JP7002871B2 - Covered vacuum heat insulating material - Google Patents

Description

The present invention relates to a coated vacuum heat insulating material in which the vacuum heat insulating material is coated with a heat shrink film.

In recent years, energy saving and resource saving are strongly desired from the viewpoint of prevention of global warming. In particular, in the fields of household appliances such as refrigerators, freezers, heat insulating boxes, jar rice cookers, water heaters, vending machines, commercial appliances, automobiles, copying machines, floor heating, housing, etc., heat energy is used efficiently. From the viewpoint of this, vacuum insulation materials have come to be used.

Refrigerators and the like are mainly insulated with vacuum heat insulating materials and urethane foam materials. There is a resin housing inside the refrigerator, the vacuum heat insulating material is attached to the housing, and the space around it is filled with urethane foam material. When the urethane foaming agent is injected after the vacuum heat insulating material is attached to the housing inside the refrigerator, the urethane foaming material may enter the gap between the ear folds of the vacuum heat insulating material. If the urethane foam material enters the gap between the ear folds of the vacuum heat insulating material, the fluidity and filling property of the urethane foam material deteriorate.

Patent Document 1 discloses a vacuum heat insulating material in which the outer peripheral surface and the ear fold portion are covered with a heat-shrinkable heat-shrinkable material for protection from external impact and prevention of peeling of the ear fold portion. In Patent Document 1, by enclosing the vacuum heat insulating material with a heat-shrinkable material, urethane is prevented from entering the gap between the ear folds, and the fluidity and filling property of the urethane foam material in the refrigerator are improved.

Japanese Unexamined Patent Publication No. 2016-89962

However, if the heat-shrinkable film is simply heat-shrinked to enclose the vacuum heat insulating material, air remains between the heat-shrinkable film and the vacuum heat insulating material. Since the thermal conductivity of air is higher than that of the vacuum insulation material, if air remains between the heat shrinkable film and the vacuum insulation material, the heat insulation performance of the entire vacuum insulation material covered with the heat shrinkage film will be vacuum. There is a problem that it is lower than the heat insulating material itself. Generally, a heat-shrinkable film in which a large number of small vents are provided so that air between the film and the vacuum heat insulating material can escape during heat shrinkage is known. Even when the sex film is used, a certain amount of air remains between the heat-shrinkable film and the vacuum heat insulating material, so that the heat insulating performance of the obtained coated vacuum heat insulating material is not sufficient.

An object of the present invention is to provide a coated vacuum heat insulating material in which a vacuum heat insulating material is coated with a heat shrinkable film, which has excellent heat insulating performance.

It has been found that the above problem can be solved by providing at least one degassing hole for air release having an area of 0.1 to 5 cm ² at the corner of the coated vacuum heat insulating material. That is, the present invention relates to the following [1] to [11].

[1] A coated vacuum heat insulating material including a vacuum heat insulating material and a heat shrinkable film for covering the vacuum heat insulating material.
The vacuum heat insulating material has a polygonal plate shape and has a polygonal plate shape.
The heat-shrinkable film is in close contact with at least the outer peripheral surface of the vacuum heat insulating material.
The coated vacuum heat insulating material has at least one degassing hole in a region within 70 mm from at least one corner of the coated vacuum heat insulating material on the outer peripheral surface.
The degassing hole has an area of 0.1-5 cm ² .
Covered vacuum heat insulating material.

[2] The coated vacuum heat insulating material according to the above [1], wherein the amount of air between the upper surface and the lower surface of the vacuum heat insulating material and the heat shrinkable film is 0 to 10 cm ³ / m ² .

[3] The above-mentioned [1] or [2], wherein the coated vacuum heat insulating material has at least one degassing hole in a region within 70 mm from at least three corners of the coated vacuum heat insulating material on the outer peripheral surface. Covered vacuum heat insulating material.

[4] The coated vacuum heat insulating material according to any one of [1] to [3] above, wherein the heat-shrinkable film does not have ventilation holes on the upper surface and the lower surface of the coated vacuum heat insulating material.

[5] The coated vacuum heat insulating material according to any one of [1] to [4] above, wherein the vacuum heat insulating material has a square plate shape.

[6] The following steps,
1. 1. In the step of putting the polygonal plate-shaped vacuum heat insulating material into a polygonal bag made of a heat-shrinkable film, the bag has an opening and the heat-shrinkable film has a thickness of 20 to 200 μm. Have, process,
2. 2. The step of sealing the opening,
3. 3. A step of cutting at least a part of the sealed bag, wherein the at least part includes the apex of the bag.
4. The step of heating the cut bag at 80 ° C. to 200 ° C. to heat shrink it, and 5. The step of cooling the heat-shrinked bag to 50 ° C. or lower,
The method for producing a coated vacuum heat insulating material according to the above [1].

[7] The following steps,
1. 1. A step of cutting at least a part of a polygonal bag made of a heat-shrinkable film, wherein the bag has an opening, the heat-shrinkable film has a thickness of 20 to 200 μm, and at least one of the above. The process, where the part includes the top of the bag,
2. 2. The process of putting the polygonal plate-shaped vacuum heat insulating material into the cut bag,
3. 3. The step of sealing the opening,
4. The step of heating the sealed bag at 80 ° C. to 200 ° C. to heat shrink it, and 5. The step of cooling the heat-shrinked bag to 50 ° C. or lower,
The method for producing a coated vacuum heat insulating material according to the above [1].

[8] The method according to the above [6] or [7], wherein the length of two sides constituting the apex in at least a part of the bag to be cut is 70 mm or less.

[9] The unheat-shrinkable film is a single-layer or multi-layer film selected from the group consisting of a polyvinyl chloride film, a polystyrene film, a polyethylene film, a polypropylene film, an ethylene vinyl alcohol resin film, and a polyolefin film. The method according to any one of [6] to [8].

[10] The method according to any one of [6] to [9] above, wherein the shrinkage rate of the unheated shrink film is 10 to 80%.

[11] The method according to any one of [6] to [10] above, wherein the unheated shrink film has a tensile strength of 70 to 1800 kg / cm ² .

INDUSTRIAL APPLICABILITY According to the present invention, a coated vacuum heat insulating material in which a vacuum heat insulating material is coated with a heat-shrinkable film, which has excellent heat insulating performance, is provided.

FIG. 1 shows a rectangular plate-shaped vacuum heat insulating material shape. FIG. 2 shows a rectangular bag made of an unheat-shrinkable film and a cut portion thereof. FIG. 3 shows a cut portion of the bag.

The present invention is a coated vacuum heat insulating material including a vacuum heat insulating material and a heat shrinkable film that covers the vacuum heat insulating material. The vacuum heat insulating material has a polygonal plate shape, and the heat shrinkable film is formed. It is in close contact with at least the outer peripheral surface of the vacuum heat insulating material, and the coated vacuum heat insulating material has at least one degassing hole in a region of 70 mm or less from at least one corner of the coated vacuum heat insulating material on the outer peripheral surface. The degassed hole is a coated vacuum heat insulating material having an area of 0.1 to 5 cm ² .

The coated vacuum heat insulating material of the present invention includes the vacuum heat insulating material. The vacuum heat insulating material includes a core material and a gas barrier film, and may contain an adsorbent. The core material is vacuum-sealed in a gas barrier film. As the vacuum heat insulating material, the one of the prior art can be used without particular limitation.

As the core material used in the present invention, those used in the vacuum heat insulating material field can be used without particular limitation. For example, an inorganic fiber, a fiber in which an inorganic fiber and an organic fiber are mixed, a powder core material containing silica particles as a main component, a foamed heat insulating material, or the like can be used as the core material. The main component of the core material is preferably glass fiber or silica particles containing SiO ₂ .
Core materials are known and are readily available or available on the market.

The gas barrier film used in the present invention is not particularly limited as long as it is a film having gas barrier properties, but a film in which a seal layer and a gas barrier layer are laminated is preferable, and the seal layer, the gas barrier layer and the resin are in order from the side in contact with the core material. A laminated film layer is more preferable. The thickness of the gas barrier film is not particularly limited, but is usually 5 to 60 μm, preferably 6 to 30 μm. The gas barrier layer is a layer that does not allow gas to permeate, and is used from the viewpoint of preventing a decrease in the degree of vacuum of the vacuum heat insulating material.

Examples of the gas barrier layer include a metal foil and a laminated film (deposited film film) deposited on a resin film. Examples of the metal of the metal foil include aluminum, copper, stainless steel, iron and the like. Preferably, aluminum is used. The thin-film film is formed by vapor-filming a metal such as aluminum, stainless steel, cobalt, nickel, silica, alumina, or a combination thereof by a thin-film deposition method, a sputtering method, or the like. Examples of the resin film used as the base material of the vapor-deposited film film include aromatic polyester-based resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefin resins such as polyethylene, polypropylene, and olefin copolymers; and polyvinyl chloride. , Vinyl chloride resin such as vinyl chloride copolymer; Polyamide resin such as nylon 6, nylon 66, metaxylylene diamine / adipic acid condensate; polyvinyl alcohol, acrylonitrile / butadiene / styrene copolymer, acrylonitrile / styrene co-weight Polystyrene resin such as coalescence; Acrylic resin such as polymethylmethacrylate, acrylic acid ester and methylmethacrylic acid ester copolymer, ethylene-vinyl alcohol copolymer, polyvinyl alcohol and partially saponified product, etc. A film produced from a thermosetting resin such as a resin, a phenol resin, or a urea resin is used. The gas barrier layer is preferably aluminum foil. The thickness of the gas barrier layer is not particularly limited, but is usually 5 to 60 μm, preferably 6 to 30 μm. Metal leafs and vapor-film film films used for gas barrier layers are known and are readily available or available on the market.

The seal layer is a resin that can be fused by heating. There is no particular limitation as long as it is a heat-fusing resin. Specifically, a film composed of a polyolefin resin such as polyethylene and polypropylene, polyacrylonitrile, PET, an ethylene-vinyl alcohol copolymer, or a mixture thereof can be used. Preferably, polyethylene, polypropylene, or an ethylene-vinyl alcohol copolymer is used. The polyethylene preferably has a density of 0.90 to 0.98 g / cm ³ . The polypropylene preferably has a density of 0.85 to 0.95 g / cm ³ . The thickness of the seal layer is not particularly limited, but is usually 10 to 100 μm, preferably 25 to 60 μm. The resins used for the seal layer are known and are readily available or available on the market.

The resin film layer is a layer arbitrarily provided on the gas barrier layer for the purpose of protecting the gas barrier layer. The resin film layer includes aromatic polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefin resins such as polyethylene, polypropylene and olefin copolymers; polyvinyl chloride, vinyl chloride copolymer and the like. Vinyl chloride resin; polyamide resin such as nylon 6, nylon 66, metaxylylene diamine / adipic acid condensate; styrene resin such as polyvinyl alcohol, acrylonitrile / butadiene / styrene copolymer, acrylonitrile / styrene copolymer; A film produced from a thermoplastic resin such as an acrylic resin such as polymethylmethacrylate, an acrylic acid ester and a methylmethacrylic acid ester copolymer, and a thermosetting resin such as a phenol resin and a urea resin is used. Preferably, it is PET, nylon 6 or nylon 66. Organic and inorganic fillers can also be added to these resin films. These resins can be used alone or in admixture of two or more. In order to further improve the gas barrier performance of the gas barrier film, the resin film layer is coated with or laminated with a gas barrier resin obtained by polymerizing and copolymerizing vinyl monomers such as vinylidene chloride, acrylonitrile, and vinyl alcohol. , Those particles can also be mixed and dispersed in the resin film layer. The thickness of the resin film layer is not particularly limited, but is usually 5 to 40 μm, preferably 10 to 30 μm. The resins used for the resin film layer are known and are readily available or available on the market.

The adsorbent used in the present invention is not particularly limited as long as it is a substance that adsorbs gas, but is, for example, a substance that adsorbs gas such as nitrogen, oxygen, and carbon dioxide, and / or water. Examples of the adsorbent include calcium oxide, magnesium oxide, silica gel, zeolite, activated carbon, barium oxide, barium-lithium alloy, porous coordination polymer, metal-organic framework, or a mixture thereof. Calcium oxide is preferable from the viewpoint of gas adsorption performance and productivity. Adsorbents are known and are readily available or available on the market.

The internal pressure of the vacuum heat insulating material is, for example, 0.5 to 20 Pa, preferably 0.5 to 10 Pa. When the internal pressure is within the above range, heat conduction through the gas inside the vacuum heat insulating material can be suppressed, so that the heat insulating property of the vacuum heat insulating material can be improved.

In the present invention, the vacuum heat insulating material is generally in the shape of a quadrangular plate, and may have another polygonal shape, for example, a pentagon or more depending on the application. The shape of the square plate-shaped vacuum heat insulating material is shown in FIG. The plate shape refers to a thin and flat shape, and has two facing surfaces (upper surface 1 and lower surface 2 in FIG. 1) and an outer peripheral surface connecting these two surfaces (four side surfaces 3 in FIG. 1). In the present specification, the “corner portion” refers to a short side (side in the thickness direction) of the outer peripheral surface (side 4 in FIG. 1). The size of the vacuum heat insulating material can be appropriately set depending on the application, but the small one is from about 200 mm square, and the large one is about 1000 mm × 2000 mm.

The coated vacuum heat insulating material of the present invention includes a heat-shrinkable film that covers the vacuum heat insulating material. As used herein, the term "heat-shrinkable film" refers to a film that has been heat-shrinked. Further, "non-heat shrinkable film" or "heat shrinkable film" refers to a film before heat shrinkage.

The heat shrink film is in close contact with at least the outer peripheral surface of the vacuum heat insulating material. Since the heat-shrinkable film is in close contact with at least the outer peripheral surface, heat loss from the heat-shrinkable film can be suppressed, and the coated vacuum heat insulating material can exhibit sufficient heat insulating performance.

In the conventional coated vacuum heat insulating material, air of about 100 to 250 cm ³ / m ² remains between the upper surface and the lower surface of the vacuum heat insulating material and the heat shrinkable film in many cases. On the other hand, in the present invention, the amount of air between the upper and lower surfaces of the vacuum heat insulating material and the heat-shrinkable film is, for example, 0 to 10 cm ³ / m ² . The amount of air can be measured, for example, based on the volume of the coated vacuum heat insulating material minus the volume of the vacuum heat insulating material and the volume of the heat-shrinkable film. When the amount of air between the upper and lower surfaces of the vacuum heat insulating material and the heat-shrinkable film is within the above range, deterioration of the heat insulating performance of the coated vacuum heat insulating material can be suppressed.

The coated vacuum heat insulating material of the present invention has at least one corner portion of the coated vacuum heat insulating material, for example, at least two corner portions, preferably at least three corner portions, and more preferably within 70 mm from all the corner portions on the outer peripheral surface. It has at least one degassing hole in a region of preferably within 50 mm, more preferably within 30 mm. In the present invention, the degassing hole refers to a portion of the surface of the coated vacuum heat insulating material that is not covered with the heat-shrinkable film and has an area described later. For example, the degassing hole may be a hole provided in the heat-shrinkable film, or may be a gap portion of the film when the band-shaped film is wound in the vertical and horizontal directions of the vacuum heat insulating material. good. An example of the above region is shown in FIG. 1 as region 5. The location of the degassing hole is determined based on the position of the degassing hole end farther from the corner. The degassing holes may span a plurality of surfaces of the coated vacuum heat insulating material. When the position of the degassing hole is within the above range, the adhesion between the heat-shrinkable film and the vacuum heat insulating material can be maintained. Further, it is possible to prevent the film from being damaged due to heat shrinkage during the production of the coated vacuum heat insulating material.

In the present invention, the degassing hole has an area of 0.1 to 5 cm ² , preferably 0.2 to 4 cm ² , and more preferably 0.3 to 3 cm ² . If the degassing hole spans multiple surfaces of the coated vacuum heat insulating material, the area of the hole is determined based on the area of the portion of the vacuum heat insulating material exposed from the degassing hole. When the area of the degassing hole is within the above range, the air between the film and the vacuum heat insulating material is easily released during the heat shrinkage of the heat-shrinkable film, and the residual amount of air between the heat-shrinkable film and the vacuum heat insulating material. Can be sufficiently reduced. Further, it is possible to prevent the film from being damaged due to heat shrinkage during the production of the coated vacuum heat insulating material. Furthermore, when injecting urethane foam material during the manufacture of a refrigerator, it is possible to prevent the urethane foam material from flowing between the vacuum heat insulating material and the heat shrink film through the degassing holes at the corners, and the fluidity and filling of the urethane foam material. It is possible to prevent deterioration of sex.

In the present invention, the heat-shrinkable film may have ventilation holes similar to those of the conventional heat-shrinkable film, for example, on the upper surface and / or the lower surface of the coated vacuum heat insulating material.

The coated vacuum heat insulating material of the present invention is a step of (1) inserting a polygonal plate-shaped vacuum heat insulating material into a polygonal bag made of an unheat-shrinkable film, wherein the bag has an opening and is described above. A step in which the heat-shrinkable film has a thickness of 20 to 200 μm, (2) a step of sealing the opening, and (3) a step of cutting at least a part of the sealed bag. A step of including the apex of the bag, (4) a step of heating the cut bag at 80 ° C. to 200 ° C. and heat-shrinking it, and (5) a step of cooling the heat-shrinked bag to 50 ° C. or lower. It can be manufactured by a method including.

The heat-shrinkable film has a thickness of 20 to 200 μm, preferably 40 to 160 μm, more preferably 60 to 120 μm. When the thickness is within the above range, the protective property of the heat-shrinkable film is increased, and damage to the coated vacuum heat insulating material can be prevented.

The shrinkage rate of the non-heat-shrinkable film varies depending on the resin material of the non-heat-shrinkable film, but is adjusted to, for example, 10% to 80%, preferably 10% to 50%. The shrinkage rate is the side of the unheat-shrinkable film and the film after heat-shrinkage when the heat-shrinkable film is heated for 1 minute or more at a temperature higher than the shrinkage temperature of the non-heat-shrinkable film and lower than the melting temperature. It can be measured by the ratio of the lengths of. When the shrinkage rate is within the above range, the shrinkage of the unheated shrinkage film allows the air between the film and the vacuum heat insulating material to be sufficiently evacuated from the degassing hole without changing the shape of the vacuum heat insulating material. The unheat-shrinkable film preferably has a tensile strength of 70 to 1800 kg / cm ² , more preferably 300 to 1000 kg / cm ² , and even more preferably 500 to 800 kg / cm ² . The tensile strength can be measured by a known method, for example, according to JIS K 7127. When the tensile strength is within the above range, the heat-shrinkable film has a protective property, and the coated vacuum heat insulating material is easy to handle. The non-heat-shrinkable film may have the same ventilation holes as the conventional heat-shrinkable film.

The unheat-shrinkable film may be a single-layer or multi-layer film, and the material is not particularly limited as long as it has the above-mentioned heat-shrinkability. Preferred films include, for example, polyvinyl chloride film, polystyrene film, polyethylene film, polypropylene film, polyolefin film, polyethylene terephthalate film, teflon film, polyamide film, polyether ether ketone film, fluororesin film, polyethylene vinyl alcohol resin. Examples thereof include a film and a multilayer heat-shrinkable film containing these.

In the step (1), the bag made of the unheat-shrinkable film has an opening through which the vacuum heat insulating material can be put. There is no particular limitation on the means of putting the vacuum heat insulating material in the bag. The bag preferably has a shape similar to the surface of the vacuum heat insulating material.

In the step (2), the means for sealing the opening of the bag containing the vacuum heat insulating material is not particularly limited, and can be sealed by, for example, a heat sealing method, a hot plate method, an impulse sealing method, or laser welding. By sealing the opening, the vacuum heat insulating material can be held inside the non-heat shrink film.

Step (3) is a step of cutting at least a part of the bag. The cut portion may include a portion of the sealed opening. When the bag is a quadrangle, the bag and its cut portion are shown in FIG. 2, and the enlarged cut portion is shown in FIG. As shown in FIG. 2, the cut portion 6 includes the apex 7 of the bag. Further, as shown in FIG. 3, the length of the two sides 8 constituting the apex 7 in at least a part of the bag to be cut is, for example, 70 mm or less, preferably 50 mm or less, and more preferably 30 mm or less. If the length is within the above range, the cut surface constitutes a degassing hole having an area of 0.1 to 5 cm ² in a region of 70 mm or less from the corner of the outer peripheral surface in the coated vacuum heat insulating material of the final product. be able to. Further, by using at least a part including the apex as the cut portion, it is possible to prevent the film from being damaged when the unheat-shrinkable film is heat-shrinked. The same applies when the bag is a polygon other than a quadrangle. Cutting can be performed with, for example, scissors, a cutter, or the like.

The step (4) is a step of heating the cut bag to heat shrink it, and the heating temperature can be appropriately set based on the shrinkage temperature of the unheated shrink film, but is, for example, 80 ° C. to 200 ° C. and is not heated. It can be adjusted according to the resin material of the shrink film. If the heating temperature is within the above range, the unheat-shrinkable film can be heat-shrinked. The heating of the unheat-shrinkable film can be performed by, for example, a hot air circulation oven, a dryer, a heater, or the like.

The step (5) is a step of cooling the heat-shrinked bag, and the cooling temperature is 50 ° C. or lower, preferably 40 ° C. or lower. When the cooling temperature is within the above range, the heat shrinkage and deformation of the heat shrink film can be stopped. The heat-shrinkable film can be cooled by, for example, a cooler, a fan, or natural cooling.

In the production of the coated vacuum heat insulating material of the present invention, the bag of the heat-shrinkable film may be cut in advance before inserting the vacuum heat insulating material. That is, the coated vacuum heat insulating material of the present invention is a step of (a) cutting at least a part of a polygonal bag made of an unheat-shrinkable film, wherein the bag has an opening and the unheat-shrinkable film. A step of having a thickness of 20 to 200 μm, wherein at least a part thereof contains the apex of the bag, (b) a step of putting a polygonal plate-shaped vacuum insulation material in the cut bag, (c) the opening. A method including a step of sealing a portion, (d) a step of heating the sealed bag at 80 ° C. to 200 ° C. and heat-shrinking it, and (e) a step of cooling the heat-shrinked bag to 50 ° C. or lower. It can also be manufactured by. The steps (a) to (e) can be carried out in the same manner as the above steps (3), (1), (2), (4) and (5), respectively.

In another embodiment, the band-shaped unheat-shrinkable film is wound around the vacuum heat insulating material in the vertical and horizontal directions, and the heat-shrinkable film is heat-shrinked to have degassing holes at the corners of the coated vacuum heat insulating material of the present invention. The material can be manufactured.

The vacuum heat insulating material of the present invention can be used in the same applications as the conventional vacuum heat insulating material, for example, a refrigerator, a vending machine, a heat insulating box, and the like.

The coated vacuum heat insulating material of the present invention can be used as a heat insulating material for a refrigerator, for example. Inside the refrigerator, a vacuum heat insulating material is attached to the housing, and the gap around the vacuum heat insulating material is filled with a urethane foam material or the like. Since the heat-shrinkable film shrinkage wrinkles remain at the corners of the conventional coated vacuum heat insulating material, when the conventional coated vacuum heat insulating material is used, the urethane foam material is injected into the gap. There was a problem that the fluidity and filling property of the urethane were deteriorated. In addition, if a conventional coated vacuum heat insulating material having small vents on the surface of the heat-shrinkable film is used, the vents are blocked by the urethane foam material, so that the air between the heat-shrinkable film and the vacuum heat insulating material is completely removed. There was also a problem that the heat insulating performance of the refrigerator was adversely affected. In the coated vacuum heat insulating material of the present invention, shrinkage wrinkles can be reduced by providing degassing holes at the corners, so that the fluidity and filling property of urethane can be improved. Further, since the coated vacuum heat insulating material of the present invention has a degassing hole larger than the conventional ventilation hole in the corner region, air was temporarily present between the heat-shrinkable film of the coated vacuum heat insulating material and the vacuum heat insulating material. Even so, air is pushed out from the degassing holes when the urethane is injected, and it is possible to prevent the heat insulating property of the refrigerator from deteriorating. Further, in the coated vacuum heat insulating material of the present invention, since the heat shrink film is in close contact with the outer peripheral surface of the vacuum heat insulating material, the fluidity and fillability of the urethane foam material are improved.

Example 1
From the opening of a rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² (measured according to JIS K 7127)) without vents. , A square plate-shaped vacuum heat insulating material (300 mm × 300 mm × 20 mm) was put in, and the opening was sealed with an impulse sealer. Four points including the apex of the sealed bag were cut. In each cut portion, the two sides constituting the apex were 10 mm and 30 mm. The bag was heated at 100 ° C. for 15 seconds in a hot air circulation oven to heat shrink the film. Next, the bag was cooled at an ambient temperature of 25 ° C. by natural cooling to obtain a coated vacuum heat insulating material. The heat-shrinkable film was in close contact with the vacuum heat insulating material on the outer peripheral surface. The covered vacuum heat insulating material has a degassing hole (minor axis 2 mm and major axis 20 mm) having an area of about 0.3 cm ² at a position 20 mm from the corner (distance from the corner to the distal end of the degassing hole) on the outer peripheral surface. It had an oval shape).

Example 2
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 mm in length and width. Four points including the vertices were cut. In each cut portion, the two sides constituting the apex were 10 mm and 30 mm. A square plate-shaped vacuum heat insulating material (300 mm × 300 mm × 20 mm) was inserted from the opening of the bag, and the opening was sealed with an impulse sealer. The bag was heated at 100 ° C. for 15 seconds in a hot air circulation oven to heat shrink the film. Next, the bag was cooled at an ambient temperature of 25 ° C. by natural cooling to obtain a coated vacuum heat insulating material. The heat-shrinkable film has ventilation holes (circles with a diameter of 1 mm) having an area of about 0.008 cm ² on the upper surface and the lower surface at an average interval of 48 mm in the vertical and horizontal directions, and is in close contact with the vacuum heat insulating material on the outer peripheral surface. It was. The coated vacuum heat insulating material had a degassing hole (minor axis 2 mm and major axis 20 mm oval) having an area of about 0.3 cm ² at a position 20 mm from the corner on the outer peripheral surface.

Example 3
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 m in length and width. Four points including the vertices were cut. In each cut portion, the two sides constituting the apex were 10 mm and 20 mm. In the following procedure, the coated vacuum heat insulating material was obtained in the same manner as in Example 2. The heat-shrinkable film has ventilation holes (circles with a diameter of 1 mm) having an area of about 0.008 cm ² on the upper surface and the lower surface at an average interval of 48 mm in the vertical and horizontal directions, and is in close contact with the vacuum heat insulating material on the outer peripheral surface. It was. The coated vacuum heat insulating material had a degassing hole (minor axis 1 mm and major axis 15 mm oval) having an area of about 0.1 cm ² at a position 15 mm from the corner on the outer peripheral surface.

Example 4
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 m in length and width. Four points including the vertices were cut. In each cut portion, the two sides constituting the apex were 10 mm and 60 mm. In the following procedure, the coated vacuum heat insulating material was obtained in the same manner as in Example 2. The heat-shrinkable film has ventilation holes (circles with a diameter of 1 mm) having an area of about 0.008 cm ² on the upper surface and the lower surface at an average interval of 48 mm in the vertical and horizontal directions, and is in close contact with the vacuum heat insulating material on the outer peripheral surface. It was. The coated vacuum heat insulating material had a degassing hole (minor axis 6 mm and major axis 60 mm oval) having an area of about 2.8 cm ² at a position 60 mm from the corner on the outer peripheral surface.

Comparative Example 1
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 mm vertically and horizontally. A coated vacuum heat insulating material was obtained in the same manner as in Example 2 except that the material was used without cutting. The heat-shrinkable film had vent holes (circle with a diameter of 1 mm) having an area of about 0.008 cm ² on the upper surface and the lower surface at an average interval of 48 mm in the vertical and horizontal directions.

Comparative Example 2
Cut a rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 1 mm at intervals of 50 mm vertically and horizontally. A coated vacuum heat insulating material was obtained in the same manner as in Example 2 except that it was used without. The heat-shrinkable film had ventilation holes (minor axis 2 mm and major axis 20 mm oval) having an area of about 0.3 cm ² on the upper surface and the lower surface at intervals of 40 mm on average in the vertical and horizontal directions.

Comparative Example 3
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 mm in length and width. Four points including the vertices were cut. In each cut portion, the two sides constituting the apex were 20 mm and 90 mm. In the following procedure, the coated vacuum heat insulating material was obtained in the same manner as in Example 2. The heat shrink film was broken from the cut part of the corner.

Comparative Example 4
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 mm in length and width. Four points including the vertices were cut. In each cut portion, the two sides constituting the apex were 1 mm and 5 mm. In the following procedure, the coated vacuum heat insulating material was obtained in the same manner as in Example 2. The heat-shrinkable film had vent holes (circle with a diameter of 1 mm) having an area of about 0.008 cm ² on the upper surface and the lower surface at an average interval of 48 mm in the vertical and horizontal directions. The coated vacuum heat insulating material had a hole (minor axis 0.5 mm and major axis 4 mm oval) having an area of about 0.02 cm ² at a position 4 mm from the corner on the outer peripheral surface.

Comparative Example 5
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 mm in length and width. On one side, a 10 mm × 30 mm region extending 135 mm to 165 mm from the apex was cut. In the following procedure, the coated vacuum heat insulating material was produced in the same manner as in Example 2. The heat-shrinkable film was damaged from the cut portion of the outer peripheral surface.

Comparative Example 6
A rectangular bag of polyvinyl chloride film (thickness 75 μm, shrinkage rate 20% horizontal / 20% vertical, tensile strength 630 kg / cm ² ) having circular vents with a diameter of 0.1 mm at intervals of 60 mm in length and width. On one side, a central 10 mm × 30 mm region was cut. In the following procedure, the coated vacuum heat insulating material was produced in the same manner as in Example 2. The heat shrink film was broken from the cut part.

Measurement of the amount of air between the upper and lower surfaces of the vacuum heat insulating material and the heat shrinkable film For each of the coated vacuum heat insulating materials of Examples 1 to 4 and Comparative Examples 1 to 6, the upper and lower surfaces of the vacuum heat insulating material and the heat shrinkable film The amount of air between the and was measured by subtracting the volume of the vacuum heat insulating material and the volume of the heat shrinkable film from the volume of the coated vacuum heat insulating material. From the measured air amount, the air amount (internal air amount) per unit area of the upper surface and the lower surface was calculated. The results of the coated vacuum heat insulating materials of Examples 1 to 4 are shown in Table 1, and the results of the coated vacuum heat insulating materials of Comparative Examples 1 to 6 are shown in Table 2.

Measurement of Thermal Conductivity For each of the coated vacuum heat insulating materials of Examples 1 to 4 and Comparative Examples 1 to 6, the thermal conductivity was measured according to JIS A 1412 Annex B method. The results of the coated vacuum heat insulating materials of Examples 1 to 4 are shown in Table 1, and the results of the coated vacuum heat insulating materials of Comparative Examples 1 to 6 are shown in Table 2.

The vacuum heat insulating material of the present invention is particularly useful as a heat insulating performance improving material for refrigerators, cool boxes, vending machines and the like.

1 Top surface 2 Bottom surface 3 Outer surface surface 4 Corner part 5 Area within a certain range from the corner part 6 Cut part 7 Vertex 8 Two sides constituting the vertex

Claims (11)

A coated vacuum heat insulating material including a vacuum heat insulating material and a heat-shrinkable film for covering the vacuum heat insulating material.
The vacuum heat insulating material has a polygonal plate shape and has a polygonal plate shape.
The heat-shrinkable film is in close contact with at least the outer peripheral surface of the vacuum heat insulating material.
The coated vacuum heat insulating material has at least one degassing hole in a region within 70 mm from at least one corner of the coated vacuum heat insulating material on the outer peripheral surface.
The degassing hole has an area of 0.1-5 cm ² .
Covered vacuum heat insulating material. The coated vacuum heat insulating material according to claim 1, wherein the amount of air between the upper surface and the lower surface of the vacuum heat insulating material and the heat shrinkable film is 0 to 10 cm ³ / m ² . The coated vacuum heat insulating material according to claim 1 or 2, wherein the coated vacuum heat insulating material has at least one degassing hole in a region within 70 mm from at least three corners of the coated vacuum heat insulating material on the outer peripheral surface. The coated vacuum heat insulating material according to any one of claims 1 to 3, wherein the heat-shrinkable film does not have ventilation holes on the upper surface and the lower surface of the coated vacuum heat insulating material. The coated vacuum heat insulating material according to any one of claims 1 to 4, wherein the vacuum heat insulating material has a square plate shape. The following process,
1. 1. In the step of putting the polygonal plate-shaped vacuum heat insulating material into a polygonal bag made of a heat-shrinkable film, the bag has an opening and the heat-shrinkable film has a thickness of 20 to 200 μm. Have, process,
2. 2. The step of sealing the opening,
3. 3. A step of cutting at least a part of the sealed bag, wherein the at least part includes the apex of the bag.
4. The step of heating the cut bag at 80 ° C. to 200 ° C. to heat shrink it, and 5. The step of cooling the heat-shrinked bag to 50 ° C. or lower,
The method for producing a coated vacuum heat insulating material according to claim 1. The following process,
1. 1. A step of cutting at least a part of a polygonal bag made of a heat-shrinkable film, wherein the bag has an opening, the heat-shrinkable film has a thickness of 20 to 200 μm, and at least one of the above. The process, where the part includes the top of the bag,
2. 2. The process of putting the polygonal plate-shaped vacuum heat insulating material into the cut bag,
3. 3. The step of sealing the opening,
4. The step of heating the sealed bag at 80 ° C. to 200 ° C. to heat shrink it, and 5. The step of cooling the heat-shrinked bag to 50 ° C. or lower,
The method for producing a coated vacuum heat insulating material according to claim 1. The method according to claim 6 or 7, wherein the length of the two sides constituting the apex in at least a part of the bag to be cut is 70 mm or less. Claims 6 to 8 wherein the unheat-shrinkable film is a single-layer or multi-layer film selected from the group consisting of a polyvinyl chloride film, a polystyrene film, a polyethylene film, a polypropylene film, an ethylene vinyl alcohol resin film, and a polyolefin film. The method according to any one of the above. The method according to any one of claims 6 to 9, wherein the shrinkage rate of the unheat-shrinkable film is 10 to 80%. The method according to any one of claims 6 to 10, wherein the unheat-shrinkable film has a tensile strength of 70 to 1800 kg / cm ² .

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