Sealant for refrigerators and refrigerators

Abstract

To provide a sealing material for refrigerators that can improve the heat insulation of refrigerators, and a refrigerator with excellent heat insulation properties. [Solution] The sealing material for refrigerators contains a thermoplastic resin and aerogel particles, and the content of the aerogel particles is in the range of 82% by mass or more and 99% by mass or less.

Description

Technical Field

[0001] The present invention relates to a sealing material for a refrigerator and a refrigerator.

Background Art

[0002] A refrigerator includes a heat-insulating container having an opening at the front, and a door for closing the opening at the front of the heat-insulating container. The heat-insulating container is a double structure having an inner box and an outer box, and a heat-insulating material is filled in the space between the inner box and the outer box. The gap between the inner box and the outer box is sealed with a sealing material to prevent the outflow of the heat-insulating material. As the sealing material, a hot-melt adhesive is used (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a refrigerator, in order to increase the capacity, the thickness of the heat-insulating material in the heat-insulating container is reduced to increase the capacity of the inner box. However, if the thickness of the heat-insulating material is reduced, the heat-insulating property of the heat-insulating container may decrease. Therefore, it is desired to develop a technology that can improve the heat-insulating property of the refrigerator regardless of the thickness of the heat-insulating material.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a sealing material for a refrigerator that can improve the heat-insulating property of the refrigerator, and a refrigerator having excellent heat-insulating property.

Means for Solving the Problems

[0006] The inventors of the present invention have discovered that a thermoplastic resin containing aerogel particles in an amount of 1% to 18% by mass has low melt viscosity and excellent heat insulation properties, and that by using this as a sealing material for refrigerators, it is possible to improve the heat insulation of refrigerators, thus completing the present invention. Accordingly, the present invention provides the following.

[0007] (1) A sealing material for refrigerators comprising a thermoplastic resin and aerogel particles, wherein the content of the aerogel particles is in the range of 1% by mass or more and 18% by mass or less.

[0008] The sealing material for refrigerators described in (1) contains aerogel particles within the above range, resulting in high thermal insulation and low melt viscosity when melted, thus providing excellent applicability. Therefore, by using the sealing material for refrigerators described in (1), gaps in the refrigerator, such as between the inner and outer boxes, can be efficiently sealed, and the thermal insulation of the refrigerator can be improved.

[0009] (2) The sealing material for refrigerators according to (1), wherein the thermoplastic resin is an ethylene vinyl acetate copolymer.

[0010] (2) In the sealing material for refrigerators, the ethylene vinyl acetate copolymer used as the thermoplastic resin has high weather resistance and is less susceptible to deterioration due to moisture and temperature changes. Therefore, it can efficiently seal gaps in refrigerators over long periods of time and improve the insulation performance of the refrigerator.

[0011] (3) The sealing material for refrigerators according to (1) or (2), wherein the average particle size of the aerogel particles is in the range of 10 μm or more and 200 μm or less.

[0012] In the case of the sealing material for refrigerators described in (3), the average particle size of the aerogel particles is within the above range, so the aerogel particles disperse uniformly in the thermoplastic resin. As a result, the heat insulation and coatability are stable at a high level.

[0013] (4) A refrigerator comprising an insulated container having an inner box, an outer box, and an insulating material filled in the space between the inner box and the outer box, wherein the gap between the inner box and the outer box is sealed with a refrigerator sealing material according to any one of (1) to (3).

[0014] According to the refrigerator in (4), the gap between the inner box and the outer box is sealed with the above-mentioned sealing material, thus improving the thermal insulation between the inner box and the outer box. In addition, when filling the space between the inner box and the outer box with polyurethane foam as insulation, the polyurethane foam is less likely to leak out from the gap between the inner box and the outer box.

[0015] (5) A refrigerator comprising an insulated container having an inner box, an outer box, an insulating material filled in the space between the inner box and the outer box, and a partition plate disposed in the inner box, wherein the gap between the inner box and the partition plate is sealed with a sealing material for refrigerators described in any one of (1) to (3).

[0016] According to the refrigerator in (5), the gap between the inner box and the partition plate is sealed with the above-mentioned sealing material, thus improving the thermal insulation of the space inside the inner box partitioned by the partition plate.

[0017] (6) A refrigerator comprising an insulated container having an inner box, an outer box, and an insulating material filled in the space between the inner box and the outer box, wherein each side of the outer box has a folded portion that is folded inward, the ends of the folded portions on adjacent sides of the outer box are cut off so as not to come into contact with each other, and the gap between the ends of the folded portions on adjacent sides of the outer box is sealed with a refrigerator sealing material according to any one of (1) to (3).

[0018] According to the refrigerator in (6), the gaps at the ends of the folded parts on adjacent sides of the outer box are sealed with the above-mentioned sealing material, thereby improving the heat insulation of the outer box. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a sealing material for a refrigerator that can improve the heat insulation performance of the refrigerator, and a refrigerator having excellent heat insulation performance.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view of a heat insulation container used in a refrigerator according to an embodiment of the present invention. [Figure 2] It is a sectional view taken along line II-II of FIG. 1. [Figure 3] It is a sectional view taken along line III-III of FIG. 1.

Mode for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] FIG. 1 is a perspective view of a heat insulation container used in a refrigerator according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. 1.

[0023] In FIGS. 1 to 3, the heat insulation container 1 is a container with an open front surface. The heat insulation container 1 includes an inner box 10, an outer box 20, and a heat insulating material 30 filled in the space between the inner box 10 and the outer box 20. A partition plate 15 for partitioning the space of the inner box 10 is disposed in the inner box 10.

[0024] The inner box 10 includes an inner box upper surface plate 10a, an inner box right side surface plate 10b, an inner box left side surface plate 10c, an inner box lower surface plate 10e, and an inner box back surface plate 10f. The gaps between the inner box upper surface plate 10a, the inner box right side surface plate 10b, the inner box left side surface plate 10c, the inner box lower surface plate 10e, and the inner box back surface plate 10f are sealed with a sealing material 40. The partition plate 15 is supported by the inner box right side surface plate 10b and the inner box left side surface plate 10c. The gaps between the inner box right side surface plate 10b and the inner box left side surface plate 10c and the partition plate 15 are sealed with a sealing material 40. Each side surface plate of the inner box upper surface plate 10a, the inner box right side surface plate 10b, the inner box left side surface plate 10c, and the inner box lower surface plate 10e has a bent portion bent inward.

[0025] The outer box 20 includes an outer box top surface 20a, an outer box right side surface 20b, an outer box left side surface 20c, an outer box bottom surface 20e, and an outer box back surface 20f. Each of the sides of the outer box top surface 20a, the outer box right side surface 20b, the outer box left side surface 20c, and the outer box bottom surface 20e has a folded portion that is folded inward.

[0026] As shown in Figure 2, the gap between the folded portion 21b of the right side portion 20b of the outer box and the folded portion 11b of the right side panel 10b of the inner box is sealed with sealing material 40, and the gap between the folded portion 21c of the left side portion 20c of the outer box and the folded portion 11c of the left side panel 10c of the inner box is sealed with sealing material 40. Similarly, the gap between the folded portion 21a of the top portion 20a of the outer box and the folded portion of the top panel 10a of the inner box is sealed with sealing material, and the gap between the folded portion 21e of the bottom portion 20e of the outer box and the folded portion of the bottom panel 10e of the inner box is sealed with sealing material.

[0027] As shown in Figure 1, the folded portion 21a of the top surface 20a of the outer box, the folded portion 21b of the right side surface 20b of the outer box, the folded portion 21c of the left side surface 20c of the outer box, and the folded portion 21e of the bottom surface 20e of the outer box have their ends cut off to form a trapezoid shape. The gap between the slanted sides of the trapezoidal folded portions 21a to 21e is filled with a sealing material (not shown). Note that the shape of the folded portions 21a to 21e is not limited to a trapezoid shape. However, it is preferable that the folded portions on adjacent sides do not come into contact with each other.

[0028] The sealing material 40 includes a thermoplastic resin and aerogel particles. The inclusion of aerogel particles improves the thermal insulation properties of the sealing material 40.

[0029] The thermoplastic resin may have a softening temperature within the range of 80°C to 120°C. Examples of thermoplastic resins include ethylene vinyl acetate copolymer (EVA), olefin, polyamide, and polyurethane. The thermoplastic resin may also be EVA.

[0030] As the aerogel particles, for example, silica aerogel particles can be used. The average particle size of the aerogel particles may be in the range of 10 μm to 200 μm, 10 μm to 100 μm, or 10 μm to 50 μm.

[0031] The aerogel particle content of the sealing material 40 is set to be within the range of 1% by mass or more and 18% by mass or less. If the aerogel particle content is too high, the viscosity of the sealing material 40 when melted may become too high, making it difficult to apply the sealing material 40 to the desired location. If the aerogel particle content is too low, the thermal conductivity of the sealing material 40 may increase, potentially reducing its heat insulation properties. For this reason, in this embodiment, the aerogel particle content is set to be within the range of 1% by mass or more and 18% by mass or less. The aerogel particle content may also be within the range of 1% by mass or more and 15% by mass or less, or within the range of 1% by mass or more and 12.5% ​​by mass or less.

[0032] There are no particular restrictions on the materials used for the inner box 10, partition plate 15, outer box 20, and insulation material 30; various materials used for insulated containers in refrigerators can be used. For example, ABS resin and polypropylene can be used for the inner box 10 and partition plate 15. Metals such as iron and stainless steel can be used for the outer box 20. Polyurethane foam and vacuum insulation material can be used for the insulation material 30.

[0033] The sealing material 40 of this embodiment, configured as described above, contains aerogel particles within the above range, resulting in high heat insulation and low melt viscosity when melted, thus providing excellent applicability. Therefore, by using the sealing material 40 of this embodiment, gaps in the refrigerator, such as between the inner box 10 and the outer box 20, can be efficiently sealed, and the heat insulation of the refrigerator can be improved.

[0034] In the sealing material 40 of this embodiment, when the thermoplastic resin is an ethylene vinyl acetate copolymer, the ethylene vinyl acetate copolymer has high weather resistance and is less susceptible to deterioration due to moisture and temperature changes. Therefore, it is possible to efficiently seal gaps in the refrigerator over a long period of time and improve the heat insulation performance of the refrigerator.

[0035] In the sealing material 40 of this embodiment, when the average particle size of the aerogel particles is within the above range, the aerogel particles are more easily dispersed uniformly in the thermoplastic resin. As a result, the heat insulation and coatability are stable at a high level.

[0036] With the insulated container 1 of this embodiment configured as described above, the gap between the inner box 10 and the outer box 20 is sealed with the sealing material 40, thereby improving the thermal insulation performance between the inner box 10 and the outer box 20. Furthermore, when foamed urethane is filled as the insulating material 30 between the inner box 10 and the outer box 20, the foamed urethane is less likely to leak out from the gap between the inner box 10 and the outer box 20.

[0037] Furthermore, according to the heat-insulating container 1 of this embodiment, since the gap between the inner box 10 and the partition plate 15 is sealed with the sealing material 40, the heat insulation of the space inside the inner box 10 partitioned by the partition plate 15 is improved. In addition, since the gaps at the ends of the folded portions 21a to 21d on adjacent sides of the outer box 20 are sealed with the sealing material 40, the heat insulation of the outer box is improved.

[0038] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. [Examples]

[0039] Next, the present invention will be described with reference to examples.

[0040] [Example 1] Ethylene vinyl acetate copolymer (EVA) was heated and melted. The molten EVA and silica aerogel particles with an average particle size of 20 μm were mixed in a mass ratio of 90:10 to prepare aerogel particle-containing EVA.

[0041] [Example 2] Aerogel particle-containing EVA was prepared in the same manner as in Example 1, except that silica aerogel particles with an average particle diameter of 128 μm were used.

[0042] [evaluation] The melt viscosity, softening point, and thermal conductivity of the aerogel particle-containing EVA prepared in Examples 1 and 2 were measured by the following method. The results, along with the average particle size and blending ratio of the aerogel particles used in Examples 1 and 2, are shown in Table 1 below. As Comparative Example 1, the melt viscosity, softening point, and thermal conductivity of the EVA alone used in Examples 1 and 2 are also shown in Table 1.

[0043] (Melting viscosity) The measurement will be performed in accordance with the method specified in JAI7-1999 (Japan Adhesive Industry Association Standard). The sample will be heated to 160°C to melt, and the viscosity of the resulting molten material will be measured using a viscometer (DV2T digital viscometer manufactured by Eiko Seiki Co., Ltd.) under the following conditions: spindle: No. 4, rotation speed: 10 rpm, and measurement temperature: 160°C.

[0044] (softening point) Measurements are performed in accordance with the method specified in JAI7-1999 (Japan Adhesive Industry Association Standard). A test apparatus, the ADM-1E model manufactured by Maytec Co., Ltd., is used. The sample is placed in an annular cylinder and left overnight to harden, thereby obtaining a test specimen. Next, a sphere is placed on the obtained specimen and immersed in glycerin, and the temperature is increased at a rate of 5°C / min. The temperature at which the sphere falls is defined as the softening point.

[0045] (Thermal conductivity) The thermal conductivity was measured using a thermal conductivity measuring device (FOX-200, manufactured by Eiko Seiki Co., Ltd.) under the following conditions: hot plate setting: 38°C, cold plate setting: 10°C, sample size: 200mm × 200mm × T25mm.

[0046] [Table 1]

[0047] The results in Table 1 show that the aerogel particle-containing EVA prepared in Examples 1 and 2 have lower thermal conductivity and superior heat insulation properties compared to EVA alone (Comparative Example 1).

[0048] [Examples 3-6, Comparative Example 2] Aerogel particle-containing EVA was prepared in the same manner as in Example 1, except that the mixing ratio of molten EVA and aerogel particles (average particle size: 20 μm) was changed to the ratio shown in Table 2 below. The melt viscosity, softening point, and thermal conductivity of the prepared aerogel particle-containing EVA were then measured using the method described above. The results are shown in Table 2.

[0049] [Table 2]

[0050] The results in Table 2 show that the aerogel particle-containing EVA of Examples 3 to 6, which contain aerogel particles within the scope of the present invention, have a melt viscosity within a practical range for use as a sealant for refrigerators, high applicability, low thermal conductivity, and excellent heat insulation properties. In contrast, the aerogel particle-containing EVA of Comparative Example 2, which contains aerogel particles beyond the scope of the present invention, had a melt viscosity that was too high (over 5,000,000 mPa·s), making application difficult, and therefore the thermal conductivity could not be measured. [Explanation of Symbols]

[0051] 1. Insulated container 10 Inner box 15 partition plates 20 Outer box 30 Insulation 40 Sealing material

Claims

1. It contains thermoplastic resin and aerogel particles. A sealing material for refrigerators, wherein the content of the aerogel particles is within the range of 82% by mass or more and 99% by mass or less.

2. The sealing material for a refrigerator according to claim 1, wherein the thermoplastic resin is an ethylene vinyl acetate copolymer.

3. The sealing material for a refrigerator according to claim 1, wherein the average particle size of the aerogel particles is within the range of 10 μm to 200 μm.

4. The insulated container comprises an inner box, an outer box, and an insulating material filled in the space between the inner box and the outer box. A refrigerator in which the inner box and the outer box are sealed with a sealing material for refrigerators according to any one of claims 1 to 3.

5. An insulated container comprising an inner box, an outer box, and an insulating material filled in the space between the inner box and the outer box, and a partition plate disposed in the inner box, A refrigerator in which the space between the inner box and the partition plate is sealed with a sealing material for refrigerators according to any one of claims 1 to 3.

6. The insulated container comprises an inner box, an outer box, and an insulating material filled in the space between the inner box and the outer box. Each side of the outer box has a folded portion that is folded inward. The edges of the folded portions on adjacent sides of the outer box are cut off so that they do not come into contact with each other. A refrigerator in which the gaps at the ends of the folded portions on adjacent sides of the outer box are sealed with a refrigerator sealing material according to any one of claims 1 to 3.

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