JPH08178176A - Vacuum heat insulating material - Google Patents

Abstract

PURPOSE: To provide a vacuum heat insulation material high in strength and preventing the fluctuation of size and a shape even when the vacuum heat insulation material is left standing under an atmospheric pressure for a long period. CONSTITUTION: The upper and under surfaces of an aggregate 1 formed in such a manner that a breathable middle bag 1b is filled with fine powder 1a of an organic or an inorganic material are nipped between aggregate molding reinforcing plates 3a and 3b. After, with this state, the aggregate 1 and the aggregate molding reinforcing plates 3a and 3b are contained in a breathable outer bag 2, after a vacuum at the interior of the outer bag 2 is drawn and deaerated through the opening part of the outer bag 2, the opening part of the outer bag 2 is sealed through thermal fusion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum heat insulating material, and more particularly to a vacuum heat insulating material having excellent shape and dimensional stability.

[0002]

2. Description of the Related Art Conventionally, as a heat insulating material for a heat insulating box used for refrigeration and heat retention, calcium silicate, perlite, etc. are filled in a breathable inner bag with a fine powder having a low thermal conductivity and a low weight, The product obtained by sealing the opening of this inner bag is housed in an air-impermeable outer bag, and the inside of this outer bag is vacuum deaerated and the opening obtained is sealed to obtain a vacuum. Insulation is used.

FIG. 6 is a cross-sectional view showing the structure of this conventional vacuum heat insulating material. In the figure, 10 is a vacuum heat insulating material, which is a fine powder of calcium silicate, pearlite, etc. having a low thermal conductivity and a light weight. 1a, and an aggregate 1 made of a breathable inner bag 11b filled with the fine powder 1a, and the aggregate 1 housed therein, and the inside thereof is brought into a vacuum state by vacuum deaeration. And an air-impermeable outer bag 2 whose opening is sealed. Here, breathable inner bag 1
Kraft paper, non-woven fabric, etc. are used as b.
As the non-breathable outer bag 2, an airtight plastic film, a laminated film in which a metal is vapor-deposited on the plastic film, or the like is used.

The conventional method for manufacturing the vacuum heat insulating material will be described below with reference to the drawings. FIG. 7 is a schematic cross-sectional view showing the configuration of an apparatus for manufacturing the vacuum heat insulating material 10. In the figure, the same reference numerals as those in FIG. 6 denote the same or corresponding parts,
11 is a vacuum evacuation furnace, 12a and 12b are exothermic heaters, 13
Is a vacuum pump.

First, the inner bag 1 whose three sides are sealed
b is filled with the fine powder 1a from the opening on the other side,
The remaining one side (opening) is sealed to obtain the aggregate 1. Next, after accommodating the aggregate 1 through the opening 2a on the remaining one side in the outer bag 2 whose three sides are sealed, as shown in FIG. 1 is placed in the outer bag 2, and the internal pressure of the vacuum evacuation furnace 11 is evacuated (0.1 to 1 Torr) by the vacuum pump 13. In this state, the opening 2a on the remaining side is sandwiched by the heaters 12a and 12b. By heat-sealing (sealing) by doing so, the vacuum heat insulating material 1
0 is completed. Here, when the internal pressure of the evacuation furnace 11 becomes a vacuum, the inside of the outer bag 2 also becomes a vacuum.

[0006]

The conventional vacuum heat insulating material is manufactured as described above, but such a manufacturing method causes the following problems. That is, when the outer bag 2 accommodating the aggregate 1 is placed inside the vacuum evacuation furnace 11 and the inside of the vacuum evacuation furnace 11 is degassed by the vacuum pump 13,
The vicinity of the opening 2a inside the outer bag 2 is strongly degassed and its vacuum degree becomes high, but the area far from the opening 2a is weakly degassed and its vacuum degree is near the opening 2a. Since it is lower than that in the vicinity, a vacuum degree distribution occurs inside the outer bag 2. Further, due to the distribution of the degree of vacuum, the fine powder 1a filled in the inner bag 1b flows, and the density thereof becomes irregular. Therefore, after that, if the vacuum heat insulating material 10 obtained by sealing the opening 2a is left under atmospheric pressure (1.1 kg / cm ² ), the vacuum heat insulating material 10 is deformed into an arc shape, and the desired shape is obtained. Shape,
And it becomes impossible to obtain the dimensions. FIG. 8 shows a cross-sectional view of the vacuum heat insulating material deformed in the shape of an arc. This problem is more remarkable as the size (area) of the vacuum heat insulating material is increased and the degree of vacuum distribution and density are increased.

Further, when the inside of the outer bag 2 is evacuated, the inner bag 1b and the outer bag 2 are brought into close contact with the surface of the fine powder 1a filled in the inner bag 1b, as shown in FIG. According to the accumulation state of the fine powder 1a, wrinkles 2b are generated in the outer bag 2, and as a result, the pulling force applied to the outer bag 2 becomes uneven, and the obtained vacuum heat insulating material 10 has an unexpected shape. It deforms, and it becomes impossible to obtain the desired shape and size.

Further, the conventional vacuum heat insulating material 10 has some strength because the fine powder 1a in the inner bag 1b is strongly aggregated when the inside of the outer bag 2 is vacuum deaerated. Become. However, such vacuum insulation 10
Is always used under atmospheric pressure (1.1 kg / cm ² ),
It must have the strength to withstand this atmospheric pressure (1.1 kg / cm ² ), but its constituent materials (fine powder 1
Since a, the inner bag 1b, and the outer bag 2) are all poor in strength themselves, they are kept at atmospheric pressure (1.1
If it is left at (kg / cm ² ), it may be deformed due to the above-mentioned vacuum distribution, and there is a problem in that the strength has not yet reached a satisfactory level.

By the way, FIG. 10 is a perspective view showing the structure of a vacuum heat insulating material proposed in Japanese Patent Laid-Open No. 60-256699.
As shown in the figure, this vacuum heat insulating material uses the same aggregate 21 as the aggregate 1, and the outer bag 2 has this aggregate 21 and hollow pipes 22a, 2b in which a plurality of small diameter holes are formed in the wall surface. And
The hollow pipes 22a and 22b are housed so as to be arranged along a pair of side surfaces of the aggregate 21 that face each other, and in this state, the inside of the outer bag 2 is vacuum-degassed to manufacture. According to this manufacturing method, the air present in the aggregate of the fine powder 21a inside the aggregate (medium bag) 21 enters the inside of the pipe through the small diameter holes 22c formed in the side walls of the hollow pipes 22a and 22b. Then, through the inside of the pipe, the outer bag 2
Since it is guided to the opening of the outer bag 2, the air existing in the agglomerates of the fine powder 21a at a position far from the opening of the outer bag 2 can be efficiently degassed, and as a result, the above-mentioned outer bag 2
The distribution of the degree of vacuum and the density of the fine powder that occur inside the are reduced to some extent, so that the deformation and size variation of the resulting vacuum heat insulating material can be suppressed to some extent. However, even in this manufacturing method, the pipe 22a (2
2b) and a position far away from the pipe 22a (22b), that is, near the end of the aggregate 21 and the aggregate 21.
The difference in vacuum level between the center and
In addition, since the density difference of the density of the fine powder occurs, the obtained vacuum heat insulating material may have a shape bent in a direction orthogonal to the longitudinal direction of the hollow pipe 22, and the vacuum heat insulating material having a desired shape and size. Cannot be obtained with good reproducibility. Further, in such a manufacturing method, the variation of the shape and size of the vacuum heat insulating material, which is caused by the inner bag and the outer bag being in close contact with each other on the surface of the fine powder described above and wrinkles occurring in the outer bag, is completely prevented. You cannot do it. Further, the vacuum heat insulating material obtained by such a manufacturing method is a hollow pipe 22.
Since a and 22b function as core materials, they have higher strength than the vacuum heat insulating material 10 obtained by the above conventional method, but when left for a long time under atmospheric pressure (1.1 kg / cm ² ). However, there is a problem that the hollow pipes 22a and 22b may bend in a direction orthogonal to the longitudinal direction.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a vacuum heat insulating material which can secure the stability of the size and shape during its manufacture.

Still another object of the present invention is high strength,
It is an object of the present invention to provide a vacuum heat insulating material which does not change in size and shape even if it is left under atmospheric pressure (1.1 kg / cm ² ) for a long time.

Still another object of the present invention is to provide a vacuum heat insulating material having a flat appearance surface without wrinkles on the outer bag.

Still another object of the present invention is to provide a vacuum heat insulating material in which the outer bag is not broken by an external impact.

[0014]

A vacuum heat insulating material according to the present invention (Claim 1) fills a breathable inner bag with a fine powder of an inorganic or organic substance and seals the opening of the inner bag. The aggregate obtained, or an aggregate made of a plate-shaped molded product of foamed plastic, an aggregate-forming reinforcing plate disposed on the upper and lower surfaces of the aggregate, and the inside of the aggregate and the aggregate-forming reinforcing plate And a non-air-permeable outer bag to be housed in the outer bag, the inside of the outer bag is vacuum deaerated, and the opening of the outer bag is sealed.

Further, according to the present invention (claim 2), in the vacuum heat insulating material, the outer surface of the outer bag is covered with a protective layer made of a styrene foam resin.

[0016]

In the present invention (Claim 1), because of the above-mentioned structure, when the inside of the outer bag is vacuum degassed during manufacturing, the periphery of the aggregate, that is, the side surface of the aggregate and the outer bag is obtained. 12
A space is formed between the inner surface of the aggregate and the
Even in a portion other than the vicinity of the opening of the outer bag that serves as a deaeration opening during vacuum deaeration, air (gas) existing inside the aggregate is led to the space, and the outer bag passes through this space. Therefore, the air (gas) inside the aggregate can be degassed uniformly.

Further, in the present invention (Claim 2), since the outer bag is covered with the protective layer made of the styrenic foam resin because of the above-mentioned constitution, even if an impact is applied from the outside,
The outer bag will not be broken, and the reliability of the vacuum heat insulating material can be improved.

[0018]

EXAMPLES Example 1 1 is a sectional view showing the structure of a vacuum heat insulating material according to a first embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 3 denote the same or corresponding parts, and 100 is a vacuum heat insulating material, and 3a and 3b are bones. It is a material forming reinforcement plate.

In the vacuum heat insulating material 100 of this embodiment, the aggregate forming reinforcing plates 3a and 3b are inserted between the upper and lower surfaces of the aggregate 1 and the inner side surface of the outer bag 2, respectively. The point that the molded reinforcing plates 3a and 3b are provided is different from the conventional vacuum heat insulating material shown in FIG. Here, the aggregate forming and reinforcing plate 3a,
As 3b, for example, paperboard having a thickness of about 0.1 mm to 2 mm,
A plastic plate or a metal plate is used, and its size is a size with which the aggregate 1 is completely covered, that is,
An aggregate having a larger area than the upper and lower surfaces of the aggregate 1 is used. Further, the other constituent materials are basically the same as those of the conventional vacuum heat insulating material shown in FIG. 6, and as the fine powder 1a of the aggregate 1 which has a low thermal conductivity and is lightweight, calcium silicate, Fine powder made of inorganic materials such as pearlite and silica, and PMMA (polymethylmethacrylate)
An organic resin fine powder such as is used, and kraft paper, non-woven fabric, or the like is used as the air-permeable inner bag 11b. As the air-impermeable outer bag 2, for example, an airtight plastic film such as a PET (polyethylene terephthalate) film, a laminated film obtained by vapor-depositing a metal foil such as an aluminum foil on the plastic film, or the like is used. As described below, this vacuum heat insulating material 1
In the production of 00, the opening 2 of the outer bag 2 is the same as the conventional one.
Since a is sealed by heat fusion, the inner surface of the outer bag 2, that is, the inner surface of the plastic film is provided with an adhesive layer made of ethylene-vinyl acetate copolymer or the like that exhibits adhesiveness by heat fusion. There is.

The method for manufacturing the vacuum heat insulating material 100 of this embodiment will be described below. 2 and 3 are a perspective view and a cross-sectional view showing the main steps of the manufacturing process of the vacuum heat insulating material of the present embodiment, in which the same reference numerals as those in FIGS. 1 and 6 indicate the same or corresponding parts. Is a space. First, in the same way as before,
The inner bag 1b whose three sides are sealed is filled with the fine powder 1a through the opening on the remaining side, and the opening on the remaining side is sealed to obtain the aggregate 1.

Next, as shown in FIG. 2, the aggregate forming and reinforcing plates 3a and 3b are arranged on the upper surface and the lower surface of the aggregate 1, respectively. here,
As described above, the aggregate forming / reinforcing plates 3a and 3b are larger in size (area) than the upper and lower surfaces of the aggregate 1.
The aggregate 1 is covered and hidden by the aggregate forming and reinforcing plates 3a and 3b.

Next, as shown in FIG. 3, the aggregate 1 and the aggregate forming and reinforcing plates 3a and 3b are inserted into the outer bag 2 whose three sides are sealed from the opening 2a on the remaining side. And store it. Here, a space 4 is formed between the side surface of the aggregate 1 and the inner surface of the outer bag 2.

Next, in the same manner as in the prior art (see FIG. 7), the above-mentioned aggregate 1, aggregate-forming reinforcing plate 3a, and
The outer bag 2 accommodating 3b is arranged and the inner pressure of the vacuum evacuation furnace is set to about 0.1 to 1 Torr, so that the inside of the outer bag 2 is evacuated from the opening 2a on the remaining one side of the outer bag 2. Then, in this state, the remaining one side opening 2a is sandwiched by the heaters 12a and 12b to heat-seal (seal) the opening 2a. 100 is obtained. Here, in the vicinity of the opening 2a of the outer bag 2 of the aggregate 1, naturally, the air present in the agglomerates of the fine powder 1a therein is efficiently degassed from the opening 2a. In the embodiment, since the space 4 is formed around the aggregate 1, that is, between the side surfaces of the aggregate 1 (three side surfaces other than the opening side) and the inner surface of the outer bag 2, the aggregate 4 is formed. Air existing in the agglomerates of the fine powder 1a inside the outer bag 2 of the (middle bag) 1 other than the vicinity of the opening 2a is led to the space 4 and passes through the space 4 to open the opening. Two
Therefore, the gas is efficiently degassed.

Therefore, the vacuum heat insulating material 100 of the present embodiment obtained in this way has a difference in the degree of vacuum inside the outer bag 2 and the density of the fine powder 1a in the aggregate 1 as in the conventional case. There is no difference, and as shown in FIG. 1, a straight plate-like structure having no bending or bending is obtained. Further, since the aggregate forming and reinforcing plates 3a and 3b have high strength themselves, the vacuum heat insulating material 100 is deformed even if left under atmospheric pressure (1.1 kg / cm ² ) for a long period of time. It is possible to maintain the above straight plate-like structure without causing the above. Further, since the flat surfaces of the aggregate forming and reinforcing plates 3a and 3b appear as the upper and lower surfaces of the vacuum heat insulating material 100 as they are,
The outer bag 2 has a beautiful appearance without wrinkles or irregularities.

Example 2 FIG. 4 is a perspective view showing the structure of a plate-shaped article in which an aggregate and an aggregate-forming reinforcing plate constituting a vacuum heat insulating material according to Example 2 of the present invention are integrally joined, and in the figure, the same as FIG. Symbols indicate the same or corresponding parts,
1c uses expanded particles of a plurality of styrene-maleic anhydride copolymers or expanded particles of a blend of a plurality of styrene-maleic anhydride copolymers and another thermoplastic resin (for example, polybutadiene), and is used between adjacent particles. Is an aggregate formed by heat-sealing each other into a plate shape.

In the vacuum heat insulating material of Example 2, as the aggregate 1c, foamed particles of a plurality of styrene-maleic anhydride copolymers, or a plurality of styrene-maleic anhydride copolymers and another thermoplastic resin ( For example, the vacuum heat insulating material of Example 1 is different in that foamed particles of a blend of polybutadiene) and foamed particles formed by heat-sealing adjacent particles are used. The manufacturing method thereof is basically the same as the manufacturing method of the vacuum heat insulating material of the first embodiment.

In the second embodiment, the aggregate forming reinforcing plates 3a and 3b are used.
Is bonded to the upper and lower surfaces of the plate-shaped molded product (aggregate 1c) when the aggregate 1c is formed, that is, when a plurality of expanded particles are heat-sealed to form a plate-shaped molded product. As a method of forming the aggregate 1c, the applicant's patent No. 1403833 (Japanese Patent Publication No.
The method for manufacturing a laminated plate described in JP 62-10173 A) is applied. That is, a plurality of expanded particles of a styrene-maleic anhydride copolymer or a plurality of styrene-maleic anhydride copolymers and another thermoplastic resin on one of the aggregate forming reinforcing plates 3a and 3b (for example, After laying foamed particles of a blend of polybutadiene) to a predetermined thickness, the other of the aggregate forming reinforcing plates 3a, 3b is placed on the foamed particles,
Thereafter, the aggregate-forming reinforcing plates 3a and 3b are heated while sandwiching the plurality of foamed particles between the aggregate-forming reinforcing plates 3a and 3b,
Moreover, the expanded particles are heated and expanded (secondarily expanded) by spraying heated steam onto the expanded particles. As a result, the adjacent particles of the plurality of expanded particles laid in a predetermined thickness are heat-sealed to each other, and the expanded particles in contact with the aggregate forming reinforcing plates 3a and 3b are heat-sealed to these particles, thereby A plate-shaped molded product (aggregate 1c) made of foamed particles is joined to the aggregate-forming reinforcing plates 3a and 3b to form a plate-shaped product.

In this second embodiment as well, the aggregate 1
It exists inside the expanded particles of a plurality of styrene-maleic anhydride copolymers constituting c, or the expanded particles of a blend of a plurality of styrene-maleic anhydride copolymers and another thermoplastic resin (for example, polybutadiene). Since the gas (for example, butane) introduced at the time of manufacturing the foamed particles is uniformly degassed from the entire aggregate 1c when the inside of the outer bag is degassed in vacuum, the same as in Example 1 above. The effect can be obtained. That is, it is composed of a straight plate-like structure that does not bend or bend, and is kept under atmospheric pressure (1.1
Even if it is allowed to stand at (kg / cm ² ), this straight plate-like structure can be maintained, and a vacuum heat insulating material having a beautiful appearance without wrinkles or irregularities on the surface can be obtained.

In this embodiment, the aggregate 1c is formed of a plurality of expanded particles of styrene-maleic anhydride copolymer or a plurality of styrene-maleic anhydride copolymer and other thermoplastic resin (for example, polybutadiene). When the foamed particles of the blend are used for forming, the aggregate 1c and the aggregate-forming reinforcing plate 3
The joints a and 3b were joined together, and the jointed article was accommodated in the outer bag 2. However, the aggregate 1c was formed as a single body without joining with the aggregate forming reinforcing plates 3a and 3b, and the obtained bone was obtained. The same effect can be obtained by sandwiching the aggregate 1c between the aggregate forming and reinforcing plates 3a and 3b and accommodating the aggregate 1c and the aggregate forming and reinforcing plates 3a and 3b in the outer bag 2. In this case, as the aggregate 1c, foamed particles of a styrene-maleic anhydride copolymer or a blend of a styrene-maleic anhydride copolymer and another thermoplastic resin (for example, polybutadiene) is foamed in a prepared mold. The particles are laid down to a predetermined thickness, the mold is closed with a metal lid (where the foamed particles are sandwiched between the bottom of the mold and the metal lid), and heated steam is sprayed onto the foamed particles in this state. By applying heat to expand the expanded particles (secondary expansion) and heat-adhere adjacent expanded particles to each other, a plate-shaped molded article composed of a plurality of expanded particles is obtained,
After that, the mold and the metallic lid are cooled, and the metallic mold and the metallic lid and the plate-shaped molded product are released from the mold.

Further, in this embodiment, foamed particles of a plurality of styrene-maleic anhydride copolymers or a foamed product of a blend of a plurality of styrene-maleic anhydride copolymers and another thermoplastic resin (for example, polybutadiene). Although the particles were used and the aggregate formed by molding the same into a plate shape was used, in the present invention, the same effect can be obtained by using a foamed product of another resin different from these, which is formed into a plate shape. It goes without saying that you can get

Example 3 5 is a sectional view showing a structure of a vacuum heat insulating material according to a third embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding portions, and 15 denotes a plurality of styrene-maleic anhydride copolymers. Coalesced foamed particles,
Alternatively, the protective layer is formed by using foamed particles of a blend of a plurality of styrene-maleic anhydride copolymers and another thermoplastic resin (for example, polybutadiene), and molding the foamed particles into a layer.

In the vacuum heat insulating material 100 of the first embodiment, the outer bag 2 is exposed to the outside, and the outer bag 2 is broken by some impact from the outside, and the function as the vacuum heat insulating material is impaired. There is a risk. In order to eliminate such a risk, the vacuum heat insulating material of the present Example 3 is the same as the vacuum heat insulating material 100 of Example 1 except that a plurality of expanded particles of styrene-maleic anhydride copolymer or a plurality of styrene-maleic anhydride are used. A foamed particle of a blend of an acid copolymer and another thermoplastic resin (for example, polybutadiene) is used, and this is covered with a protective layer 15 formed into a layer.

Here, as a method of forming the protective layer 15,
Laminated foamed particles of styrene-maleic anhydride copolymer or foamed particles of a blend of styrene-maleic anhydride copolymer and other thermoplastic resin (for example, polybutadiene) to a prepared mold with a predetermined thickness, After placing the vacuum heat insulating material 100 of Example 1 on the foamed particles, the foamed particles are laid on the vacuum heat insulating material 100 so that the vacuum heat insulating material 100 is completely hidden.

Then, the mold is closed with a metal lid (here, the foamed particles and the vacuum heat insulating material 100 are sandwiched between the bottom of the mold and the metal lid). By blowing heated steam onto the foamed particles, the expanded particles are thermally expanded (secondarily expanded), and the adjacent expanded particles are thermally fused to each other to form the protective layer 15. Here, the foamed particles are also fused to the outer bag 2 of the vacuum heat insulating material 100. After this,
The mold and the metal lid are cooled, and the mold and the metal lid are separated from the protective layer 15.

In the vacuum heat insulating material of Example 3 as described above, the outer bag is covered with the protective layer 15 made of styrenic foam resin, so that the outer bag is not broken even when an external impact is applied, The reliability of the vacuum heat insulating material can be improved. Further, in this example, since the protective layer 15 was formed by the secondary foaming of the styrene-based foamed resin, the protective layer was formed as the Japanese Patent Publication No.
-17263, the product cost can be reduced and the impact resistance can be improved as compared with the case where the foamed polyurethane is formed as described in JP-A-17263. This is because when foamed polyurethane is obtained, an outer frame material (metal, plastic) is required when foaming polyurethane, and if this outer frame material is used as it is as the outer wall material of the vacuum heat insulating material, the cost will increase. This is because if the outer frame material is released from the foamed polyurethane after foaming the polyurethane, the foamed polyurethane itself is fragile and is damaged by impact.

In this example, the vacuum heat insulating material of Example 1 was coated with a protective layer made of styrene foam resin, but the vacuum heat insulating material of Example 2 was coated with a protective layer made of styrene foam resin. Also, the same effect can be obtained.

[0037]

As described above, according to the vacuum heat insulating material of the present invention (Claim 1), the breathable inner bag is filled with the fine powder of the inorganic or organic substance, and the opening of the inner bag is closed. Aggregate obtained by sealing or formed of a plate-shaped molded product of foamed plastic, aggregate forming reinforcing plate disposed on the upper and lower surfaces of the aggregate, and the aggregate and aggregate forming reinforcing plate A non-air-permeable outer bag for accommodating the inside of the outer bag, the inside of the outer bag is vacuum deaerated, and the opening of the outer bag is sealed. A space is formed around the material, that is, between the side surface of the aggregate and the inner surface of the outer bag, and the space other than the vicinity of the opening of the outer bag that is the deaeration opening for vacuum deaeration of the aggregate is formed. Even in the part, the air (gas) existing inside the aggregate is led out to the space, and passes through this space to Since the can is guided to the opening of the bag, it can be degassed evenly the air (gas) inside the aggregate. Therefore, there is no difference in the degree of vacuum inside the outer bag and the difference in the density of the fine powder in the aggregate as in the conventional case, and there is no bending or bending, and the vacuum heat insulation is composed of a straight plate-like structure. There is an effect that the material can be obtained.

Further, since the aggregate forming and reinforcing plate itself has high strength, it can be used under atmospheric pressure (1.1 kg) for a long period of time.
Even if it is left at / cm ² ), it does not deform, and it has an effect of maintaining the straight plate-like structure for a long period of time.

Further, since the flat surfaces of the aggregate forming and reinforcing plate appear as the upper and lower surfaces of the vacuum heat insulating material as they are, there is an effect that a vacuum heat insulating material having a beautiful appearance without wrinkles or irregularities on the outer bag can be obtained.

Further, according to the vacuum heat insulating material of the present invention (Claim 2), in the vacuum heat insulating material, the outer surface of the outer bag is covered with a protective layer made of styrene foam resin. Even if a shock is applied to the outer bag, the outer bag will not be broken, and the reliability of the vacuum heat insulating material can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a vacuum heat insulating material according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing main steps of a manufacturing process of the vacuum heat insulating material of FIG.

FIG. 3 is a cross-sectional view showing main steps of a manufacturing process of the vacuum heat insulating material of FIG.

FIG. 4 is a perspective view showing a configuration of a plate-shaped article in which an aggregate and an aggregate forming / reinforcing plate constituting a vacuum heat insulating material according to Example 2 of the present invention are integrally joined.

FIG. 5 is a sectional view showing a structure of a vacuum heat insulating material according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing the structure of a conventional vacuum heat insulating material.

FIG. 7 is a schematic cross-sectional view showing a configuration of an apparatus for producing a vacuum heat insulating material according to the present invention and a conventional one.

FIG. 8 is a cross-sectional view of a conventional vacuum heat insulating material for explaining problems that occur in the conventional vacuum heat insulating material.

FIG. 9 is a perspective view of a conventional vacuum heat insulating material for explaining the problems that occur in the conventional vacuum heat insulating material.

FIG. 10 is a perspective view showing a structure of a conventional vacuum heat insulating material.

[Explanation of symbols]

1, 1c, 21 Aggregate, 1a, 21a Fine particles, 1b
Middle bag, 2 outer bag, 2a Opening of outer bag, 3a, 3b
Aggregate reinforcement plate, 4 spaces, 10,100 vacuum insulation, 1
1 vacuum evacuation furnace, 12a, 12b exothermic heater, 13
Vacuum pump, 2b Wrinkle, 22a, 22b Hollow pipe

Claims (2)

[Claims] 1. An aggregate obtained by filling an air-permeable inner bag with a fine powder of an inorganic or organic substance and sealing the opening of the inner bag, or an aggregate made of a plate-shaped molded product of foamed plastic. And an aggregate-forming reinforcing plate disposed on the upper and lower surfaces of the aggregate, respectively, and an air-impermeable outer bag that accommodates the aggregate and the aggregate-forming reinforcing plate therein, and the inside of the outer bag Vacuum degassing and sealing the opening of the outer bag. 2. The vacuum heat insulating material according to claim 1, wherein the outer surface of the outer bag is covered with a protective layer made of styrene foam resin.