JP2009138890A - Heat insulating body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat insulating body with a gas adsorbing material which is more inexpensive than conventional one and can adsorb a great capacity of gas under room-temperature ordinary pressure or room-temperature reduced pressure, having improved heat insulating performance. <P>SOLUTION: The heat insulating body 6 comprises a core material 7, a shell material 8 having gas barrier property and covering the core material 7, and the gas adsorbing material 1 covered with the shell material 8 together with the core material 7, the shell material 8 being internally depressurized. The gas adsorbing material 1 contains at least ZSM-5 type zeolite subjected to copper ion exchange at an ion exchange rate of 100-200% and a moisture adsorptive material. In the copper ion exchange process for the ZSM-5 type zeolite, the copper ion exchange is performed in batches and the amount of copper ion containing ion exchange solution is 50-200 ml per 1 g of the ZSM-5 type zeolite before subjected to the copper ion exchange. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat insulating body in which a core material and a gas adsorbing material are covered with a jacket material having gas barrier properties, and the inside of the jacket material is decompressed.

  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, with respect to a refrigerator-freezer, a heat insulator having excellent heat insulating properties is required from the viewpoint of efficiently using cold 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 outside air. In general, powder materials, fiber materials, continuous foams, etc. are used as the core material, but in recent years, the demand for vacuum insulators has been diversified, and higher performance vacuum insulators. Is required.

  The heat insulation principle of the vacuum heat insulator is to eliminate air that conducts heat as much as possible and reduce heat conduction by gas. Therefore, in order to improve the heat insulating performance of the vacuum heat insulating body, it is necessary to set the internal pressure to a lower pressure and suppress gas heat conduction due to collision of molecules. However, the degree of vacuum practically achievable at an industrial level is about 0.1 torr, and it is difficult to achieve a higher vacuum.

  In addition, gas generated from the inside of the vacuum heat insulator and air components that permeate into the vacuum heat insulator from the outside with time also cause deterioration of the heat insulation performance of the vacuum heat insulator over time. Therefore, by adsorbing and removing these gases, that is, nitrogen, oxygen, moisture, and hydrogen in the air, it is possible to improve the initial heat insulation performance and maintain the heat insulation performance over time.

  Further, since adsorption of these gases is required to be irreversible, physical adsorption is unsuitable, and chemical adsorption that forms stronger bonds is desirable. However, nitrogen, which accounts for 80% of air, has a stable triple bond and is therefore very difficult to chemisorb.

  For example, there is a ternary alloy getter material made of zirconium, vanadium, and tungsten to remove nitrogen or hydrocarbons from a rare gas (see, for example, Patent Document 1).

  The ternary alloy removes impurities such as nitrogen from a rare gas by contacting with a rare gas containing a small amount of impurities at a temperature of 100 to 600 ° C.

  Further, as the non-evaporable getter alloy having high gas adsorption efficiency with respect to nitrogen, there is an alloy containing one element of rare earth elements such as zirconium, iron, manganese, yttrium, and lanthanum (see, for example, Patent Document 2). .

  The non-evaporable getter alloy having high gas adsorption efficiency with respect to the nitrogen described above is activated against adsorption of hydrogen, hydrocarbons, nitrogen, etc. by performing activation treatment at a temperature between 300-500 ° C. for 10-20 minutes. Thus, it can act even at room temperature.

  An alloy that removes nitrogen at a low temperature is a Ba-Li alloy (see, for example, Patent Document 3).

  The Ba-Li alloy is used together with the desiccant as a device to maintain a vacuum in the insulation jacket and is reactive to gases such as nitrogen even at room temperature.

  In addition, as a method for removing impurity gas such as nitrogen from the gas to be purified, there is a gas adsorbent made of ZMS-5 type zeolite subjected to copper ion exchange (for example, see Patent Document 4).

  This imparts nitrogen adsorption activity by introducing copper ions into the ZMS-5 type zeolite by conventional ion exchange methods and performing heat treatment.

Patent Document 4 states that the copper ion exchange amount can be adjusted to a desired amount by selecting the concentration of copper salt at the time of ion exchange, the immersion time, the immersion temperature, the number of immersions, that is, the number of ion exchanges, and the like. It is written. The maximum nitrogen adsorption amount at an equilibrium pressure of 10 Pa is 0.238 mol / kg (5.33 cc / g). The conditions at this time are as follows: the concentration of copper salt is 0.01M, the immersion time is 1 hour, and the immersion temperature is Is described in Patent Document 4 as 90 ° C. Although the number of ion exchanges is not specified in Patent Document 4, since the ion exchange rate is increased by increasing the number of ion exchanges, it is suggested that the ion exchange is performed at least three times.
JP-A-6-135707 Special table 2003-535218 gazette Japanese National Patent Publication No. 9-512088 JP 2003-31148 A

  However, in the gas adsorbent described in Patent Document 1, it is necessary to continue heating at 300 to 500 ° C., and since heating is performed at a high temperature, the energy cost is large and the environment is bad. Moreover, it cannot be used when gas adsorption at a low temperature is desired.

  Further, the gas adsorbent described in Patent Document 2 requires pretreatment at 300 to 500 ° C., and gas removal when pretreatment at high temperature is difficult, for example, gas in a plastic bag is removed at room temperature. It is difficult.

  In addition, the gas adsorbent described in Patent Document 3 does not require heat treatment for activation and can adsorb nitrogen at room temperature. However, it reacts with moisture, nitrogen, etc. in the air during handling. There's a problem.

  And since it is an irreversible reaction once it reacts, how to maintain activity until it is necessary is a problem. Moreover, since it is an alloy material, the heat conductivity of the getter itself is high, and the part where heat insulation performance deteriorates will arise by applying a getter.

  Further, a further increase in capacity for nitrogen adsorption is desired, and since Ba is a PRTR-designated substance, it is desired to have no problem for the environment and human body for industrial use.

  Moreover, in the gas adsorbent described in Patent Document 4, gas such as nitrogen can be adsorbed at room temperature. However, since the ZSM-5 type zeolite subjected to the copper ion exchange is expensive, an adsorbent that is cheaper and / or has a large adsorption capacity per unit weight is required for wide industrial use.

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide a high-performance heat insulator provided with a gas adsorbent capable of adsorbing a large volume of gas even at room temperature and normal pressure or at room temperature and reduced pressure. To do.

  In order to achieve the above object, the heat insulator of the present invention comprises at least a core material, a jacket material having gas barrier properties and covering the core material, and a gas adsorbent covered with the jacket material together with the core material A ZSM-5 type zeolite in which the gas adsorbent is at least an ion exchange rate of not less than 100% and not more than 200%. In the copper ion exchange step of the ZSM-5 type zeolite, the copper ion exchange is performed in a batch manner, and the copper ion-containing ion exchange solution is a ZSM-5 type before the copper ion exchange. The amount is from 50 ml to 200 ml per gram of zeolite.

  As a result, the gas adsorbent used in the heat insulator of the present invention has an adsorption capacity equal to or higher than that of the conventional gas adsorbent, and can be manufactured at a low cost by reducing the number of times of copper ion exchange. In addition, it is possible to adsorb and immobilize nitrogen and the like that cannot be removed at low cost by an industrial vacuum exhaust process and nitrogen that penetrates over time with a large capacity. Therefore, it is possible to provide a high-performance heat insulator provided with a gas adsorbent capable of adsorbing a large volume of gas even at room temperature and normal pressure or at room temperature and reduced pressure.

  The gas adsorbent used for the heat insulator of the present invention has an adsorption capacity equal to or higher than that of conventional gas adsorbents and can be manufactured at low cost by reducing the number of times of copper ion exchange. Nitrogen that cannot be removed by an industrial evacuation process and nitrogen that penetrates over time can be adsorbed and fixed in a large volume.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  Conventionally, it is known that a copper ion exchanged ZSM-5 type zeolite is capable of physical adsorption and chemical adsorption to a gas such as nitrogen or oxygen.

  It uses H-ZSM-5 type zeolite and Na-ZSM-5 type zeolite as raw materials, and performs copper ion exchange with an aqueous solution of a soluble salt of copper, such as an aqueous solution of copper chloride, an aqueous solution of copper ammine, and an aqueous solution of copper acetate. Nitrogen adsorption activity is imparted by reducing the introduced copper divalent ions to monovalent by performing drying and appropriate heat treatment.

  However, since ZSM-5 type zeolite is expensive and requires a high cost for the copper ion exchange process, it is necessary to increase the amount of adsorption per unit weight and to reduce the cost for extensive industrial use. Met.

  When the amount of adsorption per unit weight increases, the amount used can be reduced, and as a result, the cost per use is reduced. As a method for increasing the amount of adsorption, it is only necessary to increase the amount of introduced copper ions, which are generally adsorption active sites. For this purpose, it is effective to repeat ion exchange a plurality of times. Also in patent document 4, the Example which increases an ion exchange rate by increasing the frequency | count of ion exchange is shown.

  However, increasing the number of ion exchanges on the other hand increases process costs.

  Therefore, it is important to express the adsorption activity conventionally obtained by multiple times of copper ion exchange without increasing the number of ion exchanges.

  The invention of the heat insulator according to claim 1 of the present invention includes at least a core material, a jacket material having gas barrier properties and covering the core material, and a gas adsorbing material covered with the jacket material together with the core material A ZSM-5 type zeolite in which the gas adsorbent is at least an ion exchange rate of not less than 100% and not more than 200%. In the copper ion exchange step of the ZSM-5 type zeolite, the copper ion exchange is performed in a batch manner, and the copper ion-containing ion exchange solution is a ZSM-5 type before the copper ion exchange. The amount is from 50 ml to 200 ml per gram of zeolite.

  The process for producing a copper ion-exchanged ZSM-5 type zeolite comprises an ion exchange step, a washing step, a drying step, and a heat treatment step.

  In the present invention, the ion exchange step is performed in a batch manner. This is because the ZSM-5 type zeolite is a very fine powder, so that the outflow loss and the batch type are superior to the continuous type in order to efficiently use the ion exchange solution.

  In order to effectively exchange copper ions, it is important during batch-type ion exchange that the copper ions in the ion exchange solution containing copper ions and the sodium ions that have been exchanged with the copper ions and eluted in the solution It is a balance with cations like.

  In the solution after ion exchange, copper ions that have not been used for ion exchange coexist with cations that are exchanged and eluted with copper ions. For example, the amount of ion exchange solution containing copper ions at a certain concentration is compared. Considering the case where the amount is small, the concentration of cations present in the solution is high, and the possibility of re-exchange with the once exchanged copper ions increases.

  On the other hand, when the amount of the ion exchange solution containing a certain concentration of copper ions is relatively large, the cation concentration in the solution is low, so it is unlikely to be exchanged with copper ions, but it is used for ion exchange. If there are many surplus copper ions that did not exist, it is disadvantageous in terms of cost.

  Therefore, limiting the amount of the appropriate copper ion-containing ion exchange solution is very important in view of the balance between adsorption capacity and cost.

  In the present invention, when copper ion exchange is performed using a copper ion-containing ion exchange solution of 50 ml or more and 200 ml or less per gram of ZSM-5 type zeolite, an excellent gas adsorption amount is exhibited even at a low number of ion exchanges, and the cost balance It was confirmed that it was excellent. More preferably, it is 80 ml or more and 150 ml or less.

  In the present invention, the ion exchange rate of the ZSM-5 type zeolite subjected to copper ion exchange is in the range of 100% or more and 200% or less. Since the gas adsorption active site of the ZSM-5 type zeolite subjected to the copper ion exchange is a copper ion, if the ion exchange rate is less than 100%, the copper is insufficient to realize the large volume gas adsorption. On the other hand, 200% means a case where copper is completely exchanged with a cation before exchange, and therefore does not take a value larger than 200% except in a specific case.

  Here, how to obtain the ion exchange rate of the ZSM-5 type zeolite subjected to the copper ion exchange in the present invention will be described below.

  First, ZSM-5 type zeolite subjected to copper ion exchange is dissolved with perchloric acid or the like, and the molar amount of copper contained per unit weight of the zeolite is determined by EDTA titration or ICP measurement.

  On the other hand, the amount of water contained in the zeolite is measured from the weight reduction rate by heating using thermogravimetry, and the true weight of the zeolite excluding moisture is obtained.

  From the above two data, the copper content relative to the true weight of the zeolite can be calculated, and the ratio of ion exchange to the cation contained before being exchanged with copper can be calculated.

The here shown ion exchange rate, the cation of the pre-copper exchange is the Na ^+, a calculated value on the assumption that Cu ²⁺ is exchanged per two Na ^+, copper is exchanged as Cu ⁺ In the case of calculation, it is calculated to exceed 100%, and 200% when completely exchanged.

  As the copper ion-containing ion exchange solution in the present invention, an aqueous solution of a conventional copper compound can be used. However, in order to realize an increase in gas adsorption amount, particularly chemical adsorption amount, a compound in which the copper ion contains carboxylate. It is preferable to be generated from the above, and copper acetate, copper propionate, etc. that generate acetate ions, propionate ions, and the like are preferable.

  The number of ion exchanges is not particularly limited here, but according to the present invention, the number of ion exchanges is reduced as compared with conventional processes, and a gas adsorption amount equal to or higher than that can be obtained. For example, the adsorption capacity obtained by ion exchange of 10 to 30 times in a conventional process can be expressed by ion exchange of about 1 to 3 times.

  The concentration of the ion exchange solution containing copper ions is not particularly limited, and the effect can be obtained at any concentration, but the range of 0.01 M to 0.1 M is desirable, and more preferably 0.01 M to 0. .06M. Even if it is higher than 0.06M, there is an effect, but in terms of cost, 0.01M to 0.03M is more dominant.

  The ion exchange time is not particularly limited, but is about 10 to 60 minutes per time.

  The ion exchange temperature is not particularly limited, but is preferably 40 ° C to 90 ° C. More preferably, it is 40 degreeC or more and 60 degrees C or less.

  In the washing step, it is desirable to wash with distilled water.

  In the drying process, it is desirable to dry under conditions of less than 100 ° C., and vacuum drying at room temperature may be used.

In the heat treatment step, it is desirable to perform heat treatment at a temperature of 500 ° C. or higher and 800 ° C. or lower under a reduced pressure, preferably under 10 ⁻⁵ Pa. The heat treatment time depends on the amount of ZSM-5 type zeolite exchanged with copper ions, but a sufficient time is required to reduce the copper ions from divalent to monovalent.

  Note that heat treatment at a temperature of 500 ° C. or more and 800 ° C. or less is desirable because if it is less than 500 ° C., the reduction to monovalent may be insufficient, and if it exceeds 800 ° C., the structure of the zeolite is destroyed. This is because there is a fear of being done.

  ZSM-5 type zeolite having an ion exchange rate of 100% or more and 200% or less, which has been subjected to copper ion exchange using the copper ion-containing ion exchange solution within the scope of the present invention through the above-described steps, is a conventional adsorption. Compared to the material, it was confirmed that the number of ion exchanges was reduced, so that it was possible to manufacture at a low cost and an amount of gas adsorption equal to or higher than that was obtained.

  With this configuration, it is possible to adsorb and immobilize nitrogen and the like that cannot be removed by an industrial evacuation process and nitrogen and the like that invade over time with a large volume by applying an inexpensive and high-performance gas adsorbent.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  The invention of the heat insulator according to claim 2 is characterized in that, in the invention according to claim 1, the temperature of the copper ion-containing ion exchange solution is 40 ° C. or higher and 90 ° C. or lower.

  When the temperature of the copper ion-containing ion exchange solution is in the range of 40 ° C. or higher and 90 ° C. or lower, copper ion exchange is promoted, and as a result, an increase in gas adsorption amount is obtained. This is probably because copper ions have a higher exchange efficiency than other cations in that temperature range.

  The increase in the amount of adsorption due to heating is remarkable at 40 ° C. or higher. Further, when the heating is excessive, when an ion exchange solution containing an organic substance such as copper acetate is used as the copper ion-containing ion exchange solution, it is transformed into copper hydroxide or copper oxide. More preferably, it is 40 degreeC or more and 60 degrees C or less.

  With this configuration, the copper ion-containing ion exchange solution was subjected to copper ion exchange in an amount of 50 to 200 ml per gram of ZSM-5 type zeolite before the copper ion exchange, and the ion exchange rate was 100% to 200%. The effect of increasing the adsorption amount of the exchanged ZSM-5 type zeolite is further promoted, the number of ion exchanges is reduced compared to the existing ones, and the effect of obtaining equivalent or higher adsorption has been confirmed. By applying a gas adsorbent, it is possible to adsorb and immobilize nitrogen or the like that cannot be removed by an industrial vacuum exhaust process and nitrogen or the like that penetrates over time with a large capacity.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the concentration of the copper ion-containing ion exchange solution is 0.01M or more and 0.1M or less. is there.

  Although the details are not clear, in the concentration range of 0.01 M or more and 0.1 M or less, the balance between the copper ion concentration present in the copper ion-containing exchange solution and the cation concentration eluted by exchange with copper ions is It was thought that it had an effect on ion exchange, and it was confirmed that ion exchange efficiency was improved. More desirably, it is 0.01M or more and 0.06M or less. More desirably, it is 0.01M or more and 0.03M or less.

  With this configuration, the copper ion-containing ion exchange solution was subjected to copper ion exchange in an amount of 50 to 200 ml per gram of ZSM-5 type zeolite before the copper ion exchange, and the ion exchange rate was 100% to 200%. The effect of increasing the adsorption amount of the exchanged ZSM-5 type zeolite is further promoted, the number of ion exchanges is reduced compared to the existing ones, and the effect of obtaining equivalent or higher adsorption has been confirmed. By applying a gas adsorbent, it is possible to adsorb and immobilize nitrogen or the like that cannot be removed by an industrial vacuum exhaust process and nitrogen or the like that penetrates over time with a large capacity.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  The invention of the heat insulator according to claim 4 is the invention according to any one of claims 1 to 3, wherein the copper ion contained in the copper ion-containing ion exchange solution is generated from a compound containing carboxylate. It is characterized by being.

  The compound containing carboxylate herein includes copper acetate, copper propionate, copper formate, and the like, and promotes reduction to copper monovalent during heat treatment by ion exchange in an ion exchange solution containing these. Since it has an effect | action, the ratio of a copper monovalent site is increased, As a result, the increase in gas adsorption amount, especially chemical adsorption amount is obtained. From the viewpoints of handleability and versatility, copper acetate can be particularly preferably used.

  With this configuration, the copper ion-containing ion exchange solution was subjected to copper ion exchange in an amount of 50 to 200 ml per gram of ZSM-5 type zeolite before the copper ion exchange, and the ion exchange rate was 100% to 200%. The effect of increasing the adsorption amount of the exchanged ZSM-5 type zeolite is further promoted, the number of ion exchanges is reduced compared to the existing ones, and the effect of obtaining equivalent or higher adsorption has been confirmed. By applying a gas adsorbent, it is possible to adsorb and immobilize nitrogen or the like that cannot be removed by an industrial vacuum exhaust process and nitrogen or the like that penetrates over time with a large capacity.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  The invention of claim 5 is characterized in that, in the invention of claim 4, the compound containing carboxylate is copper acetate.

  Among the compounds containing carboxylate, copper acetate is excellent in ion exchange efficiency because its ion size is appropriate. Moreover, it is industrially inexpensive and excellent in productivity.

  With this configuration, the copper ion-containing ion exchange solution was subjected to copper ion exchange in an amount of 50 to 200 ml per gram of ZSM-5 type zeolite before the copper ion exchange, and the ion exchange rate was 100% to 200%. The effect of increasing the adsorption amount of the exchanged ZSM-5 type zeolite is further promoted, the number of ion exchanges is reduced compared to the existing ones, and the effect of obtaining equivalent or higher adsorption has been confirmed. By applying a gas adsorbent, it is possible to adsorb and immobilize nitrogen or the like that cannot be removed by an industrial vacuum exhaust process and nitrogen or the like that penetrates over time with a large capacity.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  The invention of a heat insulator according to claim 6 is the copper ion exchange step of the process for producing a ZSM-5 type zeolite subjected to copper ion exchange in the invention according to any one of claims 1 to 5. The exchange is performed in a batch manner, and the number of ion exchanges is one.

  Even if the number of ion exchanges is one, the effect of obtaining adsorption equal to or higher than that obtained when performing ion exchange a plurality of times is increased. With this configuration, an inexpensive and high-performance gas adsorbent can be obtained. It is possible to adsorb and immobilize nitrogen and the like that cannot be removed by an industrial evacuation process and nitrogen that invades with time with a large capacity.

  As a result, the ultimate pressure in the inner space of the jacket material is lower than when only a vacuum pump is used, and the heat insulation performance of the heat insulator can be improved, so a high performance heat insulator having excellent heat insulation performance Can be provided.

  Further, it is possible to provide a high-performance heat insulator that enables stronger gas adsorption and is excellent in reliability.

  In the heat insulator according to claim 7, the gas adsorbent according to any one of claims 1 to 6 contains at least a moisture adsorbing substance in addition to the ZSM-5 type zeolite subjected to copper ion exchange. It is characterized by.

With this configuration, even in a humid environment, the gas adsorbing material has a moisture adsorbing substance, Cu ^+, which is an adsorption active point in the copper ion exchange type zeolite, forms Cu—OH by moisture contact, and gas adsorption is inactive. In the short time, even if it exposes to air | atmosphere, it does not deactivate.

  Further, since the moisture adsorbing substance removes the adverse effect of moisture adhering to the core material, the gas adsorption activity is maintained. In order to suppress Cu—OH formation more reliably, it is desirable to cover the periphery of the copper ion exchanged zeolite of the present invention with a moisture adsorbing substance.

  An example of a method for producing a gas adsorbent in this configuration will be described.

  ZSM-5 zeolite exchanged with copper ion having gas adsorption activity can be mixed with water adsorbents or adsorbed under high vacuum or inert gas atmosphere such as Ar without contact with nitrogen, water or oxygen. Cover the periphery with a substance, etc. to form pellets or shape that is easy to handle. Furthermore, it is desirable to seal this with a gas-impermeable container filled with an inert gas and store it until application to a heat insulator.

  As a result, the water adsorbent can suppress the decrease in the gas adsorption capacity of the copper ion exchange type zeolite by water and can adsorb and remove the water in the heat insulator, so that the copper ion exchanged ZSM-5 type Zeolite can adsorb and remove gases that cannot be removed by an industrial exhaust process in the insulator and gases that invade over time.

  Larger volume of gas species can be adsorbed and fixed more strongly than existing gas adsorbents, and gas that cannot be removed by industrial exhaust process in heat insulator and gas that invades over time can be adsorbed and removed. Therefore, it is possible to provide a high-performance heat insulator with excellent reliability.

  As the moisture adsorbing substance in the present invention, moisture adsorbing materials such as oxides and hydroxides of alkali metals and alkaline earth metals, and physical moisture adsorbing materials such as zeolite and silica gel can be used. is not. A moisture adsorbent that can chemically immobilize moisture without reversibility is more desirable.

  According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the physical evacuation step of reducing the inside of the outer cover material by a vacuum pump and the gas adsorbent at least. It is manufactured through an adsorption exhaust process in which the gas inside the jacket material is removed.

  With this configuration, it is possible to efficiently achieve a high vacuum, and the ultimate vacuum is further reduced, so that a heat insulator having high heat insulation performance with good manufacturing efficiency can be obtained.

  That is, evacuation is performed for several minutes by a vacuum pump, the internal pressure of the heat insulator is set to about 10 torr, and thereafter, air components are adsorbed and removed by a gas adsorbent.

A heat insulator according to claim 9 is the invention according to any one of claims 1 to 8, wherein the gas adsorbent adsorbs nitrogen, so that the FT-IR spectrum of the gas adsorbent has copper 1 A peak in the vicinity of 2295 cm ^{−1 that} can be attributed to triple bond stretching vibration of nitrogen molecules adsorbed by valence ions appears.

With this configuration, the ZSM-5 type zeolite exchanged with copper ions, which has been able to adsorb and immobilize a large volume of gas, especially nitrogen, which is the most abundant in the air, has copper in the FT-IR spectrum of the gas adsorbent. This can be confirmed by the appearance of a peak near 2295 cm ^{−1 that} can be attributed to triple bond stretching vibration of nitrogen molecules adsorbed to monovalent ions.

  Hereinafter, embodiments of the heat insulator 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 flowchart showing a method for producing a gas adsorbent used in a heat insulator according to Embodiment 1 of the present invention.

  In the embodiment of the present invention, the production of the gas adsorbent comprising the ZSM-5 type zeolite subjected to the copper ion exchange includes the ion exchange step (STEP 1) using the copper ion-containing ion exchange solution and the copper ion exchanged ZSM. It comprises a washing step (STEP 2) for washing −5 type zeolite, a drying step (STEP 3), and a heat treatment step (STEP 4) for reducing copper ions.

  A commercially available material can be used for the ZSM-5 type zeolite which is a raw material before exchanging copper ions, but the silica to alumina ratio is preferably 2.6 or more and 50 or less. This range is desirable because when the silica to alumina ratio exceeds 50, the amount of copper ion exchange is small, that is, the nitrogen adsorption activity decreases, and ZSM-5 having a silica to alumina ratio of less than 2.6. This is because type zeolite is theoretically impossible to synthesize.

  In the ion exchange step (STEP 1), the copper ion exchange is performed in a batch system, and the copper ion-containing ion exchange solution has an amount of 50 ml or more and 200 ml or less per gram of ZSM-5 type zeolite before the copper ion exchange.

  Conventionally, an aqueous solution of a copper compound can be used as an ion exchange solution containing copper ions. However, in order to realize an increase in gas adsorption amount, particularly chemical adsorption amount, copper ions are generated from a compound containing carboxylate. Preferably, copper acetate, copper propionate, and the like that generate acetate ions, propionate ions, and the like are preferable.

  In the present invention, it is desirable that the ion exchange rate of the ZSM-5 type zeolite subjected to copper ion exchange is in the range of 100% to 200%. Since the gas adsorption active site of the ZSM-5 type zeolite subjected to the copper ion exchange is a copper ion, if the ion exchange rate is less than 100%, the copper ion is insufficient to realize the large capacity gas adsorption. On the other hand, 200% means a case where copper is completely exchanged with a cation before exchange, and therefore does not take a value larger than 200% except in a specific case.

  The effect of the ion exchange solution containing copper ions can be obtained even at room temperature, but the effect is high at 40 ° C. or higher and 90 ° C. or lower, and more desirably 40 ° C. or higher and 60 ° C. or lower.

  The concentration of the copper ion-containing ion exchange solution is preferably in the range of 0.01M to 0.1M, and more preferably 0.01M to 0.06M. More desirably, it is 0.01M or more and 0.03M or less.

  Further, the number of ion exchanges is not particularly limited, but can be reduced from the conventional process and a gas adsorption amount equal to or higher than that can be obtained. For example, the adsorption capacity obtained by ion exchange of 10 to 30 times in a conventional process can be expressed by ion exchange of about 1 to 3 times.

  The ion exchange time is not particularly limited, but is about 15 to 60 minutes.

  In the washing step (STEP 2), it is desirable to wash with distilled water.

  In the drying step (STEP 3), it is desirable to dry under conditions of less than 100 ° C., and vacuum drying at room temperature may be used.

In the heat treatment step (STEP 4), it is desirable to perform heat treatment at a temperature of 500 ° C. or higher and 800 ° C. or lower under reduced pressure, preferably under a condition of less than 10 ⁻⁵ Pa. The heat treatment time depends on the amount of ZSM-5 type zeolite exchanged with copper ions, but a sufficient time is required to reduce the copper ions from divalent to monovalent. Note that heat treatment at a temperature of 500 ° C. or more and 800 ° C. or less is desirable because if it is less than 500 ° C., the reduction to monovalent may be insufficient, and if it exceeds 800 ° C., the structure of the zeolite is destroyed. This is because there is a fear of being done.

  The copper ion exchanged ZSM-5 type zeolite produced in this way can be manufactured at a low cost by reducing the number of ion exchanges compared to conventional adsorbents, and the gas adsorption capacity is equal to or higher than that. It becomes possible.

  In the adsorbent made of ZSM-5 type zeolite subjected to copper ion exchange according to the present embodiment, the amount, type, concentration, ion exchange temperature, and number of ion exchanges of the copper ion-containing ion exchange solution are changed. The results of evaluating the exchange rate and gas adsorption characteristics are shown in Examples 1 to 5. For the gas adsorption characteristics, the amount of nitrogen adsorbed was measured with Autosorb 1-C (manufactured by Kantachrome Co., Ltd.) capable of measuring the gas adsorption capacity.

  The ZSM-5 type zeolite used has a silica-alumina ratio of 14.

  The heat treatment was performed at 600 ° C. and held for 4 hours.

  In addition, the comparison object was made into the comparative examples 1 to 4 produced through the conventional existing process and the conditions outside the claim of this invention.

(Example 1)
As the ion exchange solution, a 0.03 M aqueous solution of copper acetate was used. A copper ion exchanged ZSM-5 type zeolite was prepared by performing ion exchange once at 50 ° C. for one hour. The copper ion-containing ion exchange solution was 50 ml, 80 ml, 100 ml, 150 ml, and 200 ml per 1 g of ZSM-5 type zeolite before the copper ion exchange.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 1).

  Compared with Comparative Example 1, although the number of ion exchanges was reduced to 1/30, all of the nitrogen adsorption amounts were equal or higher. Thus, the ion exchange solution was prepared before the copper ion exchange. ZSM-5 type zeolite having a range of 50 ml to 200 ml per gram of ZSM-5 has a copper ion exchanged ZSM having an ion exchange rate of 100% or more and 200% or less having an adsorption capacity equal to or higher than that of conventional adsorbents. It is possible to produce -5 type zeolite at low cost.

  In addition, the copper ion exchanged ZSM-5 type zeolite produced in the range of 80 ml or more and 150 ml or less, which is a more preferable range, showed excellent adsorbability of 6 cc / g or more at 10 Pa nitrogen adsorption amount. .

  This is because the balance between the copper ions that were not used for ion exchange and the cations that were exchanged and eluted in the solution after ion exchange was appropriate, and the cation concentration was changed once. It is considered that this is because copper ions contributing to adsorption are effectively introduced without being re-exchanged with ions.

(Example 2)
As the ion exchange solution, a 0.03 M aqueous solution of copper acetate was used. The copper ion-containing ion exchange solution is 100 ml per 1 g of ZSM-5 type zeolite before copper ion exchange, and the ion exchange is performed at 40 ° C., 50 ° C., 60 ° C., 90 ° C., 25 ° C. and 98 ° C. for 1 hour each. By performing once, a ZSM-5 type zeolite subjected to copper ion exchange was prepared.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 2).

  When the results of the copper ion exchanged ZSM-5 type zeolite prepared at 40 ° C., 50 ° C., 60 ° C., and 90 ° C. are compared with Comparative Example 1, the number of ion exchanges is reduced to 1/30. Regardless, the nitrogen adsorption amount is equivalent or higher.

  In the range of 40 ° C. or more and 60 ° C. or less, which is a more preferable range, all showed excellent adsorbability of 6 cc / g or more at a 10 Pa nitrogen adsorption amount. This is considered to be because, in this temperature range, copper ions have higher exchange efficiency than other cations and copper ions contributing to adsorption are effectively introduced.

  Therefore, a suitable temperature range of the copper ion-containing ion exchange solution is 40 ° C. or higher and 90 ° C. or lower, more preferably 40 ° C. or higher and 60 ° C. or lower. Within this range, the ion exchange solution is in the range of 50 ml to 200 ml per gram of ZSM-5 type zeolite before copper ion exchange, and has an adsorption capacity equal to or higher than that of conventional adsorbents, with an ion exchange rate of 100. Further, the effect of inexpensively producing ZSM-5 type zeolite having a copper ion exchange of not less than 200% and not more than 200% is further promoted.

(Example 3)
As the ion exchange solution, 0.01M, 0.03M, 0.06M, 0.1M, 0.005M, and 0.11M copper acetate aqueous solutions were used. The copper ion-containing ion exchange solution was made into 100 ml per 1 g of ZSM-5 type zeolite before the copper ion exchange, and the ZSM-5 type was subjected to copper ion exchange by performing ion exchange once for one hour at 50 ° C. Zeolite was prepared.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 3).

  Comparing the results with the copper ion exchanged ZSM-5 type zeolite prepared at 0.01M, 0.03M, 0.06M, and 0.1M with Comparative Example 1, the number of ion exchanges was reduced to 1/30. Nevertheless, the amount of nitrogen adsorption is equal or higher.

  In the range of 0.01 M or more and 0.06 M or less, which is a more preferable range, all showed excellent adsorptivity of 5.5 cc / g or more at a 10 Pa nitrogen adsorption amount. This is considered because the active copper which contributes to adsorption | suction is introduce | transduced effectively.

  On the other hand, compared with the comparative example 1, the thing produced by 0.005M and 0.11M was excellent in 13200Pa, but the tendency for the 10Pa nitrogen adsorption amount to fall was seen. This is considered to be because at 0.005M, the copper ion concentration in the solution was low, and copper was not effectively introduced. At 0.11M, the factor is unknown, but it is considered that some factor that inhibits the introduction of copper acts even if the concentration is too high.

  Therefore, the appropriate concentration range of the copper ion-containing ion exchange solution is 0.01M or more and 0.1M or less, more preferably 0.01M or more and 0.06M or less.

  Within this range, the ion exchange solution is in the range of 50 ml to 200 ml per gram of ZSM-5 type zeolite before copper ion exchange, and has an adsorption capacity equal to or higher than that of conventional adsorbents, with an ion exchange rate of 100. Further, the effect of inexpensively producing ZSM-5 type zeolite having a copper ion exchange of not less than 200% and not more than 200% is further promoted.

Example 4
The ion exchange solution used was 0.03 M, 50 ° C. aqueous copper acetate solution, propionic acid aqueous solution, and 0.01 M, 90 ° C. aqueous copper chloride solution. The copper ion-containing ion exchange solution was 100 ml per 1 g of ZSM-5 type zeolite before the copper ion exchange, and each one hour of ion exchange was performed once to prepare a ZSM-5 type zeolite subjected to copper ion exchange.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 4).

  When the results of the copper ion exchanged ZSM-5 type zeolite prepared with the copper acetate aqueous solution and the propionic acid aqueous solution were compared with Comparative Example 1, the number of ion exchanges was reduced to 1/30. The amount of adsorption is the same or better. This has the effect of promoting the reduction to copper monovalent during the heat treatment, so that the ratio of copper monovalent sites is increased, and as a result, the amount of gas adsorption, particularly chemical adsorption, can be increased.

  Moreover, it turns out that especially copper acetate shows the outstanding adsorptivity compared with copper propionate. Among the compounds containing carboxylate, copper acetate is excellent in ion exchange efficiency because its ion size is appropriate. Moreover, it is industrially inexpensive and excellent in productivity.

  According to this configuration, the effect of increasing the adsorption amount obtained when the copper ion-containing ion exchange solution is 50 ml or more and 200 ml or less of the copper ion-containing ion exchange solution per 1 g of ZSM-5 type zeolite before the copper ion exchange is further promoted. It was confirmed that the number of ion exchanges was lower than that of No. 1, and the same or better adsorption was obtained.

  On the other hand, when the results of the copper ion exchanged ZSM-5 type zeolite prepared in an aqueous copper chloride solution were compared with Comparative Example 2, the amount of nitrogen adsorption was reduced although the number of ion exchanges was reduced to 1/30. In both cases, the same or better is obtained.

  This is because the balance between the copper ions that were not used for ion exchange and the cations that were exchanged and eluted in the solution after ion exchange was appropriate, and the cation concentration was changed once. It is considered that this is because copper ions contributing to adsorption are effectively introduced without being re-exchanged with ions. However, the effect was small compared with copper acetate and copper propionate aqueous solution.

(Example 5)
As the ion exchange solution, a 0.03 M aqueous solution of copper acetate was used. By performing ion exchange for 1 hour at 50 ° C. once, twice, and three times, ZSM-5 type zeolite subjected to copper ion exchange was prepared. The amount of the copper ion-containing ion exchange solution was 100 ml per gram of ZSM-5 type zeolite before the copper ion exchange.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 5).

  Compared with Comparative Example 1, although the number of ion exchanges was reduced to 1/30, 1/15, and 1/10, the nitrogen adsorption amount was all equal or higher. When the exchange solution is in the range of 50 ml or more and 200 ml or less per 1 g of ZSM-5 type zeolite before the copper ion exchange, the ion exchange rate is 100% or more and 200% having an adsorption capacity equivalent to or higher than that of the conventional adsorbent. The following copper ion exchanged ZSM-5 type zeolite can be produced at low cost.

  Of course, the amount of adsorption increases as the number of ion exchanges increases. On the other hand, as the number of ion exchanges increases from once to twice or three times, the process cost is doubled or tripled. However, the amount of adsorption does not increase proportionally by 2 or 3 times.

  Therefore, considering the process cost, the present configuration showing an excellent adsorption amount only by one replacement is considered useful. Ultimately, the optimum number of ion exchanges can be determined in consideration of total costs such as direct material costs such as the price of ZSM-5 zeolite and costs required for stirring and heating the aqueous solution.

  Further, in the ZSM-5 type zeolite subjected to the copper ion exchange in Examples 1 to 5, in addition to nitrogen, gas adsorption such as oxygen and hydrogen, carbon monoxide, carbon dioxide, and a mixed gas of nitrogen and oxygen is performed. It could be confirmed.

(Embodiment 2)
FIG. 2 is a flowchart showing a method for manufacturing a heat insulator according to Embodiment 2 of the present invention.

  In the embodiment of the present invention, the heat insulator is manufactured by inserting a core material and a gas adsorbing material into the jacket material, and evacuating the inside of the vacuum chamber. It consists of a sealing step (STEP 2) for sealing under reduced pressure conditions, and then an adsorption exhaust step (STEP 3) in which the internal gas is adsorbed and removed by the gas adsorbent by leaving the heat insulator. .

  With this configuration, the gas adsorbent material immobilizes and removes the gas remaining in the jacket material before shipment, so that high heat insulation is realized.

(Embodiment 3)
FIG. 3 is a schematic cross-sectional view of a gas adsorbent used for a heat insulator according to Embodiment 3 of the present invention.

  The gas adsorbent 1 includes a ZSM-5 type zeolite 2 subjected to copper ion exchange, a moisture adsorbing substance 3, an oxygen adsorbent 4 and a hydrogen adsorbent 5, and these materials are made of an inert gas such as argon. It was mixed in and pelletized.

  In the gas adsorbent 1 configured as described above, the moisture adsorbing substance 3 adsorbs and removes moisture and internally generated moisture that cannot be removed by an industrial evacuation process. The copper ion exchanged ZSM-5 type zeolite 2 that exhibits activity adsorbs and immobilizes gases that cannot be removed by an industrial vacuum exhaust process and gases that invade over time.

  Further, the oxygen adsorbent 4 and the hydrogen adsorbent 5 adsorb and remove oxygen and hydrogen, respectively, and adsorb and fix a gas such as nitrogen that cannot be removed by an industrial vacuum exhaust process and a gas that invades with time.

  As a result, the ultimate pressure in the inner space of the jacket material can be reduced as compared with the case where only the vacuum pump is used, and the heat insulation performance of the heat insulator can be improved.

(Embodiment 4)
FIG. 4 is a schematic cross-sectional view of a gas adsorbent used for a heat insulator according to Embodiment 4 of the present invention.

  The gas adsorbent 1 has a structure in which the water adsorbing substance 3 covers the ZSM-5 type zeolite 2 subjected to copper ion exchange, and is molded in an inert gas atmosphere.

  In the gas adsorbent 1 configured as described above, the moisture adsorbing substance 3 adsorbs and removes moisture and internally generated moisture that cannot be removed by an industrial evacuation process. The copper ion exchanged ZSM-5 type zeolite 2 that exhibits activity adsorbs and immobilizes gases that cannot be removed by an industrial vacuum exhaust process and gases that invade over time. As a result, the heat insulation performance of the heat insulator can be improved.

  Further, since the ZSM-5 type zeolite 1 subjected to copper ion exchange, which is gas adsorption activity, is covered with the moisture adsorbing substance 3, the reduction of the gas adsorption active site due to moisture is further suppressed.

  As the ZSM-5 type zeolite subjected to copper ion exchange, the effect of applying to the heat insulator is 100 ml per 1 g of ZSM-5 type zeolite before the copper ion exchange as the copper ion-containing ion exchange solution, the liquid temperature is 50 ° C., the concentration Example 6 shows the results of evaluation using a 0.03 M aqueous solution of copper acetate and one time of ion exchange for 1 hour and using calcium oxide as the moisture-adsorbing substance 3.

  Evaluation was performed as follows with the thermal conductivity of the flat panel which sealed the gas adsorbent.

  Only the gas adsorbent is sealed in the jacket material, the initial internal pressure is set to 1300 Pa by physical exhaust by a vacuum pump, and the internal pressure and thermal conductivity after 24 hours have elapsed, that is, after the adsorbed exhaust is generated by the gas adsorbent. It was measured.

  In addition, comparative examples were Comparative Examples 5 and 6.

(Example 6)
Among the effective adsorbing components, the gas adsorbing material 1 containing 75 wt% of the moisture adsorbing substance 3 and 25 wt% of the ZSM-5 type zeolite 2 subjected to copper ion exchange was prepared, and the internal pressure after 24 hours The thermal conductivity was measured.

  The internal pressure after 24 hours was 7 Pa, and the thermal conductivity was 0.067 W / mK.

  The internal pressure was comparable to that of Comparative Example 5, but the thermal conductivity was improved by 48%. This is because the gas adsorption capacity of the gas adsorbent in this example is large and the solid thermal conductivity is lower than that of the alloy material.

  Moreover, the internal pressure was reduced to 1/18 with respect to Comparative Example 6, and the thermal conductivity was improved by 30%. This is because the gas adsorption capacity of the gas adsorbent of this example is large, and the chemical adsorption capacity for adsorbing gas more firmly is also large, so the lowest pressure reached is very small, so the gas thermal conductivity is reduced. I think.

(Embodiment 5)
FIG. 5 shows a schematic cross-sectional view of the heat insulator in the fifth embodiment of the present invention.

  A heat insulator 6 according to Embodiment 5 of the present invention includes a core material 7, an outer cover material 8 that has gas barrier properties and covers the core material 7, and a gas adsorbent 1 that is covered with the outer cover material 8 together with the core material 7. And a heat insulator 6 in which the inside of the jacket material 8 is decompressed.

  The gas adsorbent 1 is a gas adsorbent 1 including at least a copper ion-exchanged ZSM-5 type zeolite 2 having an ion exchange rate of 100% or more and 200% or less, and a moisture adsorbing substance 3, and the ZSM-5 In the copper ion exchange step of type 2 zeolite, the copper ion exchange is performed in a batch system, and the copper ion-containing ion exchange solution has an amount of 50 ml or more and 200 ml or less per 1 g of ZSM-5 type zeolite before the copper ion exchange.

  The heat insulating body 6 uses the inorganic fiber aggregate as the core material 7 and the laminated film composed of the surface protective layer, the gas barrier layer, and the heat welding layer as the covering material 8 as the gas adsorbent 1 and the gas of the fourth embodiment. The adsorbent 1 is used.

  In the gas adsorbent 1 configured as described above, the moisture adsorbing substance 3 adsorbs and removes moisture and internally generated moisture that cannot be removed by an industrial evacuation process. The copper ion exchanged ZSM-5 type zeolite 2 that exhibits activity adsorbs and immobilizes gases that cannot be removed by an industrial vacuum exhaust process and gases that invade over time. As a result, the heat insulation performance of the heat insulator 6 can be improved. Moreover, the increase in the thermal conductivity by the gas adsorbent 1 can be suppressed.

An evaluation result of nitrogen adsorption in the heat insulator 6 to which the gas adsorbent 1 of Example 6 is applied is shown in Example 8. The evaluation was performed by comparing the internal pressure after 1 month with the heat insulating bodies of Comparative Examples 5 and 6 to which the gas adsorbents of Comparative Examples 3 and 4 were applied, with the initial internal pressure being 1300 Pa. In addition, the weight per gas adsorbent is about 2 g, and the space volume occupied by the core material of the heat insulator is about 400 cm ³ .

(Example 7)
In the heat insulator to which the gas adsorbent of Example 6 was applied, the internal pressure after one month with time was 13 Pa, the deterioration with time was smaller than those of Comparative Examples 7, 8, and 9, and the gas and internally generated gas that entered from the outside The gas adsorbent is considered to be more effectively adsorbed and removed.

(Embodiment 6)
FIG. 6 shows a schematic cross-sectional view of a heat insulator in Embodiment 6 of the present invention.

  A heat insulator 9 according to Embodiment 6 of the present invention includes a core material 7, a jacket material 8 that has gas barrier properties and covers the core material 7, and a gas adsorbent 1 that is covered with the jacket material 8 together with the core material 7. And a heat insulator 9 formed by decompressing the inside of the jacket material 8 and containing at least a ZSM-5 type zeolite exchanged with copper ions and the moisture adsorbing substance 3.

  The heat insulator 9 includes an inorganic fiber aggregate as the core material 7, a casing made of stainless steel as the outer jacket material 8 having gas barrier properties, at least a ZSM-5 type zeolite 2 and a water adsorbing substance exchanged with copper ions. 3 and a gas adsorbent 1 containing 3 and the inside of the jacket material 8 is decompressed.

  The gas adsorbent 1 configured as described above is formed by adsorbing and removing moisture that cannot be removed by an industrial evacuation process and moisture generated inside by the moisture adsorbing material 3 and removing moisture by adsorption. The copper ion exchanged ZSM-5 type zeolite 2 that exhibits activity adsorbs and immobilizes gases that cannot be removed by an industrial vacuum exhaust process and gases that invade over time. As a result, the heat insulation performance of the heat insulator 9 can be improved. Moreover, an increase in thermal conductivity due to the gas adsorbent can be suppressed.

As described above, the heat insulator 9 of the present invention is a gas adsorbent 1 containing at least a copper ion-exchanged ZSM-5 type zeolite having an ion exchange rate of 100% or more and 200% or less, which is a ZSM-5 type zeolite. In the copper ion exchange step, copper ion exchange is performed in a batch system, and the copper ion-containing ion exchange solution is in an amount of 50 ml or more and 200 ml or less per 1 g of ZSM-5 type zeolite before the copper ion exchange. further, by including a water adsorbing material for controlling the gas adsorption activity of the copper ion-exchanged zeolite, moisture adsorbing material 3, Cu ⁺ moisture copper ion-exchanged in ZSM-5 type zeolite Since it is possible to suppress the formation of Cu—OH by contact and becoming gas adsorption inactive, the copper ion exchange type zeolite 2 is effectively industrial vacuum exhaust. The gas that cannot be removed by the gas process is adsorbed, and as a result, the heat insulation performance of the heat insulator 9 can be improved.

  Moreover, the increase in the thermal conductivity by the gas adsorbent 1 itself can be suppressed.

  As a result, a high-performance heat insulator 9 having excellent heat insulation performance can be provided.

  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. Moreover, the result of the heat insulation which did not apply any adsorbent is shown in Comparative Example 9.

(Comparative Example 1)
In order to perform ion exchange in the conventional process of Patent Document 4, a 0.01 M copper acetate aqueous solution was used as the ion exchange solution. The copper ion-containing ion exchange solution was used in an amount of 25 ml per 1 g of ZSM-5 type zeolite before the copper ion exchange, which is outside the scope of the present invention.

  Copper ion exchanged ZSM-5 type zeolite was prepared by performing ion exchange for 30 hours at 25 ° C. for 30 times. The heat treatment was the same as in the first embodiment.

  After the heat treatment, the sample was cooled to 25 ° C. and the nitrogen adsorption characteristics were evaluated. The nitrogen adsorption amount was 10.8 cc / g at 13200 Pa and 4.6 cc / g at 10 Pa. The copper ion exchange rate was 110%.

(Comparative Example 2)
In order to perform ion exchange in a conventional existing process, an aqueous 0.01 M copper chloride solution was used as an ion exchange solution. The amount was 25 ml per 1 g of ZSM-5 type zeolite before copper ion exchange, which is outside the scope of the present invention. Copper ion exchanged ZSM-5 type zeolite was prepared by performing ion exchange for 20 hours at 90 ° C. 20 times. The heat treatment was the same as in the first embodiment.

  After the heat treatment, it was cooled to 25 ° C. and the nitrogen adsorption characteristics were evaluated. The nitrogen adsorption amount was 5.3 cc / g at 13200 Pa and 2.0 cc / g at 10 Pa. The copper ion exchange rate was 93%.

(Comparative Example 3)
In order to evaluate the adsorption characteristics of the copper ion exchanged ZSM-5 type zeolite outside the scope of the present invention, a copper ion exchanged ZSM-5 type zeolite was prepared under the following conditions. As the ion exchange solution, a 0.03 M aqueous solution of copper acetate was used. A copper ion exchanged ZSM-5 type zeolite was prepared by performing ion exchange once at 50 ° C. for one hour. The copper ion-containing ion exchange solution was in amounts of 30 ml and 220 ml per 1 g of ZSM-5 type zeolite before the copper ion exchange, which is outside the scope of the present invention.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 6).

  Compared with Example 1 to Example 5, it can be seen that the nitrogen adsorption amount is low, and in particular, the nitrogen adsorption amount at 10 Pa is low compared to Comparative Example 1 in which the number of ion exchanges is 30 times. Further, the respective ion exchange rates were 90% and 138%, and the ion exchange rate of the former was also outside the scope of the claims of the present invention.

  This is because the amount of the solution is small at 30 ml / g in the single exchange condition, and therefore, the cation concentration exchanged with copper ions is high, and there is a possibility that the exchanged copper ions are replaced once. This is because it becomes higher.

  On the other hand, since the amount of the solution is large at the amount of 220 ml / g, the cation concentration present in the solution is low and the possibility of resubstitution with copper ions is low, but it is inappropriate in terms of cost. Further, although the cause is not clear, it was confirmed that the adsorption amount was reduced, and that the adsorption characteristics were also lowered when an excessive amount of the solution was used.

(Comparative Example 4)
In order to evaluate the adsorption characteristics of the copper ion exchanged ZSM-5 type zeolite outside the scope of the present invention, a copper ion exchanged ZSM-5 type zeolite was prepared under the following conditions.

  As the ion exchange solution, a 0.03 M aqueous solution of copper acetate was used. Copper ion exchanged ZSM-5 type zeolite was prepared by performing ion exchange once at 25 ° C. and 98 ° C. for one hour. The amount of the copper ion-containing ion exchange solution was 100 ml per gram of ZSM-5 type zeolite before the copper ion exchange.

  These copper ion exchanged ZSM-5 type zeolites were heat-treated and then cooled to 25 ° C. to evaluate nitrogen adsorption characteristics. The respective ion exchange rates and the nitrogen adsorption amounts at 13200 Pa and 10 Pa are shown in (Table 7).

  Compared with Example 1 to Example 5, the nitrogen adsorption amount is low, and it can be seen that the nitrogen adsorption amount at 10 Pa is particularly low as compared with Comparative Example 1. Also, it was confirmed that the respective ion exchange rates were 97% and 202%, which were outside the scope of the claims of the present invention.

  With respect to those manufactured at 25 ° C., the ion exchange rate is low, and a sufficient amount of copper introduced to realize large-capacity adsorption is not obtained, so the amount of adsorption is low. The ion exchange rate exceeds 200%. Although details are not clear about this, it is thought that it is because the form in which copper is introduced into the zeolite is different.

  That is, since the solution temperature at the time of ion exchange is as high as 98 ° C., it is assumed that at least a part of copper is ion-exchanged in the form of an organic-copper compound ion complex.

  The organic-copper compound ion complex here refers to a cation of a polymer or oligomer of an organic substance and a copper compound, and one cation may contain one copper or a plurality of copper. .

  As a result, not only cations having one copper but also cations having a plurality of coppers are exchanged at one ion exchange site, so that the ion exchange rate apparently exceeds 200%. However, copper that appears in such high ion exchange efficiency seems to include those that hardly contribute to gas adsorption.

  Therefore, it is very important to limit the amount and ion exchange rate of an appropriate copper ion-containing ion exchange solution in view of the balance between adsorption capacity and cost.

(Comparative Example 5)
Among the effective adsorbing components, a pellet containing 75 wt% calcium oxide, 5 wt% Ba-Li alloy, and 20 wt% cobalt oxide was produced.

  The internal pressure after 24 hours was 13 Pa, and the thermal conductivity was 0.130 W / mk. Ba-Li alloy is a PRTR-designated substance and a substance whose working environment is regulated.

(Comparative Example 6)
A gas adsorbent 1 containing 75 wt% of calcium oxide and 25 wt% of the copper ion exchanged ZSM-5 type zeolite of Comparative Example 1 among the effective adsorbing components was prepared. The thermal conductivity was measured.

  The internal pressure after 24 hours was 130 Pa, and the thermal conductivity was 0.097 W / mK.

(Comparative Example 7)
In the heat insulator to which the gas adsorbent of Comparative Example 5 was applied, the internal pressure after one month with time was 102 Pa.

(Comparative Example 8)
In the heat insulator to which the gas adsorbent of Comparative Example 6 was applied, the internal pressure after 1 month was 130 Pa.

(Comparative Example 9)
With a heat insulator that does not apply the gas adsorbent, the internal pressure after one month was 197 Pa.

  In the present invention, the copper ion-exchanged ZSM- having a copper ion exchange rate of 100% or more and 200% or less, obtained by performing copper ion exchange using a copper ion-containing ion exchange solution of 50 ml or more and 200 ml or less per gram of ZSM-5 type zeolite. It was confirmed that the type 5 zeolite exhibited an excellent gas adsorption amount even at a low number of ion exchanges and was excellent in cost balance. More preferably, it is 80 ml or more and 150 ml or less.

  The heat insulator according to the present invention uses a gas adsorbent that is cheaper than conventional products and can adsorb a large volume of gas, so that nitrogen and other gases that cannot be removed by an industrial vacuum exhaust process are removed. As a result, the heat insulation performance of the heat insulator can be improved. On the other hand, the zeolite structure can suppress an increase in thermal conductivity due to the gas adsorbent, and thus can exhibit excellent heat insulation performance. It is a thing. Therefore, it can be efficiently used for heating and cooling devices such as refrigerators and refrigerators, and can be applied to all devices that can contribute to energy saving and to various heat insulation applications such as physical objects to be protected from heat and cold.

The flowchart which shows the manufacturing method of the gas adsorbent used for the heat insulating body by Embodiment 1 of this invention. The flowchart which shows the manufacturing method of the heat insulating body by Embodiment 2 of this invention. Schematic sectional view of a gas adsorbent used for a heat insulator according to Embodiment 3 of the present invention Schematic sectional view of a gas adsorbent used for a heat insulator according to Embodiment 4 of the present invention Schematic sectional view of a heat insulator according to Embodiment 5 of the present invention Schematic sectional view of a heat insulator according to Embodiment 6 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas adsorption material 2 Copper ion exchanged ZSM-5 type zeolite 3 Moisture-absorbing substance 6 Heat insulator 7 Core material 8 Cover material 9 Heat insulator

Claims (9)

  At least a core material, a jacket material having gas barrier properties and covering the core material, and a gas adsorbing material covered with the core material together with the core material, and the inside of the jacket material is decompressed It is a heat insulator, and the gas adsorbent is a gas adsorbent containing at least an ion exchange rate of 100% or more and 200% or less of copper ion exchanged ZSM-5 type zeolite, wherein the ZSM-5 type zeolite In the copper ion exchange step, copper ion exchange is performed in a batch system, and the copper ion-containing ion exchange solution is in an amount of 50 ml or more and 200 ml or less per gram of ZSM-5 type zeolite before the copper ion exchange. Insulation.   The temperature of a copper ion containing ion exchange solution is 40 degreeC or more and 90 degrees C or less, The heat insulating body of Claim 1 characterized by the above-mentioned.   The heat insulator according to claim 1 or 2, wherein the concentration of the copper ion-containing ion exchange solution is 0.01M or more and 0.1M or less.   The heat insulating body according to any one of claims 1 to 3, wherein the copper ions contained in the copper ion-containing ion exchange solution are produced from a compound containing carboxylate.   The heat insulating body according to claim 4, wherein the compound containing carboxylate is copper acetate.   6. The copper ion exchange step of the process for producing a ZSM-5 type zeolite subjected to copper ion exchange, wherein the copper ion exchange is performed in a batch manner, and the number of times of ion exchange is one. The heat insulation as described in any one.   The heat-insulating body according to any one of claims 1 to 6, wherein the gas adsorbent contains at least a moisture-adsorbing substance in addition to the copper ion-exchanged ZSM-5 type zeolite.   It is produced through at least a physical exhaust process for reducing the pressure inside the outer cover material by a vacuum pump and an adsorption exhaust process for removing the gas inside the outer cover material by the gas adsorbent. The heat insulating body according to any one of claims 1 to 7. When the gas adsorbent adsorbs nitrogen, the FT-IR spectrum of the gas adsorbent shows that a peak near 2295 cm ^{−1 that} can be attributed to triple bond stretching vibrations of nitrogen molecules adsorbed on copper monovalent ions appears. The heat insulator according to any one of claims 1 to 8, wherein the heat insulator is characterized by the following.