Insulation panels and insulated boxes

Abstract

The present invention aims to propose an insulating panel that contributes to the realization of a simple, insulating box with high thermal insulation performance. [Solution] The present invention provides a U-shaped insulation panel comprising a vacuum insulation material with a U-shaped cross-section, a resin sheet, and a foam, which allows for the formation of an insulated box body through simple assembly.

Description

Technical Field

[0001] The present invention relates to a heat insulation panel used as a heat insulation material for daily necessities, vehicles, buildings, etc., and a heat insulation box body formed by combining the heat insulation panels.

Background Art

[0002] In recent years, energy conservation and resource conservation have been strongly desired from the perspective of preventing global warming and the like. In particular, in the field of logistics for transporting and storing various items such as food, precision instruments, and pharmaceuticals, heat insulation containers have come to be used from the perspective of efficiently using thermal energy. As the heat insulation container, a box made of a foam material mainly formed by molding a bead foam into a box shape is widely used in a fish box for transporting fish, a transport box for food, and the like.

[0003] However, in a box body formed only by a foam material such as a conventional foam box body, the heat insulation performance is not so high, and when considering long-term transportation, it is difficult to maintain a low temperature state, which is not preferable for the object to be refrigerated. In addition, a method of enhancing the cold storage function by packing a cold storage material or the like inside such a box body has also been adopted. However, in this method, the space for storing the object to be refrigerated is reduced due to the compression of the volume of the cold storage material itself, and the total weight of the box body itself increases, so there are problems such as complicated handling and high running costs.

[0004] Therefore, a molding technique for a heat insulation box body using a member provided with a vacuum heat insulation element has been developed.

[0005] For example, Patent Document 1 discloses a low-temperature storage container using a vacuum heat insulation panel. The low-temperature storage container is characterized in that a soft foam heat insulation material and a hard foam heat insulation material can be combined without using fastening means such as screws.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-164241 [Overview of the project] [Problems that the invention aims to solve]

[0007] The low-temperature storage container disclosed in Patent Document 1 above achieves improved thermal insulation performance by preventing heat leakage. However, in order to prevent heat leakage without using fastening means, the number of components required for assembling the box itself increases, and consequently, the manufacturing time also increases. Therefore, there is a need for a thermal insulation box that achieves high thermal insulation performance with a simple structure.

[0008] The present invention aims to propose an insulating panel that contributes to the realization of a simple, insulating box with high thermal insulation performance. [Means for solving the problem]

[0009] The inventors of the present invention have diligently investigated ways to solve the above problems and have come up with a U-shaped insulation panel comprising a vacuum insulation material with a U-shaped cross-section, a resin sheet, and a foam, which enables the molding of an insulated box body by simple assembly. In other words, the gist of the present invention is as follows.

[0010] 1. An insulating panel having a U-shaped cross-section, comprising a vacuum insulating material with a U-shaped cross-section, a resin sheet bonded to at least the inner surface of the vacuum insulating material, and a foam covering the surface of the vacuum insulating material other than the surface bonded to the resin sheet.

[0011] 2. The thermal insulation panel according to claim 1, having a pair of horizontal parts corresponding to the horizontal sides of the U-shape and vertical parts corresponding to the vertical sides of the U-shape, wherein the vertical parts are square in shape, and the outline of the inner space of the U-shape partitioned by the vertical and horizontal sides is the same as the shape of the horizontal parts.

[0012] 3. The thermal insulation panel according to 1 or 2, wherein the foam is a bead foam.

[0013] 4. The thermal insulation panel according to 1 or 2, wherein the resin sheet is a single sheet.

[0014] 5. The thermal insulation panel according to 1 or 2, wherein the resin sheet and the foam include at least one of polystyrene resin, polystyrene-polyolefin composite resin, and polypropylene resin.

[0015] 6. The thermal insulation panel according to 1 or 2, wherein the resin sheet and the foam are of the same material.

[0016] 7. An insulated box made by combining two of the insulated panels described in 1 or 2 above, wherein the U-shaped openings of the two insulated panels are facing each other and fitted together.

[0017] 8. The insulated box described in 7, wherein the two insulated panels are of the same shape.

[0018] 9. The heat insulating box according to 7 or 8, wherein the vertical portion of the heat insulating panel has a protrusion at its edge, and the horizontal portion has a recess at its edge for interlocking with the protrusion.

[0019] 10. The insulated box according to 7 or 8, wherein each of the two insulated panels has a groove for accommodating fasteners.

[0020] 11. The insulated box according to 7 or 8, wherein the coverage rate of the vacuum insulation material on the six wall surfaces constituting the internal space of the insulated box is 60% or more, preferably 70% or more, more preferably 80% or more, even more preferably 90% or more, and most preferably 100%.

[0021] 12. A method for manufacturing an insulating panel having a U-shaped cross-section, The steps include: attaching a resin sheet to the inner surface of the mold in a U-shape cross-section, The steps include: joining a vacuum insulation material to the aforementioned resin sheet; Closing the mold and injecting a foaming material into the mold; Foaming the foaming material to coat the surface of the vacuum heat insulating material other than the bonding surface with the resin sheet with a foam; A method for manufacturing a heat insulating panel, comprising:

[0022] 13. The manufacturing method according to 12, wherein in the step of attaching the resin sheet, the U-shaped end portion of the resin sheet is further extended and attached outward in a direction perpendicular to the horizontal portion of the U-shape.

[0023] 14. The manufacturing method according to 12, wherein in the step of bonding the vacuum heat insulating material to the resin sheet, the vacuum heat insulating material is bonded to the resin sheet through ribs provided on the resin sheet.

Advantages of the Invention

[0024] The heat insulating panel of the present invention is formed in a U-shape that can be fitted, so that two of the heat insulating panels can be combined to easily form a heat insulating box body with a high heat insulating effect. Further, by using a vacuum heat insulating material and a resin sheet in the manufacture of the heat insulating panel, the thickness of the panel can be reduced while maintaining the heat insulating function, resulting in an increase in the volume when forming a box body and an improvement in the strength of the inner surface of the box body.

Brief Description of the Drawings

[0025] [Figure 1A] A perspective view of the heat insulating panel according to the first embodiment. [Figure 1B] A cross-sectional view taken along line a-a of the perspective view of the heat insulating panel according to the first embodiment. [Figure 1C] A cross-sectional view taken along line b-b of the perspective view of the heat insulating panel according to the first embodiment. [Figure 2A] A perspective view of the heat insulating box body according to the first embodiment. [Figure 2B] A perspective view (immediately before assembly) of the heat insulating box body according to the first embodiment. [Figure 2C]This is a cross-sectional view of the insulated box body of the first embodiment, shown along line aa in the perspective view. [Figure 2D] This is a cross-sectional view along line bb in the perspective view of the insulated box body of the first embodiment. [Figure 3] This is a diagram of an insulated box body with grooves for bands. [Figure 4A] This is a perspective view of an insulated box using irregularly shaped insulation panels, representing another embodiment. [Figure 4B] This is a perspective view (just before assembly) of an insulated box body using irregularly shaped insulation panels, as another embodiment. [Figure 5A] This is a perspective view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 5B] This is a cross-sectional view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 6A] This is a perspective view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 6B] This is a cross-sectional view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 7A] This is a perspective view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 7B] This is a cross-sectional view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 8A] This is a perspective view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 8B] This is a cross-sectional view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 9A] This is a perspective view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 9B] This is a cross-sectional view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 10A] This is a perspective view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 10B] This is a cross-sectional view showing the manufacturing process flow of the thermal insulation panel according to the first embodiment. [Figure 11A]This is a perspective view illustrating an example of the manufacturing process for a resin panel with ribs, representing another embodiment. [Figure 11B] This is a cross-sectional view illustrating an example of the manufacturing process for a thermal insulation panel with ribs, representing another embodiment. [Figure 12A] This is a perspective view illustrating an example of the manufacturing process for a resin panel with ribs, representing another embodiment. [Figure 12B] This is a cross-sectional view illustrating an example of the manufacturing process for a thermal insulation panel with ribs, representing another embodiment. [Figure 13] This diagram shows a conceptual diagram of the cooling effect test of the insulated box body of this embodiment. [Modes for carrying out the invention]

[0026] [Insulation Panel] The thermal insulation panel of the present invention comprises a vacuum thermal insulation material with a U-shaped cross-section, a resin sheet bonded to at least the inner surface of the vacuum thermal insulation material, and a foam covering the surface of the vacuum thermal insulation material other than the surface bonded to the resin sheet. In other words, the thermal insulation panel is a three-sided body following the shape of a U, formed by attaching a resin sheet to the inside of a vacuum thermal insulation material with a U-shaped cross-section and covering the outer surface with foam, and the panel itself also has a U-shaped cross-section. Here, "U-shaped cross-section" means that the cross-section is a U-shaped cross-section drawn by two horizontal sides (horizontal sides) extending from both ends of one vertical side (vertical side) in a direction in which the angle between the vertical side and the horizontal side is right angle. Note that the angle between the vertical side and the horizontal side does not need to be exactly right angle; in other words, the two horizontal sides do not need to be exactly parallel. Also, like a U-shape, there may be no boundary between the vertical side and the horizontal side, and the vertical side and the horizontal side may be continuous with curvature. The embodiments of the insulation panel and the insulation box will be described in detail below.

[0027] [First Embodiment] The first embodiment of the thermal insulation panel of the present invention will be described in detail below with reference to Figures 1A to 1C. Figure 1A is a perspective view of the thermal insulation panel 1, and Figures 1B and 1C are cross-sectional views of the thermal insulation panel 1 of Figure 1A along lines aa and bb, respectively.

[0028] As described above, the insulation panel 1 in Figure 1A is a three-sided body that follows the shape of a U in cross-section. The square-shaped faces corresponding to the vertical sides of the U are called vertical parts 2, and the rectangular faces corresponding to the horizontal sides of the U are called horizontal parts 3 and 4. These three faces, vertical parts 2, horizontal parts 3 and 4, are connected in a U-shape to form the insulation panel 1 with a U-shaped cross-section, as shown in the cross-sectional view along line aa in Figure 1B. In other words, the heat-insulating panel 1 consists of one vertical section 2 and two horizontal sections 3 and 4 that extend from the ends of two opposing sides of the vertical section 2 in a direction that is perpendicular to the angle between the vertical section 2 and the horizontal sections 3 and 4. Here, the direction along the side of the vertical section 2 on which the horizontal sections 3 and 4 are provided is called the "X direction", the direction perpendicular to the X direction (the direction along the side of the vertical section 2 on which no horizontal section is provided) is called the "Y direction", and the direction perpendicular to the vertical section 2 (the direction in which the horizontal sections 3 and 4 extend from the vertical section 2) is called the "Z direction".

[0029] The inner surface of the U-shape of the insulation panel 1 is covered with a resin sheet 12, shown in gray in Figure 1A, and a vacuum insulation material 10 with a U-shaped cross-section is bonded to the inside of this resin sheet 12. As shown by the dotted outline in Figure 1A, the vacuum insulation material 10 is embedded inside the resin sheet 12 in the central area, excluding the ends in the X direction of the vertical section 2 and horizontal sections 3 and 4. The outer surface of the insulation panel 1 is formed of foam 11 by covering the surface of the vacuum insulation material 10 other than the surface bonded to the resin sheet 12 with foam 11. Here, from the viewpoint of strength such as impact resistance and puncture strength, as well as adhesion with the foam 11, it is most preferable for the resin sheet 12 to cover the entire inner surface (gray area) of the U-shape of the insulation panel 1 as shown in Figure 1A, but it is sufficient if it covers the entire surface of the vacuum insulation material 10 for protection. Details of the laminated structure of the resin sheet 12, vacuum insulation material 10, and foam 11 will be described later. Furthermore, the end faces of the horizontal sections 3 and 4 have notches 5 (two on each end face) where both ends in the X direction of each end face are removed in a rectangular parallelepiped shape, and the edges of the convex portions 6a and 6b sandwiched in the notches 5 have recesses 7a and 7b that extend in a stepped manner in the X direction. On the other hand, the edges of the two sides that form the contour lines of the inner space 50a and 50b of the U-shape, where the horizontal sections 3 and 4 are not provided for the vertical section 2, have convex portions 8a and 8b that extend in a stepped manner in the Y direction. In the illustrated example, the recesses 7a and 7b and the convex portions 8a and 8b are shaped to interlock without gaps, and when two of the heat insulating panels 1 are combined as described later, a recessed interlock is achieved, contributing to improved airtightness of the box. However, when forming the heat insulating box, these recessed portions (7a and 7b and 8a and 8b) on both ends are not required. Conversely, the parts may be fitted together via a more complex shape.

[0030] Next, the laminated structure of the vacuum insulation material 10, foam 11, and resin sheet 12 will be described in detail with reference to Figure 1B. Figure 1B is a cross-sectional view of the insulation panel 1 along line aa. The innermost surface of the insulation panel 1 is covered with a resin sheet 12 (shown by a thick black line) extending from recess 7a to 7b. The vacuum insulation material 10 is embedded continuously in the vertical section 2 and the two horizontal sections 3 and 4 so as to be joined to the resin sheet 12. Furthermore, the surfaces of the vacuum insulation material 10 other than those joined to the resin sheet 12 are covered with foam 11, forming a U-shaped insulation panel overall.

[0031] The above-described insulation panel 1 can be easily assembled into a box by aligning the U-shaped openings of two panels 1 and fitting them together so that the lateral portions 3 and 4 of the panels do not overlap. The insulation box 100, which is made by combining two of these insulation panels 1, will be described in detail with reference to Figures 2A to 2D. Figure 2A is a perspective view of the insulation box 100, Figure 2B shows the arrangement of the panels when the two insulation panels 1 are interlocked, and Figures 2C and 2D are cross-sectional views of the insulation box 100 in Figure 2A, taken along lines aa and bb, respectively.

[0032] As shown in Figures 2A and 2B, the insulated box 100 is assembled by interlocking two insulation panels 1 in the illustrated arrangement. At this time, the vertical portions 2 of the insulation panel 1 form, for example, the top surface 101 and the bottom surface 102 of the insulated box 100, and the horizontal portions 3 and 4, and the Y-direction end faces of the vertical portions 2, are integrated to form the four sides 103 of the insulated box 100. As for the assembly method, as shown in Figure 2B, the box is formed by facing the U-shaped opening sides of one insulation panel 1 and the other insulation panel 1' towards each other and fitting them together in the Z-direction in a direction where the horizontal portions 3 and 4 of the panels do not overlap. In the illustrated example, the interlocking of the notches 5 of both panels 1 and 1', and the recesses 7a and 7b and protrusions 8a and 8b, results in a box that is sealed without gaps. In other words, in the heat insulating panel 1, the contours of the U-shaped inner spaces 50a and 50b and the planar shapes of the lateral portions 3 and 4 are molded to be identical down to the smallest detail, including their concave and convex shapes, thereby achieving the concave and convex fitting between the notches 5 of both panels 1 and 1' and the concave and convex portions 7a and 7b and 8a and 8b as described above.

[0033] As shown in the cross-sectional views of Figures 2C and 2D, the insulated box 100 assembled in this manner has a rectangular parallelepiped shape inside, and since most of the six walls are covered with vacuum insulation material 10, it is possible to efficiently enhance the insulation performance. Here, the coverage rate of the vacuum insulation material 10 on the six walls is 60% or more, preferably 70% or more, more preferably 80% or more, even more preferably 90%, and most preferably 100%. The greater the coverage rate of the vacuum insulation material, the greater the insulation effect. Even more preferably, the insulation effect can be reliably enhanced by achieving the coverage rate described above on each of the six surfaces. Furthermore, since the outermost surface on the inside of the box is entirely covered with resin sheet 12, the strength of the inner surface is also considered to be sufficiently strong.

[0034] The insulated box described above requires that the length of the vertical section 2 in the X direction and the length in the Y direction are the same, that is, the vertical section 2 is square in shape. On the other hand, the length in the Z direction can be any length. The longer the length in the Z direction, the more elongated the assembled insulated box will be in the longitudinal direction.

[0035] In other embodiments, as shown in Figure 3, when the insulated box 100' is secured with a fastener such as a band, a cross-shaped groove 9 may be provided to accommodate the fastener. By securing the box with a band in accordance with the groove of the insulated box, it is possible to prevent the box from being accidentally opened due to vibrations during transportation, for example.

[0036] The insulated box described above is a rectangular prism assembled using two insulation panels of the same shape, with square-shaped vertical sections of equal length in the X and Y directions. However, in another embodiment, it is also possible to assemble the insulated box using insulation panels of different shapes. In other words, it is also possible to create a rectangular prism with rectangular-shaped vertical sections of different lengths in the X and Y directions.

[0037] For example, as shown in Figures 4A and 4B, the vertical portions 32 and 32' of the insulating panels 30 and 30' that constitute the insulating box are rectangular parallelepipeds in shape, with the longer side extending parallel to the X direction being longer than the shorter side extending parallel to the Y direction. The insulating panel 30 consists of one vertical portion 32 and two horizontal portions 33 and 34 extending from the end of the longer side of the vertical portion 32 in the X direction, in a direction that creates a right angle between the vertical portion 32 and the horizontal portion 33 and 34. On the other hand, the insulating panel 30' consists of one vertical portion 32' and two horizontal portions 33' and 34' extending from the end of the shorter side of the vertical portion 32 in the Y direction, in a direction that creates a right angle between the vertical portion 32' and the horizontal portion 33' and 34'. In other words, the insulating panel 30 has a U-shaped cross-section with the vertical portion extending in the Y direction, and the insulating panel 30' has a U-shaped cross-section with the vertical portion extending in the X direction.

[0038] The same applies when constructing an insulated box using the above-described insulation panels 30 and 30'. That is, as shown in Figure 4B, the insulated box 300 is formed by aligning the U-shaped openings of one insulation panel 30 and the other insulation panel 30', and fitting them together in the Z direction so that the lateral portions 33 and 34 and 33' and 34' of the panels do not overlap. In other words, the lateral portions 33 and 34 of one insulation panel 30 and the U-shaped inner space of the other insulation panel 30' have the same shape, and the lateral portions 33' and 34' of the insulation panel 30' and the U-shaped inner space of the insulation panel 30 have the same shape, thereby enabling the interlocking of the differently shaped insulation panels 30 and 30' and forming a rectangular parallelepiped insulated box 300. The vertical portions 32 and 32' of the insulation panels 30 and 30' form, for example, the top surface 301 and the bottom surface 302 of the insulation box 300, and the horizontal portions 33 and 34 and the X-direction end faces of the vertical portion 32', as well as the horizontal portions 33' and 34' and the Y-direction end faces of the vertical portion 32, together form the four sides 303 of the insulation box 300.

[0039] [Manufacturing method for insulating panels] Figures 5 to 10 show the manufacturing method of the U-shaped heat insulating panel 1 according to the present invention. In each figure, Figure A is a perspective view of the mold used to manufacture the heat insulating panel, and Figure B is a cross-sectional view along line aa in Figure A. Furthermore, Figures 5 to 10 are schematic diagrams showing the outline of the manufacturing method, and details of the heat insulating panel 1 can be provided as shown in Figure 1, such as notches and uneven shapes. As the first step, a mold is prepared, as shown in Figure 5, consisting of a convex metal mold surface 200 and a concave metal mold surface 201. As the second step, as shown in Figure 6, a resin sheet 12 is pre-formed to conform to the convex portion (U-shaped cross-section) of the convex mold surface 200, and the molded resin sheet 12 is attached to the mold convex portion. At this time, as shown in Figure 6B, the resin sheet 12 inevitably forms a U-shaped cross-section. Here, as shown in the illustrated example, it is preferable to give the U-shaped end of the resin sheet 12 a shape that extends further outward in the direction perpendicular to the side of the U-shape, and to attach this extended portion to the mold surface 200 as well. This is because, when a vacuum insulation material is joined to the resin sheet in a later process, the U-shaped end of the vacuum insulation material is completely covered by the resin sheet, and the resin sheet portion that extends further outward beyond the vacuum insulation material portion is brought into contact with the foam material in a later process and strongly welded together. This ensures the strength of the U-shaped end of the insulation panel.

[0040] As the third step, the vacuum insulation material 10 is joined to the resin sheet 12 as shown in Figure 7. Figure 7 As shown in A, the vacuum insulation material 10 has a three-sided structure that can cover the portion of the resin sheet 12 corresponding to the three surfaces continuous with the U-shape of the mold protrusion. And in this case as well, as shown in Figure 7B, the vacuum insulation material 10 inevitably forms a U-shape along the resin sheet 12. Preferably, the vacuum insulation material is pre-folded so that it can easily form a U-shape. Here, as a method of joining the vacuum insulation material to the resin sheet, for example, one method is to attach it by interposing an adhesive member such as double-sided tape. Alternatively, as in another embodiment, as shown in Figures 11 and 12, when the vacuum insulation material is joined to the resin sheet, a rib 40 is provided that is formed to stand upright so as to surround and fix the peripheral edge of the vacuum insulation material, and the U-shaped end of the vacuum insulation material is fitted between the rib 40 and the U-shaped side portion of the resin sheet. In particular, the method of providing ribs at the U-shaped ends of the resin sheet allows for easy and stable fixing of the vacuum insulation material, thus enabling the vacuum insulation material to be fixed in the correct position, which is advantageous in terms of quality stability and cost. Furthermore, the strength of the resin sheet itself is improved by forming the ribs. In the illustrated example, the ribs 40 are provided on the resin sheet 12 along the entire periphery of the vacuum insulation material 10, but it is not necessary to provide them around the entire periphery as long as the vacuum insulation material can be fixed. That is, it is sufficient to provide them at least at the U-shaped ends of the vacuum insulation material.

[0041] In the fourth step, as shown in Figure 8, the concave side of the mold 201 is placed over the convex side of the mold and the mold is closed. In the fifth step, as shown in Figure 9, foam beads are injected into the mold and foamed. This foaming process covers all surfaces of the vacuum insulation material 10 except the joint surface with the resin sheet 12 with the foam 11. In the sixth step, as shown in Figure 10, the mold is opened and the completed U-shaped insulation panel 1 is removed.

[0042] The vacuum insulation material 10, foam 11, and resin sheet 12 that constitute the insulation panel 1 of the present invention will be described in more detail below.

[0043] <Vacuum insulation material> In this embodiment, the vacuum insulation material 10 includes a core material, an adsorbent, and a gas barrier film (hereinafter also referred to as the "gas barrier film"). The core material and the adsorbent are sealed under reduced pressure within the gas barrier film. In this embodiment, the internal space of the gas barrier film is depressurized by the action of the vacuum evacuation means and the adsorbent during manufacturing of the vacuum insulation material 10. The internal pressure of the vacuum insulation material is not particularly limited, but is preferably, for example, 0.5 to 20 Pa. When the internal pressure is within the above range, heat conduction through the gas inside the vacuum insulation material is suppressed, and the vacuum insulation material tends to have high thermal insulation properties.

[0044] [Core material] The core material is the component responsible for the thermal insulation performance of the vacuum insulation material 10. The core material is glass wool. The core material may be a glass wool mat consisting of glass wool and an organic binder, a single layer consisting of one glass wool mat, or a laminate consisting of 2 to 10 layers of glass wool. When the glass wool fibers of the glass wool mat are fixed together by the organic binder, it has appropriate rigidity, is resistant to crushing, and does not easily increase in density or thermal conductivity between fibers, thus contributing to maintaining the thermal insulation performance of the vacuum insulation material 10.

[0045] The density of the core material is not particularly limited, but for example, the density of the core material in the vacuum insulation material 10 (density at the time of vacuum insulation material molding) could be 130 kg / m³. 3 More than 300kg / m 3 It is preferable that the core material density be less than 130 kg / m³. 3 If the density falls below this range, the amount of glass wool is too small, resulting in unstable surface smoothness and reduced insulation performance, making it difficult to use. When the density of the core material is within the above range, the vacuum insulation material becomes lightweight, and even when the gas barrier film compresses the core material due to the rapid pressure drop during vacuum forming, the core material's shape can be sufficiently maintained. The density of the core material can be measured in accordance with JIS A 9521.

[0046] glass wool While the glass wool is not particularly limited, it is preferable that its average fiber diameter is, for example, 2 to 10 μm. When the average fiber diameter of the glass wool is within this range, it tends to provide appropriate core strength and excellent insulation properties that reduce tearing of the mat during press molding of the core material, uneven thickness of the molded product, and skin irritation caused by the glass wool, while also suppressing the aging deterioration of the vacuum insulation material (aging increase in thermal conductivity). The average fiber diameter can be measured by the air permeability resistance method or by an optical microscope.

[0047] Organic binder The organic binder is not particularly limited, and conventionally known binders can be used, such as aldehyde condensation thermosetting resins such as phenolic resins, ester-based thermosetting resins such as acrylic resins, and epoxy-based thermosetting resins.

[0048] The content (amount of adhering) of the organic binder in the total 100% by mass of glass wool and organic binder is not particularly limited, but is preferably 0.5 to 9.0% by mass in terms of solid content. When the organic binder content is within the above range, a lightweight vacuum insulation material is obtained, and appropriate rigidity can be imparted to the core material, so that the core material shape can be sufficiently maintained even when the gas barrier film compresses the core material due to the rapid pressure drop during vacuum forming. In addition, the density of the core material and the thermal conductivity between fibers do not increase easily, and outgassing is suppressed, so a vacuum insulation material with excellent thermal conductivity and suppressed deterioration of insulation performance over time (increase in thermal conductivity over time) can be obtained.

[0049] [Adsorbent] The adsorbent is not particularly limited, but one or more adsorbents can be enclosed. Preferably, it may include adsorbent A, which adsorbs moisture (water vapor) by chemical adsorption, and adsorbent B, which has a slower moisture adsorption rate than adsorbent A. By including adsorbents with different moisture adsorption rates, outgassing (carbon monoxide, carbon dioxide, formaldehyde, amines, or aromatic hydrocarbons, etc.) generated from the core material when an organic binder is used, gases entering from the outside (nitrogen, oxygen, or carbon dioxide, etc.), and moisture are adsorbed more effectively. As a result, a vacuum insulation material with excellent thermal conductivity and suppressed deterioration of insulation performance over time (increase in thermal conductivity over time) can be obtained.

[0050] The form (shape) of the adsorbent is not particularly limited. For example, adsorbent A and adsorbent B may be separate powders, pellets, or tablets, or they may be a mixture containing adsorbent A and adsorbent B in the form of powder, pellets, or tablets. Alternatively, adsorbent A may cover part or all of the surrounding area of ​​adsorbent B, and then be pelletized or tableted (for example, a pellet or tablet with a structure in which adsorbent B is the core and a layer of adsorbent A surrounds it).

[0051] Preferred examples of adsorbents include alkaline earth metal oxides such as calcium oxide and magnesium oxide, alkali metal oxides such as sodium oxide, and silica gel. Among these, calcium oxide is preferred because it has a particularly fast water adsorption rate.

[0052] [Gas barrier film] The gas barrier film is not particularly limited as long as it has gas barrier properties, but it is preferably a multilayer film in which a sealing layer and a gas barrier layer are pre-laminated, and more preferably a multilayer film in which a sealing layer, a gas barrier layer, and a protective layer are laminated in that order from the side in contact with the core material.

[0053] The thickness of the gas barrier film is not particularly limited, but from the viewpoint of preventing damage or a decrease in vacuum, it is preferable that it be thicker than conventional films, for example, 50 to 150 μm.

[0054] A gas barrier layer is a layer that does not allow gas to pass through and is provided to prevent a decrease in the vacuum level of the vacuum insulation material. Examples of gas barrier layers include metal foil and laminated films (deposited films) on which metal or the like is deposited onto a resin film.

[0055] Examples of metals used for the metal foil include aluminum, copper, stainless steel, and iron, with aluminum being preferred.

[0056] Vapor-deposited films are formed by depositing metals such as aluminum, stainless steel, cobalt, and nickel, or silica, alumina, or combinations thereof, using methods such as vapor deposition and sputtering. Examples of resin films used as substrates for vapor-deposited films include films made from thermoplastic resins such as polyester resins, polyolefin resins, vinyl chloride resins, polyamide resins, styrene resins, acrylic resins, ethylene-vinyl alcohol copolymers, polyvinyl alcohol resins and partially saponified versions thereof, as well as thermosetting resins such as phenolic resins and urea resins.

[0057] The gas barrier layer is preferably a vapor-deposited film formed by depositing aluminum onto an ethylene-vinyl alcohol copolymer resin, or a vapor-deposited film formed by depositing aluminum or silica onto a PET resin, or aluminum foil, or a laminated structure thereof. Metal foils and vapor-deposited films used in the gas barrier layer are well known and readily available or can be prepared on the market.

[0058] The thickness of the gas barrier layer is not particularly limited, but in the case of a vapor-deposited film, the thickness of the vapor-deposited film is preferably 200 to 2000 Å, and in the case of a metal foil, it is preferably 5 to 10 μm.

[0059] The sealing layer is a heat-sealable layer that is provided for the purpose of fusing gas barrier films together to seal the core material and adsorbent within the film. Examples of the sealing layer include heat-sealable resin films. Examples of heat-sealable resins include polyethylene resin, polypropylene resin, and ethylene-vinyl alcohol copolymer. The density of the polyethylene resin film is not particularly limited, but is generally between 0.90 and 0.98 g / cm³. 3 It is preferable that the polypropylene resin film has a density of 0.85 to 0.95 g / cm³. 3 It is preferable that this be the case.

[0060] The thickness of the seal layer is not particularly limited, but it is preferably 25 to 70 μm, as this improves the airtightness of the fused portion (the "ear portion" described later) formed by fusing the seal layers together and prevents leakage from the fused portion after vacuum packaging. The heat-sealable resin used for the seal layer is well known and readily available or can be prepared on the market.

[0061] A protective layer is a layer optionally placed on top of the gas barrier layer for the purpose of protecting the gas barrier layer.

[0062] Examples of protective layers include films made from thermoplastic resins such as aromatic polyester resins, polyolefin resins, vinyl chloride resins, polyamide resins, styrene resins, and acrylic resins, as well as thermosetting resins such as phenolic resins and urea resins.

[0063] The above resins may be used individually or as a mixture of two or more. The resins used for the protective layer are well known and readily available or can be prepared on the market.

[0064] The protective layer may contain organic or inorganic fillers. To further improve the gas barrier performance of the gas barrier film, the protective layer may be coated with, laminated with, or have particles of a gas barrier resin obtained by polymerizing or copolymerizing vinyl monomers such as vinylidene chloride resin, acrylonitrile resin, or vinyl alcohol resin, or these particles may be mixed and dispersed in the resin film layer.

[0065] The thickness of the protective layer is not particularly limited, but it is preferably 10 to 30 μm from the viewpoint of effectively preventing damage to the gas barrier film.

[0066] In the vacuum insulation material 10 of this embodiment, "ears" are usually formed around the portion where the core material and adsorbent are sealed under reduced pressure, with the sealing layers of the gas barrier film adhering to each other. The ears may be folded by "ear folding," which involves folding the ears along the core material, and in this case, it is preferable to fold them to the side that does not come into contact with the heat source during the installation of the vacuum insulation material 10.

[0067] In the vacuum insulation material 10 of this embodiment, as a measure against damage due to heat or impact, an insulating material such as glass wool or foam may be bonded to the surface of the vacuum insulation material 10 to protect it.

[0068] The manufacturing method for the vacuum insulation material 10 of this embodiment is not particularly limited, but it can be manufactured by placing a core material and an adsorbent inside a bag-shaped gas barrier film, depressurizing the air inside the gas barrier film by removing the air, and then sealing the gas barrier film. The bag-shaped gas barrier film can be made, for example, by overlapping two gas barrier films so that their sealing layers are in contact with each other, and then heat-sealing the outer periphery while leaving an opening for inserting the core and adsorbent to form a bag. For depressurization sealing, conventionally known methods in the art, such as using a vacuum packaging machine, can be used. Before depressurization sealing, preferably until just before insertion into the depressurization sealing device, the thermal conductivity of the resulting vacuum insulation material can be reduced by heating and drying the core material and gas barrier film. The drying temperature is, for example, 130 to 250°C for the core material and, for example, 50 to 80°C for the gas barrier film. To prevent the adsorbent from shifting position during depressurization sealing, depressions or holes corresponding to the shape of the adsorbent may be provided in the core material beforehand. In the manufacturing process described above, air may remain in the internal space of the gas barrier film. The moisture (water vapor) contained in this air acts as a heat transfer substance, which can increase the thermal conductivity and potentially lead to a decrease in the thermal insulation performance of the vacuum insulation material. In the vacuum insulation material 10 of this embodiment, excellent thermal performance can be achieved by adsorbing this moisture onto the adsorbent. The thickness of the vacuum insulation material thus manufactured is preferably 5 mm to 40 mm, and more preferably 6 mm to 20 mm. If the thickness of the vacuum insulation material is too small, the number of layers of glass wool core material will decrease, which may reduce the thermal insulation performance. Conversely, if the thickness is too large, it may adversely affect the handling of the vacuum insulation material during manufacturing and the setting process during foam molding.

[0069] <Foam> In this embodiment, the foam 11 is integrally molded with the vacuum insulation material 10 and the resin sheet 12. The thickness of the foam layer 11 is preferably about 10mm to 50mm, more preferably 15mm to 30mm. A thickness within this range ensures good manufacturing yield and maintains good thermal insulation performance of the insulation panel. However, if the thickness of the foam layer 11 is less than 10mm, the moldability of the foam portion deteriorates, potentially leading to poor manufacturing yield. Conversely, if it exceeds 50mm, the influence of thermal bridging in the foam portion increases, and the relative proportion of the vacuum insulation material decreases, potentially reducing the thermal insulation performance of the panel. The foaming material used for the foam 11 may be any material obtained by foaming thermoplastic resins such as polystyrene (PS) resin, bead-processed polystyrene (EPS) resin, polyethylene resin, polyvinyl chloride resin, polystyrene-polyolefin composite resin, polypropylene resin, and (meth)acrylic resin, but polystyrene resin, polystyrene-polyolefin composite resin, and polypropylene resin are particularly preferred. The foam material in this embodiment is preferably a polystyrene-polyolefin composite resin bead foam from the viewpoint of impact resistance, oil resistance, and chemical resistance, but is not limited to this, and may be other bead foams such as expanded polystyrene or expanded polystyrene. When molding the bead foam, dimensional tolerances can be stabilized by using a mold, making it possible to manufacture the insulation panel 1 with actual tolerances of ±1 mm for each of its width, length, and thickness. Furthermore, the method for producing the foam 11 is not limited to the bead foaming method, but any other foaming method may be used, such as the extrusion foaming method, injection foaming method, and press foaming method.

[0070] The foaming ratio of the bead foam (foaming material) used in the foam 11 is not particularly limited, but from the viewpoint of puncture resistance and impact resistance, it is preferably 5 to 100 times, preferably 10 to 50 times, and more preferably 20 to 30 times. If the foaming ratio of the material used in the foam 11 is 30 times or less, sufficient strength can be obtained to prevent damage such as dents or holes in each surface of the insulated box body due to various impacts that occur in logistics sites, such as assembly, disassembly, storage, transportation, and loading and unloading of contents. In this embodiment, appropriate foaming conditions for forming the foam 11 (in particular, foaming conditions for bead-type polystyrene resin and polystyrene-polyolefin composite resin) are exemplified below. • Pre-foaming bead size: Polystyrene resin, average particle size 0.75 mm Polystyrene / polyolefin composite resin, average particle size 1.6 mm • Foaming temperature: 100°C to 130°C, preferably 110°C to 120°C • Pressure during foaming: 0.02 MPa to 0.1 MPa, preferably 0.03 MPa to 0.07 MPa

[0071] <Resin sheet> In this embodiment, the resin sheet 12 used is a sheet having a thickness of approximately 0.1 mm to 4.0 mm, preferably 0.2 mm to 3.0 mm, and most preferably 0.3 mm to 2.0 mm. Furthermore, it is preferable that the resin sheet 12 is a single resin sheet. Here, "single" means a single layer and continuous sheet, and furthermore, it does not contain any components other than the specific resin (for example, it does not contain metal). By using a single resin sheet, the number of steps required to attach the vacuum insulation material to the resin sheet attached to the mold during the molding of the insulation panel can be simplified compared to the case where multiple resin sheets are used. Also, when multiple resin sheets are laminated, gaps are created between the laminated resin sheets, which may cause foam to enter the gaps during the subsequent foam molding process, potentially resulting in molding defects. Furthermore, it is preferable that the resin sheet 12 is of the same material as the foam 11 described in the above paragraph. Herein, in this specification, "homogeneous" refers to materials made of the same components, such as polyethylene foam and polyethylene resin sheet, or polystyrene foam and polystyrene resin sheet, or in the case of composite resins, one of the components overlaps (for example, in the case of polyethylene-polystyrene composite resin foam, polyethylene or polystyrene resin sheet is used). When the resin sheet 12 and foam 11 used are homogeneous, their adhesion to each other is improved. Therefore, it becomes possible to weld the resin sheet 12 and the foam 11 together without using an adhesive such as a hot-melt adhesive. [Examples]

[0072] [Example 1: Test of the cooling effect of the insulated box according to the present invention] To verify the cooling effect of the insulated box, insulated boxes 100 of various specifications shown in Table 1 were assembled using two insulated panels of the shape shown in Figure 1 according to the present invention, in the manner shown in Figure 2. The details of the insulated panels are as follows. • Resin sheet (thickness 0.8mm): PS resin sheet • Vacuum insulation material (20mm thick); • Core: Glass wool core • Film: Hybrid type of aluminum vapor-deposited film and aluminum foil film. • Foam (thickness 10-35mm): EPS bead foam (expansion ratio 20x) ·Box external dimensions: 226mm x 226mm x t135mm ·Box internal dimensions: 153.9mm x 153.9mm x t65mm • Coverage rate of vacuum insulation material relative to the internal dimensions of the box: 78%

[0073] The inside of the resulting box was kept cool to -10°C. Furthermore, 300g of latent heat storage material (PCM) 20, pre-cooled to -20°C, was placed inside the box as the object to be refrigerated, and a thermometer 21 was placed on top of it. Figure 13 shows a schematic diagram of the inside of the insulated box used in the test. The box was then placed in a constant temperature bath at 30°C, and the temperature rise of the PCM over time was observed at fixed points every 5 minutes. At the same time, a box consisting only of foam 11 without vacuum insulation material (VIP) 10 was used as a comparative example and the same test was conducted. Temperature measurements were taken for each test specimen every 5 minutes, and the time (minutes) required to reach each temperature point (0°C, 5°C, 10°C, 15°C, and 20°C) is shown in Table 1.

[0074] [Table 1]

[0075] The insulated box according to the present invention showed an extremely high cooling effect compared to a box made solely of foam. It was found that the time required to reach each temperature point was approximately twice as long in the example compared to the comparative example. In other words, the box of the example provided approximately twice the cooling effect in terms of time compared to the box of the comparative example. In particular, it was revealed that the example was capable of maintaining a temperature of 5°C or lower for approximately 1200 minutes (about 20 hours). [Explanation of symbols]

[0076] 1. Insulation panel 2 Vertical section 3 Side view 4 Side view 5. Notch 6a Convex part 6b Convex part 7a recess 7b recess 8a Convex part 8b Convex part 9 grooves 10 Vacuum insulation material 11 Foam 12 Resin Sheets 20 Latent heat storage material (PCM) 21 Thermometer 30 One of the irregularly shaped insulation panels 32 The vertical section of one of the irregularly shaped insulation panels 33 Side view of one of the irregularly shaped insulation panels 34 Side view of one of the irregularly shaped insulation panels 30' Other irregularly shaped insulation panel 32' The vertical section of the other irregularly shaped insulation panel 33' Side view of the other irregularly shaped insulation panel 34' Side view of the other irregularly shaped insulation panel 40 Ribs 50a U-shaped inner space 50b U-shaped inner space 100 Insulated Box 100' Insulated box body of another embodiment 101 Top surface 102 Bottom surface 103 Side view 200 Convex mold, one side 201 Concave mold, one side 300 Irregularly Shaped Insulated Panels for Insulated Boxes 301 Top surface of irregularly shaped insulation panel 302 Bottom surface of irregularly shaped insulation panel 303 Side view of an irregularly shaped insulation panel

Claims

1. An insulating panel having a U-shaped cross-section, comprising a vacuum insulating material with a U-shaped cross-section, a resin sheet bonded to at least the inner surface of the vacuum insulating material, and a foam covering the surface of the vacuum insulating material other than the surface bonded to the resin sheet.

2. The thermal insulation panel according to claim 1, having a pair of horizontal parts corresponding to the horizontal sides of the U-shape and vertical parts corresponding to the vertical sides of the U-shape, wherein the vertical parts are square in shape, and the outline of the inner space of the U-shape partitioned by the vertical and horizontal sides is the same as the shape of the horizontal parts.

3. The thermal insulation panel according to claim 1 or 2, wherein the foam is a bead foam.

4. The thermal insulation panel according to claim 1 or 2, wherein the resin sheet is a single sheet.

5. The thermal insulation panel according to claim 1 or 2, wherein the resin sheet and the foam include at least one of polystyrene resin, polystyrene-polyolefin composite resin, and polypropylene resin.

6. The thermal insulation panel according to claim 1 or 2, wherein the resin sheet and the foam are of the same material.

7. An insulated box body comprising two insulated panels according to claim 1 or 2, wherein the U-shaped openings of the two insulated panels are facing each other and fitted together.

8. The insulated box according to claim 7, wherein the two insulated panels are of the same shape.

9. The heat insulating box according to claim 7, wherein the vertical portion of the heat insulating panel has a protrusion at its edge, and the horizontal portion has a recess at its edge for interlocking with the protrusion.

10. The insulated box according to claim 7, wherein each of the two insulated panels has a groove for accommodating fasteners.

11. The insulated box according to claim 7, wherein the coverage rate of the vacuum insulation material on the six wall surfaces constituting the internal space of the insulated box is 60% or more.

12. A method for manufacturing an insulating panel having a U-shaped cross-section, The steps include: attaching a resin sheet to the inner surface of the mold in a U-shape cross-section, The steps include: joining a vacuum insulation material to the aforementioned resin sheet; The steps include closing the mold and injecting foaming material into the mold, The steps include: foaming the aforementioned foam material to cover the surface of the vacuum insulation material other than the surface to be attached to the resin sheet with the foam; A method for manufacturing an insulating panel, including the invention of the insulating panel.

13. The manufacturing method according to claim 12, wherein in the step of attaching the resin sheet, the U-shaped end of the resin sheet is further extended outward in a direction perpendicular to the horizontal part of the U and attached.

14. The manufacturing method according to claim 12, wherein in the step of joining the vacuum insulation material to the resin sheet, the vacuum insulation material is joined to the resin sheet via ribs provided on the resin sheet.

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