JP2006118637A - Vacuum heat insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum heat insulating material capable of being used in a medium to high temperature range at a relatively low price. <P>SOLUTION: In a face material of a cover material 2, polyethylenenaphthalate is used for an innermost layer 4, aluminum foil is used for metal foil 5 of an outer layer thereof, and polyethylenenaphthalate is used for an outermost layer 6; and a back material of the cover material 2 is constituted by bonding two sheets of vapor deposition surfaces 7 of polyethylenenaphthalate to which aluminum vapor deposition is applied, and they are an innermost layer 8 and an outermost layer 9, respectively. A core material 3 is a molded body constituted by dry silica and glass fiber. The vacuum heat insulating material 1 is obtained by inserting the core material 3 in the cover material 2 three-side sealed in advance by an ultrasonic seal so as to have a recessed and protruded shape on a seal part, and by sealing in vacuum by the ultrasonic seal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum heat insulating material that can be used in various devices that require heat insulation or heat insulation.

  Conventionally, heat-resistant resin with a glass transition point of 88 ° C or higher is used for at least one of the protective layer, vapor-deposited layer, and support layer of the outer cover material as a vacuum heat insulating material used for heat insulation of cooking equipment and heat insulation equipment. Thus, there is a vacuum heat insulating material that prevents cracking of the deposited layer and improves the heat insulating performance even when used at a high temperature of about 100 ° C. (see, for example, Patent Document 1).

Conventionally, as a packaging material for foods, pharmaceuticals, cosmetics, etc., by limiting the components of polyethylene naphthalate, heat-sealability is imparted to polyethylene naphthalate, and this is used as a heat-seal layer to provide gas barrier properties and heat resistance. There are packaging materials with improved dimensional stability at high temperatures, chemical resistance, weather resistance, mechanical properties, and the like (see, for example, Patent Document 2).
JP 2000-310392 A JP-A-8-156208

  However, in the configuration of the above-mentioned Patent Document 1, polypropylene having low heat resistance is used for the innermost heat-welding layer, although a resin having high heat resistance is used for the protective layer, the vapor deposition layer, and the support layer. Therefore, it could not be used in a temperature environment higher than the melting point of polypropylene (about 160 ° C.). Moreover, since the heat-resistant resin is used on both surfaces of the vacuum heat insulating material, the cost is extremely increased.

  In Patent Document 2, heat resistance is improved by using polyethylene naphthalate having a high melting point for the innermost layer. However, since the structure is premised on heat-sealing, the structure is as follows. Challenges arise.

  The heat seal is a heating method (external heating method) that generates a temperature gradient such that the outermost layer of the jacket material becomes the highest temperature during welding. For this reason, if a resin having a lower melting point than that of the innermost layer resin is used for the outer layer, the outer layer resin melts and adheres to a seal bar or the like, thereby reducing productivity.

  In Patent Document 2, the material used for the outer layer is not particularly limited, but in order not to melt the outer layer, the resin used for the outer layer is a resin having a higher melting point than the polyethylene naphthalate used for the innermost layer. Limited. Therefore, there is a problem that the configuration is limited and the cost is increased.

  In addition, when using this packaging material as a jacket for vacuum insulation, the vacuum insulation is effective in this configuration on the high temperature side because the ambient temperature of the front and back is different due to its own insulation performance. When the cover material having such a configuration is used also on the low temperature side, a resin having a low melting point is used for the outer layer of the cover material, which causes a problem that the cost is very high.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a vacuum heat insulating material that can be used in a medium and high temperature range at a relatively low cost.

  In order to solve the above-described conventional problems, the vacuum heat insulating material of the present invention uses a thermoplastic resin having a melting point higher than that of the environment in which the vacuum heat insulating material is used for the innermost layer of the outer cover material, and is subjected to ultrasonic sealing or high frequency sealing. The innermost surface of the jacket material is welded.

  First, if a resin with a melting point higher than the operating environment temperature is selected for the innermost layer of the vacuum insulation material, the innermost layer can be prevented from melting, so that rapid leakage does not occur. Can be maintained.

  Ultrasonic seals and high-frequency seals are heating methods (internal heating methods) that generate a temperature gradient such that the weld surface of the jacket material becomes the highest temperature, and the outer layer has a higher melting point than the innermost layer as in the external heating method. If there is no need to select a resin and the resin has a melting point higher than the environmental temperature, a resin having a melting point equal to or lower than that of the innermost layer can be used in a portion other than the innermost layer of the jacket material.

  In particular, in the case of a vacuum heat insulating material, even if one surface is in a high temperature environment, the other surface is in a relatively low temperature environment due to its heat insulating performance, so the outer layer of the low temperature side jacket material is the There is no need to use a resin having a melting point higher than that of the inner layer, and an internal heating method that can widen the configuration selection range of the jacket material is very effective.

  The vacuum heat insulating material of the present invention can freely configure the jacket material from a resin having a melting point higher than that of the use environment even when the use environment temperature is high. Expanding the selection range of the configuration of the jacket material suppresses the increase in cost. In particular, when the high temperature part is thermally insulated with a vacuum heat insulating material, the present invention is very effective in the outer cover material on the surface which becomes the low temperature side, and the cost can be reduced.

  In addition, since any resin can be welded as long as it is a thermoplastic resin, it is possible to select a resin according to the purpose such as heat resistance, flame retardancy, gas barrier properties, and pinhole resistance. In addition, since the welding surface is at the highest temperature, the reliability of the seal is improved and the reliability is improved.

  The invention of the vacuum heat insulating material according to claim 1 includes a core material and a jacket material having at least a metal foil or a vapor-deposited resin film covering the core material, and the surface of the jacket material. In at least one of the material and the backing material, a resin other than the innermost layer contains a resin having a melting point equal to or lower than the melting point of the resin of the innermost layer, and is sealed with an ultrasonic seal or a high frequency seal.

  In an internal heating method such as an ultrasonic seal or a high frequency seal, a temperature gradient is generated so that the welding surface becomes the highest temperature, and therefore, it becomes possible to use a resin having a melting point of the innermost layer resin or less as the outer layer.

  For this reason, also when producing the vacuum heat insulating material used in a high temperature range, a cost increase can be suppressed without a structure being limited. In particular, the combination of this configuration and this method is effective for the jacket material on the surface that becomes the low temperature side in the environment where the vacuum heat insulating material is used.

  Also, since any resin can be welded if it is a thermoplastic resin, the innermost layer should be selected according to the application such as heat resistance, flame retardancy, gas barrier properties, water vapor barrier properties, pinhole resistance, etc. Can do. In addition, since the welding surface has the highest temperature, the reliability of the seal is improved.

  As the metal foil, a foil such as aluminum, stainless steel, titanium, or copper can be used. As a material for vapor deposition, aluminum, cobalt, nickel, zinc, copper, silver, silica, alumina, or the like can be used.

  As the resin used for the innermost layer, any resin can be used as long as it is a thermoplastic resin having a melting point higher than the use environment temperature, and can be selected according to the purpose. If heat resistance of about 100 ° C. is required, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polyvinylidene chloride, etc. can be used.

  In order to use in a higher temperature environment, it is desirable to select a resin having a higher melting point, such as polyethylene naphthalate, polyphenylene sulfide, polyether imide, polyamide imide, polyether sulfone, polyether ether ketone, fluororesin, etc. Can be used.

  Moreover, any resin can be used for the outer layer as long as the resin has a melting point higher than the ambient temperature, and any resin can be used. In addition to a resin having a melting point lower than that of the innermost layer, the melting point is higher than that of the innermost layer. It is also possible to use a resin and have a structure of four or more layers.

  Further, in order to further improve the initial performance and the temporal heat insulation performance of the vacuum heat insulating material, it is possible to use a gas adsorbent or a moisture adsorbent.

  The invention of the vacuum heat insulating material according to claim 2 is the invention according to claim 1, wherein the resin of the layer other than the innermost layer is a resin having a melting point equal to or lower than the melting point of the resin of the innermost layer.

  This configuration is particularly effective for the configuration of the jacket material on the surface on the low temperature side of the vacuum heat insulating material. In an environment where a vacuum heat insulating material is used, the outer cover material of the low temperature side is in a lower temperature environment. Therefore, even if all the resins constituting the outer layer are made of a resin having a melting point equal to or lower than the melting point of the innermost layer, there is no problem in heat insulation performance. The fact that a resin having a low melting point can be used as the resin constituting the outer layer is very cost-effective.

  The invention of the vacuum heat insulating material according to claim 3 is the invention according to claim 1 or 2, wherein the innermost layer and the outermost layer are the same resin, and the stock of the material can be reduced. Since it is possible to use the same resin in all layers, a very low-cost configuration is possible if a low-cost material is selected.

  The invention of the vacuum heat insulating material according to claim 4 is the invention according to any one of claims 1 to 3, wherein the innermost layer resin is an amorphous resin, and the amorphous resin is Since the softening temperature range is wide, when ultrasonic sealing is employed, ultrasonic vibration can be transmitted very efficiently, so that energy can be suppressed and productivity can be improved.

  The invention of the vacuum heat insulating material according to claim 5 is the invention according to any one of claims 1 to 4, wherein the resin constituting the covering material is a flame retardant resin, Since flame retardance can be imparted to the material, it can also be used in applications where flame retardancy is required.

  Parts of electronic equipment such as personal computers are required to have flame resistance equivalent to UL94V-2, and it is most desirable to use a fluororesin equivalent to V-0 as the flame retardant resin, but it is equivalent to V-2 Any resin can be used as long as it is the above resin.

  The invention of the vacuum heat insulating material according to claim 6 is the invention according to any one of claims 1 to 5, wherein the outermost material of the outer cover material and the innermost layer of the backing material are different resins. Because it is possible to use a configuration in which a high heat resistance resin is used on the high temperature side of the environment where the vacuum heat insulating material is used and a low heat resistance resin is used on the low temperature side than the high temperature side. Cost can be reduced compared to the case of using a heat-resistant resin on the surface. It is also possible to give the front and back materials different functionality.

  The invention of the vacuum heat insulating material according to claim 7 is the invention according to claim 6, wherein the difference in melting point of the resin of the innermost layer of the outer cover material and the outer cover material is 22 ° C. or less. Energy during welding can be suppressed, and good seal strength can be obtained.

  The invention of a vacuum heat insulating material according to claim 8 is the invention according to any one of claims 1 to 7, wherein the innermost layer is a vapor-deposited resin film, and the innermost layer of the jacket material. Can also be produced at a low cost with a simpler structure. Moreover, since the distance from the welding surface to the vapor deposition layer is small, gas intrusion from the end portion of the vacuum heat insulating material can be suppressed, and reliability is improved.

  The invention of a vacuum heat insulating material according to claim 9 is the invention according to any one of claims 1 to 7, wherein at least one of the surface material and the back material of the outer covering material is polyethylene in the innermost layer. Naphthalate, metal foil for the outer layer, polyethylene naphthalate for the outermost layer, and because it uses the cheapest polyethylene naphthalate among heat resistant resins that can be used continuously at 150 ° C, The cost can be reduced while imparting the property. Moreover, gas intrusion from the vacuum heat insulating material surface can be suppressed by using the foil.

  The invention for a vacuum heat insulating material according to claim 10 is the invention according to any one of claims 1 to 7, wherein at least one of the surface material and the backing material of the outer cover material is fluorine in the innermost layer. Resin, metal foil for the outer layer, and fluororesin for the outermost layer. By using the fluororesin having flame resistance equivalent to UL94V-0, not only heat resistance but also flame resistance is vacuum insulated. Can be applied to the material. In addition, the fluororesin also has high insulating properties, and therefore, it can be applied to uses that require flame retardancy and insulating properties.

  An invention of a vacuum heat insulating material according to an eleventh aspect is the invention according to any one of the first to eighth aspects, wherein at least one of the front material and the back material of the outer cover material is subjected to metal vapor deposition. It is a structure in which two polyethylene naphthalates are used and the metal vapor-deposited surfaces are bonded together, and since it is a simple structure, it can be manufactured at low cost and productivity is improved. In addition to having heat resistance, since the distance from the welding surface to the vapor deposition surface is small, the amount of gas intrusion from the end of the vacuum heat insulating material can be suppressed. Moreover, since it is a vapor deposition film, heat leak can be suppressed.

  The invention of a vacuum heat insulating material according to claim 12 is the invention according to any one of claims 1 to 8, wherein at least one of the front material and the back material of the outer cover material is subjected to metal vapor deposition. It is a structure in which two fluororesins are used and the metal vapor-deposited surfaces are bonded together, and since it is a simple structure, it can be manufactured at low cost and productivity is also improved. Moreover, in addition to heat resistance, a flame retardance and insulation can be provided. Since the distance from the welding surface to the vapor deposition surface is small, the amount of gas intrusion from the end of the vacuum heat insulating material can be suppressed. Moreover, since it is a vapor deposition film, heat leak can be suppressed.

  The invention of a vacuum heat insulating material according to claim 13 is the invention according to any one of claims 1 to 12, wherein the seal portion has a concavo-convex shape, the engagement between the films becomes strong, and the seal Certainty increases. Further, since the cross-sectional area of the seal portion is reduced, gas intrusion from the end portion of the vacuum heat insulating material can be suppressed, and reliability is improved.

  The invention of a vacuum heat insulating material according to claim 14 is the invention according to any one of claims 1 to 13, wherein the core material is a powder containing dry silica as a main component. When is used as a core material, the pressure dependency is excellent, so that it is not easily affected by gas intrusion from the outside, and the heat insulation performance is easily maintained.

  Among these, dry silica is excellent in heat resistance and heat insulation performance. As dry silica, silicon oxide compounds having various particle diameters produced by dry methods such as silicic acid produced by an arc method and silicic acid produced by thermal decomposition can be used.

  Since the heat insulation performance is excellent, the primary particle diameter is preferably 50 nm or less, and when the high heat insulation performance is required, the primary particle diameter is preferably 10 nm or less. Mixtures of dry silica having various particle sizes can also be used.

  For example, even if the product is out of regular lots, the particle size generated when switching between mass-produced product A and mass-produced product B with specified particle size is not controlled between mass-produced product A and mass-produced product B. It is possible to manufacture a heat insulating material at a lower cost.

  In addition, when conductive powder is added to dry silica, the conductive powder crushes the aggregated particles of silica, so that the solid contact points are reduced and the heat insulation performance is improved.

  The invention of the vacuum heat insulating material according to claim 15 is the invention according to claim 14, wherein the powder mainly composed of dry silica is a molded body, and the inner bag is not required, so the cost can be reduced. Further, the thickness can be reduced by the amount not using the inner bag, and the effective heat insulation area can be expanded because there is no fin portion of the inner bag.

  Moreover, since it is a molded object, it is uniform thickness and is excellent in surface property. Moreover, it is preferable to use glass fiber as the aggregate of the molded body. The combination of dry silica and glass fiber is affected by the fact that the glass fiber has hydroxyl groups on the surface, so it has a high affinity with hydroxyl groups present on the dry silica powder surface and is easily attached to each other. This is because a strong molded body can be obtained as compared with the case where is used.

  Moreover, heat insulation performance can be improved more when electroconductive powder is contained in the structure of a molded object. Further, when an ultrasonic seal is employed, the powder can be removed by vibration due to ultrasonic waves even if powder falls off from the molded body, so that the reliability of the seal is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a vacuum heat insulating material according to Embodiment 1 of the present invention, and FIG. 2 is a plan view of the vacuum heat insulating material.

  As shown in FIG. 1, the vacuum heat insulating material 1 is obtained by covering a core material 3 with a jacket material 2 and decompressing the inside of the jacket material 2.

  As the jacket material 2, a resin to be used was selected on the assumption that the vacuum heat insulating material 1 is used in an environment of 150 ° C. or higher. For the jacket material 2, laminated films having different structures were used for the front material and the back material, respectively.

  The front material uses polyethylene naphthalate for the innermost layer 4, aluminum foil for the outer layer metal foil 5, and polyethylene naphthalate for the outermost layer 6, and the backing material is polyethylene naphthalate subjected to two aluminum vapor depositions. The vapor deposition surfaces 7 are bonded to each other, and each has an innermost layer 8 and an outermost layer 9.

  The core material 3 is a molded body composed of dry silica and glass fibers. The vacuum heat insulating material 1 is formed by inserting a core material 3 into a jacket material 2 that has been sealed in three directions so as to form an uneven shape as shown in FIG. It is obtained by sealing with a sonic seal.

  The heat conductivity of the vacuum heat insulating material 1 is 0.0055 W / mK at 24 ° C., and since the core material 3 is excellent in pressure dependency, it is hardly affected by gas intrusion from the outside, and is insulated for a long time. Performance can be maintained.

  Further, by providing the seal portion 10 with an uneven shape, the seal strength was very good. Although the vacuum heat insulating material 1 was left in an environment of 150 ° C., the jacket material was not melted.

  As described above, in the present embodiment, by employing an ultrasonic seal, the heat resistant resin can be used for the innermost layer, so that it can be used at a high temperature.

(Embodiment 2)
FIG. 3 is a cross-sectional view of the vacuum heat insulating material in Embodiment 2 of the present invention.

  As shown in FIG. 3, the vacuum heat insulating material 11 is obtained by covering the core material 13 with the jacket material 12 and reducing the pressure inside the jacket material 12.

  As the covering material 12, a resin to be used was selected on the assumption that the vacuum heat insulating material is used in an environment of 150 ° C. or higher. As the jacket material 12, laminate films having different structures were used for the front material and the back material, respectively.

  The front material uses fluororesin for the innermost layer 14, aluminum foil for the outer metal foil 15, and fluororesin for the outermost layer 16, and the backing material has a fluororesin vapor deposition surface 17 applied with aluminum vapor deposition. The combined structure is the innermost layer 18 and the outermost layer 19.

  The core material 13 is a molded body composed of dry silica and glass fibers. The vacuum heat insulating material 11 is obtained by inserting a core material 13 into a jacket material 12 that has been sealed in three directions with an ultrasonic seal in advance, and sealing with an ultrasonic seal in a vacuum.

  The heat conductivity of the vacuum heat insulating material 11 is 0.0055 W / mK at 24 ° C., and the core material 13 is excellent in pressure dependency. Thermal insulation performance can be maintained. Further, although the vacuum heat insulating material 11 was left in an environment of 150 ° C., the jacket material 12 was not melted. In addition to this, a combustion test of the vacuum heat insulating material 11 was performed, but combustion did not occur due to the use of the fluororesin.

  As described above, in the present embodiment, since the heat resistant resin can be used for the innermost layer, it can be used at a high temperature and also has the feature of flame retardancy due to the use of the fluororesin. I was able to.

(Embodiment 3)
FIG. 4 is a cross-sectional view of the vacuum heat insulating material in Embodiment 3 of the present invention.

  As shown in FIG. 4, the vacuum heat insulating material 20 is obtained by covering the core material 22 with the jacket material 21 and reducing the pressure inside the jacket material 21.

  As the jacket material 21, a resin to be used was selected on the assumption that the vacuum heat insulating material 20 is used in an environment where the high temperature side is 150 ° C. and the low temperature side is 100 ° C. or less. For the jacket material 21, laminated films having different structures were used for the front material and the back material, respectively.

  The front material uses polyethylene naphthalate for the innermost layer 23, aluminum foil for the outer layer metal foil 24, and polyethylene naphthalate for the outermost layer 25, and the backing material uses polyethylene terephthalate for the innermost layer 26 and metal foil 27. In addition, biaxially oriented polypropylene is used for the outermost layer 28.

  Moreover, the core material 22 puts dry silica in the inner bag comprised with a nonwoven fabric. The vacuum heat insulating material 20 is obtained by inserting a core material 22 into an outer cover material 21 that has been three-side sealed with an ultrasonic seal in advance and sealing it with an ultrasonic seal in a vacuum.

  The heat conductivity of this vacuum heat insulating material 20 is 24 ° C. and 0.0050 W / mK, and the core material 22 is excellent in pressure dependency. Heat insulation performance.

  In addition, polyethylene naphthalate was used for the innermost layer of the front material, but because polyethylene terephthalate was used for the innermost layer of the backing material, compared to the case where polyethylene naphthalate was used for the innermost layer of both the front material and the backing material. Cost reduction. Moreover, the melting point difference of these resins was 22 ° C. or less, and the sealing strength was also good.

(Embodiment 4)
FIG. 5 is a cross-sectional view of the vacuum heat insulating material in Embodiment 4 of the present invention.

  As shown in FIG. 5, the vacuum heat insulating material 29 is obtained by covering the core material 31 with the covering material 30 and reducing the pressure inside the covering material 30.

  As the jacket material 30, a resin to be used was selected on the assumption that the vacuum heat insulating material 29 is used in an environment of about 120 ° C. For the jacket material 30, a laminate film having the same structure as the front material and the back material was used. The outer covering material 30 uses polyvinylidene chloride for the innermost layer 32, aluminum foil for the metal foil 33 of the outer layer, and biaxially oriented polypropylene for the outermost layer 34.

  Moreover, the core material 31 puts dry silica in the inner bag comprised with a nonwoven fabric. The vacuum heat insulating material 29 is obtained by inserting a core material 31 and a moisture adsorbent into an outer cover material 30 that has been three-side sealed with a high-frequency seal in advance and sealing it with a high-frequency seal in a vacuum.

  The heat conductivity of the vacuum heat insulating material 29 is 0.0050 W / mK at 24 ° C., and the core material 31 is excellent in pressure dependency. However, since both the gas barrier property and the water vapor barrier property are excellent, the heat insulation performance can be maintained for a long time.

  As described above, since the vacuum heat insulating material according to the present invention has characteristics such as heat resistance and insulation, it has a high-temperature part such as a printing apparatus such as a copying machine or a laser printer, an electronic device such as a computer, a hot water supply device, or the like. It can also be applied to uses such as heat insulation and heat insulation of equipment, and uses that require flame retardancy.

Sectional drawing of the vacuum heat insulating material in Embodiment 1 of this invention The top view of the vacuum heat insulating material in Embodiment 1 of this invention Sectional drawing of the vacuum heat insulating material in Embodiment 2 of this invention Sectional drawing of the vacuum heat insulating material in Embodiment 3 of this invention Sectional drawing of the vacuum heat insulating material in Embodiment 4 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum heat insulating material 2 Outer coating material 3 Core material 4 Innermost layer 8 Innermost layer 10 Seal part 11 Vacuum heat insulating material 12 Outer coating material 13 Core material 14 Innermost layer 18 Innermost layer 20 Vacuum heat insulating material 21 Outer coating material 22 Core material 23 Outermost material Inner layer 24 Innermost layer 29 Vacuum heat insulating material 30 Outer sheath material 31 Core material 32 Innermost layer

Claims (15)

  An innermost layer comprising at least one of a surface material and a backing material of the outer cover material, comprising a core material and an outer cover material having at least a metal foil or a vapor-deposited resin film covering the core material. A vacuum heat insulating material that contains a resin having a melting point equal to or lower than that of the innermost layer in a layer other than the above, and is sealed with an ultrasonic seal or a high frequency seal.   2. The vacuum heat insulating material according to claim 1, wherein the resin other than the innermost layer is a resin having a melting point equal to or lower than the melting point of the innermost layer resin.   The vacuum heat insulating material according to claim 1 or 2, wherein the innermost layer and the outermost layer are the same resin.   The vacuum heat insulating material according to any one of claims 1 to 3, wherein the resin in the innermost layer is an amorphous resin.   The vacuum heat insulating material according to any one of claims 1 to 4, wherein the resin constituting the covering material is a flame retardant resin.   The vacuum heat insulating material according to any one of claims 1 to 5, wherein the innermost layer of the outer cover material and the innermost layer of the backing material are different resins.   The vacuum heat insulating material according to claim 6, wherein a difference in melting point between the outermost resin and the innermost resin of the outer cover is 22 ° C. or less.   The vacuum heat insulating material according to any one of claims 1 to 7, wherein the innermost layer is a vapor-deposited resin film.   8. The structure according to claim 1, wherein at least one of the surface material and the back material of the covering material is a structure using polyethylene naphthalate as the innermost layer, metal foil as the outer layer, and polyethylene naphthalate as the outermost layer. The vacuum heat insulating material according to one item.   The structure of at least one of the front material and the backing material of the outer cover material is a structure using a fluororesin for the innermost layer, a metal foil for the outer layer, and a fluororesin for the outermost layer. The vacuum heat insulating material described in 1.   9. The structure according to claim 1, wherein at least one of the surface material and the back material of the jacket material is a structure in which two metal naphthalates subjected to metal vapor deposition are used and the metal vapor deposition surfaces are bonded together. The vacuum heat insulating material according to item.   9. The structure according to claim 1, wherein at least one of the surface material and the back material of the outer cover material is a structure in which two metal-deposited fluororesins are used and a metal vapor-deposited surface is bonded. The vacuum heat insulating material described in 1.   The vacuum heat insulating material as described in any one of Claim 1 to 12 which has an uneven | corrugated shape in a seal part.   The vacuum heat insulating material according to any one of claims 1 to 13, wherein the core material is a powder mainly composed of dry silica.   The vacuum heat insulating material according to claim 14, wherein the powder mainly composed of dry silica is a molded body.

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