductivity greater in the surface direction than in the thickness direction; the first wall is formed of an adhesive resin and a thermally conductive filler having a thermal conductivity greater than that of the adhesive resin and mixed in the adhesive resin.

[0013] Based on this structure, the wall is efficiently cooled by the heat storage element because it contains thermally conductive filler with high thermal conductivity. Therefore, the storage space surrounded by the wall can be cooled to a specified temperature through the cooled wall.

[0014] The third aspect of the thermal insulation container of the present invention, in the second aspect, the thermally conductive filler has anisotropic shape and is arranged in the wall such that the dimension in the thickness direction is smaller than the dimension in the surface direction.

[0015] Based on this structure, due to the thermally conductive filler, heat moves more easily in the surface direction than in the thickness direction. Therefore, it is possible to reduce heat conduction from the outside of the insulated container to the storage space, as well as temperature unevenness of the walls in the surface direction, and to achieve temperature uniformity and extended insulation time in the storage space.

[0016] In the fourth embodiment of the thermal insulation container of the present invention, in the second or third embodiment, the aforementioned thermally conductive filler has insulating properties. According to this structure, radio waves can pass through the wall. Therefore, for example, when a thermometer and a wireless device capable of transmitting the detected temperature by the thermometer are housed in the thermal insulation container, the wireless device can transmit the temperature information detected by the thermometer to the outside of the thermal insulation container via radio waves. Therefore, temperature information of the storage space can be obtained from the outside of the thermal insulation container without opening it, reducing the temperature rise in the storage space caused by opening and closing the thermal insulation container, and enabling temperature uniformity and extended insulation time within the storage space.

[0017] In the fifth aspect of the heat-insulating container of the present invention, in any one of the first to fourth aspects, the wall has a first wall in which the thermal conductivity in the surface direction is greater than the thermal conductivity in the thickness direction, wherein the ratio of the thermal conductivity in the thickness direction to the thermal conductivity in the surface direction of the first wall is 0.2 or more and less than 0.8.

[0018] Based on this structure, it is possible to achieve both the reduction in heat conduction from the outside of the insulated container to the storage space due to the lower thermal conductivity in the wall thickness direction and the reduction in uneven wall temperature due to the higher thermal conductivity in the wall surface direction.

[0019] In the sixth embodiment of the present invention, in any one of the first to fifth embodiments, the wall has a first wall with a thermal conductivity greater in the surface direction than in the thickness direction, and a second wall made of resin, wherein the first wall is laminated on at least one of the inner and outer surfaces of the second wall.

[0020] Based on this structure, by supporting the first wall with the second wall, the thickness of the first wall can be made thinner. As a result, the cost of the insulated container can be kept lower, and the heat conduction from the outside of the insulated container to the storage space can be kept lower.

[0021] In the seventh aspect of the present invention, the thickness of the first wall in the aforementioned thickness direction is 1 mm or less in the sixth aspect of the insulated container. According to this structure, the cost of the insulated container can be reduced, and heat conduction from the outside of the insulated container to the storage space can be reduced.

[0022] In the eighth aspect of the present invention, in the sixth or seventh aspect, the wall includes a side wall having a pair of openings, a top wall capable of opening and closing to cover one of the openings, and a bottom wall covering the other opening. The side wall has the first wall and the second wall, and at least one of the top wall and the bottom wall has the second wall but not the first wall.

[0023] According to this structure, at least one of the top and bottom walls does not have a first wall, thereby enabling cost reduction of the insulated container. In addition, since the side walls have a first wall, heat conduction between the top and bottom walls is achieved through the first wall, which enables temperature uniformity and extended insulation time in the storage space surrounded by the side walls, top wall, and bottom wall.

[0024] Invention Effects

[0025] According to the present invention, an insulated container can be provided that can achieve temperature uniformity in the storage space and long-term heat preservation. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the vacuum insulated container according to Embodiment 1 of the present invention.

[0027] Figure 2 It means Figure 1 An assembly diagram of the external structure of the heat storage unit housed in a vacuum insulated container, viewed from an oblique angle.

[0028] Figure 3 It is a general representation Figure 2 A diagram of the cross-section of the heat storage unit's insulated container, which is orthogonal to the front and back directions.

[0029] Figure 4 It is a general representation Figure 3 A diagram illustrating the manufacturing method of the wall of a cold-insulating container.

[0030] Figure 5 This is a cross-sectional view of the vacuum insulated container according to Embodiment 2 of the present invention.

[0031] Figure 6 This is a graph showing the relationship between the thickness of the first wall and the thermal conductivity of the wall in the planar direction.

[0032] Figure 7 This is a graph showing the relationship between the thickness of the first wall and the thermal resistivity of the wall in the thickness direction.

[0033] Figure 8 This is a graph showing the relationship between the thickness of the first wall and the uneven temperature in the storage space.

[0034] Figure 9 This is a cross-sectional view of the vacuum insulated container of Modified Example 1.

[0035] Figure 10 This is a cross-sectional view of the vacuum insulated container of variant example 2.

[0036] Figure 11 This is a cross-sectional view of the vacuum insulated container of variant example 2. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in all the following drawings, the same or corresponding elements will be labeled with the same reference numerals.

[0038] (Implementation Method 1)

[0039] Figure 1 The vacuum insulated container 10 shown in the example can be used for the transportation or storage of items such as pharmaceuticals, samples, and food. This vacuum insulated container 10 includes an outer bag 20, a protective box 30, an insulated container body 40, an insulated cover 50, and a heat storage unit 60. Furthermore, in the following description, the side of the insulated container body 40 closest to the insulated cover 50 is referred to as "upper," and the side opposite to it is referred to as "lower." Additionally, directions that intersect (e.g., orthogonal) with and are mutually intersecting (e.g., orthogonal) with the vertical direction are referred to as the left-right direction and the front-back direction. However, the configuration of the vacuum insulated container 10 is not limited to this.

[0040] The outer bag 20 is made of a flexible material, such as nylon or polyester fiber, and has a rectangular bag shape with an opening on the upper surface leading to the interior space, and a plate-shaped lid that can open and close the opening. Additionally, a handle 21 for gripping is installed on each of the left and right sides of the outer bag 20, and a strap 22 is provided between the left and right sides. The outer bag 20 houses a protective box 30 and a heat-insulating cover 50.

[0041] The protective box 30 is a protective component made of foamed material such as polyethylene foam, and is a cuboid shape with an opening on its upper surface leading to the interior space. The outer surface of the protective box 30 is covered by an outer bag 20, and an insulated container 40 is housed inside the protective box 30.

[0042] The heat-insulating container body 40 has, for example, a first outer skin 41 and a first core material 42. The first outer skin 41 is a molded body of non-metallic material, possessing gas barrier properties, for example, a double-walled structure forming an internal space. The first core material 42 is, for example, a non-metallic porous body such as a continuous bubble body of continuous bubble polyurethane foam, a foamed resin material such as expanded polystyrene, an aggregate of fibers, or an aggregate of inorganic particles. The first core material 42 is housed inside the first outer skin 41, and the internal pressure of the first outer skin 41 is lower than the external pressure, for example, reduced to below a specified pressure, and the first outer skin 41 is sealed. The heat-insulating container body 40 is formed in a cuboid shape with an opening on its upper surface leading to the internal space. The outer surface of the heat-insulating container body 40 is covered by a protective box 30, and a heat storage unit 60 is housed within the heat-insulating container body 40.

[0043] The heat-insulating cover 50 is formed into a rectangular flat plate shape and can be opened and closed to cover the opening of the heat-insulating container body 40. The heat-insulating cover 50 has a second outer skin 51 and a second core material 52. The second outer skin 51 is made of a flexible membrane with gas barrier properties, including a metal layer, and has a bag shape. The second core material 52 is, for example, a continuous bubble body such as continuous bubble polyurethane foam, a foamed resin material such as expanded polystyrene, an aggregate of fibers, an aggregate of inorganic particles, or a non-metallic porous body. The second outer skin 51 is housed inside the second outer skin 51, and the internal pressure of the second outer skin 51 is lower than the external pressure, for example, reduced to below a specified pressure, and the second outer skin 51 is sealed. Furthermore, the outer surface of the heat-insulating cover 50 is covered by an outer packaging bag 20.

[0044] In such a vacuum insulated container 10, an internal space formed by an insulated container body 40 and an insulated cover 50 covering the opening of the insulated container body 40 is formed as an insulated space. A heat storage unit 60 is housed in this insulated space, and a storage item A such as a medicine or sample is housed in the heat storage unit 60. As a result, the temperature around the item formed by the heat storage unit 60 is maintained for a long time by the insulated container body 40 and the insulated cover 50.

[0045] <Heat Storage Unit>

[0046] like Figure 2 and Figure 3 As shown in the example, the heat storage unit 60 includes a basket 61, multiple heat storage components 62, and an insulated container 70. The basket 61 is a storage container made of a non-metallic material such as resin, and is formed into a shallow box shape with an opening at the top. The basket 61 has a pair of upwardly extending portions 61a located on the left and right sides, and a strap 61b is provided between the pair of extending portions 61a. The basket 61 has a connection with the insulated container body 40 (… Figure 1 The inner space of the container is roughly the same shape, but slightly smaller than the inner space. Its outer surface is recessed into the inner space of the heat insulation container 40 along the inner surface of the heat insulation container 40.

[0047] For example, six heat storage elements 62 surround a hexahedral insulated container 70, with each heat storage element 62 disposed on a face of the insulated container 70. The heat storage elements 62 are formed in a flat plate shape and are filled with a heat storage agent within a bag made of a non-metallic material such as resin. The heat storage element 62 is a component that suppresses temperature changes by utilizing latent heat and sensible heat during state changes between solid, liquid, and gas. As a cooling element of the heat storage element 62, the insulated container 70 is cooled, for example, by absorbing heat during the change from a solid state solidified by cooling to a liquid state that melts at its melting point. Known materials such as inorganic hydrates and organic hydrates can be used, which correspond to the state change temperature (e.g., melting point) of a specified temperature (e.g., 2°C or higher and 8°C or lower) within the storage space 71 of the insulated container 70.

[0048] <Insulated Container>

[0049] The insulated container 70 has a storage space 71 as its internal space and multiple walls 72. The walls 72 are, for example, flat and have an inner surface 72i, an outer surface 72o, and an end face 72g.

[0050] The inner surface 72i surrounds the storage space 71. The outer surface 72o is positioned further away from the storage space 71 in the thickness direction of the wall 72 than the inner surface 72i. The inner surface 72i and the outer surface 72o are flat rectangular shapes and are arranged parallel to a plane direction orthogonal to the thickness direction. The thickness of the wall 72 between the inner surface 72i and the outer surface 72o in the thickness direction is constant. An end face 72g connects the outer periphery of the inner surface 72i and the outer periphery of the outer surface 72o, has a smaller area than the inner surface 72i and the outer surface 72o, and is arranged parallel to the thickness direction.

[0051] The insulated container 70 includes, for example, a top wall 72a, a bottom wall 72b, and side walls. The side walls include, for example, a front side wall 72c, a rear side wall 72d, a left side wall 72e, and a right side wall 72f. The front side wall 72c and the rear side wall 72d are arranged spaced apart in the front-rear direction with their inner surfaces 72i facing each other. The left side wall 72e and the right side wall 72f are arranged spaced apart in the left-right direction with their inner surfaces 72i facing each other. These four side walls 72c to 72f connect with adjacent side walls 72c to 72f to form cylindrical side walls with rectangular upper openings and rectangular lower openings.

[0052] The bottom wall 72b is larger than the size of the lower opening of the cylindrical side wall. The bottom wall 72b is connected to the lower ends of the side walls 72c to 72f in a manner that covers the lower opening. The bottom wall 72b and the side walls 72c to 72f form the container part of the heat-insulating container 70, which is a cuboid shape with an upper opening on the upper surface leading to the internal space.

[0053] The top wall 72a has dimensions above the upper opening of the cylindrical side wall. The top wall 72a is connected to the rear side wall 72d such that the upper opening can be opened and closed to cover it, forming the lid of the insulated container 70. With the top wall 72a covering the upper opening of the container portion, the top wall 72a and the bottom wall 72b are arranged vertically spaced apart from each other with their inner surfaces 72i facing each other. Thus, the storage space 71 of the insulated container 70 is covered by six walls 72.

[0054] In this heat storage unit 60, a lower heat storage element 62 is disposed on the bottom surface of the inner side of the basket 61. Then, an insulated container 70 is placed on the lower heat storage element 62 with the outer surface 72o of the bottom wall 72b facing the upper surface of the lower heat storage element 62. Furthermore, the heat storage element 62 is inserted into the gap between the outer surfaces 72o of each side wall 72c-72f and the inner side surface of the basket 61 facing each side wall 72c-72f. And, an upper heat storage element 62 is placed on the outer surface 72o of the top wall 72a. Thus, the insulated container 70 is surrounded by the heat storage element 62 with each of its six walls 72 in contact with it.

[0055] Here, the gap between the outer surface 72o of each sidewall 72c-72f and the inner side of the basket 61 is equal to or approximately equal to the thickness of the heat storage element 62 between the surface of the heat storage element 62 opposite to the outer surface 72o of the sidewall 72c-72f and the surface of the heat storage element 62 opposite to the inner side of the basket 61. Therefore, the heat storage element 62 inserted into the gap contacts the insulation container 70 and is embedded in the gap between the insulation container 70 and the basket 61. As a result, the heat storage element 62 efficiently cools the insulation container 70 and supports the insulation container 70 relative to the basket 61, thereby reducing vibrations of the insulation container 70 and its contents A.

[0056] The upper surface of the lower heat storage element 62 has an area equal to or larger than the outer surface 72o of the opposite bottom wall 72b, covering the entire outer surface 72o of the bottom wall 72b. Furthermore, the surfaces of the upper, front, rear, left, and right heat storage elements 62, like the lower heat storage element 62, have an area equal to or larger than the outer surface 72o of the opposite wall 72, covering the entire outer surface 72o of that wall. Therefore, each wall 72 of the heat-insulating container 70 is uniformly cooled by the heat storage element 62 in the direction along that surface, and the storage space 71 surrounded by the cooled walls 72 is cooled and maintained at a predetermined temperature.

[0057] <The wall of the insulated container>

[0058] The wall 72 of the insulated container 70 is composed of a first wall 75. The first wall 75 has a greater thermal conductivity c2 in the planar direction than its thermal conductivity c1 in the thickness direction. Therefore, the wall 72 has a greater thermal conductivity c2 in the planar direction than its thermal conductivity c1 in the thickness direction. Consequently, in the wall 72, the amount of heat moving per unit area per unit time relative to the direction of heat movement orthogonal to the direction of heat movement is greater in the planar direction than in the thickness direction. Figure 3 In the example, the thickness direction of the top wall 72a and the bottom wall 72b is vertical, the thickness direction of the front side wall 72c and the rear side wall 72d is front-back, and the thickness direction of the left side wall 72e and the right side wall 72f is horizontal.

[0059] For example, the ratio of the thermal conductivity c1 in the thickness direction to the thermal conductivity c2 in the surface direction of the first wall 75 of wall 72, c1 / c2, is 0.2 or more and less than 0.8. For example, the thermal conductivity c1 in the thickness direction of the first wall 75 of wall 72 is 0.5 W / mK or more and 2.5 W / mK or less, and the thermal conductivity c2 in the surface direction is 1 W / mK or more and 5 W / mK or less.

[0060] For example, when heat is transferred from the outside of the insulated container 70 through the wall 72 in the thickness direction to the storage space 71, the temperature of the storage space 71 rises, and the cooling time of the insulated container 70 becomes shorter. In contrast, since the thermal conductivity c1 of the wall 72 in the thickness direction is relatively small, the heat transferred from the outer surface 72o of the wall 72 to the inner surface 72i is suppressed less. As a result, the heat transferred from the outside of the insulated container 70 to the storage space 71 through the wall 72 can be reduced, and the cooling time in the storage space 71 can be extended.

[0061] Furthermore, the heat storage element 62 melts from its surface, so the temperature of the heat storage element 62 decreases towards the center. Therefore, the wall 72 of the heat-insulating container 70 cooled by the heat storage element 62 tends to cool more easily towards the center in the planar direction compared to the outer periphery. In contrast, since the thermal conductivity c2 in the planar direction of the wall 72 is relatively large, heat easily moves in the planar direction within the wall 72, and the temperature of the wall 72 becomes more uniform in the planar direction. As a result, temperature uniformity can be achieved in the storage space 71 surrounded by the wall 72.

[0062] In this way, the temperature of the wall 72 is uniformized in the planar direction, thereby also uniformizing the temperature of the heat storage element 62 in contact with the wall 72 in the planar direction. Therefore, the uniform distribution of the molten material in the heat storage element 62 in the planar direction enables the long-term uniform cooling effect of the heat storage element 62. As a result, a uniform temperature state can be maintained in the storage space 71 surrounded by the wall 72 for a long period of time.

[0063] The first wall 75 of wall 72 is formed of adhesive resin 73 and thermally conductive filler 74. The thermally conductive filler 74, having a higher thermal conductivity than the adhesive resin 73, is mixed into the adhesive resin 73. Through this thermally conductive filler 74 with higher thermal conductivity, wall 72 is efficiently cooled by the heat storage element 62. This enables temperature uniformity within the storage space 71 surrounded by wall 72.

[0064] The adhesive resin 73 is a resin that can form the wall 72 even when mixed with thermally conductive filler 74, such as a thermoplastic resin. Examples of adhesive resin 73 include ABS, polypropylene, polycarbonate, polybutylene terephthalate, nylon 6, nylon 66, polyphenylene sulfide, polystyrene, etc.

[0065] The thermally conductive filler 74 is, for example, an inorganic material, such as magnesium oxide (MgO), magnesium carbonate (MgCO3), magnesium hydroxide (Mg(OH)2), silicon dioxide (fused silica) (SiO2), aluminum oxide (Al2O3), hexagonal boron nitride (BN), silicon nitride (Si3N4), aluminum nitride (AlN), and talc (Mg3Si4O). 10 (OH)2, etc.

[0066] The thermally conductive filler 74 may have anisotropic shapes, such as plate-like (flat and scaly) or needle-like (rod-like and fibrous). The thermally conductive filler 74 is oriented such that its long side direction is parallel or approximately parallel to the surface direction of the wall 72. The angle between the long side direction and the surface direction of the thermally conductive filler 74 is 0 degrees or more, and smaller than the angle between the long side direction and the thickness direction. Therefore, the thermally conductive filler 74 is arranged in the wall 72 such that its dimension in the thickness direction is smaller than its dimension in the surface direction.

[0067] For example, the plate-shaped thermally conductive packing 74 has multiple faces, and the largest principal face among these faces is oriented parallel or nearly parallel to the inner surface 72i of the wall 72. The angle between the principal face of the plate-shaped thermally conductive packing 74 and the face direction is 0 degrees or more, and smaller than the angle between the principal face and the thickness direction. Similarly, the needle-shaped thermally conductive packing 74 is oriented with its long side direction parallel or nearly parallel to the inner surface 72i of the wall 72. The angle between the long side direction of the needle-shaped thermally conductive packing 74 and the face direction is 0 degrees or more, and smaller than the angle between the long side direction of the thermally conductive packing 74 and the thickness direction.

[0068] Therefore, in the wall 72, the thermally conductive filler 74 is arranged such that its maximum dimension in the planar direction is larger than its maximum dimension in the thickness direction. As a result, the proportion of thermally conductive filler 74 per unit length relative to the adhesive resin 73 in the planar direction of the wall 72 is greater than the proportion of thermally conductive filler 74 per unit length relative to the adhesive resin 73 in the thickness direction of the wall 72.

[0069] Since the thermal conductivity c1 in the thickness direction of wall 72 is smaller than the thermal conductivity c2 in the surface direction of wall 72, heat transfer from the outside of the insulation container 70 to the storage space 71 can be reduced, thereby extending the insulation time in the storage space 71. On the other hand, since the thermal conductivity c2 in the surface direction of wall 72 is larger than the thermal conductivity c1 in the thickness direction of wall 72, the temperature of the wall 72 of the insulation container 70 and the heat storage element 62 in the surface direction can be made uniform.

[0070] The thermally conductive filler 74 and the adhesive resin 73, for example, have insulating properties. In this case, the wall 72 formed by the adhesive resin 73 and the thermally conductive filler 74 mixed therewith has insulating properties and is difficult to conduct electricity.

[0071] For example, a thermometer B is stored in a storage space 71 surrounded by an insulating wall 72. Figure 1 ) and radio equipment C ( Figure 1The thermometer B is electrically connected to the wireless device C, detects the temperature of the storage space 71, and outputs the temperature to the wireless device C. The wireless device C transmits the detected temperature based on the thermometer B wirelessly. The radio waves of the wireless device C pass through the insulating wall 72.

[0072] Outside the vacuum insulated container 10, a wireless device C and other wireless devices capable of wireless communication are arranged. The temperature detected by the thermometer B, transmitted from the wireless device C, is received via these other wireless devices. Therefore, without opening the insulated container 70 and without providing a through hole for extending the thermometer B's signal to the outside of the insulated container 70, the temperature within the storage space 71 of the insulated container 70 can be obtained from outside the insulated container 70. This reduces temperature unevenness in the storage space 71 caused by opening and closing the insulated container 70 and by any through holes.

[0073] Furthermore, the heat storage element 62, basket 61, insulated container body 40, protective box 30, and outer bag 20 located outside the insulated container 70 in the vacuum insulated container 10 are also made of non-metallic materials, for example. In this case, radio waves from the wireless device C outside the vacuum insulated container 10 can be received by other wireless devices. Therefore, it is possible to reduce temperature unevenness in the storage space 71 caused by the opening and closing of the vacuum insulated container 10 and the through holes.

[0074] The thermally conductive filler 74 may, for example, be carbon-free. Carbon has a darker color, making it difficult to color the wall 72 containing it. In contrast, with the carbon-free thermally conductive filler 74, it is easy to color the wall 72 containing the thermally conductive filler 74. This allows for improved design flexibility and color-based visibility of the insulation container 70.

[0075] <Methods of Wall Formation>

[0076] The wall 72 containing such thermally conductive filler 74 is formed, for example, by injection molding. Figure 4 In this example, the adhesive resin 73 mixed with thermally conductive filler 74 is heated and melted using a cylinder 80. A nozzle 82 at the front end of the cylinder 80 is connected to an injection path 84 of the mold 83, and the adhesive resin 73 is extruded from the cylinder 80 using a screw propeller 81. Thus, the adhesive resin 73 is forced from the cylinder 80 into the internal space, or cavity 85, of the mold 83 via the nozzle 82 and the injection path 84. After the adhesive resin 73 cools and solidifies in the cavity 85 of the mold 83, the mold 83 is divided, and the adhesive resin 73 mixed with thermally conductive filler 74 is removed from the cavity 85 as a wall 72.

[0077] The nozzle 82 of the cylinder 80 is a cylindrical space with an axis extending in the planar direction. The injection path 84 is a cylindrical space with an axis extending in the planar direction, and one end of the planar direction is connected to the cavity 85. During the injection of adhesive resin 73 from the cylinder 80 into the mold 83, the other end of the injection path 84 is connected to the nozzle 82. Thus, the cylinder 80 communicates with the cavity 85 via the nozzle 82 and the injection path 84. The cavity 85 is a space with a shape and size corresponding to that of the wall 72, for example, having a rectangular flat plate shape. The inner surface of the mold 83 surrounds the cavity 85 and has a surface forming the inner surface 72i, outer surface 72o, and end face 72g of the wall 72. The injection path 84 is connected to the surface forming the end face 72g of the wall 72 within the inner surface of the mold 83, and is orthogonal to the planar direction.

[0078] In this manner, the nozzle 82 and injection path 84 extend along the planar direction, and the adhesive resin 73 mixed with thermally conductive filler 74 moves in the planar direction within the nozzle 82 and injection path 84. Furthermore, the cross-sections of the nozzle 82 and injection path 84, orthogonal to the planar direction, are equal or approximately equal to each other, and are smaller than the cross-sections of the cylinder 80 and cavity 85, orthogonal to the planar direction. Therefore, during the passage of the adhesive resin 73 mixed with thermally conductive filler 74 through the nozzle 82 and injection path 84 in the planar direction, the thermally conductive filler 74 is aligned with its long side direction parallel or approximately parallel to the planar direction. Consequently, within the adhesive resin 73 injected from the injection path 84 into the cavity 85, the thermally conductive filler 74 is oriented with its long side direction parallel or approximately parallel to the planar direction.

[0079] (Implementation Method 2)

[0080] In the insulated container 70 of Embodiment 1, the entire wall 72 is formed by the first wall 75. In contrast, in the insulated container 70 of Embodiment 2, as... Figure 5 As shown in the example, a portion of wall 72 is formed by a first wall 75. Because of the first wall 75, wall 72 has a larger thermal conductivity c2 in the surface direction than thermal conductivity c1 in the thickness direction.

[0081] Specifically, wall 72 has a first wall 75 with a thermal conductivity c2 in the surface direction that is greater than its thermal conductivity c1 in the thickness direction, and a second wall 76 made of resin. The first wall 75 is stacked on the outer surface of the second wall 76. The first wall 75 and the second wall 76 have, for example, flat rectangular shapes on their inner and outer surfaces, and have a flat plate shape. The dimension of the inner surface of the first wall 75 is greater than the dimension of the outer surface of the second wall 76, and the inner surface of the first wall 75 covers the entire outer surface of the second wall 76. In this way, the first wall 75 and the second wall 76 are stacked in the thickness direction to form wall 72.

[0082] In this wall 72, the inner surface of the first wall 75 is in contact with the outer surface of the second wall 76. The inner surface 72i of the wall 72 is formed by the inner surface of the second wall 76, and the outer surface 72o of the wall 72 is formed by the outer surface of the first wall 75. Thus, the first wall 75 comes into contact with the heat storage member 62 and is uniformly cooled in the planar direction by the heat storage member 62. Furthermore, heat is transferred between the first wall 75 and the second wall 76, and the entire wall 72 is cooled, thus cooling the temperature of the storage space 71 surrounded by the wall 72 to a predetermined temperature. Here, because the thermal conductivity c2 in the planar direction is greater than the thermal conductivity c1 in the thickness direction, the temperature of the storage space 71 can be homogenized and the heat preservation time extended.

[0083] exist Figure 5 In the example of the insulated container 70, five second walls 76, one in each of the bottom wall 72b and the side walls 72c to 72f, are arranged to form a container shape. The container portion formed by these second walls 76 is a box shape with an opening at the top and is integrally formed. On the outer surface of each container portion of the second walls 76, a first wall 75 is fixed by a fixing member such as an adhesive or double-sided tape. Thus, the bottom wall 72b and the side walls 72c to 72f, formed by the first wall 75 and the second walls 76 stacked on their inner surfaces, constitute the container portion of the insulated container 70.

[0084] The second wall 76 of the top wall 72a is configured such that the upper opening of the container portion of the second wall 76 can be opened and closed. The first wall 75 is fixed to the outer surface of the second wall 76 by means of adhesive and double-sided tape or similar fasteners. Thus, the top wall 72a, formed by the first wall 75 and the second wall 76 stacked on its inner surface, constitutes a lid of the insulated container 70 that covers the upper opening of the container portion of the insulated container 70 in a manner that allows the upper opening of the container portion to be opened and closed.

[0085] The thermal conductivity of the second wall 76 is lower than that of the first wall 75. For example, the thermal conductivity of the second wall 76 in the thickness direction is equal to that in the surface direction, and the difference between them is 0. Compared with the first wall 75, the second wall 76 has greater mechanical strength such as tensile strength, compressive strength, and impact strength, and is made of resin such as polypropylene resin.

[0086] This wall 72 has a second wall 76 with excellent mechanical strength. As a result, the thickness of the first wall 75 can be made thinner, and damage to the insulation container 70 can be reduced. By making the first wall 75 thinner, cost reduction can be achieved, and heat conduction of the wall 72 in the thickness direction can be suppressed, thereby achieving temperature uniformity in the storage space 71 and extending the insulation time.

[0087] In the first wall 75, the ratio of the thermal conductivity c1 in the thickness direction to the thermal conductivity c2 in the surface direction, c1 / c2, is 0.2 or more and less than 0.8. The first wall 75 is formed of an adhesive resin 73 and a thermally conductive filler 74 having a higher thermal conductivity than the adhesive resin 73 and mixed in the adhesive resin 73. The thermally conductive filler 74, for example, has anisotropic shape and is arranged in the wall 72 such that its dimension in the thickness direction is smaller than its dimension in the surface direction. The thermally conductive filler 74, for example, has electrical insulating properties. The wall 72, for example, is as follows: Figure 4 The example shows that it is formed by injection molding.

[0088] The thickness of the first wall 75 in the thickness direction is 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less. For example... Figure 6 As shown in the figure, the thickness of the first wall 75 is less than 5 mm, and the wall 72 containing the first wall 75 exhibits a high thermal conductivity (W / mK) in the planar direction. Therefore, the wall 72 containing the first wall 75 can reduce temperature unevenness in the planar direction, and can achieve temperature uniformity and long-term heat preservation in the storage space 71 inside the heat preservation container.

[0089] like Figure 6 As shown in the figure, the greater the thickness of the first wall 75, the higher the thermal conductivity (W / mK) of the wall 72 containing the first wall 75 in the surface direction, and the better the temperature uniformity of the wall 72 in the surface direction. However, as Figure 7 As shown in the figure, the greater the thickness of the first wall 75, the higher the thermal resistivity (m) of the wall 72 containing the first wall 75 in the thickness direction. 2 The smaller the K / W ratio, the easier it is for heat from the outside of the insulation container 70 to be transferred to the storage space 71 via the wall 72 in the thickness direction. In this way, the thicker the first wall 75, the better its temperature uniformity. The heat transferred from the outside to the wall 72 increases, and the temperature at the corners of the storage space 71 tends to be higher than the temperature in the center, which easily leads to uneven temperature in the thickness direction of the storage space 71.

[0090] In contrast, such as Figure 8 As shown in the figure, the thickness of the first wall 75 is 3 mm or less, resulting in a small temperature unevenness in the thickness direction within the storage space 71. This temperature unevenness is calculated by subtracting the temperature at the corners from the temperature at the center of the storage space 71, and dividing by the temperature at the center. In this way, a thickness of 3 mm or less for the first wall 75 enables temperature uniformity within the storage space 71 of the insulated container and extends the insulation time. Furthermore, a thickness of 1 mm or less for the first wall 75 results in minimal temperature unevenness, further enabling temperature uniformity within the storage space 71 of the insulated container and extending the insulation time, thus reducing costs.

[0091] <Variation Example 1>

[0092] exist Figure 5 In the example of the insulated container 70, the first wall 75 of wall 72 is stacked on the outer surface of the second wall 76. In contrast, in the insulated container 70 of modified example 1, as... Figure 9 As shown in the example, the first wall 75 of wall 72 is stacked on the inner surface of the second wall 76. Alternatively, the first wall 75 in wall 72 may also be stacked on both the inner and outer surfaces of the second wall 76.

[0093] Specifically, such as Figure 9 As shown in the example, wall 72 has a first wall 75 with a thermal conductivity c2 in the planar direction greater than its thermal conductivity c1 in the thickness direction, and a second wall 76 made of resin. The first wall 75 is laminated on the inner surface of the second wall 76. The outer surface of the first wall 75 is in contact with the inner surface of the second wall 76, and the first wall 75 and the second wall 76 form a flat plate-shaped wall 72. The outer surface 72o of wall 72 is formed by the outer surface of the second wall 76, and the inner surface 72i of wall 72 is formed by the inner surface of the first wall 75. Thus, the second wall 76 and the first wall 75 are cooled by the heat storage member 62, and the temperature in the planar direction is homogenized in the first wall 75. Therefore, the temperature of the storage space 71 surrounded by the first wall 75 is homogenized, and the heat preservation time is extended.

[0094] <Variation Example 2>

[0095] exist Figure 5 and Figure 9 In the example of the insulated container 70, each wall 72 of the top wall 72a, bottom wall 72b, and side walls 72c-72f has a first wall 75 and a second wall 76. In contrast, in the insulated container 70 of Modified Example 2, each wall 72 of the side walls 72c-72f has a first wall 75 and a second wall 76. At least one of the top wall 72a and the bottom wall 72b has a second wall 76 but does not have a first wall 75.

[0096] Figure 10 In the example of the insulated container 70, each wall 72 of the side walls 72c to 72f is formed by a first wall 75 stacked on the second wall 76 and the outer surface of the second wall 76. Therefore, the inner surface of the side walls 72c to 72f is formed by the inner surface of the second wall 76, and the outer surface of the side walls 72c to 72f is formed by the outer surface of the first wall 75. Conversely, each wall 72 of the top wall 72a and the bottom wall 72b is formed by the second wall 76. Therefore, the inner surface of the top wall 72a and the bottom wall 72b is formed by the inner surface of the second wall 76, and the outer surface of the top wall 72a and the bottom wall 72b is formed by the outer surface of the second wall 76. Alternatively, the top wall 72a may also be formed by the first wall 75 and the second wall 76. Or, the bottom wall 72b may also be formed by the first wall 75 and the second wall 76.

[0097] exist Figure 11 In the example of the insulated container 70, each wall 72 of the side walls 72c to 72f is formed by a first wall 75 stacked on the second wall 76 and the inner surface of the second wall 76. Therefore, the inner surface of the side walls 72c to 72f is formed by the inner surface of the first wall 75, and the outer surface of the side walls 72c to 72f is formed by the outer surface of the second wall 76. Conversely, each wall 72 of the top wall 72a and the bottom wall 72b is formed by the second wall 76. Therefore, the inner surface of the top wall 72a and the bottom wall 72b is formed by the inner surface of the second wall 76, and the outer surface of the top wall 72a and the bottom wall 72b is formed by the outer surface of the second wall 76. Alternatively, the top wall 72a may also be formed by the first wall 75 and the second wall 76. Or, the bottom wall 72b may also be formed by the first wall 75 and the second wall 76.

[0098] like Figure 10 and Figure 11 As shown in the example, in the insulated container 70, the top wall 72a can be opened and closed to cover the upper openings of the side walls 72c to 72f. Therefore, when heat from outside the insulated container 70 enters the storage space 71 through the upper openings and the wall 72, the temperature on the top wall 72a side in the storage space 71 tends to become higher than the temperature on the bottom wall 72b side. In contrast, the thermal conductivity of the side walls 72c to 72f disposed between the top wall 72a and the bottom wall 72b is greater in the planar direction than in the thickness direction. For example, when the top wall 72a and the bottom wall 72b are orthogonally disposed with respect to the vertical direction, the thermal conductivity of the side walls 72c to 72f is greater in the vertical direction. Therefore, heat moves along the side walls 72c to 72f between the top wall 72a and the bottom wall 72b, thereby reducing temperature unevenness in the vertical direction within the storage space 71. As a result, temperature uniformity within the storage space 71 and extended insulation time can be achieved.

[0099] Furthermore, all the above embodiments can be combined with each other as long as they are not mutually exclusive. Additionally, based on the above description, those skilled in the art will be able to recognize further modifications or other embodiments of the present invention. Therefore, the above description should be explained as an example only, and is provided to demonstrate to those skilled in the art the best mode for carrying out the present invention. The details of its structure and / or function can be substantially changed without departing from the spirit of the present invention.

[0100] Industrial utilization potential

[0101] The insulated container of the present invention is applicable to insulated containers that can achieve temperature uniformity in the storage space and long-term heat preservation.

[0102] Explanation of reference numerals in the attached figures

[0103] 70: Insulated containers

[0104] 71: Storage Space

[0105] 72: wall

[0106] 72a: Top wall

[0107] 72b: Bottom wall

[0108] 72c: Sidewall

[0109] 72d: Sidewall

[0110] 72e: Sidewall

[0111] 72f: Sidewall

[0112] 72i: Inner surface

[0113] 72o: Outer surface

[0114] 73: Adhesive resin

[0115] 74: Thermally conductive fillers

[0116] 75: First Wall

[0117] 76: Second wall.

Claims

1. A heat-insulating container, characterized in that: Includes storage space and a wall having an inner surface surrounding the storage space. The wall includes a sidewall having a pair of openings, a top wall capable of opening and closing to cover one of the openings, and a bottom wall covering the other opening. In the wall, the thermal conductivity in the thickness direction orthogonal to the inner surface is greater than that in the thickness direction. The wall has a first wall with a thermal conductivity greater in the surface direction than in the thickness direction, and a second wall made of resin. The first wall is stacked on at least one of the inner and outer surfaces of the second wall. The sidewall has the first wall and the second wall. The wall of at least one of the top wall and the bottom wall does not have the first wall but has the second wall. The insulated container is used while it is surrounded by multiple heat storage elements.

2. The heat-insulating container as described in claim 1, characterized in that: The first wall is formed of an adhesive resin and a thermally conductive filler having a higher thermal conductivity than the adhesive resin and mixed in the adhesive resin.

3. The heat-insulating container as described in claim 2, characterized in that: The thermally conductive filler is shape-anisotropic and is arranged in the wall such that its dimension in the thickness direction is smaller than its dimension in the surface direction.

4. The heat-insulating container as described in claim 2 or 3, characterized in that: The thermally conductive filler has insulating properties.

5. The heat-insulating container as described in claim 1, characterized in that: In the first wall, the ratio of the thermal conductivity in the thickness direction to the thermal conductivity in the surface direction is 0.2 or more and less than 0.

8.

6. The heat-insulating container as described in claim 1, characterized in that: The thickness of the first wall in the thickness direction is less than 1 mm.

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