JP2006046512A - Heat insulating body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high performance vacuum heat insulating body having improved heat insulating performance by using adsorbing materials for reducing pressure in the vacuum heat insulating body, maintaining the pressure and effectively adsorbing nitrogen of small solid heat conduction and low reactivity when applied to the heat insulating body. <P>SOLUTION: The heat insulating body 4 comprises a core material 5, a gas adsorbing material 7 consisting of a nitrogen adsorptive metal and a nitrogen adsorbing film manufactured of a high polymer with simultaneous adsorption, a moisture adsorbing material 8, an oxygen adsorbing material 9, and a gas barrier shell material 6 depressurized for covering all of these. The used core material 5 is an inorganic fiber assembly and the used shell material 6 is a laminate film which consists of a surface protecting layer, a gas barrier layer and a thermally welded layer. The nitrogen adsorbing film adsorbs and removes nitrogen which cannot be removed in an industrial evacuation process. As a result, the heat insulating body 4 has improved heat insulating performance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat insulator including a gas adsorbent.

  In recent years, energy saving is desired because of the importance of preventing global warming, which is a global environmental problem, and energy saving is also promoted for consumer devices. In particular, in a heat and cold insulation device such as a refrigerator, a freezer, or a vending machine, a heat insulating material having excellent heat insulating performance is required from the viewpoint of efficiently using heat.

  As a means for solving such a problem, there is a vacuum heat insulating body constituted by a core material that holds a space and a jacket material that blocks the space and the outside air. In general, a powder material, a fiber material, a continuous foam, or the like is used as the core material.

  For example, as a vacuum heat insulating material often used in refrigerators and the like, there is a vacuum heat insulating panel, and the vacuum heat insulating panel covers a core material using an inorganic fiber aggregate with a gas barrier metal-plastic laminate film or the like, The inside is evacuated and then packed into a panel.

  When this is used for a heat-insulating box such as a refrigerator, it is affixed to the inner surface of the container material of the box, and further has a double structure in which a foamed urethane resin is injected and foam-molded. In recent years, demands for vacuum insulators such as refrigerators have been diversified, and higher performance vacuum insulators have been demanded.

  In the case where heat conduction is performed through the presence of air, there is a mean free path of gas as a physical property that affects the heat insulation performance. The mean free path of a gas is the distance traveled by one of the molecules that make up the air before colliding with another molecule. If the void formed is larger than the mean free path, Since the molecules collide with each other and heat conduction by gas occurs, the thermal conductivity increases.

  The heat insulation principle of a vacuum heat insulator is to eliminate as much air as possible to transfer heat and reduce heat conduction by gas. On the other hand, when the void is smaller than the mean free path, the thermal conductivity is small. This is because there is almost no heat conduction due to air collision.

  Therefore, in order to maintain the performance of the vacuum insulator for a long period of time, the initial internal pressure needs to be lower. However, it is difficult to make a high vacuum at an industrial level, and the degree of vacuum that can be achieved practically is up to about 13.3 Pa.

  Moreover, the gas generated from the inside of the vacuum heat insulator or the gas that permeates and enters the vacuum heat insulator from the outside becomes a factor that causes deterioration of the heat insulation performance of the vacuum heat insulator over time. In particular, nitrogen, which is the most abundant in air, is poorly reactive and is a non-polar molecule, so it is difficult to remove it with a physical adsorbent such as activated carbon at low pressure. is there.

  On the other hand, hydrogen contained in a trace amount in the air can pass through any outer jacket material and penetrate into the vacuum insulator, and since it has a low molecular weight, it has a small amount of gas because of its high thermal conductivity. However, its presence is a factor that deteriorates the heat insulation performance.

  As means for solving such problems, there are metal-based adsorbents called nitrogen storage alloys and nitrogen getter materials. For example, what are called nitrogen getter materials include 70% Zr-15% V-3.3% Fe-8 and 69% Zr-2.6% V-0.6% Fe-24.8% Mn-3. There are alloys having a composition of% Mm (Mm: Misch metal), and these are installed in the heat insulation space where the temperature is highest and used for maintaining the degree of vacuum (see Patent Document 1).

Examples of nitrogen storage alloys include NdFe ₇ and CeO ₂ —Fe (see Patent Document 2).

  In addition, there has been proposed a getter including a mixture of a transition metal oxide selected from cobalt oxide, copper oxide or a mixture thereof and metal palladium as a hydrogen adsorbent (see Patent Document 3).

  In addition, a method of adsorbing hydrogen using a composite material in which a coating containing metal palladium, palladium oxide, and silver is applied to the surface of the getter material has been proposed (see Patent Document 4).

Further, it has been proposed that oxygen, nitrogen, and hydrogen can be adsorbed by a gas adsorbent containing a spherical carbon material such as C60 or C70 in addition to a metal system (see Patent Document 5).
Special table 2003-535218 gazette JP 2000-247613 A Japanese Patent Laid-Open No. 9-47652 Special table 2003-501556 gazette Special table 2003-514653 gazette

  However, in the gas adsorbent using the nitrogen getter material having the configurations of Patent Document 1 and Patent Document 2, the gas adsorbent is installed at the highest temperature in the heat insulating space in order to increase the reaction rate as much as possible. Since the nitrogen getter material itself is a metal material, the solid heat conductivity is high, and therefore the heat conduction is increased.

  Further, the nitrogen molecule has a triple bond and is very difficult to cleave due to a very large bond energy of about 940 kJ / mol. In many nitrogen getter materials and nitrogen storage alloys, the nitrogen molecule is cleaved. Therefore, Fe is mixed, but still a high temperature of several hundred degrees is necessary to quickly adsorb nitrogen.

  Therefore, in order to obtain a sufficient nitrogen adsorption rate at a low temperature of 100 ° C. or lower, it is necessary to increase the amount of nitrogen getter material used, and as a result, the solid thermal conductivity of the portion where the adsorbent material is disposed is significantly increased. However, there exists a subject that the heat insulation performance of a heat insulating body deteriorates.

  In the configurations of Patent Document 3 and Patent Document 4, since the gas adsorbent is a mixture of a metal oxide and a metal, the gas adsorbent itself has a high thermal conductivity, and by applying many gas adsorbents. As a result, a portion where the heat insulation performance deteriorates is generated.

  Further, in the configuration of Patent Document 5, since the gas adsorbent is a spherical carbon material such as C60 or C70, in a spherical structure in which a 5-membered ring and a 6-membered ring formed by carbon-carbon bonds are combined and closed, A large amount of gas adsorption is difficult.

  An object of the present invention is a heat insulator provided with a gas adsorbent that reduces the internal pressure of the heat insulator and maintains the pressure, and particularly has low reactivity and is difficult to remove by adsorption, or An object of the present invention is to provide a heat insulator having excellent heat insulation performance using a gas adsorbent capable of quickly adsorbing hydrogen that passes through any jacket material.

  It is another object of the present invention to provide a heat insulator with excellent heat insulation performance in which the deterioration of solid thermal conductivity is reduced by reducing the amount of metal material used. Another object of the present invention is to provide a high-performance heat insulator having a further excellent heat insulating performance by reducing the gap diameter of the core material.

  In order to achieve the above object, the heat insulating body of the present invention is a heat insulating body formed by covering a core material and a gas adsorbing material with a gas barrier outer covering material and depressurizing the inside of the outer covering material. The adsorbent includes at least a nitrogen adsorbing film produced by a co-evaporation method in which a nitrogen adsorbing metal and a polymer are vapor-deposited simultaneously.

  As a result, the nitrogen-adsorbing metal is dispersed as fine particles in the nitrogen-adsorbing film, has a high surface area and high catalytic activity, and is fixed in the polymer, thereby improving the handleability and the deposited nitrogen adsorption. The active metal is highly active without activation treatment, and therefore adsorbs residual nitrogen that cannot be removed by the industrial vacuum exhaust process and nitrogen that enters from the outside over time, and has high performance. Insulation can be provided.

  Further, the nitrogen-adsorbing metal is dispersed in the polymer, and can be handled in the atmosphere without losing activity for a short time. Moreover, since it is not necessary to perform the activation process at high temperature, it can carry | support also to the jacket material with low heat resistance. Furthermore, since the polymer serves as a base material, the solid thermal conductivity of the gas adsorbent is greatly reduced.

  Moreover, the heat insulating body of the present invention is characterized in that the nitrogen-adsorbing metal is a single nanoparticle.

  The nitrogen adsorbing film produced by the co-evaporation method has a single nanosize with nitrogen adsorbing metal particles of 10 nanometers or less, so that it has a unique catalytic ability due to the particle size effect, and mechanical grinding such as ball mill Compared with micrometer-sized particles obtained by the method, the catalytic activity is remarkably improved.

  In addition, the reaction rate increases as the surface area of the gas adsorbent increases significantly. Thereby, even at a low temperature of 100 degrees or less, a small amount of nitrogen-adsorbing metal has sufficient catalytic activity and reaction rate, the amount of nitrogen-adsorbing metal used can be greatly reduced, and the solid thermal conductivity is greatly reduced. It is done. Furthermore, since the crystal size is very small, heat conduction by phonons is reduced, and the solid thermal conductivity of the gas adsorbent can be further greatly reduced.

  The heat insulator of the present invention is characterized by having a mesoporous structure as a core material.

  Thereby, the high performance heat insulating body which has the further outstanding heat insulation performance can be provided by reducing the space | gap diameter of a core material.

  The heat insulator of the present invention includes a nitrogen adsorbing film prepared by a co-evaporation method in which a nitrogen adsorbing metal and a polymer are simultaneously deposited as a gas adsorbing material, thereby reducing the solid heat conduction of the gas adsorbing material and It is possible to adsorb residual gas in the heat insulating material, gas generated from the core material, and gas that enters from the outside over time, particularly nitrogen with low activity and hydrogen that passes through any jacket material. By adsorbing residual nitrogen that cannot be removed by the industrial vacuum exhaust process, nitrogen that enters from the outside over time, and hydrogen that passes through any jacket material, it is possible to improve heat insulation performance Can do.

  Moreover, the heat insulating body of this invention can reduce the space | gap diameter of a core material by having a mesoporous structure as a core material, and can provide the high-performance heat insulating body which has the further outstanding heat insulation performance.

  The invention of the heat insulator according to claim 1 is a heat insulator formed by covering the core material and the gas adsorbing material with a gas barrier outer covering material and decompressing the inside of the outer covering material. , Which includes at least a nitrogen-adsorbing film produced by a co-evaporation method in which a nitrogen-adsorbing metal and a polymer are vapor-deposited at the same time. In addition, the handleability is increased by being fixed in the polymer, and the deposited nitrogen-adsorbing metal has high activity without performing the activation treatment. Residual nitrogen that cannot be removed or nitrogen that enters from the outside over time can be adsorbed to improve the heat insulation performance of the heat insulator.

  Furthermore, it is dispersed in the polymer, and for a short time, contact with oxygen, which is a major cause of losing activity, is suppressed, and it can be handled in the atmosphere without losing activity.

  Further, since it is not necessary to carry out the activation treatment at a high temperature, the nitrogen adsorption film can also be carried on the jacket material having low heat resistance.

  In addition, since the polymer of the nitrogen adsorption film is a base material, the solid thermal conductivity of the gas adsorbent is greatly reduced.

  Further, the nitrogen-adsorbing metal indicates an alkali metal, an alkaline earth metal, a rare earth element, or a transition element, and may contain any of these, and may be a mixture or a compound.

  In addition, the polymer is not particularly specified, but it needs to have a gas permeation rate faster than the nitrogen penetration rate from the outside into the heat insulating body. Moreover, as long as it is a laminate film composed of a surface protective layer, a gas barrier layer, and a heat welding layer, the heat welding layer may be made of a nitrogen adsorption film.

  The gas adsorbent is composed of a nitrogen adsorbent film and other gas adsorbents, such as a known one, in order to adsorb gases other than nitrogen, such as oxygen, hydrogen, carbon dioxide, water, and carbon monoxide. It is also possible to hybridize with a chemical adsorbent or a physical adsorbent. The composition ratio can be selected depending on the use environment and the type of internally generated gas.

  In addition, as the jacket material in the present invention, a material having a gas barrier property can be used. Various materials and composite materials that can inhibit gas intrusion can be used, such as laminated films.

  In addition, as the core material in the present invention, open cells of polymer materials such as polystyrene and polyurethane, open cells of inorganic materials, inorganic and organic powders, inorganic and organic fiber materials, and the like can be used. A mixture thereof may also be used.

  The invention of claim 2 is a heat insulating body according to claim 1, wherein the nitrogen adsorbing metal in the invention of claim 1 is a single nanoparticle, and the nitrogen adsorbing metal comprising a single nanoparticle has a particle size effect. Due to the peculiar catalytic activity and extremely large surface area, the nitrogen occlusion rate is remarkably large even at a low temperature of 100 ° C or less, and a small amount of nitrogen-adsorbing metal cannot be removed by an industrial vacuum exhaust process. It can adsorb nitrogen entering from outside and supply high-performance insulation. Furthermore, since the activity is large and the effect is obtained with a small amount of nitrogen-adsorbing metal having a large solid thermal conductivity, the solid thermal conductivity of the gas adsorbent can be reduced. Furthermore, since the solid thermal conductivity due to phonons is reduced due to the ultrafine particles, the solid thermal conductivity of the gas adsorbent itself can be reduced, and as a result, the thermal insulation performance of the thermal insulator can be improved.

  According to a third aspect of the present invention, the gas adsorbent in the first aspect of the invention includes at least a hydrogen adsorption film produced by a co-evaporation method in which a hydrogen adsorbing metal and a polymer are simultaneously deposited. The hydrogen-adsorbing metal is dispersed as fine particles in the hydrogen-adsorbing film, has a high surface area and a high catalytic activity, and is fixed in a polymer, so that the handleability is increased, and the deposited nitrogen Since the adsorptive metal has a high degree of activity without performing an activation treatment, it adsorbs hydrogen that passes through any jacket material and enters from the outside over time, thereby improving the heat insulation performance of the heat insulator. be able to.

  In addition, since the hydrogen adsorption film is made of a polymer, the solid thermal conductivity of the gas adsorbent is greatly reduced.

  Further, the hydrogen-adsorbing metal indicates alkali metal, alkaline earth metal, rare earth element, group 4 element, group 5 element, palladium, and any material may be used as long as it contains these, and may be a mixture or a compound. .

  In addition, the polymer is not particularly specified, but the heat welding layer may be made of a hydrogen adsorption film as long as it is a laminate film composed of a surface protective layer, a gas barrier layer, and a heat welding layer.

  Further, the gas adsorbent is composed of a hydrogen adsorbent film and other gas adsorbents, for example, a known one, in order to adsorb gases other than hydrogen, such as oxygen, nitrogen, carbon dioxide, water, and carbon monoxide It is also possible to hybridize with a chemical adsorbent or a physical adsorbent. The composition ratio can be selected depending on the use environment and the type of internally generated gas.

  According to a fourth aspect of the invention, the hydrogen-adsorbing metal in the invention according to the third aspect is a single nanoparticle, and the hydrogen-adsorbing metal comprising a single nanoparticle has a particle size effect. Due to its unique catalytic activity and extremely large surface area, the hydrogen storage rate is extremely large even at low temperatures of 100 degrees or less, and it passes through any jacket material with a small amount of hydrogen-adsorbing metal, and penetrates from the outside over time. Adsorbs incoming hydrogen and supplies high-performance insulation.

  Furthermore, since the activity is large and the effect is obtained with a small amount of the hydrogen-adsorbing metal having a large solid thermal conductivity, the solid thermal conductivity of the gas adsorbent can be reduced. Furthermore, since the solid thermal conductivity due to phonons is reduced due to the ultrafine particles, the solid thermal conductivity of the gas adsorbent itself can be reduced, and as a result, the thermal insulation performance of the thermal insulator can be improved.

  According to a fifth aspect of the present invention, the core material according to any one of the first to fourth aspects has a mesoporous structure, and the gas adsorbent is industrial. Adsorbs residual nitrogen that cannot be removed by the evacuation process, nitrogen that enters from the outside over time, or hydrogen that passes through any jacket material and enters from the outside over time. While the heat insulation performance of the heat insulator can be improved, since the void diameter of the core material is in the range of 2 to 50 nm, the void is smaller than the mean free path. As a result, it is also removed by the gas adsorbent. This makes it possible to further reduce the gas heat conduction of the residual gas that has not been completely removed.

  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 schematic diagram of a nitrogen adsorption film 1 according to Embodiment 1 of the present invention.

  In FIG. 1, a nitrogen adsorbing film 1 is produced by simultaneous vapor deposition of a nitrogen adsorbing metal 2 and a polymer 3, and the nitrogen adsorbing metal 2 is taken into the polymer 3 as fine particles of 10 nanometers or less. It is.

  FIG. 2 is a cross-sectional view of a heat insulator to which the gas adsorbent 7 made of the nitrogen adsorption film 1 according to Embodiment 1 of the present invention is applied.

  In FIG. 2, the heat insulator 4 includes a gas adsorbent 7, a moisture adsorbent 8, and an oxygen adsorbent 9 made of a core material 5 and a nitrogen adsorbing film 1 covered with a gas barrier outer covering 6. And a laminated film composed of an inorganic fiber aggregate as the core material 5 and a surface protective layer, a gas barrier layer, and a heat-welded layer as the jacket material 6 is used as an industrial material. Nitrogen adsorption film adsorbs and removes nitrogen that cannot be removed by the evacuation process, and as a result, the heat insulation performance of the heat insulator 4 can be improved.

  Example 1 to Example 4 show the results of gas adsorption evaluation in a heat insulator to which a gas adsorbent with a different type of nitrogen storage metal is applied. In Examples 1 to 4, calcium oxide was used as the moisture adsorbing material, and an iron-based deoxidizing material was used as the oxygen adsorbing material. In all the evaluations, the initial internal pressure was set to 13 Pa, and the subsequent increase in internal pressure over time was compared with the heat insulating body of Comparative Example 1.

Example 1
Nitrogen-adsorptive metal consisting of NdFe ₇ is co-deposited with polyethylene as a gas adsorbent, and the produced nitrogen adsorbent film is attached to the inside of the jacket material, calcium oxide as the moisture adsorbent, and iron-based oxygen adsorption as the oxygen adsorbent A heat insulator using the material was produced.

  The internal pressure after one month with time is 16 Pa, and there is little deterioration over time as compared with Comparative Example 1. This is thought to be because the nitrogen-adsorbing metal maintains its activity and rapidly adsorbs nitrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

(Example 2)
As a gas adsorbent, a nitrogen-adsorbing metal composed of Sm ₂ Fe ₁₇ is co-deposited with polyethylene, and the produced nitrogen adsorbing film is pasted on the inner side of the jacket material, calcium oxide as the moisture adsorbent, and iron-based oxygen as the oxygen adsorbent. A heat insulator using an adsorbent was prepared.

  The internal pressure after one month with time is 18 Pa, and there is little deterioration over time as compared with Comparative Example 1. This is thought to be because the nitrogen-adsorbing metal maintains its activity and rapidly adsorbs nitrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

(Example 3)
A nitrogen-adsorbing metal composed of LaNi _4.5 Fe _0.5 is co-deposited with polyethylene as a gas adsorbing material, and the produced nitrogen-adsorbing film is attached to the inside of the jacket material, calcium oxide as the moisture adsorbing material, and iron-based oxygen as the oxygen adsorbing material A heat insulator using an adsorbent was prepared.

  The internal pressure after one month with time is 17 Pa, and deterioration with time is small as compared with Comparative Example 1. This is thought to be because the nitrogen-adsorbing metal maintains its activity and rapidly adsorbs nitrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

Example 4
As a gas adsorbent, a nitrogen-adsorbing metal composed of Zr _0.7 V _0.15 Fe _0.15 is co-deposited with polyethylene, and the produced nitrogen adsorbing film is attached to the inner side of the outer jacket material, and calcium oxide is used as a moisture adsorbing material, and iron is used as an oxygen adsorbing material. A heat insulator using a system oxygen adsorbent was prepared.

  The internal pressure after one month with time is 17 Pa, and deterioration with time is small as compared with Comparative Example 1. This is thought to be because the nitrogen-adsorbing metal maintains its activity and rapidly adsorbs nitrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

(Embodiment 2)
FIG. 3 is a schematic diagram of the hydrogen adsorption film 10 according to Embodiment 2 of the present invention.

  In FIG. 3, a hydrogen adsorption film 10 is formed by simultaneously depositing a hydrogen adsorbing metal 11 and a polymer 12, and the hydrogen adsorbing metal 11 is taken into the polymer 12 as fine particles of 10 nanometers or less. It is.

  FIG. 4 is a cross-sectional view of a heat insulator 14 to which a gas adsorbent 13 made of the hydrogen adsorption film 10 according to Embodiment 2 of the present invention is applied.

  In FIG. 4, the heat insulator 14 covers the gas adsorbent 13, the moisture adsorbent 8, and the oxygen adsorbent 9 made up of the core material 5 and the hydrogen adsorbing film 10 with a gas barrier outer covering 6 and the inside of the outer covering 6. The pressure is reduced. The core material 5 and the jacket material 6 are the same as those in the first embodiment.

  As a result, the hydrogen adsorption film 10 absorbs and removes hydrogen that cannot be removed by the industrial vacuum exhaust process and hydrogen that passes through the outer cover material 6 and enters from the outside. As a result, the heat insulation performance of the heat insulator 14 is improved. Can be planned.

  The evaluation results of the gas adsorption in the heat insulator to which the gas adsorbent in which the kind of the hydrogen storage metal is changed are shown in Examples 5 to 7. In Examples 5 to 7, calcium oxide was used as the moisture adsorbing material, and Ba—Li alloy was used as the nitrogen and oxygen adsorbing materials. In all the evaluations, the initial internal pressure was 13 Pa, and the subsequent increase in internal pressure over time was compared with that of the heat insulating body of Comparative Example 2.

(Example 5)
As a gas adsorbent, a hydrogen-adsorbing metal composed of La is co-deposited with polyethylene, and the produced hydrogen-adsorbing film is attached to a heat-welded layer, calcium oxide as a moisture adsorbent, and Ba-Li alloy as a nitrogen / oxygen adsorbent. The heat insulator used was produced.

  The internal pressure after one month with time was 22 Pa, and the deterioration with time was almost the same as in Comparative Example 2. This is thought to be because the hydrogen-adsorbing metal maintains its activity and rapidly adsorbs hydrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

(Example 6)
As a gas adsorbent, a hydrogen-adsorbing metal composed of ZrNi ₂ is co-deposited with polyethylene, and the produced hydrogen adsorbing film is attached to a heat-welded layer, calcium oxide as a moisture adsorbing material, and Ba-Li alloy as a nitrogen / oxygen adsorbing material. A heat insulator using was manufactured.

  The internal pressure after one month with time is 21 Pa, and the deterioration with time is almost the same as in Comparative Example 2. This is thought to be because the hydrogen-adsorbing metal maintains its activity and rapidly adsorbs hydrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

(Example 7)
As a gas adsorbent, a hydrogen-adsorbing metal composed of MgNi ₂ is co-deposited with polyethylene, and the produced hydrogen adsorbing film is attached to the heat-welded layer, calcium oxide as the moisture adsorbing material, and Ba—Li alloy as the nitrogen / oxygen adsorbing material. A heat insulator using was manufactured.

  The internal pressure after one month with time is 20 Pa, and the deterioration with time is almost the same as that of Comparative Example 2. This is thought to be because the hydrogen-adsorbing metal maintains its activity and rapidly adsorbs hydrogen that permeates and penetrates the jacket material due to its high surface area and high catalytic activity.

(Embodiment 3)
FIG. 5 is a cross-sectional view of the heat insulator 15 to which the gas adsorbent 7 made of the nitrogen adsorbing film 1 is applied in Embodiment 3 of the present invention.

  The heat insulator 15 is formed by covering the core material 5 and the gas adsorbing material 7 made of the nitrogen adsorbing film 1 with a gas barrier outer covering material 6 and reducing the pressure inside the outer covering material 6. The core material 5 and the jacket material 6 are the same as those in the first embodiment.

  The evaluation result of the heat insulation performance in the heat insulating body to which the gas adsorbent used in Example 1 is applied as the nitrogen adsorbing metal is shown in Example 8. Evaluation measured the thermal conductivity of the site | part containing an adsorbent, and compared with the heat insulating body of the comparative example 3. FIG.

(Example 8)
As a gas adsorbent, a nitrogen adsorbing metal composed of NdFe ₇ was co-evaporated with polyethylene, and a heat insulator was produced using the produced nitrogen adsorbing film. The thermal conductivity of the portion including the gas adsorbent is 0.0027 W / mK, which is smaller than that of Comparative Example 3. This is because the nitrogen adsorbing film in which the nitrogen adsorbing metal is highly dispersed is used in the gas adsorbing material, so that the adsorbent itself has a low thermal conductivity because the metal adsorbing effect is exhibited with a small amount of metal components. .

(Embodiment 4)
FIG. 6 is a cross-sectional view of the heat insulator 16 to which the gas adsorbent 13 made of the hydrogen adsorption film 10 is applied in Embodiment 4 of the present invention.

  The heat insulator 16 is formed by covering the core material 5 and the gas adsorbing material 13 made of the hydrogen adsorbing film 10 with a gas barrier covering material 6 and reducing the pressure inside the covering material 6. The core material 5 and the jacket material 6 are the same as those in the first embodiment.

  Example 9 shows the evaluation results of the heat insulating performance of the heat insulating body to which the gas adsorbent used in Example 5 is applied as the hydrogen adsorbing metal. Evaluation measured the thermal conductivity of the site | part containing an adsorbent, and compared with the heat insulating body of the comparative example 4.

Example 9
As a gas adsorbent, a heat insulating body was manufactured using a nitrogen adsorbing film prepared by co-depositing a hydrogen-adsorbing metal made of La with polyethylene. The thermal conductivity of the part including the gas adsorbent is 0.0026 W / mK, which is smaller than that of Comparative Example 4. This is because the hydrogen adsorbing film in which the hydrogen adsorbing metal is highly dispersed is used in the gas adsorbing material, so that the heat conductivity of the adsorbing material itself is reduced because the metal adsorbing effect is exhibited even with a small amount of metal components. .

(Embodiment 5)
FIG. 7 is a cross-sectional view of a heat insulator 17 to which the gas adsorbent 7 made of the nitrogen adsorption film 1 is applied in the fifth embodiment of the present invention.

  The heat insulator 17 is formed by covering the core material 18 having a mesoporous structure and the gas adsorbent 7 composed of the nitrogen adsorbing film 1 with a gas barrier outer sheath material 6 and reducing the pressure inside the outer sheath material 6. Gas adsorption of a mesoporous material obtained by compression-molding silica powder produced by a vapor phase method as the core material 18 and a laminate film composed of a surface protective layer, a gas barrier layer, and a heat-welded layer as the jacket material 6 As the material 7, the gas adsorbent 7 of Embodiment 1 is used, and the nitrogen adsorbing film 1 adsorbs nitrogen that cannot be removed by the industrial vacuum exhaust process and nitrogen that enters from the outside over time. As a result, the heat insulation performance of the heat insulator 17 can be improved.

  Moreover, since the void diameter of the core material 18 is in the range of 2 to 50 nm, the void is smaller than the mean free path. Since it can suppress, the heat insulating body which has the outstanding heat insulation performance can be provided.

(Embodiment 6)
FIG. 8 shows a sectional view of a heat insulator 19 to which the gas adsorbent 7 made of the nitrogen adsorbing film 1 is applied in the sixth embodiment of the present invention.

  The heat insulator 19 is formed by covering the core material 5 and the gas adsorbing material 7 that adsorbs gas with the gas barrier outer material 20 and reducing the pressure inside the outer material 20. The body is made of stainless steel as the jacket material 20 and the gas adsorbing material 7 of the first embodiment is used as the gas adsorbing material 7 and can be removed by an industrial vacuum exhaust process. The nitrogen adsorbing film absorbs and removes no nitrogen, and as a result, the heat insulating performance of the heat insulating body 19 can be improved.

  Next, the comparative example with respect to the gas adsorbent of this invention and a heat insulating body is shown. The evaluation method shall be in accordance with the example.

(Comparative Example 1)
As an adsorbent, calcium oxide and Zr _0.7 V _0.15 Fe _0.15 alloy were pelletized, and an iron-based deoxidation material was used as an oxygen adsorbent to produce a heat insulator. The internal pressure after 1 month was 22 Pa.

(Comparative Example 2)
As an adsorbent, calcium oxide, Ba-Li alloy, and cobalt oxide were pelletized to produce a heat insulator. The internal pressure after 1 month was 23 Pa.

(Comparative Example 3)
A heat insulator was produced using Zr _0.7 V _0.15 Fe _0.15 alloy as the adsorbent. The thermal conductivity of the part including the adsorbent was 0.0064 W / mK.

(Comparative Example 4)
A heat insulator was produced using cobalt oxide as an adsorbent. The thermal conductivity of the part including the adsorbent was 0.0054 W / mK.

  The heat insulator according to the present invention is capable of adsorbing gas in a vacuum heat insulating material, particularly nitrogen having particularly low reactivity, thereby improving heat insulation performance and capable of expressing excellent heat insulation performance. Therefore, it can be applied to various heat insulation applications such as a refrigerator / freezer and a heating / cooling apparatus such as a refrigeration apparatus and a physical object to be protected from heat and cold.

The schematic diagram of the nitrogen adsorption film of the heat insulating body in Embodiment 1 of this invention Sectional drawing of the heat insulating body in Embodiment 1 of this invention The schematic diagram of the hydrogen adsorption film of the heat insulating body in Embodiment 2 of this invention Sectional drawing of the heat insulating body in Embodiment 2 of this invention Sectional drawing of the heat insulating body in Embodiment 3 of this invention Sectional drawing of the heat insulating body in Embodiment 4 of this invention Sectional drawing of the heat insulating body in Embodiment 5 of this invention Sectional drawing of the heat insulating body in Embodiment 6 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nitrogen adsorption film 2 Nitrogen adsorption metal 3 Polymer 4 Heat insulator 5 Core material 6 Cover material 7 Gas adsorption material 8 Moisture adsorption material 9 Oxygen adsorption material 10 Hydrogen adsorption film 11 Hydrogen adsorption metal 12 Polymer 13 Gas adsorption material DESCRIPTION OF SYMBOLS 14 Heat insulator 15 Heat insulator 16 Heat insulator 17 Heat insulator 18 Core material which has mesoporous structure 19 Heat insulator 20 Jacket | cover material

Claims (5)

  A heat insulator formed by covering a core material and a gas adsorbing material with a gas barrier outer covering material and depressurizing the inside of the outer covering material, wherein the gas adsorbing material includes at least a nitrogen adsorbing metal and a polymer at the same time. A thermal insulator comprising a nitrogen adsorption film produced by a co-evaporation method for vapor deposition.   The heat insulating body according to claim 1, wherein the nitrogen-adsorbing metal is a single nanoparticle.   The heat insulator according to claim 1, wherein the gas adsorbent includes at least a hydrogen adsorbing film produced by a co-evaporation method in which a hydrogen adsorbing metal and a polymer are vapor-deposited simultaneously.   The heat insulator according to claim 3, wherein the hydrogen-adsorbing metal is a single nanoparticle.   The heat insulating body according to any one of claims 1 to 4, wherein the core member has a mesoporous structure.

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