Vacuum heat insulating material with built-in resin block

Abstract

To provide a vacuum heat insulating material with a built-in resin block capable of preventing outside air from flowing into a place where a core material is sealed even if drilling is performed through the resin block.SOLUTION: The vacuum heat insulating material 1 with the built-in resin block includes a resin block 3 having a boring processing area 2 on two opposed faces, a core material 4 arranged around the resin block 3, a film 5 for covering the core material 4 and the resin block 3 and keeping the inside in vacuum, and a plurality of uneven parts 6 annularly formed to surround the boring processing area 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vacuum insulation material incorporating a resin block. [Background technology]

[0002] From the viewpoint of efficient use of thermal energy, vacuum insulation materials are widely used in the fields of heat and cold insulation equipment such as refrigerators and chillers, as well as insulation materials for floors and walls of buildings. This vacuum insulation material is formed by covering a core material made of porous material or glass wool with a film that acts as an exterior body. The internal vacuum is maintained by covering it with a film that has gas barrier properties. Maintaining this internal pressure in a vacuum state ensures high insulation performance.

[0003] However, if a hole is made in the film of vacuum insulation material, air will flow inside, making it impossible to maintain the vacuum and reducing its insulating performance. As a result, vacuum insulation material cannot be post-processed, such as by drilling holes, making it difficult to use around piping, etc. To address this problem, a method is known in which a resin block is embedded in the vacuum insulation material and heat-sealed to the film, making it possible to drill holes (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 084763 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the surface of the resin block is flat, even if the resin block is heat-sealed to the film, the resin block and the film will peel off at the processing location during the hole drilling process, and this may spread to the core material, causing the film to peel off and outside air to flow into the inside of the vacuum insulation material, causing the inside to reach atmospheric pressure. Patent Document 1 describes that the surface of the resin block may be made finely uneven, but does not go so far as to mention how to create these irregularities in order to effectively prevent outside air from flowing into the inside of the vacuum insulation material.

[0006] The present invention has been made in consideration of the above-mentioned conventional technology, and aims to provide a vacuum insulation material with a built-in resin block that can prevent outside air from flowing into the area where the core material is sealed, thereby maintaining performance, even if holes are drilled through the resin block. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a vacuum insulation material built into a resin block, characterized by comprising: a resin block having perforation areas on two opposing sides; a core material arranged around the resin block; a film covering the core material and the resin block to maintain a vacuum inside; and a plurality of irregularities formed in a ring shape surrounding the perforation areas.

[0008] Preferably, the top of the uneven portion is formed flat, the top is welded to the film, and the bottom of the uneven portion has a non-welded portion that is not welded to the film.

[0009] Preferably, the top portion is formed at a position higher than the surfaces of the resin block and the core material.

[0010] Preferably, the bottom is formed at a position lower than the surfaces of the resin block and the core material.

[0011] Preferably, at the boundary between the resin block and the core material, the core material has an expanding portion that expands toward the outer periphery of the resin block.

[0012] Preferably, the film has a welding layer, a gas barrier layer, and a protective layer, and the welding layer and the resin block are made of the same material and are welded to each other. [Effects of the Invention]

[0013] According to the present invention, annular concave-convex portions are formed on two opposing surfaces of the resin block so as to surround the perforation area, and a plurality of these concave-convex portions are arranged, so that even if outside air tries to flow into the core material from a location where the film is torn when a hole is drilled through the resin block, the concave-convex portions prevent this. Even if one of the concave-convex portions is destroyed during the drilling process, the multiple concave-convex portions can prevent outside air from flowing in.

[0014] Furthermore, the flat tops of the uneven portions allow for reliable and easy welding with the film. In particular, when ultrasonic sealing is used, welding can be achieved by simply applying the horn of the ultrasonic sealing device for approximately two seconds, preventing film deterioration due to prolonged welding operations and ensuring reliable welding. The flat tops provide a location where energy can be concentrated during ultrasonic sealing when viewed from the entire welding surface of the resin block. Furthermore, the flatness of the tops alone disperses the energy, minimizing the risk of tearing the film during welding. Furthermore, forming non-welded areas at the bottoms of the uneven portions prevents outside air from flowing over the uneven portions into the core material from the perforation sites during hole drilling. Because the film is vacuum inside, these non-welded areas are also vacuum. If adjacent bottoms among a plurality of lined-up bottoms are in the same vacuum, there is no pressure difference, so even if outside air tries to flow in, the movement of the outside air from the vacuum bottom toward the bottom of the adjacent vacuum is suppressed, and the flow of the outside air toward the core material can be prevented.

[0015] Furthermore, since the top is formed at a position higher than the surfaces of the resin block and the core material, heat is easily transferred to the welding layer of the film and the resin block, and the top can be reliably sealed during welding.

[0016] Furthermore, since the bottom portion is formed at a position lower than the surfaces of the resin block and the core material, a non-welded portion in a vacuum state can be reliably formed.

[0017] Furthermore, by providing an expansion section in the core material, it is possible to prevent the core material from covering the resin block when creating a vacuum inside the film, thereby preventing adverse effects on subsequent welding of the film and the resin block.

[0018] Furthermore, since the welding layer of the film and the resin block are made of the same material, the weldability increases when they are melted together, making it possible to provide high-quality welding. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic cross-sectional view of a vacuum insulation material incorporating a resin block according to the present invention. [Figure 2] FIG. 2 is a schematic perspective view of a resin block. [Figure 3] FIG. 2 is a schematic cross-sectional view of a resin block. [Figure 4] FIG. 3 is a schematic cross-sectional view showing a welded portion between the concave-convex portion and the film. [Figure 5] FIG. 10 is a schematic perspective view of a resin block provided with a through hole. [Figure 6] 1 is a schematic cross-sectional view of a vacuum insulation material with a resin block built in and a through hole formed therein. [Figure 7] FIG. 2 is a schematic cross-sectional view showing a welded state between a resin block and a film. [Figure 8] FIG. 10 is an explanatory diagram for explaining the positional relationship between the top and bottom. [Figure 9] 10 is a schematic diagram showing the results of an experiment on welding a resin block and a film. FIG. [Figure 10]FIG. 10 is a schematic diagram showing the results of an experiment on welding a resin block and a film with through holes provided therein. DETAILED DESCRIPTION OF THE INVENTION

[0020] As shown in FIG. 1, a vacuum insulation panel 1 incorporating a resin block according to the present invention includes a resin block 3 having perforation regions 2 on two opposing surfaces. A core material 4 is disposed around the resin block 3. Examples of the core material 4 include glass wool, silica, and aerogel. The resin block 3 and core material 4 are covered with a film 5. A vacuum is maintained within the film 5. Although not shown, an adsorbent is disposed within the film 5 to maintain this vacuum. Examples of adsorbents include moisture adsorbents and gas adsorbents. Moisture adsorbents include calcium oxide and silica gel, while gas adsorbents include porous materials such as activated carbon and metal-organic frameworks (MOFs). The adsorbent is disposed, for example, sandwiched between the core material 4. A ring-shaped irregularity 6 is disposed around the perforation region 2, surrounding the perforation region 2. Multiple irregularities 6 are formed. All of the irregularities 6 surround the perforation region 2. Since the hole processing region 2 is for forming a through hole penetrating the resin block 3, the hole processing region 2 is formed on two opposing surfaces of the resin block 3. Therefore, the concave-convex portions 6 are also formed on two opposing surfaces of the resin block 3. Although the resin block 3 is shown to have a cylindrical shape in the figure, it may also have a rectangular parallelepiped or cubic shape.

[0021] 2 and 3, the uneven portion 6 has a top portion 7 that is the convex portion and a bottom portion 8 that is the concave portion. The top surface of the top portion 7 is formed flat. And, as is clear from FIG. 4, the top portion 7 is welded to the film 5. At this time, the bottom portion 8 of the uneven portion 6 has a non-welded portion 9 that is not welded to the film 5.

[0022] This structure prevents outside air from entering the film 5 and reaching the core material 4 even if the film 5 tears during the hole drilling process when drilling holes through the hole drilling region 2 of the resin block 3. This effect is achieved by the following factors. First, the top surface of the top portion 7 is flat. This allows the welding surface with the film 5 to be flat, preventing film tearing during welding and achieving reliable welding. Therefore, by arranging multiple top portions 7 surrounding the hole drilling region 2, the multiple top portions 7 can prevent the inflow of outside air. In particular, when welding using ultrasonic sealing, welding can be achieved by applying the horn of the ultrasonic sealing device for about two seconds (requiring short welding time), preventing film tearing due to prolonged welding operations and ensuring reliable welding. If welding takes a long time, heat may be transferred not only to the desired welding area but also to the surrounding area, potentially melting and tearing the film 5. Furthermore, when ultrasonic sealing is used for welding, the flatness of the top 7 provides a location where energy can be concentrated during ultrasonic sealing when viewed from the perspective of the entire welding surface of the resin block 3. Furthermore, when focusing only on the top 7, the flat upper surface disperses the energy, minimizing the risk of tearing the film 5 during welding. The width of the flat portion on the top surface of the top 7 can be appropriately set within a range of 0.1 mm to 3 mm, preferably 0.1 mm to 1 mm. The presence of such a top 7 allows ultrasonic vibrations to be transmitted effectively, achieving reliable welding. Furthermore, by limiting the welding area, excessive output is not required, thereby preventing tearing of the film 5.

[0023] Next, non-welded portions 9 are formed on the bottom 8. By forming the non-welded portions 9 on the bottom 8 of the uneven portion 6, it is possible to prevent outside air from flowing from the hole-making region 2 across the uneven portion 6 toward the core material 4 during hole-making. Because the inside of the film 5 is a vacuum, these non-welded portions 9 (the space surrounded by the film 5 and the inner wall of the uneven portion 6) are also vacuum. If adjacent bottoms 8 among a plurality of lined-up bottoms 8 are at the same vacuum, there is no pressure difference, so even if outside air tries to flow in, it is prevented from transmitting from the vacuum bottom 8 toward the adjacent vacuum bottom 8, and therefore the outside air can be prevented from flowing into the core material 4.

[0024] The perforation processing in the perforation processing area 2 may be performed via the uneven portion 6. Essentially, the location where the through-hole is provided is the perforation processing area 2, and the above-mentioned effect can be achieved as long as there are multiple uneven portions 6 surrounding this area 2. Even if one of the uneven portions 6 (the apex 7) is destroyed during such perforation processing, the multiple uneven portions 6 arranged outside it can prevent outside air from entering. A minimum of three apexes 7 outside the perforation processing area 2 is sufficient. In other words, the presence of multiple uneven portions 6 also prevents outside air from entering the film 5. With this configuration, the perforation processing area 2 can be set at any position in the resin block 3 surrounded by multiple uneven portions 6, and a perforation can be formed there. This allows the vacuum insulation material with this through-hole to be installed in a location where a pipe is located.

[0025] As shown in Figure 5, even if a through hole 10 is provided in the hole drilling region 2 of the resin block 3, the through hole 10 is surrounded by a plurality of uneven portions 6, so the above effect can be obtained. The through hole 10 may be provided to the user in advance as part of the vacuum insulation material 1, or the material may be provided to the user without the through hole 10, and the user may provide it themselves as appropriate. As is clear from Figure 6, even if a through hole 10 is provided, it is surrounded by uneven portions 6.

[0026] Meanwhile, an expanded portion 11 is formed at the boundary between the resin block 3 and the core material 4. This expanded portion 11 is formed by expanding the core material 4 toward the outer periphery of the resin block 3. While FIG. 1 shows the expanded portion 11 at the boundary between the resin block 3 and the core material 4, where the upper portion is stepped more than the lower portion, it may be formed at an angle relative to either side, or expanded portions 11 may be provided at both the upper and lower portions. During the manufacturing process of the vacuum insulation panel 1, the core material 4 and the resin block 3 are sealed in a film 5 and evacuated. The presence of the expanded portion 11 prevents the core material 4 from covering the resin block 3. This prevents the core material 4 from being placed on the top portion 7 of the uneven portion 6, which would adversely affect the subsequent welding between the film 5 and the resin block 3. In other words, welding between the top portion 7 and the film 5 via the core material 4 can be prevented, improving the reliability of the welding.

[0027] As shown in FIG. 7, the film 5 has at least a three-layer structure, consisting of, from the core material 4 side, a welding layer 5a welded to the resin block 3, a gas barrier layer 5b adjacent to the welding layer 5a, and a protective layer 5c serving as the outermost layer. The welding layer 5a is made of the same material as the resin block 3. If the welding layer 5a and the resin block 3 are made of the same material, they will be more easily welded together when melted, preventing outside air from entering the vacuum insulation material. The welding layer 5a and the resin block 3 are made of polyethylene or polypropylene, with polyethylene being preferred. Polyethylene has a relatively low melting temperature, which reduces the thermal load on the film 5 during welding. The gas barrier layer 5b can be made of, for example, aluminum foil or aluminum-deposited film, and the protective layer 5c can be made of a material with high heat resistance and toughness, such as polyamide or polyethylene terephthalate.

[0028] 8, the top 7 is formed at a position higher than the surfaces of the resin block 3 and the core material 4. In the figure, line A representing the height of the top 7 is shown to be higher than line B representing the height of the resin block 3 and the core material 4. Note that the film 5 is omitted from the figure. This ensures that the horn comes into contact with the top 7 during ultrasonic sealing, thereby ensuring reliable welding of the film 5 and the top 7.

[0029] On the other hand, the bottom 8 (the lowest point of the bottom 8) is formed at a position lower than the surfaces of the resin block 3 and the core material 4. In the figure, the height line C of the bottom 8 is shown lower than the height line B of the resin block 3 and the core material 4. This allows a space to be formed between the film 5 and the bottom 8, thereby reliably forming the non-welded portion 9 in a vacuum state. This prevents outside air from flowing into the core material 4 from the hole-forming area, over the uneven portion 6. Since the film 5 is a vacuum, the non-welded portion 9 is also a vacuum. If adjacent bottoms 8 in a row are at the same vacuum, there is no pressure difference, so even if outside air tries to flow in, the inflow of outside air from the vacuum bottom 8 toward the adjacent vacuum bottom 8 is suppressed, preventing the outside air from flowing toward the core material 4.

[0030] An experiment was conducted below to examine the sealing properties of a vacuum insulation material 1 incorporating a resin block according to the present invention. The resin block 3 was made of polyethylene, and the film 5 had a welding layer 5a made of polyethylene, a gas barrier layer 5b made of aluminum foil, and a protective layer 5c made of polyethylene terephthalate and polyamide. The results are shown below. For the experiment, a Branson 2000XE ultrasonic sealing device was used. The horn was placed on top of a cylindrical resin block 3 with a diameter of 44 mm and fixed in place to prevent vibrations from escaping. The horn was then vibrated at 20 kHz while pressing down on the resin block 3. This melted the resin block 3 and film 5 due to frictional heat generated by the vibrations, and the resin block 3 and film 5 were cooled by applying pressure with the horn, resulting in ultrasonic sealing. As shown in Figure 9, experiments were conducted on Examples 1 to 3 by changing the thickness (t in Figure 8), diameter of resin block 3, horn tip shape (an oval horn with a width of 37 mm and a length of 47 mm was used, and a circular horn with a diameter of 40 mm), welding time (the time to generate frictional heat by ultrasonic vibration), hold time (the time to press down on resin block 3 to fix the seal after ultrasonic vibration for welding), trigger pressure (the pressure to press down on resin block 3 to fix the seal after thermal welding), ultrasonic amplitude (expressed in units of %, with the maximum amplitude at which the vibration system can normally vibrate being taken as 100 being set as a percentage), and horn pressure. The results showed that for all vacuum insulation panels 1 incorporating resin blocks according to the present invention with concave and convex portions 6, the film 5 did not tear and a good seal was obtained.

[0031] Similar experiments were also conducted on a vacuum insulation material 1 built into a resin block using a resin block 3 having through holes 10, as shown in Fig. 10. At that time, experiments were also conducted on a comparative example having through holes 10 but no uneven portion 6 (the two opposing surfaces of the resin block 3 are flat). The results showed that no tearing of the film 5 was observed when the uneven portion 6 was present, even for a resin block 3 having through holes 10. In the comparative example, the effect of the uneven portion 6 was not obtained, and tears occurred in the film 5.

[0032] From the above experiments, it can be said that the best welding conditions for the ultrasonic sealing equipment used in this experiment are a welding time of less than 1.3 seconds, a hold time equal to or longer than the welding time, a trigger pressure of more than 100N, and an amplitude of 70% or less. [Industrial Applicability]

[0033] The vacuum insulation material of the present invention can be drilled through the built-in resin block, and can be placed in places where heat retention, cooling, or insulation is required, without having to worry about piping, etc., such as in the residential field where energy conservation is required, such as the walls, roofs, floors, and thermal equipment of homes and buildings; in the field of heat retention and cold retention, such as water heaters, refrigerators, vending machines, cooler boxes, and chillers; and in the transportation field, such as trucks, shipping containers, refrigerated vehicles, and ships. [Explanation of symbols]

[0034] 1: Vacuum insulation material built into resin block, 2: Perforated area, 3: Resin block, 4: Core material, 5: Film, 5a: Welded layer, 5b: Gas barrier layer, 5c: Protective layer, 6: Concave and convex portion, 7: Top, 8: Bottom, 9: Non-welded portion, 10: Through hole, 11: Expanded portion

Claims

1. a resin block having hole-forming regions on two opposing surfaces; a core material disposed around the resin block; a film for covering the core material and the resin block and maintaining a vacuum inside; A vacuum insulation material with a built-in resin block, characterized in that it is provided with a plurality of uneven portions formed in a ring shape so as to surround the perforation processing area.

2. The top of the uneven portion is formed flat, the top is welded to the film, 2. The vacuum heat insulating material with a built-in resin block according to claim 1, wherein the bottom of the uneven portion has a non-welded portion that is not welded to the film.

3. 3. The vacuum insulation material with a built-in resin block according to claim 2, wherein the top is formed at a position higher than the surfaces of the resin block and the core material.

4. 3. The vacuum heat insulating material with a built-in resin block according to claim 2, wherein the bottom is formed at a position lower than the surfaces of the resin block and the core material.

5. A vacuum insulation material with a built-in resin block as described in claim 1, characterized in that at the boundary between the resin block and the core material, the core material has an expanded portion that expands toward the outer periphery of the resin block.

6. The vacuum insulation material with a built-in resin block as described in claim 1, characterized in that the film has a welding layer, a gas barrier layer, and a protective layer, and the welding layer and the resin block are made of the same material and are welded to each other.

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