Refrigerator door and refrigerator

Abstract

The present invention provides a refrigerator door in which a resin outer plate and a resin inner plate are connected around the perimeter with a gap between them, thereby making it less likely for the interior to be obscured by the influence of the environment outside the refrigerator, and a refrigerator equipped with such a refrigerator door. [Solution] A refrigerator door 10 comprising a resin outer plate 11, a resin inner plate 12 facing the outer plate, and a connecting part 14 that connects the outer plate and the inner plate around the periphery such that a gap 13 is provided, characterized in that a layer 15 containing a metal with a heat ray transmittance lower than that of the outer plate 11 is provided on the surface of the outer plate 11 adjacent to the gap 13.

Description

Technical Field

[0001] The present invention relates to a refrigerator door and a refrigerator equipped with the same.

Background Art

[0002] In various stores such as department stores, supermarkets, and convenience stores, products such as drinking water are stored in refrigerators, and the display status of products such as drinking water inside the refrigerator can be seen at a glance from the outside. Such a refrigerator door is configured by attaching a frame to a glass plate, and the door is attached to a window frame of the refrigerator such as a hinge.

[0003] Patent Document 1 discloses that since such a refrigerator door made of a glass plate is thick and heavy, the refrigerator door is composed of two resin plates, and their edge portions are connected all around.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In such a refrigerator door configured by connecting the edge portions of two resin plates all around, there is a problem that the inside becomes difficult to see due to the influence of the environment outside the refrigerator.

[0006] Therefore, an object of the present invention is to provide a refrigerator door in which a gap is provided between a resin outer plate and a resin inner plate and the periphery is connected so that the inside is less likely to be difficult to see due to the influence of the environment outside the refrigerator, and a refrigerator equipped with the same.

Means for Solving the Problems

[0007] This invention has the following concept. [1] A resin outer plate and An inner plate made of resin facing the outer plate, The outer plate and the inner plate are connected by a connecting portion that connects their periphery such that a gap is provided between them. In a refrigerator door equipped with, A refrigerator door characterized in that a layer containing a metal with a heat transmittance lower than that of the outer plate is provided on the surface of the outer plate adjacent to the gap. [2] The refrigerator door according to [1], characterized in that the outer plate, the layer containing the metal, the gap, and the inner plate have a visible light transmittance of at least 60%. [3] The refrigerator door according to [1], wherein the metal-containing layer comprises either a metal layer made of at least one of Ag, Cr, In, and Ti, or a stainless steel layer. [4] The refrigerator door according to [1], wherein the metal-containing layer comprises a metal layer made of at least one of Ag, Cr, In, and Ti, a stainless steel layer, a film body supporting the layer, and an adhesive layer for adhering to the outer plate. [5] A refrigerator equipped with a refrigerator door as described in any one of paragraphs [1] through [4]. [Effects of the Invention]

[0008] According to the present invention, a refrigerator door comprises a resin outer plate, a resin inner plate facing the outer plate, and a connecting portion that connects the outer plate and the inner plate so as to create a gap between them, characterized in that a layer containing metal with a lower heat ray transmittance than the outer plate is provided on the surface of the outer plate adjacent to the gap. As a result, when heat rays enter the metal-containing layer from outside the refrigerator, a portion of the heat rays are absorbed by the outer plate while passing through and reaching the metal-containing layer. Since the metal-containing layer has a lower heat ray transmittance than the outer plate, the heat rays that have passed through the outer plate are shielded by the metal-containing layer and have difficulty reaching the inner plate. Therefore, when the refrigerator door is attached to the refrigerator window frame as a part of the refrigerator and the inside of the refrigerator is being refrigerated, the temperature difference between the outer plate and the inner plate is larger compared to when there is no metal-containing layer. Therefore, the inside of the refrigerator is less likely to be obscured by the influence of the environment outside the refrigerator through the outer plate and inner plate. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1A is a schematic front view showing a refrigerator door according to an embodiment of the present invention, and Figure 1B is a schematic side view showing a refrigerator door according to an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view along line II-II relating to a refrigerator door according to an embodiment of the present invention. [Figure 3] Figure 3 is a cross-sectional view showing the specific structure of the metal-containing layer shown in Figure 2. [Figure 4] Figure 4 is a cross-sectional view along line II-II relating to a refrigerator door according to a different embodiment of the present invention than that shown in Figure 2. [Figure 5] Figure 5 is a schematic diagram showing a refrigerator fitted with a refrigerator door according to an embodiment of the present invention. [Figure 6] Figure 6A is a rear view of a refrigerator door according to an embodiment, and Figure 6B is a cross-sectional view along the line VIB-VIB. [Figure 7] Figure 7 is a schematic diagram of the room used in the tests in the examples and comparative examples. [Figure 8A]FIG. 8A shows an image of the refrigerator door as seen diagonally to the right from the first room to the second room, when the humidity in the first room is 70%, for the examples and comparative examples. [Figure 8B] FIG. 8B shows an image of the refrigerator door as seen straight ahead from the first room to the second room, when the humidity in the first room is 70%, for the examples and comparative examples. [Figure 8C] FIG. 8C shows an image of the refrigerator door as seen diagonally to the left from the first room to the second room, when the humidity in the first room is 70%, for the examples and comparative examples. [Figure 9A] FIG. 9A shows an image of the refrigerator door as seen diagonally to the right from the first room to the second room, when the humidity in the first room is 75%, for the examples and comparative examples. [Figure 9B] FIG. 9B shows an image of the refrigerator door as seen straight ahead from the first room to the second room, when the humidity in the first room is 75%, for the examples and comparative examples. [Figure 9C] FIG. 9C shows an image of the refrigerator door as seen diagonally to the left from the first room to the second room, when the humidity in the first room is 75%, for the examples and comparative examples. [Figure 10A] FIG. 10A shows an image of the refrigerator door as seen diagonally to the right from the first room to the second room, when the humidity in the first room is 80%, for the examples and comparative examples. [Figure 10B] FIG. 10B shows an image of the refrigerator door as seen straight ahead from the first room to the second room, when the humidity in the first room is 80%, for the examples and comparative examples. [Figure 10C] FIG. 10C shows an image of the refrigerator door as seen diagonally to the left from the first room to the second room, when the humidity in the first room is 80%, for the examples and comparative examples. <好

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, some embodiments of the present invention will be described in detail with reference to the drawings. Design changes can be appropriately made within the scope that does not change the scope of the present invention regarding the matters described in the embodiments of the present invention.

[0011] FIG. 1A is a front view schematically showing a refrigerator door according to an embodiment of the present invention, and FIG. 1B is a side view schematically showing a refrigerator door according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II with respect to the refrigerator door according to an embodiment of the present invention.

[0012] The refrigerator door 10 according to an embodiment of the present invention includes an outer plate 11 made of resin, an inner plate 12 made of resin facing the outer plate 11, and a connecting portion 14 that connects the periphery so that the outer plate 11 and the inner plate 12 provide a gap portion 13. The connecting portion 14 is configured by connecting the outer plate 11 and the inner plate 12 in an annular shape, that is, a seamless shape. The connecting portion 14 only needs to be provided in a circumferential shape. The gap portion 13 may be an air layer, a layer containing an inert gas such as a rare gas, or a layer containing decompressed air. For example, Ar gas and krypton gas are adopted as the rare gas. The gap portion 13 may contain air or a mixed gas containing one or more types. The outer plate 11 and the inner plate 12 are adhered or closely attached so that the gap portion 13 contains as little water vapor as possible.

[0013] The outer plate 11 faces the outside of the refrigerator, that is, the non-cooled region (high-temperature region), and the inner plate 12 faces the inside of the refrigerator, that is, the cooled region (low-temperature region).

[0014] The outer plate 11 is in a flat plate shape. The inner plate 12 is integrally formed by a flat plate main body portion 12a, upper, lower, left, and right edge portions 12b located at positions different from the plate main body portion 12a in the thickness direction, and inclined portions 12c where the plate main body portion 12a and the edge portions 12b are smoothly connected. The edge portion 12b may also be called a flange portion or an edge portion. The inner plate 12 is molded. The connecting portion 14 is configured by thermally welding or adhering the outer plate 11 and the edge portion 12b of the inner plate 12 with an adhesive.

[0015] Both the outer plate 11 and the inner plate 12 are molded from a transparent resin that transmits visible light. The type of resin can be one or more materials selected from the group consisting of acrylic resins, polycarbonate resins, polyester resins, polystyrene resins, polyvinyl chloride resins, polyvinylidene resins, and polyolefin resins. In particular, acrylic resins are selected from the viewpoints of transparency, high rigidity, and processability. The thicknesses of the outer plate 11 and the inner plate 12 may be the same or different. The outer plate 11 has a thickness in the range of 1 mm to 10 mm. If the thickness of the outer plate 11 is within this range, the heat transmission rate is lower than that of the outer plate 11. The outer plate 11 is preferably 2 mm or thicker from the viewpoint of rigidity. The outer plate 11 is preferably 5 mm or less from the viewpoint of lightweight design for the refrigerator door 10.

[0016] As shown in Figure 2, the refrigerator door 10 according to an embodiment of the present invention is provided with a layer 15 containing metal, which has a lower heat transmittance than the outer plate 11, on the surface of the outer plate 11 adjacent to the gap 13. The "surface of the outer plate 11 adjacent to the gap 13" refers to the surface of the outer plate 11 facing the inner plate 12, and is the surface on the gap 13 side. Because the layer 15 containing metal is provided, when the refrigerator door 10 is attached to the window frame of the refrigerator as a component and the inside of the refrigerator is being refrigerated, the temperature difference between the outer plate 11 and the inner plate 12 becomes larger compared to when the layer 15 containing metal is not present. Therefore, the inside of the refrigerator is not obscured by the influence of the environment outside the refrigerator.

[0017] Let me explain in detail. When heat rays (e.g., infrared rays or radiant heat) enter from outside the refrigerator (high temperature region), some of the heat rays are absorbed by the outer plate 11, while the rest of the heat rays pass through and reach the metal-containing layer 15. Since the metal-containing layer 15 has a lower heat ray transmittance than the outer plate 11, the heat rays that have passed through the outer plate 11 are shielded by the metal-containing layer 15 and have difficulty reaching the inner plate 12. Therefore, when the refrigerator door 10 is attached as a component to the refrigerator window frame and the inside is being refrigerated, the temperature difference between the outer plate 11 and the inner plate 12 is larger compared to when there is no metal-containing layer 15. As a result, the inside of the refrigerator is less likely to be obscured by the influence of the environment outside the refrigerator.

[0018] The metal-containing layer 15 may be a metal layer containing Ag (silver), Cr (chromium), In (indium), or titanium (Ti), and may be, for example, a sputtered film or a vapor-deposited film (including sputtered films) created by an electron beam, because it has good adhesion to the outer plate 11. In addition, after the metal-containing layer 15 is provided on one surface of the outer plate 11, the surface of the metal-containing layer 15 may be partially or entirely oxidized in order to connect the outer edges of the outer plate 11 and the inner plate 12. The "metal" in the metal-containing layer 15 includes alloys, for example, TiZn. The metal-containing layer 15 may also be composed of stainless steel (SUS).

[0019] It is preferable that a layer 15 containing metal is provided on the surface of the outer plate 11 other than the connection portion 14 with the inner plate 12 (the surface facing the inner plate 12). This is because, when the refrigerator door 10 is attached to the window frame of the refrigerator as a component and the inside of the refrigerator is being refrigerated, the temperature difference between the outer plate 11 and the inner plate 12 becomes larger compared to when there is no layer 15 containing metal, which has a significant effect.

[0020] The metal-containing layer 15 could also be attached to the outer surface of the outer plate 11, rather than to the surface adjacent to the gap 13 of the outer plate 11 in the refrigerator door 10. The outer surface of the outer plate 11 is likely to accumulate fingerprints due to contact with users' or customers' hands, which is undesirable.

[0021] The metal-containing layer 15 could also be provided on the surface adjacent to the gap 13 of the inner plate 12, rather than on the surface adjacent to the gap 13 of the outer plate 11 in the refrigerator door 10. Since the inner plate 12 is molded from a resin material, irregularities occur, and although it is not impossible to provide the metal-containing layer 15 in a planar manner, it would complicate the manufacturing process and is therefore undesirable.

[0022] Figure 3 is a cross-sectional view showing the specific configuration of the metal-containing layer shown in Figure 2. The metal-containing layer 15, as shown in Figure 3, includes a metal layer 15a made of at least one of Ag, Cr, In, and Ti, a film body 15b supporting the metal layer 15a, and an adhesive layer 15c for adhering to the outer plate 11, and these layers may be laminated in this order. The adhesive layer 15c of such a film may be attached to the outer plate 11 because it makes it easier to manufacture the refrigerator door 10. As shown in Figure 3, the metal-containing layer 15 may also include a stainless steel layer instead of the metal layer 15a, a film body supporting the stainless steel layer, and an adhesive layer for adhering to the outer plate.

[0023] In the refrigerator door 10 according to an embodiment of the present invention, the structure comprising an outer plate 11, a metal-containing layer 15, a gap 13, and an inner plate 12 has a visible light transmittance of at least 60%, preferably 70%, and more preferably 80%.

[0024] The thickness of the metal-containing layer 15, particularly the metal layer (including the alloy layer), is set to satisfy the requirements for the visible light transmittance of the above structure. This is because if the metal-containing layer 15 is thicker, it becomes more difficult to see inside the refrigerator from the outside. Since the area of ​​the metal-containing layer 15 is relatively large, as in the embodiment described later, the thickness does not need to be uniform. The metal-containing layer 15 has a thickness in the range of 1 nm to 100 nm, preferably 1 nm to 50 nm, and more preferably 1 nm to 30 nm. The metal-containing layer 15 has dimensions in the range of 0.5 m to 2 m in length and 0.3 m to 1 m in width. When the dimensions of the connection part 14 with the inner plate 12 are added to the outer plate 11, the length and width dimensions of the outer plate 11 are generally within the range of the metal-containing layer 15.

[0025] Because the metal-containing layer 15 includes a metal layer (including an alloy layer) or stainless steel layer made up of at least one of Ag, Cr, In, and Ti, some of the heat rays incident from the outside and transmitted through the outer plate 11 are reflected by the metal layer and return to the outer plate 11, thus increasing the temperature difference between the outer plate 11 and the inner plate 12. As a result, the inside of the refrigerator is not obscured by the influence of the environment outside the refrigerator.

[0026] The metal-containing layer 15 is a film structure as shown in Figure 3, and since the film body 15b and adhesive layer 15c are made of resin, a resin molded body exists between the outer plate 11 and the gap 13. When the refrigerator door 10 is attached to the window frame of the refrigerator as a component and the inside of the refrigerator is being refrigerated, the gap 13 is cooled through the inner plate 12, so the amount of heat transferred per unit time between the gap 13 and the outer plate 11 is reduced, and the temperature difference between the outer plate 11 and the inner plate 12 is increased. As a result, the inside of the refrigerator is not obscured by the influence of the environment outside the refrigerator.

[0027] Figure 4 is a cross-sectional view along line II-II relating to a refrigerator door according to an embodiment of the present invention different from that shown in Figure 2. The refrigerator door 10 shown in Figure 4 comprises a resin outer plate 11, a resin inner plate 12 facing the outer plate 11, and a connecting portion 14 that connects the outer plate 11 and the inner plate 12 so as to provide a gap 13. The gap 13 may be an air layer, a layer containing an inert gas such as a noble gas, or a layer containing reduced-pressure air. These points are the same as described with reference to Figure 2.

[0028] Unlike Figure 2, the outer plate 11 is integrally composed of a flat plate body 11a, upper, lower, left, and right edges 11b located at different positions in the thickness direction from the plate body 11a, and an inclined portion 11c where the plate body 11a and the edges 11b are smoothly connected. The edges 11b may also be called flanges. The outer plate 11 is molded. The inner plate 12 is flat. The connecting portion 14 is constructed by heat welding the edges 11b of the outer plate 11 and the inner plate 12 together or by bonding them with an adhesive. The materials of the outer plate 11 and the inner plate 12 are the same as described above. The thickness of the outer plate 11 is also the same as described above.

[0029] As shown in Figure 4, the refrigerator door 10 according to an embodiment of the present invention is provided with a layer 15 containing metal, which has a lower heat transmittance than the outer plate 11, on the surface adjacent to the gap 13 of the outer plate 11. Because the layer 15 containing metal is provided, when the refrigerator door 10 is attached as a component to the window frame of the refrigerator body and the inside is being refrigerated, the temperature difference between the outer plate 11 and the inner plate 12 is larger compared to when the layer 15 containing metal is not present. Therefore, the inside of the refrigerator is not obscured by the influence of the environment outside the refrigerator. This point is the same as described above.

[0030] The metal-containing layer 15 is provided not only on the main plate portion 11a of the outer plate 11, but also on the inclined portion 11c. In the illustration, the edge portion 11b forms a connection portion 14 with the inner plate 12, so the metal-containing layer 15 is not provided there. However, if there is a portion that is not connected to the inner plate 12, the metal-containing layer 15 may be provided in that portion.

[0031] Here, the refrigerator door 10 may be constructed not only as shown in Figures 2 and 4, but also, for example, by using an outer plate 11 as shown in Figure 4 and an inner plate 12 as shown in Figure 2, and bonding the edge 11b of the outer plate 11 shown in Figure 4 and the edge 12b of the inner plate 12 shown in Figure 2 with heat welding or adhesive.

[0032] Figure 5 is a schematic diagram showing a refrigerator fitted with a refrigerator door according to an embodiment of the present invention. The refrigerator 1 includes a refrigerator door 10 that is installed to open and close relative to the opening of the refrigerator compartment. The refrigerator door 10 may be a sliding type or a rotating type. It is preferable that no frame material is attached to the connection portion 14 of the outer plate 11 and the inner plate 12, and that the refrigerator door 10 is rotatably attached to the refrigerator compartment frame (including the wall surface) on the front of the refrigerator compartment opening by a mounting device such as a hinge. This is because adding a frame material would increase the weight. This does not preclude the installation of a sealing member to ensure tight contact between the inner plate 12 and the window frame of the refrigerator 1. [Examples]

[0033] Figure 6A is a rear view of a refrigerator door according to an embodiment, and Figure 6B is a cross-sectional view along the line VIB-VIB. A refrigerator door 10 according to an embodiment as shown in Figures 6A and 6B was manufactured. For the outer plate 11, a transparent flat plate of acrylic resin with a thickness of 3 mm and dimensions of 1426 mm x 594 mm was used. The upper and lower edge portions 12A, 12B and the left and right edge portions 12C, 12D, the upper and lower frame portions 12E, 12F and the left and right frame portions 12G, 12H were bonded to the outer plate 11, and a film 15A having a metal layer 15a (see Figure 3) with a metal layer (Ti layer with an average thickness of 2 nm to 30 nm) 15a was attached to the surface of the outer plate 11 surrounded by the upper and lower frame portions 12E, 12F and the left and right frame portions 12G, 12H. The Ti layer had a thickness of 75 nm in some areas, although the area was small. Then, the main plate section 12I was bonded to the upper and lower frame sections 12E, 12F and the left and right frame sections 12G, 12H. The main plate section 12I was made of a transparent flat plate of acrylic resin.

[0034] The upper and lower edges 12A and 12B were made of square timber with a thickness of 3 mm and dimensions of 15 mm x 594 mm. The left and right edges 12C and 12D were made of square timber with a thickness of 3 mm and dimensions of 1396 mm x 15 mm. The upper and lower frame sections 12E and 12F were made of square timber with a thickness of 18 mm and dimensions of 10 mm x 564 mm. The left and right frame sections 12G and 12H were made of square timber with a thickness of 18 mm and dimensions of 1376 mm x 10 mm. The main plate section 12I was made of timber with a thickness of 3 mm and dimensions of 1396 mm x 564 mm. The adjacent components of the upper and lower edges 12A and 12B, left and right edges 12C and 12D, upper and lower frame sections 12E and 12F, left and right frame sections 12G and 12H, and main plate section 12I were bonded together without any gaps.

[0035] (Comparative example) In the comparative example, the refrigerator door 10A did not have a film 15A attached as a metal-containing layer 15. Instead, the upper and lower edge portions 12A, 12B, left and right edge portions 12C, 12D, upper and lower frame portions 12E, 12F, left and right frame portions 12G, 12H were bonded to the outer plate 11, and the plate body portion 12I was bonded onto the upper and lower frame portions 12E, 12F and left and right frame portions 12G, 12H. The upper and lower edge portions 12A, 12B, left and right edge portions 12C, 12D, upper and lower frame portions 12E, 12F, left and right frame portions 12G, 12H, and plate body portion 12I were the same as in the example. The adjacent members of the upper and lower edge portions 12A, 12B, left and right edge portions 12C, 12D, upper and lower frame portions 12E, 12F, left and right frame portions 12G, 12H, and plate body portion 12I were bonded together without any gaps.

[0036] In both the examples and comparative examples, a gap 13 was formed between the outer plate 11 and the plate body portion 12I corresponding to the inner plate, and dry air was contained in the gap 13.

[0037] Figure 7 is a schematic diagram of the room used in the test in the example and comparative example. The room 50 used in the test consists of a first room 51 and a second room 52, and the temperature and humidity of the first room 51 and the second room 52 can be controlled independently. The first room 51 was used as the area that was not refrigerated. The second room 52 was used as the refrigerated room. An insulating board 53 was placed between the first room 51 and the second room 52. The insulating board 53 has openings so that the refrigerator door 10 according to the example and the refrigerator door 10A according to the comparative example can be installed side by side, and the refrigerator doors 10 and 10A are placed in the two openings of the insulating board 53 to seal the gap between the refrigerator doors 10 and 10A and the insulating board 53. Looking at the insulating board 53 from the first room 51, the refrigerator door 10 according to the example was placed on the left side and the refrigerator door 10A according to the comparative example was placed on the right side.

[0038] The temperature inside the second room 52, which serves as the refrigerator compartment, was set to 5°C. The temperature inside the first room 51 was set to 27°C. The behavior of the refrigerator door 10 according to the embodiment and the refrigerator door 10A according to the comparative example was observed when the humidity inside the first room 51 was varied to 70%, 75%, and 80%.

[0039] The temperature of the surface of the outer plate 11 adjacent to the first chamber 51 and the surface of the inner plate 12 adjacent to the second chamber 52 was measured. As a first condition, the temperature of the first chamber 51 was set to 27°C and the humidity to 70%. As a second condition, the temperature of the first chamber 51 was set to 27°C and the humidity to 75%. As a third condition, the temperature of the first chamber 51 was set to 27°C and the humidity to 80%. In both the first and second conditions, the temperature of the second chamber 52 was set to 5°C, and the humidity of the second chamber 52 was set to be sufficiently lower than the humidity of the first chamber 51. On the refrigerator doors 10 and 10A, measurements were taken on the surface of the outer plate 11 adjacent to the first chamber 51 and the surface of the inner plate 12 adjacent to the second chamber 52, specifically above the upper and lower parts, and in the upper and lower middle parts, respectively. In Figures 6A and 6B, P11, P12, P21, P22, P31, and P32 indicate the measurement positions in the refrigerator door 10 according to the embodiment. P11 indicates the upper measurement position of the surface adjacent to the first chamber 51 on the outer plate 11, P12 indicates the upper measurement position of the surface adjacent to the second chamber 52 on the inner plate 12, P21 indicates the middle measurement position of the surface adjacent to the first chamber 51 on the outer plate 11, P22 indicates the middle measurement position of the surface adjacent to the second chamber 52 on the inner plate 12, P31 indicates the lower measurement position of the surface adjacent to the first chamber 51 on the outer plate 11, and P32 indicates the lower measurement position of the surface adjacent to the second chamber 52 on the inner plate 12.

[0040] Table 1 shows the temperatures at the top, middle, and bottom of the outer plate 11 adjacent to the first chamber 51 (the first chamber side) and the inner plate 12 adjacent to the second chamber 52 (the second chamber side) for each of the three conditions, from the first to the third.

[0041] [Table 1]

[0042] Figure 8A shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 70%, viewed from the first room 51 to the second room 52, at a rightward angle, relating to the examples and comparative examples. Figure 8B shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 70%, viewed from the first room 51 to the second room 52, at a frontal angle, relating to the examples and comparative examples. Figure 8C shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 70%, viewed from the first room 51 to the second room 52, at a leftward angle, relating to the examples and comparative examples. In all of Figures 8A to 8C, the refrigerator door 10 according to the examples is positioned on the left side of the page, and the refrigerator door 10A according to the comparative examples is positioned on the right side. As shown in Figures 8A to 8C, the interior of the second room 52 can be seen from the first room 51 through either the refrigerator door 10 according to the examples or the refrigerator door 10A according to the comparative examples. When the humidity in the first room 51 was 70%, the inside of the second room 52 could be clearly observed, regardless of the presence or absence of the metal layer 15 (film 15A), and no condensation occurred.

[0043] Figure 9A shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 75%, viewed from the right diagonally across the second room 52, relating to the examples and comparative examples. Figure 9B shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 75%, viewed from the front across the second room 52, relating to the examples and comparative examples. Figure 9C shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 75%, viewed from the left diagonally across the second room 52, relating to the examples and comparative examples. In all of Figures 9A to 9C, the refrigerator door 10 according to the examples is positioned on the left side of the page, and the refrigerator door 10A according to the comparative examples is positioned on the right side. As shown in Figures 9A to 9C, the interior of the second room 52 can be seen from the first room 51 through the refrigerator door 10 of the embodiment, whereas the interior of the second room 52 is difficult to see from the first room 51 through the refrigerator door 10A of the comparative example. When the humidity of the first room 51 was 75%, with the metal layer 15 (film 15A) present, the interior of the second room 52 could be clearly observed and no condensation occurred. On the other hand, when the humidity of the first room 51 was 75%, without the metal layer 15 (film 15A), condensation occurred on the refrigerator door 10A.

[0044] Figure 10A shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 80%, viewed from the right diagonally across the second room 52, relating to the examples and comparative examples. Figure 10B shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 80%, viewed from the front, relating to the examples and comparative examples. Figure 10C shows the refrigerator door of the first room 51 when the humidity in the first room 51 is 80%, viewed from the left diagonally across the second room 52, relating to the examples and comparative examples. In all of Figures 10A to 10C, the refrigerator door 10 according to the examples is positioned on the left side of the page, and the refrigerator door 10A according to the comparative examples is positioned on the right side. As shown in Figures 10A to 10C, the interior of the second room 52 is difficult to see from the first room 51 through either the refrigerator door 10 according to the embodiment or the refrigerator door 10A according to the comparative example. When the humidity in the first room 51 was 80%, condensation formed on the refrigerator door regardless of the presence or absence of the metal layer 15 (film 15A). Furthermore, the refrigerator door 10A according to the comparative example made it more difficult to see from the first room 51 into the interior of the second room 52 compared to the refrigerator door 10 according to the embodiment.

[0045] When the humidity in the first chamber 51 was 70%, the temperature difference between the upper part P11 of the surface adjacent to the first chamber 51 on the outer plate 11 and the upper part P12 of the surface adjacent to the second chamber 52 on the inner plate 12 was 14.9°C in the example and 12.4°C in the comparative example. When the humidity in the first chamber 51 was 70%, the temperature difference between the middle part P21 of the surface adjacent to the first chamber 51 on the outer plate 11 and the middle part P22 of the surface adjacent to the second chamber 52 on the inner plate 12 was 13.8°C in the example and 11.2°C in the comparative example. When the humidity in the first chamber 51 was 70%, the temperature difference between the lower part P31 of the surface adjacent to the first chamber 51 on the outer plate 11 and the lower part P32 of the surface adjacent to the second chamber 52 on the inner plate 12 was 12°C in the example and 10°C in the comparative example.

[0046] When the humidity in the first room 51 was 70%, the temperature difference between the upper part P11 of the surface adjacent to the first room 51 on the outer plate 11 and the upper part P12 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.5°C due to the provision of the metal-containing layer 15. When the humidity in the first room 51 was 70%, the temperature difference between the middle part P21 of the surface adjacent to the first room 51 on the outer plate 11 and the middle part P22 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.6°C due to the provision of the metal-containing layer 15. When the humidity in the first room 51 was 70%, the temperature difference between the lower part P31 of the surface adjacent to the first room 51 on the outer plate 11 and the lower part P32 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2°C due to the provision of the metal-containing layer 15.

[0047] When the humidity in the first chamber 51 was 75%, the temperature difference between the upper part P11 of the surface adjacent to the first chamber 51 on the outer plate 11 and the upper part P12 of the surface adjacent to the second chamber 52 on the inner plate 12 was 14.6°C in the example and 12.3°C in the comparative example. When the humidity in the first chamber 51 was 75%, the temperature difference between the middle part P21 of the surface adjacent to the first chamber 51 on the outer plate 11 and the middle part P22 of the surface adjacent to the second chamber 52 on the inner plate 12 was 13.7°C in the example and 11°C in the comparative example. When the humidity in the first chamber 51 was 75%, the temperature difference between the lower part P31 of the surface adjacent to the first chamber 51 on the outer plate 11 and the lower part P32 of the surface adjacent to the second chamber 52 on the inner plate 12 was 12.1°C in the example and 9.8°C in the comparative example.

[0048] When the humidity in the first room 51 was 75%, the temperature difference between the upper part P11 of the surface adjacent to the first room 51 on the outer plate 11 and the upper part P12 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.3°C due to the provision of the metal-containing layer 15. When the humidity in the first room 51 was 75%, the temperature difference between the middle part P21 of the surface adjacent to the first room 51 on the outer plate 11 and the middle part P22 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.7°C due to the provision of the metal-containing layer 15. When the humidity in the first room 51 was 75%, the temperature difference between the lower part P31 of the surface adjacent to the first room 51 on the outer plate 11 and the lower part P32 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.3°C due to the provision of the metal-containing layer 15.

[0049] When the humidity in the first chamber 51 was 80%, the temperature difference between the upper part P11 of the surface adjacent to the first chamber 51 on the outer plate 11 and the upper part P12 of the surface adjacent to the second chamber 52 on the inner plate 12 was 14.6°C in the example and 12.1°C in the comparative example. When the humidity in the first chamber 51 was 80%, the temperature difference between the middle part P21 of the surface adjacent to the first chamber 51 on the outer plate 11 and the middle part P22 of the surface adjacent to the second chamber 52 on the inner plate 12 was 13.6°C in the example and 10.9°C in the comparative example. When the humidity in the first chamber 51 was 80%, the temperature difference between the lower part P31 of the surface adjacent to the first chamber 51 on the outer plate 11 and the lower part P32 of the surface adjacent to the second chamber 52 on the inner plate 12 was 12.1°C in the example and 9.6°C in the comparative example.

[0050] When the humidity in the first room 51 was 80%, the temperature difference between the upper part P11 of the surface adjacent to the first room 51 on the outer plate 11 and the upper part P12 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.5°C due to the provision of the metal-containing layer 15. When the humidity in the first room 51 was 80%, the temperature difference between the middle part P21 of the surface adjacent to the first room 51 on the outer plate 11 and the middle part P22 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.7°C due to the provision of the metal-containing layer 15. When the humidity in the first room 51 was 80%, the temperature difference between the lower part P31 of the surface adjacent to the first room 51 on the outer plate 11 and the lower part P32 of the surface adjacent to the second room 52 on the inner plate 12 increased by 2.5°C due to the provision of the metal-containing layer 15.

[0051] From these findings, it was found that the temperature differences in the upper, middle, and lower parts of the surface of the outer plate 11 adjacent to the first chamber 51 and the surface of the inner plate 12 adjacent to the second chamber 52 were greater when the metal layer 15 was provided compared to when the metal layer 15 was not provided. This confirms that the metal layer 15 shields against heat rays, and that the temperature rise of the outer plate 11 due to heat rays such as infrared rays and radiant heat is greater than that of the inner plate 12. In other words, the metal layer 15 makes it difficult for the influence of the second chamber 52 (refrigeration chamber) to be transmitted to the outer plate 11.

[0052] In the refrigerator door 10 according to the embodiment, it was found that the temperature of the surface adjacent to the first chamber 51 on the outer plate 11 was generally higher compared to the refrigerator door 10A according to the comparative example. In other words, in the refrigerator door 10A according to the comparative example, it was found that the temperature of the surface adjacent to the first chamber 51 on the outer plate 11 was generally lower compared to the refrigerator door 10 according to the embodiment.

[0053] Table 1 shows that the temperature difference between the lower part P32 of the surface adjacent to the second chamber 52 in the inner plate 12 and the lower part P31 of the surface adjacent to the first chamber 51 in the outer plate 11 was 12°C, 12.1°C, 12.1°C, 10°C, 9.8°C, and 9.6°C in the example at humidity levels of 70%, 75%, and 80%, and in the comparative example at humidity levels of 70%, 75%, and 80%, respectively. The temperature difference between the upper part P12 of the surface adjacent to the second chamber 52 in the inner plate 12 and the upper part P11 of the surface adjacent to the first chamber 51 in the outer plate 11 was 14.9°C, 14.6°C, 14.6°C, 12.4°C, 12.3°C, and 12.1°C in the example at humidity levels of 70%, 75%, and 80%, and in the comparative example at humidity levels of 70%, 75%, and 80%, respectively. These results indicate that the temperature difference between the inner plate 12 and the outer plate 11 at the upper position was greater than the temperature difference between the inner plate 12 and the outer plate 11 at the lower position.

[0054] On the other hand, in the embodiment, the temperature difference between the upper P11 and lower 31 of the surface adjacent to the first chamber 51 on the outer plate 11 was 2°C, 1.7°C, and 1.8°C at humidity levels of 70%, 75%, and 80%, respectively. In the comparative example, the temperature difference between the upper P11 and lower 31 of the surface adjacent to the first chamber 51 on the outer plate 11 was 1.1°C, 1.2°C, and 1.4°C at humidity levels of 70%, 75%, and 80%, respectively, showing little difference.

[0055] From these results, it is considered that even with the metal-containing layer 15, the amount of heat transferred through heat transfer in the metal-containing layer 15 is small. Therefore, it is considered that the metal-containing layer 15 does not easily conduct cold air from inside the refrigerator.

[0056] The refrigerators according to the embodiments of the present invention include not only ordinary refrigerators but also display cases and the like. The refrigerator door may be a sliding type as shown in Figure 5, as well as a rotating type. The refrigerator door according to the embodiments of the present invention may be a door component, and depending on the type of refrigerator, it may extend vertically as shown in Figures 1, 2, and 4, extend horizontally, or be inclined diagonally upward toward the user or customer. [Explanation of Symbols]

[0057] 1: Refrigerator 5: Room 51: Room 1 52: The second room 53: Insulation board 10,10A: Refrigerator door 11: Outer plate 11a: Plate body 11b:Edge 11c: Inclined part 12: Inner plate 12a: Plate body 12b:Edge 12c: Inclined part 12A, 12B: Upper and lower edges 12C, 12D: Left and right edges 12E, 12F: Upper and lower frame sections 12G, 12H: Left and right frame sections 12I: Plate body 13: Gap 14: Connection part 15: Layer containing metal 15a: Metal layer 15b: Film body 15c: Adhesive layer 15A: Film

Claims

1. A resin outer plate, An inner plate made of resin facing the outer plate, The outer plate and the inner plate are connected by a connecting portion that connects their periphery such that a gap is provided between them. In a refrigerator door equipped with, A refrigerator door characterized in that a layer containing a metal with a heat transmittance lower than that of the outer plate is provided on the surface of the outer plate adjacent to the gap.

2. The refrigerator door according to claim 1, characterized in that the outer plate, the layer containing the metal, the gap, and the inner plate have a visible light transmittance of at least 60%.

3. The refrigerator door according to claim 1, wherein the metal-containing layer includes a metal layer made of at least one of Ag, Cr, In, and Ti, or a stainless steel layer.

4. The refrigerator door according to claim 1, wherein the metal-containing layer comprises a metal layer made of at least one of Ag, Cr, In, and Ti, a stainless steel layer, a film body supporting the layer, and an adhesive layer for adhering to the outer plate.

5. A refrigerator comprising a refrigerator door according to any one of claims 1 to 4.

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