JP4534638B2 - Vacuum insulation - Google Patents

Description

  The present invention relates to a laminate film, a package, and a vacuum heat insulating material.

Conventionally, the jacket material of this type of vacuum heat insulating material has been composed of a plastic laminate film having a metal foil or a vapor-deposited film, and attempts to prevent foreign objects from piercing by improving the piercing strength of the plastic layer. Has been made. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 9-317986

  When vacuum insulation material is manufactured, the chamber is evacuated and the opening is heat-sealed. After the chamber is opened to the atmosphere, the atmosphere is introduced into the chamber, which becomes a shock wave and is added to the outer cover material of the vacuum insulation material. . Glass fibers having an average diameter of 10 μm or less are used as the core material of the vacuum heat insulating material. However, when a foreign object is produced in the glass fiber, this is applied to the jacket material by the shock wave. It pierced from the inside, pinholes were generated in the vacuum heat insulating material, and there was a problem that the vacuum state of the vacuum heat insulating material could not be maintained.

  An object of this invention is to provide the vacuum heat insulating material with high durability with respect to the pinhole by piercing in view of the said subject.

In order to achieve the above object, the present invention provides the heat seal layer of a jacket material comprising a laminate film formed by laminating with an adhesive in the order of a heat seal layer, a gas barrier layer, a low density polyethylene film layer, and a protective layer. They were welded together and filled with a core material under reduced pressure .

As a result, the vacuum heat insulating material of the present invention is less likely to be pierced by the outer shell material being deformed with respect to the foreign matter when the outer shell material has excellent flexibility with respect to the piercing of the foreign matter from the core material side. . Moreover, when it is excellent in impact resistance, the sticking by a foreign material can be suppressed when the atmosphere is introduced into the vacuum chamber. With these two effects, the jacket material can prevent the occurrence of pinholes.

  According to the present invention, durability against pinholes caused by piercing can be increased.

According to the first aspect of the present invention, the heat seal layers of an outer cover material made of a laminate film formed by laminating with an adhesive in the order of a heat seal layer, a gas barrier layer, a low density polyethylene film layer, and a protective layer are heated. It is a vacuum heat insulating material that is welded and filled with a core material under reduced pressure.

  Generally, a vacuum heat insulating material is evacuated in a vacuum chamber, and after heat-sealing the opening of the outer cover material of the vacuum heat insulating material, when the vacuum chamber is opened to the atmosphere, the introduced atmosphere becomes a shock wave, and the outer cover material A shock is applied to the outer cover material, and the foreign matter contained in the glass fiber used as the core material pierces the jacket material from the inside due to the shock.

However, the vacuum heat insulating material of the present invention uses a laminated film formed by laminating with an adhesive in the order of a heat seal layer, a gas barrier layer, a low-density polyethylene film layer, and a protective layer as the outer cover material. Because the jacket material has flexibility, the jacket material is easily deformed, and foreign matter contained in the glass fiber is hard to be pierced and has a high impact strength. The occurrence of pinholes can also be suppressed against the piercing of foreign objects of glass fiber.

In addition to the above effects, since the low density polyethylene film is located on the atmosphere side with respect to the gas barrier layer, the air penetrates into the vacuum heat insulating material through the low density polyethylene film, which may have poor gas barrier properties. Therefore, the change with time of the thermal conductivity of the vacuum heat insulating material can be kept small.

According to a second aspect of the invention, a vacuum heat insulating material according to claim 1, wherein said for using nylon film on the protective layer, if the pinhole is no longer suppressed by the polyethylene film or polypropylene film However, since the next protective layer has a nylon film with good pinhole resistance, the nylon film can further suppress the generation of pinholes and further improve the pinhole resistance.

The invention according to claim 3, a vacuum heat insulating material according to claim 1, wherein said for the use of polyethylene terephthalate film to said protective layer, in addition to the effects of the invention of claim 1, wherein the polyethylene terephthalate Since the film is excellent in pinhole resistance, the generation of pinholes can be further suppressed with a polyethylene terephthalate film.

  In addition, since polyethylene terephthalate is excellent in friction resistance, when the polyethylene terephthalate film is the outermost layer, the conveyor and the vacuum heat insulating material in the vacuum heat insulating material and vacuum heat insulating material manufacturing line or the vacuum heat insulating material applying device manufacturing line, etc. Even when rubbed, the generation of pinholes can be suppressed, and the polyethylene terephthalate film has a low hygroscopic property. Can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of the vacuum heat insulating material in the first embodiment. As shown in FIG. 1, the vacuum heat insulating material 1 is obtained by covering a core material 3 and a gas adsorbent 4 with a covering material 2 and sealing the inside of the covering material 2 under reduced pressure.

FIG. 2 shows a cross section of the jacket of the vacuum heat insulating material of the first embodiment. As shown in FIG. 2, a heat seal layer 5 having a thickness of about 50 μm made of a low density polyethylene film or polypropylene film having a density of 0.930 g / cm ³ or more, a thickness made of a metal foil or a plastic film having a melting point of 150 ° C. or more. A gas barrier comprising a base film having a thickness of about 15 μm or less, a plastic film having a vapor deposition layer of any one of metal, metal oxide, and silica, or a plastic film having a polyacrylic acid resin coating layer provided on the vapor deposition layer. A first protective layer comprising a second protective layer 7 made of a polyethylene film or a polypropylene film having a Young's modulus of 200 MPa or less and a thickness of about 50 μm, and a nylon film having a thickness of about 25 μm or less. Layer 8 is approximately 3 μm urethane between each layer The laminate film 9 formed by sequentially laminated via the adhesive layer, constituting the enveloping member 10.

  Here, the manufacturing method of a vacuum heat insulating material is demonstrated.

  The core material 3 is dried for a predetermined time in a constant temperature furnace. The core material 3 and the adsorbent 4 are inserted into a jacket material 10 which has been sealed on three sides in advance by heat welding, the jacket material 10 is installed in a vacuum chamber, and the inside of the jacket material 10 is decompressed to about 13 Pa. Then, the opening part of the jacket material 10 is sealed by heat welding. Thereafter, the atmosphere is introduced into the vacuum chamber, the atmospheric pressure is returned to the inside of the vacuum chamber, and the completed vacuum heat insulating material 1 is taken out.

  The operation of the vacuum heat insulating material 1 produced as described above will be described for pinhole resistance.

  When the vacuum heat insulating material 1 is manufactured, evacuation is performed in the vacuum chamber, and the opening of the jacket material 10 is heat-sealed, and then the vacuum chamber is opened to the atmosphere, the air is introduced into the chamber. The introduced atmosphere becomes a shock wave, and an impact is applied to the jacket material 10 of the vacuum heat insulating material 1. Glass fibers having an average diameter of 10 μm or less are used as the core material 3 of the vacuum heat insulating material 1, but foreign matters generated when the glass fibers are produced remain in the glass fibers, and foreign matters are removed by the shock waves. The phenomenon of piercing the workpiece from the inside occurs.

At this time, the outer cover material 10 has, in order from the inside, a heat seal layer 7 made of a low density polyethylene film having a density of 0.930 g / cm ³ or more and a thickness of about 50 μm, a metal foil having a thickness of about 6 μm, or a melting point. A base film made of a plastic film having a thickness of about 12 μm at 150 ° C. or more, a plastic film having a metal, metal oxide, or silica deposited layer, or a 1 μm polyacrylic resin layer on the deposited layer A gas barrier layer 6 made of a plastic film having a thickness, a second protective layer 7 made of a polyethylene film or a polypropylene film having a thickness of about 50 μm with a Young's modulus in JISK7127 of 200 MPa or less, and a second protective layer 7 made of nylon having a thickness of about 25 μm. 1 protective layer 8 is sequentially laminated between each layer via an adhesive layer of about 3 μm urethane. Since the laminated film 9 is used, the occurrence of pinholes in the outer cover material 10 can be suppressed even when the atmosphere in the vacuum chamber is released.

  That is, when the atmosphere is released, the jacket material 10 is struck against the core material 3 by the introduced atmosphere, but the jacket material 10 has a polyethylene film or a polypropylene film having excellent flexibility, In the above situation, the outer covering material 10 is easily deformed to some extent along the shape of the foreign matter, so that the foreign matter is hard to pierce, the Young's modulus in JISK7127 is 200 MPa or less, and the impact strength in JISK7124 is 100 N · Since the polyethylene film or polypropylene film 7 of cm or more has high impact strength, it is possible to suppress the occurrence of pinholes due to foreign material piercing from the core material 3 side due to the impact when released to the atmosphere.

  As an example, the results of producing 30 vacuum heat insulating materials each using the core material 3 containing a large amount of the foreign matter and four kinds of jacket materials are shown below.

Example 1
From the core material side, a low density polyethylene film with a density of 0.930 g / cm ^{3 and} a thickness of about 50 μm, an aluminum foil with a thickness of about 6 μm, a low density polyethylene film with a Young's modulus of 430 MPa and a thickness of about 50 μm. A vacuum heat insulating material was produced using a four-layer outer covering material of a nylon film having a thickness of about 15 μm.

  Immediately after production and 7 days after production, the vacuum insulation of the vacuum heat insulating material was inspected, and it was confirmed that bag breakage due to 5 pinholes occurred after being left for 7 days. The impact strength of the low density polyethylene film was about 70 N · cm as measured by JISK7124.

(Example 2)
From the core side, a low density polyethylene film with a density of 0.930 g / cm ^{3 and} a thickness of about 50 μm, an aluminum foil with a thickness of about 6 μm, and a low density polyethylene film with a Young's modulus of JISK7127 of about 50 μm and a thickness of about 50 μm. A vacuum heat insulating material was produced using a four-layer outer covering material of a nylon film having a thickness of about 15 μm.

  Immediately after the production and 7 days after the production, the vacuum insulation of the vacuum heat insulating material was inspected, and it was confirmed that two bags were broken due to pinholes after being left for 7 days. The impact strength of the low density polyethylene film was about 80 N · cm as measured by JISK7124.

(Example 3)
From the core side, a low density polyethylene film having a density of 0.930 g / cm ^{3 and} a thickness of about 50 μm, an aluminum foil having a thickness of about 6 μm, and a low density polyethylene film having a Young's modulus of 140 MPa and a thickness of about 50 μm according to JISK7127. A vacuum heat insulating material was produced using a four-layer outer covering material of a nylon film having a thickness of about 15 μm.

  Immediately after the production and 7 days after the production, the vacuum insulation of the vacuum heat insulating material was inspected, and it was confirmed that there was no bag breakage due to pinholes after standing for 7 days. The impact strength of the low density polyethylene film was about 100 N · cm as measured by JISK7124.

Example 4
From the core material side, a low density polyethylene film with a density of 0.930 g / cm ^{3 and} a thickness of about 50 μm, an aluminum foil with a thickness of about 6 μm, and a low density polyethylene film with a Young's modulus of JIS K7127 of 110 MPa and a thickness of about 50 μm. A vacuum heat insulating material was produced using a four-layer outer covering material of a nylon film having a thickness of about 15 μm.

  Immediately after the production and 7 days after the production, the vacuum insulation of the vacuum heat insulating material was inspected, and it was confirmed that there was no bag breakage due to pinholes after standing for 7 days. The impact strength of the low density polyethylene film was about 200 N · cm as measured by JISK7124.

  Moreover, in a low density polyethylene film, since the softness | flexibility and impact resistance improve, so that the Young's modulus in JISK7127 becomes small, the pinhole resistance of the jacket material 10 will improve.

Moreover, since the heat seal layer 7 of the jacket material 2 uses a low density polyethylene film having a density of 0.930 g / cm ³ or more, the heat seal layer 7 is a high density polyethylene film, an unstretched polypropylene film. Compared to the above, since it has more flexibility, it is possible to suppress the occurrence of pinholes from the inside of the jacket material 10 by the core material 3 for the same reason as described above.

In addition, a low density polyethylene film having a density of 0.930 g / cm ³ or more has better gas barrier properties than a low density polyethylene film or polypropylene film having a Young's modulus of 200 MPa or less in JISK7127. There is no need for special handling for the layer cross section and heat seal width.

  Even when the jacket material 10 is used for a package other than the vacuum heat insulating material, it has excellent flexibility and resistance to the outside of the gas barrier 6 against pinhole factors such as piercing from inside or outside the package. Since the polyethylene film or polypropylene film layer having impact properties is laminated, the generation of pinholes in the package can be suppressed.

  In addition, although the bag shape of the jacket material 3 was explained in the three-side seal bag, there are four-side seal bags, gusset bags, three-side seal bags, pillow bags, center tape seal bags, etc., which are particularly specified. It is not a thing. Moreover, it does not specifically limit about the thickness of each film.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of the jacket 12 of the vacuum heat insulating material 11 according to the second embodiment. In the present embodiment, a polyethylene terephthalate film is used for the first protective layer 13, and there is an approximately 3 μm urethane-based adhesive layer between the film layers of the outer covering material 12. Each film is laminated by the agent layer. In addition, the same code | symbol is attached | subjected about the same structure as Embodiment 1, and the detailed description is abbreviate | omitted.

  As described above, a polyethylene terephthalate film having a thickness of about 12 μm is used for the first protective layer 13 for the jacket 12 of the vacuum heat insulating material 11. This polyethylene terephthalate film has excellent friction resistance and excellent pinhole resistance compared to nylon film and polyethylene film as film properties. Since the first protective layer 13 is excellent in friction resistance, even if the vacuum heat insulating material 11 and the vacuum heat insulating material 11 are rubbed against the conveyor or the like in the vacuum heat insulating material 11 and the vacuum heat insulating material 11 production line or the vacuum heat insulating material 11 application equipment production line, The generation of pinholes due to can be suppressed. Furthermore, since the first protective layer 13 has a low hygroscopic property, it is possible to suppress the lengthening of the vacuuming time due to moisture absorption in the vacuuming step in the production of the vacuum heat insulating material 11.

  In addition, although the bag shape of the jacket material 3 was explained in the three-side seal bag, there are four-side seal bags, gusset bags, three-side seal bags, pillow bags, center tape seal bags, etc., which are particularly specified. It is not a thing. Moreover, it does not specifically limit about the thickness of each film.

(Embodiment 3)
FIG. 4 shows a cross section of the jacket 15 of the vacuum heat insulating material 14 according to the third embodiment. In the present embodiment, a polyethylene terephthalate film 17 having a thickness of about 12 μm is disposed on the side of the core 3 and adjacent to the gas barrier layer 16 with respect to the gas barrier layer 16.

Further, a polyethylene film having a density of about 0.930 g / cm ³ or more and a thickness of about 50 μm is used for the heat seal layer 17a, and the protective layer 18 adjacent to the outside of the gas barrier layer 16 has a Young's modulus according to JISK7127. Is a polyethylene film or a polypropylene film having a thickness of about 50 μm and a thickness of 200 MPa or less. There may or may not be a layer on the outer layer side of the protective layer 18.

  In addition, there is an adhesive layer of about 3 μm urethane or the like between each film layer of the jacket material 15, and each film is laminated by this adhesive layer. The same components as those in the first or second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The outer sheath material 15 of the vacuum heat insulating material 14 is a gas barrier layer 16 in which a polyethylene terephthalate film 17 is disposed on the core material 3 side and adjacent to the gas barrier layer 16. This is a configuration having a protective layer 13 made of a polyethylene film or polypropylene film having a Young's modulus in JISK7127 of 200 MPa or less.

  At this time, the pinhole resistance of the jacket material 14 is that the polyethylene naphthalate film 17 is formed between the heat seal layer 5 and the gas barrier layer 6 in contrast to the configuration described in the first embodiment. Since the polyethylene terephthalate film 17 having good pinhole resistance is provided up to the protective layer 13, the pinhole resistance of the vacuum heat insulating material 14 can be improved, and the gas barrier layer 16 can be pinned without penetrating the protective layer 13. Even if a hole is generated, since one extra polyethylene terephthalate film 17 is added from the core material 3, the diameter of the pinhole is reduced and the amount of air entering through the protective layer 13 is reduced.

Further, since the gas barrier property of the polyethylene terephthalate film 18 is very good as compared with the polyethylene film having a heat seal layer 18 density of 0.930 g / cm ³ or more, the vacuum heat insulating material 14 from the polyethylene terephthalate film 18 is used. The influence of gas intrusion into the inside can be almost ignored.

  In addition, although the bag shape of the jacket material 3 was explained in the three-side seal bag, there are four-side seal bags, gusset bags, three-side seal bags, pillow bags, center tape seal bags, etc., which are particularly specified. It is not a thing. Moreover, it does not specifically limit about the thickness of each film.

(Embodiment 4)
FIG. 5 shows a cross section of the jacket material 20 of the vacuum heat insulating material 19 according to the fourth embodiment. The jacket material 20 in the present embodiment uses a polyethylene film or a polypropylene film having a thickness of about 50 μm with a Young's modulus of JIS K7127 of 200 MPa or less as the heat seal layer 21, and a gas barrier adjacent to the outside of the heat seal layer 21. A plastic film having a metal film or a metal film or a base film made of a plastic film having a melting point of 150 ° C. or more and a thickness of about 15 μm or less, or a metal film, a metal oxide, or a silica film, or a layer of the above-mentioned Further, a nylon film is used for each of the second protective layer 23 and the first protective layer 24 adjacent to the outside of the gas barrier layer 22 using a plastic film having a polyacrylic acid resin coating layer thereon. Its thickness is about 25 μm or less.

  In addition, there is an approximately 3 μm urethane adhesive layer between the film layers of the jacket material 20, and the films are laminated by this adhesive layer. The detailed description of the same configuration as in the first to third embodiments is omitted.

  The heat seal layer 21 of the vacuum heat insulating material 19 is made of a polyethylene film or a polypropylene film having a Young's modulus of 200 MPa or less according to JISK7127. Although the outer cover material 20 includes a polyethylene film or polypropylene film having excellent flexibility, the outer cover material 20 is likely to be deformed in the above situation, so that the foreign material of the core material 3 can be deformed. Since the polyethylene film or polypropylene film 7 having a Young's modulus of 200 MPa in JISK7127 has a high impact strength, pinholes caused by foreign object piercing from the core material 3 side due to impact when released into the atmosphere are difficult to pierce. Occurrence can be suppressed.

Further, since a low density polyethylene film having a density of 0.930 g / cm ³ or more is used for the heat seal layer 21, the heat seal layer 21 is compared with a high density polyethylene film and an unstretched polypropylene film. Since it has flexibility, it is possible to suppress the occurrence of pinholes from the inside of the jacket material 20 by the core material 3 for the same reason as described above.

  Further, regarding the occurrence of pinholes, since there is a polyethylene film or polypropylene film or polypropylene film having a Young's modulus of 200 MPa or less in JISK7127 having flexibility and impact resistance in the immediate vicinity of the core material 3, Can be further suppressed.

  The polyethylene film or polypropylene film used for the heat seal layer 21 has excellent flexibility and impact resistance as described above, and the polyethylene film or polypropylene film is bonded to the other film only on one side. Since the contact with the foreign matter is made directly when the air is released, it is possible to contact the foreign matter in a more free shape, so that it is possible to further improve the occurrence of pinholes due to the foreign matter.

Moreover, when the said polyethylene film or a polypropylene film is used for the heat seal layer 21, the penetration | invasion amount of the air to the vacuum heat insulating material 19 compared with the polyethylene film whose density is applied normally 0.930 g / cm < ³ > or more. May increase, and the thermal conductivity of the vacuum heat insulating material becomes worse over time.

Since the heat seal width is 10 mm in the case of a polyethylene film having a density of 0.930 g / cm ³ or more, the density of the polyethylene film or polypropylene film of the heat seal layer 21 is changed by making the heat seal width larger than 10 mm. It is possible to suppress a decrease in gas barrier properties due to the above.

  In addition, although the bag shape of the jacket material 3 was explained in the three-side seal bag, there are four-side seal bags, gusset bags, three-side seal bags, pillow bags, center tape seal bags, etc., which are particularly specified. It is not a thing. Moreover, it does not specifically limit about the thickness of each film.

(Embodiment 5)
FIG. 6 shows a cross section of the jacket material 26 of the vacuum heat insulating material 25 of the fifth embodiment. The jacket material 26 in the present embodiment uses a polyethylene film or a polypropylene film having a thickness of about 50 μm and a Young's modulus of 200 MPa or less in JIS K7127 for the heat seal layer 27, and is adjacent to the outside of the heat seal layer 27. A plastic film having a metal foil or a base film made of a plastic film having a melting point of 150 ° C. or higher and a thickness of about 15 μm or less, a metal film, a metal oxide, or a plastic film having a deposited layer of silica; A plastic film further having a polyacrylic acid resin coating layer on the vapor deposition layer is used, and the second protective layer 29 and the first protective layer 30 adjacent to the outside of the gas barrier layer 28 have a thickness of about A nylon film of 25 μm or less is used.

  The entire circumference of the cross section of the jacket material 26 of the vacuum heat insulating material 25 is coated with an ethylene polyvinyl alcohol copolymer or a polyacrylic acid resin. Between each film layer of the jacket material 26, there is an approximately 3 μm urethane-based adhesive layer, and each film is laminated by this adhesive layer. The detailed description of the same configuration as in the first to fourth embodiments is omitted.

  The heat seal layer 27 of the vacuum heat insulating material 26 is made of a polyethylene film or a polypropylene film having a Young's modulus of 200 MPa or less according to JISK7127, and the outer covering material 26 is a core material by the introduced air when released to the atmosphere due to its flexibility. 3, since the outer covering material 26 has a polyethylene film or polypropylene film having excellent flexibility, the outer covering material 26 is easily deformed in the above situation, so that the core material 3 The polyethylene film or polypropylene film 7 having a Young's modulus of 200 MPa or less according to JISK7127 has a high impact strength, so that the foreign material is pierced by the foreign material from the core material 3 side due to the impact when released to the atmosphere. Generation of pinholes can be suppressed.

Moreover, since the heat seal layer 27 uses a low density polyethylene film having a density of 0.930 g / cm ³ or more, the heat seal layer 27 is compared with a high density polyethylene film and an unstretched polypropylene film. Since it has more flexibility, it is possible to suppress the occurrence of pinholes from the inside of the jacket material 26 by the core material 3 for the same reason as described above.

  As for the occurrence of pinholes, since there is a polyethylene film or polypropylene film having a Young's modulus of 200 MPa or less in JISK7127, which has flexibility and impact resistance, in the immediate vicinity of the core material 3, the occurrence of pinholes is prevented. It can be suppressed more.

However, when this polyethylene film or polypropylene film is used for the heat seal layer 27, the gas barrier property may be inferior compared with a polyethylene film having a density of 0.930 g / cm ³ or more which is usually applied. In such a case, the amount of air entering the vacuum heat insulating material increases, and the thermal conductivity of the vacuum heat insulating material may become worse over time.

  As the intrusion path of air into the vacuum heat insulating material 25, intrusion from the gas barrier layer 28 of the vacuum heat insulating material 25 and intrusion from the cross section of the heat seal layer 27 can be considered. Intrusion from the cross section of the heat seal layer 27 therein can be suppressed by coating the cross section with a gas barrier material.

  By using an ethylene polyvinyl alcohol copolymer or a polyacrylic acid resin with good gas barrier properties for this coating, it is possible to suppress the intrusion of air from the cross section of the jacket material 25, and therefore the heat seal layer 27. Therefore, it is possible to suppress a decrease in gas barrier properties caused by changing the Young's modulus of the polyethylene film or polypropylene film, and to obtain the jacket material 25 having very good pinhole resistance.

  As described above, the laminate film and the package of the present invention are very excellent in pinhole resistance, and thus are suitable as a jacket material for a vacuum heat insulating material. In addition, the vacuum insulation material is extremely excellent in pinhole resistance, so cooking appliances such as refrigerators, electric water heaters, and IH cooking heaters, and information equipment such as printing machines, copiers, liquid crystal projectors, notebook computers, etc. It can also be applied to industrial equipment such as semiconductor manufacturing equipment.

Sectional drawing of the vacuum heat insulating material in Embodiment 1 of this invention The principal part expanded sectional view of the jacket material of the vacuum heat insulating material in Embodiment 1 of this invention The principal part expanded sectional view of the jacket material of the vacuum heat insulating material in Embodiment 2 of this invention The principal part expanded sectional view of the jacket material of the vacuum heat insulating material in Embodiment 3 of this invention The principal part expanded sectional view of the jacket material of the vacuum heat insulating material in Embodiment 4 of this invention The principal part expanded sectional view of the jacket material of the vacuum heat insulating material in Embodiment 5 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum heat insulating material 2 Outer covering material 3 Core material 5 Heat seal layer 6 Gas barrier layer 7 Second protective layer 10 Outer covering material 11 Vacuum insulating material 12 Outer covering material 13 First protective layer 14 Vacuum insulating material 15 Outer covering Material 16 Gas barrier layer 17 Polyethylene terephthalate film 17a Heat seal layer 18 Protective layer 19 Vacuum heat insulating material 20 Outer cover material 21 Heat seal layer 22 Gas barrier layer 25 Vacuum heat insulating material 26 Outer cover material 27 Heat seal layer 28 Gas barrier layer 31 Coat layer

Claims (3)

Heat-sealing the heat-sealing layers of a jacket material made of a laminate film formed by laminating with an adhesive in the order of a heat-seal layer, a gas barrier layer, a low-density polyethylene film layer, and a protective layer, and a core material inside Vacuum insulation material that is filled under reduced pressure.   The vacuum heat insulating material according to claim 1, wherein a nylon film is used for the protective layer.   The vacuum heat insulating material according to claim 1, wherein a polyethylene terephthalate film is used for the protective layer.

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