JP2024093983A - Vacuum insulation material for refrigerators, refrigerators, and method for producing vacuum insulation material for refrigerators - Google Patents

Abstract

The present invention provides a vacuum insulation material for refrigerators that exhibits high heat insulating performance over a long period of time and has excellent design, a refrigerator, and a method for manufacturing the vacuum insulation material for refrigerators.
[Solution] A vacuum insulation material for refrigerators includes a hollow resin container having at least one opening, an interconnected urethane filled inside the hollow resin container, a glass layer formed on at least one of the inner and outer surfaces of the hollow resin container, and a sealing portion that seals the opening.
[Selected figure] Figure 5

Description

The present invention relates to a vacuum insulation material for refrigerators, a refrigerator, and a method for manufacturing a vacuum insulation material for refrigerators.

Vacuum insulation materials have traditionally been used as insulation materials for refrigerators. Vacuum insulation materials are insulation materials in which a core material is filled under reduced pressure inside a hollow resin container. A vacuum insulation material is known that uses a hollow molded body formed by blow molding as the hollow resin container and interconnected urethane as the core material (Patent Document 1).

Japanese Patent Application Laid-Open No. 9-119771

In order to improve the insulation performance of a refrigerator, it is effective to increase the coverage rate of the vacuum insulation material with respect to the entire refrigerator box. In order to increase the coverage rate of the vacuum insulation material, it is possible to shape the vacuum insulation material to fit the refrigerator box. The refrigerator box is divided into a freezer, a refrigerator, a vegetable compartment, etc., and has a complex shape. For this reason, if a resin hollow container of the vacuum insulation material is molded into a shape that fits the refrigerator box using blow molding, the thickness of the resulting resin hollow container is likely to be uneven. If the thickness of the resin hollow container of the vacuum insulation material becomes uneven, gas will easily pass through the thinner parts of the resin hollow container, reducing the airtightness of the vacuum insulation material and making it difficult to maintain the insulation performance of the vacuum insulation material for a long period of time. In addition, if the thickness of the resin hollow container becomes uneven, when the inside of the resin hollow container is depressurized with the core material filled, the resin hollow container may be partially deformed due to the pressure difference generated inside the resin hollow container, which may damage the aesthetic appearance of the vacuum insulation material.

The present invention was made in consideration of the above circumstances, and aims to provide a vacuum insulation material for refrigerators that exhibits high insulation performance over a long period of time and has excellent design, a manufacturing method thereof, and a refrigerator that exhibits high insulation performance over a long period of time.

The inventors discovered that the above problems could be solved by forming a glass layer on at least one of the inner and outer surfaces of a hollow resin container and using interconnected urethane as the core material, and thus completed the present invention. Therefore, the present invention provides the following:

(1) A vacuum insulation material for a refrigerator, comprising: a hollow resin container having at least one opening; an interconnected urethane filled inside the hollow resin container; a glass layer formed on at least one of the inner and outer surfaces of the hollow resin container; and a sealing part that seals the opening.

According to the vacuum insulation material for refrigerators (1), a glass layer is formed on at least one of the inner and outer surfaces of the hollow resin container, which prevents gas from penetrating into the interior, and therefore exhibits high insulation performance over a long period of time. In addition, even if the interior of the hollow resin container is decompressed while filled with interconnected urethane, the hollow resin container is not easily deformed, and therefore has excellent design properties.

(2) The vacuum insulation material for refrigerators described in (1) above, in which the glass layer is formed on the outside of the hollow resin container.

(2) Vacuum insulation material for refrigerators makes it easier to form the glass layer, improving productivity.

(3) The vacuum insulation material for a refrigerator according to (1) or (2) above, wherein the density of the interconnected urethane is within a range of 50 to 80 kg/ ^m3 .

(3) In the vacuum insulation material for refrigerators, the density of the interconnected urethane is within the above range, so the insulation properties are improved and the strength is increased.

(4) A vacuum insulation material for a refrigerator according to any one of (1) to (3) above, in which the sealing portion is openable and closable.

(4) According to the vacuum insulation material for refrigerators, the pressure inside the vacuum insulation material for refrigerators can be reduced by opening the sealed portion, so that high insulation performance can be maintained for a longer period of time.

(5) A refrigerator equipped with a vacuum insulation material for a refrigerator described in any one of (1) to (4) above.

The refrigerator (5) is equipped with the above-mentioned vacuum insulation material for refrigerators, and therefore exhibits high insulation performance for a long period of time.

(6) A method for manufacturing a vacuum insulation material for refrigerators, comprising: a preparation step of preparing a hollow resin container with a glass layer, the hollow resin container having at least one opening formed by blow molding and a glass layer formed on at least one of the inner and outer surfaces of the hollow resin container; a urethane filling step of filling the inside of the hollow resin container with urethane through the opening; a vacuum degassing step of degassing the inside of the hollow resin container through the opening; and a sealing step of sealing the opening of the hollow resin container.

According to the manufacturing method of vacuum insulation material for refrigerators in (6), a hollow resin container with a glass layer is prepared in the preparation process, so that vacuum insulation material for refrigerators that exhibits high insulation performance over a long period of time and has excellent design properties can be easily manufactured industrially.

The present invention makes it possible to provide a vacuum insulation material for refrigerators that exhibits high insulation performance over a long period of time and has excellent design, a manufacturing method thereof, and a refrigerator with excellent insulation performance.

1 is a front view showing a refrigerator according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II of FIG. 1. 1 is a front perspective view showing a vacuum insulation material according to one embodiment of the present invention. 2 is a rear perspective view showing a vacuum insulation material according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the periphery of a first sealing portion showing a vacuum insulation material according to one embodiment of the present invention. A cross-sectional view of the periphery of a second sealing portion showing a vacuum insulation material according to one embodiment of the present invention. 1 is a cross-sectional view showing one step of a method for producing a vacuum insulation material according to one embodiment of the present invention. 1 is a cross-sectional view showing one step of a method for producing a vacuum insulation material according to one embodiment of the present invention. 1 is a cross-sectional view showing one step of a method for producing a vacuum insulation material according to one embodiment of the present invention. 4 is a cross-sectional view showing a step of a method for producing a vacuum insulation material according to another embodiment of the present invention. FIG.

Hereinafter, a vacuum insulation material according to an embodiment of the present invention and a refrigerator using the vacuum insulation material will be described with reference to the accompanying drawings.
1 to 4, the X direction (left-right direction) indicates the width direction of refrigerator 10, the Y direction (front-back direction) indicates the depth direction of refrigerator 10, and the Z direction (up-down direction) indicates the height direction of refrigerator 10. In addition, in the description of this embodiment, the same members are generally designated by the same reference numerals, and repeated description will be omitted.

As shown in Figs. 1 and 2, the refrigerator 10 of this embodiment includes insulated doors (upper insulated doors 21a, 21b, middle insulated door 22, and lower insulated door 23) and an insulated box 30. The refrigerator 10 is divided into three sections: an upper section 11, a middle section 12, and a lower section 13. The upper section 11 can be opened and closed by the upper insulated doors 21a, 21b, the middle section 12 by the middle insulated door 22, and the lower section 13 by the lower insulated door 23. The upper insulated doors 21a, 21b are each a rotating door that can rotate left and right from the center around an axis at the end on the side. The middle insulated door 22 and the lower insulated door 23 are each a drawer-type door equipped with a storage container 24.

The insulating box 30 has a vacuum insulating material 40 and a frame 50 that covers the outside of the vacuum insulating material 40. The frame 50 can be made of, for example, a steel plate. As shown in Figures 3 and 4, the vacuum insulating material 40 has a complex shape in which a top surface 40a, a back surface 40b, a bottom surface 40c, side surfaces 40d and 40e, a first partition 40f that separates the upper stage 11 from the middle stage 12, and a second partition 40g that separates the middle stage 12 from the lower stage 13 are integrally molded. A first sealing portion 44a and a second sealing portion 44b are arranged on the back surface 40b of the vacuum insulating material 40.

A machine room 61 is provided between the vacuum insulation material 40 of the lower section 13 and the frame 50. A compressor 62 is housed in the machine room 61. A cooling chamber 63 is defined on the rear side of the middle section 12, and an evaporator 64 is housed in the cooling chamber 63. The evaporator 64 and the compressor 62 are connected to an expansion means and a condenser (not shown) via refrigerant piping to form a vapor compression refrigeration cycle.

A part of the cold air in the cooling chamber 63 cooled by the evaporator 64 is sent to the middle section 12 via the blower 65 and the cold air pipe 66 to cool the middle section 12. The cold air that has cooled the middle section 12 flows into the cooling chamber 63 and is cooled again by the evaporator 64. The remaining cold air is sent to the upper section 11 to cool the upper section 11. The cold air that has cooled the upper section 11 is sent to the lower section 13 via the cold air pipe (not shown), and after cooling the lower section 13, it is sent to the cooling chamber 63 via the cold air pipe (not shown) and is cooled again by the evaporator 64. A damper (not shown) is arranged in the cold air pipe. The control device (not shown) of the refrigerator 10 controls the opening and closing of the damper based on the internal temperature measured by the internal temperature sensor (not shown). This adjusts the flow rate of cold air to keep the internal temperature constant. In this way, the upper section 11, the middle section 12, and the lower section 13 are cooled to a predetermined temperature range. The arrows in FIG. 2 indicate the flow of cold air. In addition, a defrost heater 67 is provided below the evaporator 64 to melt frost on the evaporator 64.

As shown in Figures 5 and 6, the vacuum insulation material 40 has a resin hollow container 41, a connected urethane 42 filled inside the resin hollow container 41, and a glass layer 43 formed on the outer surface of the resin hollow container. The resin hollow container 41 has a first opening 41a shown in Figure 5 and a second opening 41b shown in Figure 6. The first opening 41a is a degassing port used when degassing the resin hollow container 41 and reducing the pressure inside the resin hollow container 41. The second opening 41b is a urethane inlet used when filling the resin hollow container 41 with the connected urethane 42. The first opening 41a is sealed with a first sealing portion 44a. The first sealing portion 44a has a first sealing material 45a that can be opened and closed, and a first coating material 46a that covers the first sealing material 45a. The first sealing portion 44a is designed so that the inside of the vacuum insulation material 40 can be depressurized by removing the first coating material 46a and opening the first sealing material 45a. The second opening 41b is sealed with the second sealing portion 44b. The second sealing portion 44b has a second sealing material 45b that cannot be opened or closed, and a second coating material 46b that covers the second sealing material 45b.

The resin hollow container 41 may be, for example, a molded body formed by blow molding. The material of the resin hollow container 41 is not particularly limited, and any thermoplastic resin that can be molded by blow molding may be used. The resin hollow container 41 may be, for example, an olefin resin, an ethylene-vinyl copolymer, a styrene resin, a vinyl resin, a polyamide resin, a polyester resin, a polycarbonate resin, or a polyphenylene oxide resin. Examples of the olefin resin include low-density polyethylene, high-density polyethylene, polypropylene, a cyclic olefin copolymer, and poly(4-methylpentene). Examples of the ethylene-vinyl copolymer include an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, and an ethylene-vinyl chloride copolymer. Examples of the styrene resin include polystyrene, an acrylonitrile-styrene copolymer, an ABS, and an α-methylstyrene-styrene copolymer. Examples of the vinyl resin include polyvinyl chloride, polyvinylidene chloride, a vinyl chloride-vinylidene chloride copolymer, polymethyl acrylate, and polymethyl methacrylate. Examples of polyamide-based resins include polyamide 6, polyamide 66, polyamide 11, polyamide 12, and polyamide 610. Examples of polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.
The thickness of the resin hollow container 41 may be, for example, within the range of 0.4 mm or more and 2.0 mm or less.

The interconnected urethane 42 is a urethane foam having interconnected pores in which a plurality of pores are continuously connected to each other. The density of the interconnected urethane 42 is not particularly limited, but is preferably in the range of 50 to 80 kg/ ^m3 . The thickness of the interconnected urethane 42 may be, for example, in the range of 20 mm to 60 mm.

The glass layer 43 has the function of suppressing the permeation of gas into the inside of the vacuum insulation material 40 and making the hollow resin container 41 less likely to deform.
The thickness of the glass layer 43 may be, for example, in the range of 3 mm or less.

The first sealing material 45a may be any material that can be opened and closed, and a known valve may be used. The material of the second sealing portion 44b is preferably one that has low gas permeability. The material of the second sealing portion 44b may be glass or resin. The material of the first coating material 46a and the second coating material 46b may be, for example, glass.

According to the vacuum insulation material 40 of this embodiment configured as described above, the glass layer 43 is formed on the outer surface of the hollow resin container 41, which suppresses the permeation of gas into the interior, and therefore exhibits high insulation performance over a long period of time. In addition, even if the interior of the hollow resin container 41 is depressurized while filled with the interconnected urethane 42, the hollow resin container 41 is not easily deformed, so wrinkles are less likely to occur on the surface and the design is excellent. Furthermore, the glass layer 43 is formed on the outer surface of the hollow resin container 41, which makes it easier to form the glass layer 43, improving productivity.

In the vacuum insulation material 40 of this embodiment, when the density of the interconnected urethane 42 is within the range of 50 to 80 kg/ ^m3 , the insulation properties are further improved and the strength is increased, as will be apparent from the results of the experimental examples described later.

In the vacuum insulation material 40 of this embodiment, the first opening 41a is sealed with an openable first sealing material 45a, and the inside of the vacuum insulation material 40 can be depressurized by opening the first sealing material 45a. Therefore, if the internal pressure of the vacuum insulation material 40 increases, the inside of the vacuum insulation material 40 can be depressurized again, thereby maintaining high insulation performance for a longer period of time.

The refrigerator 10 of this embodiment has a high insulation performance over a long period of time because the insulated box 30 has vacuum insulation material 40. In addition, because the vacuum insulation material 40 has a high designability, there is no particular need to cover the inside of the vacuum insulation material 40 with a decorative panel. By not covering it with a decorative panel, the capacity of the insulated box 30 can be increased.

Next, a method for manufacturing a vacuum insulation material according to an embodiment of the present invention will be described using the above-mentioned vacuum insulation material 40 as an example.
The vacuum insulation material 40 can be manufactured by a method including, for example, a preparation step, a communicating urethane filling step, a vacuum deaeration step, and a sealing step.

The preparation step is a step of preparing a resin hollow container 41 with a glass layer 43, which has a resin hollow container 41 having a first opening 41a and a second opening 41b, and a glass layer 43 formed on the outer surface of the resin hollow container 41. The resin hollow container 41 is produced by blow molding. The resin hollow container 41 can be produced by blow molding, for example, by pouring molten thermoplastic resin into a blow molding die and blowing air into the thermoplastic resin from the inside to mold the thermoplastic resin into the shape of the die. As a method for forming the glass layer 43 on the outer surface of the resin hollow container 41, for example, a method of removing the resin hollow container 41 from the die and attaching a glass film to the outer surface of the removed resin hollow container 41 can be used.

The first opening 41a and the second opening 41b may be formed when the resin hollow container 41 is produced by blow molding, or may be formed on the resin hollow container 41 after the glass layer 43 is formed. The first opening 41a may be formed after the interconnected urethane filling process and before the vacuum degassing process.

The interconnected urethane filling process is a process of filling the interior of the resin hollow container 41 with the interconnected urethane 42 through the second opening 41b. As a method for filling the interconnected urethane 42, a method of pouring an interconnected urethane forming material composition into the interior of the resin hollow container 41 and generating an interconnected urethane inside the resin hollow container 41 can be used. As the interconnected urethane forming material composition, a liquid composition containing a polyol component, an isocyanate component, and a foaming agent can be used. By using a liquid composition as the urethane raw material composition, the interconnected urethane 42 can be more uniformly filled inside the resin hollow container 41. In addition, when the interconnected urethane is generated inside the resin hollow container 41, it is preferable to place a moisture absorbent or a gas absorbent inside the resin hollow container 41 to absorb the moisture and gas components generated in the interconnected urethane. After the interconnected urethane 42 is filled, the second opening 41b may be sealed. In addition, a method of filling the open urethane 42 can be used in which the open urethane generated outside the resin hollow container 41 is poured into the resin hollow container 41.

The vacuum degassing process is a process of degassing the inside of a hollow resin container 41 filled with a communicating urethane 42 through the first opening 41a of the hollow resin container 41.

The sealing process is a process in which the first opening 41a of the resin hollow container 41 is sealed using a first sealing material 45a, and the second opening 41b is sealed using a second sealing material 45b.

The steps from the interconnected urethane filling step to the sealing step may be carried out in a chamber 70, for example, as shown in Figures 7A to 7C. First, as shown in Figure 7A, a resin hollow container 41 with a glass layer 43 having a first opening 41a and a second opening 41b is placed in the chamber 70. Next, an interconnected urethane forming material composition 42a is poured into the resin hollow container 41 through the second opening 41b. A moisture absorbent or gas absorbent may be poured into the resin hollow container 41.

Next, as shown in FIG. 7B, a first sealant 45a is inserted into the first opening 41a to seal the first opening 41a, and a temporary lid material 71 is inserted into the second opening 41b to temporarily seal the second opening 41b. Thereafter, the first opening 41a is left open, the chamber 70 is evacuated, and while the resin hollow container 41 is being evacuated, the interconnected urethane forming material composition 42a in the resin hollow container 41 is reacted to produce the interconnected urethane 42. By evacuating the resin hollow container 41, the reaction of the interconnected urethane forming material composition 42a is more likely to proceed uniformly, and the interconnected urethane 42 can be filled more uniformly.

Next, as shown in FIG. 7C, once the hollow resin container 41 is filled with the interconnected urethane 42, the temporary lid 71 is removed and the second opening 41b is opened. If a urethane layer without interconnected pores has formed on the surface of the interconnected urethane 42 exposed at the second opening 41b, the urethane layer is scraped off. After that, the chamber 70 is evacuated, and the hollow resin container 41 is evacuated through the first opening 41a and the second opening 41b.

When the inside of the resin hollow container 41 has been degassed, the first sealing material 45a is closed, and the second sealing material 45b is inserted into the second opening 41b to seal the second opening 41b. Next, the first sealing material 45a is covered with the first coating material 46a, and the second sealing material 45b is covered with the second coating material 46b.

The vacuum insulation material 40 is manufactured through the above steps. According to the manufacturing method of the vacuum insulation material 40 of this embodiment, since the resin hollow container 41 with the glass layer 43 is prepared in the preparation step, it is possible to easily manufacture a vacuum insulation material for refrigerators that has high insulation performance for a long period of time and has excellent design on an industrial scale. In this embodiment, an example in which the steps from the communicating urethane filling step to the sealing step are performed in the chamber 70 has been described, but the present invention is not limited to this. For example, as shown in FIG. 8, the first sealing material 45a may be inserted into the first opening 41a, a vacuum pump 72 may be connected, and the inside of the resin hollow container 41 may be degassed using the vacuum pump 72. In this case, the second opening 41b may be sealed using the second sealing material 45b and the second coating material 46b.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment.
For example, in the vacuum insulation material 40 of the present embodiment, the glass layer 43 is formed on the outer surface of the hollow resin container 41, but the present invention is not limited to this. The glass layer 43 may be formed on the inner surface of the hollow resin container 41, or may be formed on both the inner and outer surfaces of the hollow resin container 41. The hollow resin container 41 having the glass layer 43 formed on the inner surface can be obtained by forming a resin layer on the outside of the hollow glass container.

In addition, in the vacuum insulation material 40 of this embodiment, the first opening 41a is an air release port and the second opening 41b is a urethane inlet, but the present invention is not limited to this. One opening may be both an air release port and a urethane inlet. In this case, the resin hollow container 41 is filled with communicating urethane, and then the pressure inside the resin hollow container 41 is reduced, and the opening is then sealed.

In addition, in the vacuum insulation material 40 of this embodiment, the first opening 41a is sealed with the first sealing material 45a that can be opened and closed, and the second opening 41b is sealed with the second sealing material 45b that cannot be opened and closed, but the present invention is not limited to this. Both the first opening 41a and the second opening 41b may be sealed with the first sealing material 45a that can be opened and closed, or may be sealed with the second sealing material 45b that cannot be opened and closed.

In the refrigerator 10 of this embodiment, the inside of the vacuum insulation material 40 is not covered with a decorative panel, but the present invention is not limited to this. The inside of the vacuum insulation material 40 may be covered with a decorative panel. Also, in the refrigerator 10 of this embodiment, the vacuum insulation material 40 may be used as the insulation material for the insulated doors (upper insulated doors 21a, 21b, middle insulated door 22, and lower insulated door 23).

[Experimental Example]
(Experimental Example 1)
98.0 parts by mass of a urethane raw material composition (manufactured by Sumika Covestro Urethane Co., Ltd.) and 2.0 parts by mass of a blowing agent were charged into an aluminum vapor deposition bag (size: 300 mm x 200 mm, manufactured by Dai Nippon Printing Co., Ltd.) and mixed in a bag-shaped container to produce an interconnected urethane. Next, the pressure inside the bag-shaped container was reduced using a vacuum pump, and the opening of the bag-shaped container was sealed to produce a vacuum insulation material (size: 200 mm x 200 mm x 15 mm thick).

(Experimental Examples 2 to 5)
A vacuum insulation material was produced in the same manner as in Experimental Example 1, except that the amounts of the urethane raw material composition and the foaming agent added were set as shown in Table 1 below.

(evaluation)
The density, thermal conductivity, and compressive strength of the interconnected urethane were measured by the following methods for the vacuum insulation materials obtained in Experimental Examples 1 to 5. The results are shown in Table 1 below.

(Density of Interconnected Urethane)
The measurement was performed according to a method in accordance with JIS K 7222:2005 "Foamed plastics and rubber - Determination of apparent density."

(Thermal conductivity)
The measurements were performed at an average specimen temperature of 24° C. using a method in accordance with JIS A 1412-2:1999 “Method of measuring thermal resistance and thermal conductivity of thermal insulation materials - Part 2: Heat flow meter method (HFM method)”.

(Compressive strength)
The measurement was performed according to a method in accordance with JIS K 7220:2006 "Rigid foamed plastics - Determination of compression properties."

The results shown in Table 1 show that when the density of the open urethane is within the range of 50 to 80 kg/ ^m3 , the balance between thermal conductivity and compressive strength is excellent, with low thermal conductivity and high compressive strength. Therefore, a vacuum insulation material using an open urethane having a density within the range of 50 to 80 kg/ ^m3 has improved thermal insulation properties and high strength.

REFRIGERATION LIST 10 Refrigerator 11 Upper section 12 Middle section 13 Lower section 21a, 21b Upper insulated door 22 Middle insulated door 23 Lower insulated door 24 Storage container 30 Insulated box body 40 Vacuum insulation material 41 Hollow container 41a First opening 41b Second opening 42 Interconnected urethane 42a Interconnected urethane forming material composition 43 Glass layer 44a First sealing portion 44b Second sealing portion 45a First sealing material 45b Second sealing material 46a First coating material 46b Second coating material 50 Frame 61 Machine room 62 Compressor 63 Cooling chamber 64 Evaporator 65 Blower 66 Cold air piping 67 Defrosting heater 70 Chamber 71 Temporary cover material 72 Vacuum pump

Claims (6)

A vacuum insulation material for a refrigerator, comprising: a hollow resin container having at least one opening; interconnected urethane filled inside the hollow resin container; a glass layer formed on at least one of the inner and outer surfaces of the hollow resin container; and a sealing part that seals the opening. The vacuum insulation material for refrigerators according to claim 1, wherein the glass layer is formed on the outside of the hollow resin container. 2. The vacuum insulation material for a refrigerator according to claim 1, wherein the density of the interconnected urethane is in the range of 50 to 80 kg/ ^m3 . The vacuum insulation material for refrigerators according to claim 1, wherein the sealing portion is openable and closable. A refrigerator equipped with a vacuum insulation material for refrigerators according to any one of claims 1 to 4. A preparation step of preparing a resin hollow container with a glass layer, the resin hollow container having at least one opening formed by blow molding and a glass layer formed on at least one of the inner and outer surfaces of the resin hollow container;
a step of filling the inside of the hollow resin container with a urethane through the opening;
a vacuum degassing step of degassing the inside of the resin hollow container through the opening of the resin hollow container;
and a sealing step of sealing the opening of the resin hollow container.

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