Refrigerator door and refrigerator

Abstract

In a refrigerator door in which an outer plate made of resin and an inner plate made of resin are connected to each other around so as to provide a gap portion, there is provided a refrigerator door that is less likely to make the inside difficult to see due to the influence of the environment outside the refrigerator, and a refrigerator including the same. 【Solution means】In a refrigerator door 10 including an outer plate 11 made of resin, an inner plate 12 made of resin facing the outer plate, and a connecting portion 14 that connects the outer plate and the inner plate around so as to provide a gap portion 13, a layer 15 containing a metal having a lower heat ray transmittance than the outer plate 11 is provided on a surface adjacent to the gap portion 13 of the outer plate 11.

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] The present invention has the following concept. [1] A resin outer plate; an inner plate made of resin facing the outer plate; a connection portion that connects the outer plate and the inner plate at their peripheries so as to provide a gap; In a refrigerator door comprising: a layer containing a metal having a lower heat ray transmittance than the outer plate is provided on a surface of the outer plate adjacent to the gap. [2] The refrigerator door according to [1], characterized in that the outer plate, the metal-containing layer, 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 includes 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 includes either a metal layer made of at least one of Ag, Cr, In, and Ti or 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 according to any one of [1] to [4]. [Effects of the Invention]

[0008] According to the present invention, in a refrigerator door including a resin outer plate, a resin inner plate facing the outer plate, and a connecting portion that connects the periphery so that a gap is provided between the outer plate and the inner plate, a layer containing a metal having a lower heat ray transmittance than the outer plate is provided on a surface adjacent to the gap portion of the outer plate. As a result, when heat rays enter the layer containing the metal from outside the refrigerator, a part of the heat rays is absorbed and transmitted by the outer plate and reaches the layer containing the metal. Since the layer containing the metal has a lower heat ray transmittance than the outer plate, the heat rays transmitted through the outer plate are shielded by the layer containing the metal and hardly reach the inner plate. Therefore, when the refrigerator door is attached to the window frame of the refrigerator as a part of the refrigerator and the inside of the refrigerator is refrigerated, the temperature difference between the outer plate and the inner plate becomes larger than when there is no layer containing the metal. Therefore, it becomes difficult for the inside of the refrigerator to be seen due to the influence of the environment outside the refrigerator through the outer plate and the inner plate.

Brief Description of Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8A

Figure 8B

Figure 8C

Figure 9A

Figure 9B

Figure 9C

Figure 10A

Figure 10B

Figure 10C

[0010] Hereinafter, several embodiments of the present invention will be described in detail with reference to the drawings. The matters described in the embodiments of the present invention can be appropriately modified in design without changing the scope of the present invention.

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

[0012] A refrigerator door 10 according to an embodiment of the present invention includes a resin outer plate 11, a resin inner plate 12 facing the outer plate 11, and a connection portion 14 connecting the outer plate 11 and the inner plate 12 at their peripheries to provide a gap 13. The connection portion 14 is configured by connecting the outer plate 11 and the inner plate 12 in an annular, i.e., non-rectangular, shape. The connection portion 14 may be provided circumferentially. The gap 13 may be an air layer, a layer containing an inert gas such as a rare gas, or a layer containing reduced-pressure air. Examples of rare gases that can be used include Ar gas and krypton gas. The gap 13 may contain air or a mixed gas containing one or more types of gas. The outer plate 11 and the inner plate 12 are bonded or tightly attached to each other so as to minimize the presence of water vapor in the gap 13.

[0013] The outer plate 11 faces the outside of the refrigerator, ie, the uncooled area (high temperature area), and the inner plate 12 faces the inside of the refrigerator, ie, the cooled area (low temperature area).

[0014] The outer plate 11 is flat. The inner plate 12 is integrally formed with a flat plate body 12a, upper, lower, left, and right edge portions 12b at different positions in the thickness direction from the plate body 12a, and an inclined portion 12c smoothly connecting the plate body 12a and the edge portions 12b. The edge portions 12b may also be called flange portions or edge portions. The inner plate 12 is molded. The connection portion 14 is formed by heat welding the outer plate 11 and the edge portions 12b of the inner plate 12 together or by bonding them with an adhesive.

[0015] Both the outer plate 11 and the inner plate 12 are formed of a transparent resin that transmits visible light. Examples of the resin type include one or more materials selected from the group consisting of acrylic resins, polycarbonate resins, polyester resins, polystyrene resins, polyvinyl chloride resins, polyvinylidene resins, polyolefin resins, and the like. In particular, an acrylic resin is selected from the viewpoints of transparency, high rigidity, processability, and the like. 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 or more and 10 mm or less. If the thickness of the outer plate 11 is within this range, the transmittance of heat rays is lower than that of the outer plate 11. From the viewpoint of rigidity and the like, the outer plate 11 is preferably 2 mm or more. From the viewpoint of the light weight of the refrigerator door 10 and the like, the outer plate 11 is preferably 5 mm or less.

[0016] [[ID=z]] As shown in FIG. 2, the refrigerator door 10 according to the embodiment of the present invention is provided with a layer 15 containing a metal having a lower heat ray transmittance than the outer plate 11 on the surface adjacent to the gap portion 13 of the outer plate 11. The "surface adjacent to the gap portion 13 of the outer plate 11" means the surface of the outer plate 11 that faces the inner plate 12, that is, the surface on the side of the gap portion 13. Since the layer 15 containing a metal is provided, when the refrigerator door 10 is attached as a component to the window frame of the refrigerator and the inside of the refrigerator is refrigerated, the temperature difference between the outer plate 11 and the inner plate 12 becomes larger compared to the case where the layer 15 containing a metal is not provided. Therefore, it is difficult for the inside to be seen due to the influence of the external environment of the refrigerator.

[0017] This will be described in detail. When heat rays (e.g., infrared rays or radiant heat) enter from outside the refrigerator (high-temperature region), part of the heat rays is absorbed by the outer plate 11 while the rest of the heat rays pass through and reach the layer 15 containing metal. Since the layer 15 containing metal has a lower transmittance of heat rays than the outer plate 11, the heat rays that have passed through the outer plate 11 are shielded by the layer 15 containing metal and it is difficult to reach the inner plate 12. Therefore, when the refrigerator door 10 is attached as a component to the window frame of the refrigerator 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 the case where there is no layer 15 containing metal. Therefore, it is difficult for the inside to be seen due to the influence of the environment outside the refrigerator.

[0018] Examples of the layer 15 containing metal include a metal layer containing Ag (silver), Cr (chromium), In (indium), and titanium (Ti) as metals, and for example, it may be a sputtered film by sputtering or a vapor deposition film (including a sputtered film) created by an electron beam or the like. This is because it has good adhesion to the outer plate 11. Also, after providing the layer 15 containing metal on one surface of the outer plate 11, in order to connect the outer peripheral edges of the outer plate 11 and the inner plate 12, the surface of the layer 15 containing metal may be partially or entirely oxidized. The "metal" as the layer 15 containing metal includes alloys, for example, TiZn. The layer 15 containing metal may be configured to include stainless steel (SUS).

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

[0020] It is also conceivable to attach the layer 15 containing metal to the outer surface of the outer plate 11 instead of the surface adjacent to the gap portion 13 of the outer plate 11 in the refrigerator door 10. The outer surface of the outer plate 11 is likely to have fingerprints attached when touched by the hands of users or customers, which is not preferable.

[0021] The layer 15 containing metal may be provided not on the surface adjacent to the gap portion 13 of the outer plate 11 but on the surface adjacent to the gap portion 13 of the inner plate 12 in the refrigerator door 10. Since the inner plate 12 is molded from a resin material, unevenness occurs, and although it is not impossible to provide the layer 15 containing metal in a planar shape, it is not preferable because the working process becomes complicated.

[0022] FIG. 3 is a cross-sectional view showing a specific configuration of the layer containing metal shown in FIG. 2. As shown in FIG. 3, the layer 15 containing metal may include 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 may be laminated in this order. The adhesive layer 15c of such a film may be attached to the outer plate 11. This is because it becomes easier to manufacture the refrigerator door 10. As the structure shown in FIG. 3, the layer 15 containing metal may have a structure including 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 the embodiment of the present invention, the structure composed of the outer plate 11, the layer 15 containing metal, the gap portion 13, and the inner plate 12 has a visible light transmittance of at least 60% or more, preferably 70% or more, more preferably 80% or more.

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

[0025] Since the layer 15 containing metal includes a metal layer (including alloy layer) composed of at least one of Ag, Cr, In, and Ti or a stainless steel layer, a part of the heat rays incident from the outside and passing through the outer plate 11 is reflected by the metal layer and returns to the outer plate 11, so that the temperature difference between the outer plate 11 and the inner plate 12 becomes larger. As a result, the inside is not made difficult to see due to the influence of the environment outside the refrigerator.

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

[0027] FIG. 4 is a cross-sectional view taken along line II-II of a refrigerator door according to an embodiment of the present invention different from FIG. 2. The refrigerator door 10 shown in FIG. 4 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 of 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 rare gas, or a layer containing depressurized air. These points are the same as the description with reference to FIG. 2.

[0028] The difference from FIG. 2 is that the outer plate 11 is integrally formed by a flat plate main body portion 11a, upper, lower, left, and right edge portions 11b located at different positions in the thickness direction from the plate main body portion 11a, and an inclined portion 11c where the plate main body portion 11a and the edge portion 11b are smoothly connected. The edge portion 11b may be called a flange portion or a flange portion. The outer plate 11 is molded. The inner plate 12 is flat. The connecting portion 14 is configured such that the edge portion 11b of the outer plate 11 and the inner plate 12 are heat welded or adhered by an adhesive. The materials of the outer plate 11 and the inner plate 12 are the same as those described above. The thickness of the outer plate 11 is also the same as that described above.

[0029] As shown in FIG. 4, the refrigerator door 10 according to the embodiment of the present invention is provided with a layer 15 containing a metal having a lower heat ray transmittance than the outer plate 11 on the surface adjacent to the gap 13 of the outer plate 11. Since the layer 15 containing a metal is provided, when the refrigerator door 10 is attached as a component to the window frame of the refrigerator body and the inside of the cabinet is refrigerated, the temperature difference between the outer plate 11 and the inner plate 12 becomes larger compared to the case where the layer 15 containing a metal is not provided. Therefore, the inside is not difficult to see due to the influence of the external environment of the refrigerator. This point is the same as described above.

[0030] The layer 15 containing a metal is provided not only on the plate main body portion 11a of the outer plate 11 but also on the inclined portion 11c. In the drawing, since the edge portion 11b constitutes the connecting portion 14 with the inner plate 12, the layer 15 containing a metal is not provided, but if there is a portion not connected to the inner plate 12, the layer 15 containing a metal may be provided on that portion.

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

[0032] FIG. 5 is a schematic view showing a refrigerator equipped with a refrigerator door according to an embodiment of the present invention. The refrigerator 1 includes a refrigerator door 10 that is attached to the opening of the refrigerating chamber so as to be openable and closable. The refrigerator door 10 may be a slide type or a rotary type. A frame member is not attached to the connecting portion 14 of the outer plate 11 and the inner plate 12, and it is preferable that the refrigerator door 10 is rotatably attached to the refrigerator frame (including the wall surface) in front of the opening of the refrigerating chamber by a fixture such as a hinge. This is because it involves an increase in weight due to the frame member. It does not exclude attaching a seal member for bringing the inner plate 12 into close contact with the window frame of the refrigerator 1.

Example

[0033] FIG. 6A is a rear view of a refrigerator door according to an example, and FIG. 6B is a cross-sectional view taken along line VIB-VIB. A refrigerator door 10 according to an example as shown in FIGS. 6A and 6B was manufactured. For the outer plate 11, a transparent flat plate of an acrylic resin with a thickness of 3 mm and dimensions of 1426 mm × 594 mm in length and width was used. Angle members of 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 adhered to the outer plate 11, and a film 15A provided with a metal layer (Ti layer 15a with an average thickness of 2 nm or more and 30 nm or less, see FIG. 3) as a layer 15 containing metal 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. Note that the Ti layer had a thickness of 75 nm, although it was slightly small in area depending on the location. Then, a plate main body portion 12I was adhered onto the upper and lower frame portions 12E, 12F, and the left and right frame portions 12G, 12H. The plate main body portion 12I used a transparent flat plate of an acrylic resin.

[0034] The upper and lower edge portions 12A and 12B were made of square timbers 3 mm thick and 15 mm x 594 mm in length and width. The left and right edge portions 12C and 12D were made of square timbers 3 mm thick and 1396 mm x 15 mm in length and width. The upper and lower frame portions 12E and 12F were made of square timbers 18 mm thick and 10 mm x 564 mm in length and width. The left and right frame portions 12G and 12H were made of square timbers 18 mm thick and 1376 mm x 10 mm in length and width. The plate main body portion 12I was made of square timbers 3 mm thick and 1396 mm x 564 mm in length and width. Adjacent members of the upper and lower edge portions 12A and 12B, the left and right edge portions 12C and 12D, the upper and lower frame portions 12E and 12F, the left and right frame portions 12G and 12H, and the plate main body portion 12I were bonded together without any gaps.

[0035] (Comparative Example) In the refrigerator door 10A according to the comparative example, the rectangular timbers of the upper and lower edge portions 12A and 12B, the left and right edge portions 12C and 12D, the upper and lower frame portions 12E and 12F, and the left and right frame portions 12G and 12H were bonded to the outer plate 11 without attaching a film 15A as the metal-containing layer 15. The plate main body portion 12I was bonded onto the upper and lower frame portions 12E and 12F and the left and right frame portions 12G and 12H. The upper and lower edge portions 12A and 12B, the left and right edge portions 12C and 12D, the upper and lower frame portions 12E and 12F, the left and right frame portions 12G and 12H, and the plate main body portion 12I were the same as those in the example. Adjacent members of the upper and lower edge portions 12A and 12B, the left and right edge portions 12C and 12D, the upper and lower frame portions 12E and 12F, the left and right frame portions 12G and 12H, and the plate main body portion 12I were bonded together without any gaps.

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

[0037] FIG. 7 is a schematic diagram of the rooms used in the tests in the Examples and Comparative Examples. The room 50 used in the tests consisted 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 could be independently controlled. The first room 51 was used as a non-refrigerated area. The second room 52 was used as a refrigerated room. An insulating plate 53 was placed between the first room 51 and the second room 52. The insulating plate 53 had openings so that the refrigerator door 10 according to the Example and the refrigerator door 10A according to the Comparative Example could be installed side by side. The refrigerator doors 10 and 10A were placed in the two openings of the insulating plate 53, and the gaps between the refrigerator doors 10 and 10A and the insulating plate 53 were sealed. Looking at the insulating plate 53 from the first room 51, the refrigerator door 10 according to the Example was installed on the left side, and the refrigerator door 10A according to the Comparative Example was installed on the right side.

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

[0039] The temperatures of the surfaces adjacent to the first room 51 in the outer plate 11 and the surfaces adjacent to the second room 52 in the inner plate 12 were measured. As the first condition, the temperature of the first room 51 was set to 27°C and the humidity to 70%. As the second condition, the temperature of the first room 51 was set to 27°C and the humidity to 75%. As the third condition, the temperature of the first room 51 was set to 27°C and the humidity to 80%. In both the first condition and the second condition, the temperature of the second room 52 was set to 5°C, and the humidity of the second room 52 was made sufficiently lower than the humidity of the first room 51. In the refrigerator doors 10, 10A, measurements were taken at the upper part, lower part, and middle part between the upper and lower parts, respectively, of the surfaces adjacent to the first room 51 in the outer plate 11 and the surfaces adjacent to the second room 52 in the inner plate 12. In FIGS. 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 measurement position at the upper part of the surface adjacent to the first room 51 in the outer plate 11, P12 indicates the measurement position at the upper part of the surface adjacent to the second room 52 in the inner plate 12, P21 indicates the measurement position at the middle part of the surface adjacent to the first room 51 in the outer plate 11, P22 indicates the measurement position at the middle part of the surface adjacent to the second room 52 in the inner plate 12, P31 indicates the measurement position at the lower part of the surface adjacent to the first room 51 in the outer plate 11, and P32 indicates the measurement position at the lower part of the surface adjacent to the second room 52 in the inner plate 12.

[0040] Table 1 shows the temperatures at the upper part, middle part, and lower part of the surface adjacent to the first room 51 (the surface on the first room side) in the outer plate 11 and the surface adjacent to the second room 52 (the surface on the second room side) in the inner plate 12 of the refrigerator doors 10 according to the embodiment and the refrigerator door 10A according to the comparative example, respectively, for each of the first to third conditions.

[0041] [Table 1]

[0042] FIG. 8A relates to the examples and comparative examples, and is an image when the humidity in the first room 51 is 70% regarding the state of the refrigerator door seen diagonally to the right from the first room 51 to the second room 52. FIG. 8B relates to the examples and comparative examples, and is an image when the humidity in the first room 51 is 70% regarding the state of the refrigerator door seen frontally from the first room 51 to the second room 52. FIG. 8C relates to the examples and comparative examples, and is an image when the humidity in the first room 51 is 70% regarding the state of the refrigerator door seen diagonally to the left from the first room 51 to the second room 52. In any of FIGS. 8A to 8C, the refrigerator door 10 according to the example is arranged on the left toward the paper surface, and the refrigerator door 10A according to the comparative example is arranged on the right. As shown in FIGS. 8A to 8C, the inside of the second room 52 can be seen from both the refrigerator door 10 according to the example and the refrigerator door 10A according to the comparative example from the first room 51. When the humidity in the first room 51 is 70%, the inside of the second room 52 could be well observed regardless of the presence or absence of the metal layer 15 (film 15A), and no dew condensation occurred.

[0043] FIG. 9A relates to the examples and comparative examples, and is an image when the humidity of the first room 51 is 75% regarding the state of the refrigerator door seen diagonally to the right from the first room 51 to the second room 52. FIG. 9B relates to the examples and comparative examples, and is an image when the humidity of the first room 51 is 75% regarding the state of the refrigerator door seen frontally from the first room 51 to the second room 52. FIG. 9C relates to the examples and comparative examples, and is an image when the humidity of the first room 51 is 75% regarding the state of the refrigerator door seen diagonally to the left from the first room 51 to the second room 52. In any of FIGS. 9A to 9C, the refrigerator door 10 according to the example is arranged on the left toward the paper surface, and the refrigerator door 10A according to the comparative example is arranged on the right. As shown in FIGS. 9A to 9C, the inside of the second room 52 can be seen from the first room 51 through the refrigerator door 10 according to the example, whereas it is difficult to see the inside of the second room 52 from the first room 51 through the refrigerator door 10A according to the comparative example. When the humidity of the first room 51 is 75%, when there is a metal layer 15 (film 15A), the inside of the second room 52 can be observed well and no dew condensation occurred. On the other hand, when the humidity of the first room 51 is 75% and there is no metal layer 15 (film 15A), the refrigerator door 10A was dew-condensed.

[0044] FIG. 10A relates to an example and a comparative example, and is an image when the humidity of the first chamber 51 is 80% regarding the state of the refrigerator door as seen diagonally to the right from the first chamber 51 to the second chamber 52. FIG. 10B relates to an example and a comparative example, and is an image when the humidity of the first chamber 51 is 80% regarding the state of the refrigerator door as seen frontally from the first chamber 51 to the second chamber 52. FIG. 10C relates to an example and a comparative example, and is an image when the humidity of the first chamber 51 is 80% regarding the state of the refrigerator door as seen diagonally to the left from the first chamber 51 to the second chamber 52. In any of FIGS. 10A to 10C, the refrigerator door 10 according to the example is arranged on the left toward the paper surface, and the refrigerator door 10A according to the comparative example is arranged on the right. As shown in FIGS. 10A to 10C, it is difficult to see the inside of the second chamber 52 from the first chamber 51 through either the refrigerator door 10 according to the example or the refrigerator door 10A according to the comparative example. When the humidity of the first chamber 51 is 80%, the refrigerator door is dew-condensed regardless of the presence or absence of the metal layer 15 (film 15A). Also, the refrigerator door 10A according to the comparative example makes it more difficult to see the inside of the second chamber 52 from the first chamber 51 compared to the refrigerator door 10 according to the example.

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

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

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

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

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

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

[0051] From these facts, it was found that the temperature differences at the upper, middle, and lower parts of the surface of the outer plate 11 adjacent to the first room 51 and the surface of the inner plate 12 adjacent to the second room 52 became larger by providing the metal layer 15 as compared with the case where the metal layer 15 was not provided. This confirmed that the metal layer 15 shields heat rays and the temperature rise of the outer plate 11 due to heat rays such as infrared rays and radiant heat is larger than that of the inner plate 12. That is, the layer 15 containing metal makes it difficult to transmit the influence of the second room 52 (refrigerating chamber) to the outer plate 11.

[0052] In the refrigerator door 10 according to the embodiment, it was found that the temperature of the surface of the outer plate 11 adjacent to the first room 51 increased as a whole as compared with the refrigerator door 10A according to the comparative example. That is, in the refrigerator door 10A according to the comparative example, it was found that the temperature of the surface of the outer plate 11 adjacent to the first room 51 decreased as a whole as compared with the refrigerator door 10 according to the embodiment.

[0053] From Table 1, the temperature differences 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 were 12 °C, 12.1 °C, 12.1 °C, 10 °C, 9.8 °C, and 9.6 °C in this order for humidity levels of 70%, 75%, and 80% in the examples and humidity levels of 70%, 75%, and 80% in the comparative examples. The temperature differences 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 were 14.9 °C, 14.6 °C, 14.6 °C, 12.4 °C, 12.3 °C, and 12.1 °C in this order for humidity levels of 70%, 75%, and 80% in the examples and humidity levels of 70%, 75%, and 80% in the comparative examples. From these results, the temperature difference between the inner plate 12 and the outer plate 11 at the upper position was larger 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 examples, the temperature differences between the upper part P11 and the lower part 31 of the surface adjacent to the first chamber 51 in the outer plate 11 were 2 °C, 1.7 °C, and 1.8 °C in this order for humidity levels of 70%, 75%, and 80%. In the comparative examples, the temperature differences between the upper part P11 and the lower part 31 of the surface adjacent to the first chamber 51 in the outer plate 11 were 1.1 °C, 1.2 °C, and 1.4 °C in this order for humidity levels of 70%, 75%, and 80%, and there was not much difference.

[0055] From this result, even if the layer 15 containing metal is provided, it is considered that the amount of heat transfer due to heat conduction in the layer 15 containing metal is small. Therefore, it is considered that the cold air in the refrigerator compartment is difficult to be transmitted through the layer 15 containing metal.

[0056] The refrigerator according to the embodiment of the present invention includes not only ordinary refrigerators but also showcases and the like. The refrigerator door may be not only a rotary type as shown in FIG. 5 but also a slide type. The refrigerator door according to the embodiment of the present invention may be a door component, and depending on the type of refrigerator, it may extend in the vertical direction as shown in FIGS. 1, 2, and 4, may extend in the horizontal direction, or may be inclined obliquely upward with respect to the user or customer.

Explanation of Reference Numerals

[0057] 1: Refrigerator 5: Room 51: First Room 52: Second Room 53: Heat insulating 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 parts 12G, 12H: Left and right frame parts 12I: Plate body 13: Gap 14: Connection 15: Metal-containing layer 15a: Metal layer 15b: Film body 15c: Adhesive layer 15A:Film

Claims

1. An outer plate made of resin, An inner plate made of resin facing the outer plate, A connecting portion that connects the periphery so that a gap is provided between the outer plate and the inner plate, In a refrigerator door comprising: The connecting portion is constituted by either heat welding or adhesion with an adhesive between the outer plate and the inner plate, A layer containing a metal with a lower heat ray transmittance than the outer plate is provided on the surface of the outer plate adjacent to the gap, The connecting portion is not provided with the layer containing the metal, The outer plate, the layer containing the metal, the gap, and the inner plate have a visible light transmittance of at least 60% or more. A refrigerator door characterized by this.

2. The refrigerator door according to claim 1, wherein the outer plate has a thickness in the range of 2 mm or more and 5 mm or less.

3. The refrigerator door according to claim 1, wherein the layer containing the metal includes either a metal layer composed 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 layer containing the metal includes either a metal layer composed of at least one of Ag, Cr, In, and Ti or a stainless steel layer, a film body that supports the layer, and an adhesive layer for adhering to the outer plate.

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

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