JP2011092827A - Gas adsorption device and method of using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an excellent gas adsorption capacity by controlling deterioration of a gas adsorbent having a high activity with moisture. <P>SOLUTION: A gas adsorption device 1 includes the gas adsorbent 2, a barrier container 3 covering the gas adsorbent 2 and a scarcely-moisture-permeable and air-permeable film 5 covering the barrier container 3. The deterioration of the gas adsorbent 2 by water vapor is controlled by suppressing arrival of water vapor at the gas adsorbent 2, resulting in an excellent gas adsorption capacity. A higher gas adsorbing capacity is obtainable by arranging a moisture-adsorbing material additionally in vacuum equipment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas adsorption device that selectively adsorbs only air among air containing water vapor.

  In recent years, development of devices (hereinafter referred to as vacuum devices) capable of exhibiting performance in an advanced vacuum environment, such as vacuum heat insulating materials, vacuum heat insulating containers, and plasma display panels, has become active.

  For these vacuum devices, an increase in internal pressure due to residual gas at the time of manufacture or gas that penetrates over time causes deterioration in performance. Therefore, application of an adsorbent for adsorbing these gases has been attempted.

  In general, adsorption of water vapor is easier than adsorption of air. Therefore, adsorbents that adsorb water vapor (hereinafter referred to as moisture adsorbents) are physical adsorption materials such as zeolite and silica gel, and chemicals such as calcium oxide. Many cheap adsorbents have been commercialized.

  On the other hand, it is particularly difficult to adsorb inert gases such as nitrogen among gases contained in air, so adsorbents that adsorb inert gases (hereinafter referred to as gas adsorbents) are compared to moisture adsorbents. And expensive.

  On the other hand, the space for installing the gas adsorbent, such as the inside of the vacuum heat insulating material, is generally filled with a mixed atmosphere of air and water vapor.

  In general, gas adsorbents that can adsorb air are highly active and can adsorb water vapor in addition to air, so even a mixed gas of air and water vapor can be adsorbed only with a gas adsorbent. Is possible.

  However, the gas adsorbent adsorbs water vapor, thereby reducing the adsorption capacity for air. Therefore, in order to adsorb a predetermined amount of air, more gas adsorbent is required to compensate for the reduced amount by adsorbing water vapor.

  Here, as described above, since the gas adsorbent is more expensive than the moisture adsorbent, it is not a good idea to adsorb water vapor to the gas adsorbent, and air is selectively adsorbed to the gas adsorbent. It is a good idea. Therefore, a mechanism for preferentially adsorbing air to the gas adsorbent is necessary.

  Therefore, an attempt has been made to cover the gas adsorbent with a moisture adsorbent, adsorb water vapor with the moisture adsorbent, and adsorb only air with the gas adsorbent (see, for example, Patent Document 1).

Japanese National Patent Publication No. 9-512088

  However, in the method described in Patent Document 1, since the gas barrier property by the moisture adsorbent is not necessarily sufficient, when the gas adsorbent is installed in a gas having a large proportion of water vapor, the adsorption capacity of the gas adsorbent to the air is reduced. There was a problem to do.

  Accordingly, an object of the present invention is to provide a gas adsorbing device and a method of using the gas adsorbing device that allow the gas adsorbing material to selectively adsorb air by providing sufficient water vapor barrier properties.

  In order to achieve the above object, the gas adsorption device of the present invention includes a gas adsorbent, a barrier container that covers the gas adsorbent, and a moisture poorly permeable air permeable film that covers the barrier container.

  Thereby, even if water vapor is contained in the gas to be adsorbed, the gas adsorbent contains a gas with less water vapor. As a result, the gas adsorbent can suppress the decrease in the adsorption capacity of air due to water vapor adsorption, and can secure the gas adsorption capacity.

  In addition, the method of using the gas adsorption device of the present invention is to install the gas adsorption device, the core material, and the moisture adsorbent material together in the outer cover material, and vacuum the outer cover material to produce a vacuum heat insulating material. is there.

  Thereby, it can prevent that the water vapor | steam which was prevented from permeation | transmitting with the moisture permeation | air_permeable air permeable film stays in the jacket material which is closed space.

  According to the gas adsorption device of the present invention, a decrease in the adsorption capacity of air is suppressed, and a sufficient gas adsorption capacity for air can be ensured. Thereby, in order to adsorb | suck a required amount of gas with respect to adsorption | suction object gas, the amount of gas adsorbent application can be decreased, and a gas adsorption device can be obtained cheaply.

Schematic of the gas adsorption device of Embodiment 1 of the present invention Schematic of vacuum heat insulating material using gas adsorption device of the embodiment Schematic of the gas adsorption device of Embodiment 3 of the present invention

  1st invention is a gas adsorption device provided with the gas adsorption material, the barrier container which covers the said gas adsorption material, and the moisture permeation | air permeability air permeable film which covers the said barrier container.

  The activity of gas adsorbents, such as copper ion exchanged ZSM-5 type zeolite, against water vapor is stronger than that against air. For this reason, if a gas adsorbent is installed in a space where air and water vapor are mixed, that is, humid air, the amount of air adsorbed is reduced by preferentially adsorbing water vapor.

  Therefore, by covering the gas adsorbent with a film that is highly permeable to air and hardly permeable to water vapor, the amount of water vapor reached is reduced and air is selectively used as the gas adsorbent. Can be absorbed.

  A second invention is the gas adsorption device according to the first invention, wherein the moisture-permeable air-permeable film is transparent.

  Since the gas adsorbent of the gas adsorbing device is covered with the barrier container, air does not reach the gas adsorbent even in the air and can be stored for a long time.

  On the other hand, when adsorbing the gas in the target space with the gas adsorbent, it is necessary to form a through hole in the barrier container to allow the gas existing in the space to be adsorbed to pass therethrough. At this time, it is necessary to form a through hole only in the barrier container without forming a through hole in the moisture-permeable air-permeable film. Therefore, it is necessary to confirm whether or not the through hole of the barrier container is formed from the outside of the moisture-permeable air permeable film.

  Here, since the moisture poorly permeable air permeable film is transparent, it can be easily confirmed from the outside whether or not a through hole is formed in the barrier container.

  A third invention is the gas adsorption device according to the first or second invention, wherein the moisture poorly permeable air permeable film contains either polyethylene or polypropylene.

  The polyethylene film and the polypropylene film have high permeability to air and hardly permeability to water vapor. In general, these films are inexpensive.

  A fourth invention is the gas adsorption device according to any one of the first to third inventions, wherein the air permeability of the hardly moisture permeable air permeable film is 10 cc / day · atm or more.

  In order to maintain the characteristics of the vacuum equipment by the gas adsorption device, it is necessary to adsorb air at a speed that exceeds the intrusion speed of air into the vacuum equipment.

  For example, if the vacuum equipment is a vacuum heat insulating material, the reason is as follows. When the air permeability is 10 cc / day · atm or more, the performance of the vacuum equipment can be maintained.

  By keeping the inside of the outer cover material of the vacuum heat insulating material at approximately 10 Pa or less, excellent heat insulating performance can be maintained. If the inside of the jacket material is 10 Pa, the pressure difference between the inside and outside of the moisture-permeable air permeable film of the gas adsorption device is approximately 10 Pa. Accordingly, the amount of air that passes through the moisture-permeable air-permeable film is 10 cc / day · atm × (10/101300) atm≈0.001 cc / day. On the other hand, the amount of air entering the vacuum heat insulating material having a thickness of 100 μm and a peripheral length of 1000 mm from the seal layer is approximately 0.0003 cc / day. Therefore, if the pressure inside the jacket material of the vacuum heat insulating material is 10 Pa, the amount of air adsorbed by the gas adsorbing device is larger than the invading air. This means that the pressure inside the vacuum heat insulating material becomes an equilibrium state at 10 Pa or less. Therefore, when the air permeability of the moisture poorly permeable air permeable film is 10 cc / day · atm or more, a gas adsorbing device that exhibits the performance of the vacuum equipment can be obtained.

  According to a fifth aspect of the present invention, the gas adsorbing device according to any one of the first to fourth aspects, the core material, and the moisture adsorbing material are installed together in the outer jacket material, and the inner surface of the outer jacket material is evacuated to provide vacuum insulation. It is the usage method of the gas adsorption device which produces a material.

  When a moisture adsorbent and a gas adsorbent capable of adsorbing moisture coexist in a closed space where air and water vapor exist, generally, the adsorption equilibrium water vapor pressure of the highly active gas adsorbent is lower than the adsorption equilibrium water vapor pressure of the moisture adsorbent. Therefore, the equilibrium state is reached by the following process.

  If the initial water vapor pressure is higher than the equilibrium water vapor pressure of either the water adsorbent or the gas adsorbent capable of adsorbing water, the elapsed time is short after the water adsorbent and the gas adsorbent capable of adsorbing water are installed in a closed space. Each adsorbent adsorbs water vapor.

  When the water vapor pressure in the closed space decreases and becomes lower than the equilibrium vapor pressure of the moisture adsorbing material, the moisture adsorbing material cannot adsorb moisture, and thereafter, the water vapor is adsorbed only by the gas adsorbing material.

  On the other hand, when the initial water vapor pressure is lower than the equilibrium water vapor pressure of the moisture adsorbing material, the moisture adsorbing material cannot adsorb moisture, and only the gas adsorbing material absorbs water vapor.

  As described above, it is difficult to suppress the deterioration of the gas adsorbent due to water vapor by using the moisture adsorbent together.

  Therefore, a gas adsorbing device covered with a moisture poorly permeable air permeable film that is highly permeable to air and hardly permeable to water vapor is effective.

  When the gas adsorption device and the moisture adsorbent are installed in a closed space where air and water vapor are mixed, the moisture contained in the humid air is difficult to permeate the moisture-permeable air permeable film that covers the gas adsorbent. Most of the water vapor is adsorbed by the moisture adsorbent, and the vapor pressure in the closed space becomes the equilibrium vapor pressure of the moisture adsorbent.

  After that, the amount of water vapor that penetrates into the inside of the moisture permeable air permeable film is proportional to the water vapor pressure difference inside and outside the moisture permeable air permeable film, but the amount of water vapor that reaches the gas adsorbent is small and the gas adsorbent deteriorates due to water vapor. Therefore, a gas adsorption device having an excellent air adsorption amount can be obtained.

  6th invention is the usage method of the gas adsorption | suction device installed in the jacket material of a vacuum heat insulating material, after forming a through-hole in a barrier container in 5th invention.

  It is easier and more reliable to form the through hole of the barrier container of the gas adsorption device in the external space before applying it to the vacuum heat insulating material. As a result, the through hole can be reliably formed in the barrier container of the gas adsorption device installed in the straight heat insulating material.

  Therefore, it is possible to obtain a gas adsorption device that reduces the defective penetration and improves the yield of the applied vacuum heat insulating material.

  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 view of a gas adsorption device according to Embodiment 1 of the present invention.

  In FIG. 1, a gas adsorbing device 1 includes a gas-adsorbing material 2 covered with a barrier container 3, a protrusion 4 adjacent to the gas adsorbing material 2, a polyethylene film overlapped two-sided, and sealed in three directions. It will be covered with.

  About the gas adsorption device 1 comprised as mentioned above, the operation | movement at the time of a storage until it applies to a vacuum equipment, an effect | action, and the operation | movement after an application to a vacuum equipment, an effect | action are demonstrated.

  First, when the gas adsorption device 1 is stored in the atmosphere, air and water vapor do not reach the gas adsorbent 2 by the barrier container 3, and the deterioration of the gas adsorbent 2 is suppressed.

  Next, the operation | movement and effect | action which suppress adsorption | suction of a water | moisture content and adsorb | suck air after installing the gas adsorption device 1 in a vacuum device are shown.

  The inside of the vacuum apparatus is depressurized after the gas adsorption device 1 is installed, and is sealed by a member that prevents air from entering.

  Here, the member which prevents intrusion of air can be deformed while maintaining continuity, and an example is a plastic film laminated with an aluminum foil.

  Although it is necessary to form a through-hole in the barrier container 3 in order for the gas adsorption device 1 to adsorb air, an example will be described below.

  When a vacuum device using a plastic film laminated with aluminum foil is taken out into the atmosphere as a member to prevent air from entering from the outside, atmospheric pressure is applied to the plastic film, and the force caused by the pressure difference between the inside and outside In addition, the member that prevents the intrusion of air from the outside is deformed in the inner direction (hereinafter referred to as deformation of vacuum equipment). Due to the deformation of the vacuum device, the protrusion 4 is pressed against the barrier container 3, and a through hole is formed in the barrier container 3. Air can pass through the through hole and reach the gas adsorbent 2.

  Hereinafter, the operation | movement and effect | action which the gas adsorption device 1 adsorb | sucks air are shown.

  First, since the moisture poorly permeable air permeable film is sealed only in three directions, one side is an opening. Here, the amount of gas that reaches the gas adsorbent 2 from the opening per unit time is proportional to the area of the opening, but this amount is extremely small due to the mechanism described below and need not be considered.

  Due to the deformation of the vacuum equipment, the polyethylene film that forms the hardly moisture permeable air permeable film 5 of the gas adsorbing device 1 has a force to adhere to each other. Therefore, the invasion of gas from the portion of the polyethylene film that does not seal the moisture-permeable air-permeable film 5 that has not been sealed becomes slight, and the gas that reaches the gas adsorbent 2 permeates the moisture-permeable air-permeable film 5. The invading gas becomes dominant.

  Furthermore, it heats from the exterior of a vacuum device, makes the moisture hardly permeable air permeable film 5 more than the welding temperature of a polyethylene film, and welds an opening part, From the opening part of the polyethylene film which makes the moisture permeable air permeable film 5 from It is also possible to further reduce the gas intrusion.

  Moisture-resistant air-permeable film refers to a film that has a small amount of water vapor per unit area and a small amount of water vapor per unit time and a large amount of air permeation. Polyethylene films such as polyethylene and polypropylene correspond to this, but are not limited thereto. Not what you want.

Air permeability 1000cc / m ² · d this y · atm or more, preferably 3000cc / m ² · day · atm or more, more desirably fulfills the above ^{10000cc / m 2 · day · atm} .

The water vapor transmission rate is 20 g / m ² · day or less, preferably 10 g / m ² · day or less, more preferably 5 g / m ² · day or less.

For example, when the area of the moisture-permeable air-permeable film 5 applied to the gas adsorption device 1 is 100 cm ^2, a film having a water vapor permeability of 3 g / m ² · day and an oxygen permeability of 30000 cc / m ² · day · atm When used, the water vapor permeability per area is 0.03 g / m 2 · day. That is, the water vapor permeation amount per area reaching the gas adsorption device 1 is about 37 cc per day.

Here, since the oxygen permeability of the film is 30000 cc / m ² · day · atm, the amount of oxygen per day per area applied to the gas adsorption device 1 is 300 cc. Therefore, the ratio of the oxygen transmission rate to the water vapor transmission rate is 300/37. This means that, assuming that the adsorption capacity of the gas adsorbent 2 is 337, 300 is used for oxygen adsorption and 37 is used for adsorption of water vapor. When described in terms of a 100-percentage with respect to the adsorption amount of the gas adsorbent 2, 89% is used for oxygen adsorption.

  Thus, by using a film having a large oxygen permeability relative to the water vapor permeability, it is possible to reduce the water vapor adsorption amount relative to the oxygen adsorption amount of the gas adsorbent 2.

  Here, the oxygen permeability is taken as an example, but it is considered that the permeability of a gas such as nitrogen is not significantly different from the oxygen permeability.

  The gas adsorption device 1 configured as described above can suppress a decrease in the adsorption capacity of air, and can secure a sufficient gas adsorption capacity for air. Thereby, in order to adsorb | suck a required amount of gas with respect to adsorption | suction object gas, the performance of a vacuum device can be exhibited with the small gas adsorbent application amount.

  Here, the gas adsorbent is capable of adsorbing low molecular weight gases such as oxygen and nitrogen contained in the gas, such as CuZSM-5 obtained by ion exchange of ZSM-5 type zeolite with copper, alkali metal or alkaline earth. Metal oxides and alkali metal or alkaline earth metal hydroxides can be used, and in particular, lithium oxide, lithium hydroxide, barium oxide, barium hydroxide, and the like.

The barrier container has a gas permeability of 10 ⁴ [cm ³ / m ² · day · atm] or less, more preferably 10 ³ [cm ³ / m 2 · day · atm] or less. Although the material is not particularly specified, any material can be used as long as it can be filled with a gas adsorbent and can easily form a through hole in a vacuum device, such as a plastic film laminated with a metal foil.

The protrusion is a shape like a needle in which the stress is concentrated on a small area to increase the stress applied per unit area, and the penetrating force with respect to the contacting substance is increased. For example, in order to easily form a through hole in a plastic film, any structure may be used as long as stress can be concentrated on a portion having an area of 0.1 mm ² or less. The material is not particularly specified, but a structural material such as metal or fiber reinforced plastic can be used.

(Embodiment 2)
FIG. 2 is a schematic view of a vacuum heat insulating material using the gas adsorption device according to the second embodiment of the present invention.

  In FIG. 2, a vacuum heat insulating material 6 is formed by covering a gas adsorbing device 1, a water adsorbing material 7, and a core material 8 made of an aggregate of glass fibers with an outer covering material 9 made of a laminate film containing a metal foil. is there.

  The operation | movement and effect | action are demonstrated about the vacuum heat insulating material 6 comprised as mentioned above.

  The vacuum heat insulating material 6 is prepared by sealing the outer covering material 9 in a reduced pressure space after the gas adsorbing device 1, the moisture adsorbing material 7 and the core material 8 are installed in the outer covering material 9 sealed in three directions. After sealing the jacket material 9, the moisture adsorbing material 7 accelerates the moisture adsorption action in the jacket material 9 by holding the vacuum heat insulating material 6 at 80 ° C. for 2 hours (hereinafter referred to as aging).

  Since the moisture adsorption of the moisture adsorbing material 7 is accelerated by aging, the amount of moisture in the jacket material 9 decreases to the equilibrium vapor pressure of the moisture adsorbing material 7 in a short time. The speed at which water vapor permeates the moisture poorly permeable air permeable film 5 is proportional to the difference in water vapor pressure inside and outside the moisture permeable air permeable film 5.

  After reaching the equilibrium vapor pressure of the moisture adsorbing material 7, the difference in water vapor pressure inside and outside the moisture-permeable air permeable film 5 becomes small. Deterioration of the adsorbent can be suppressed.

  On the other hand, air enters the vacuum heat insulating material 6 from the outside through the sealing layer of the jacket material 9, but the rate of adsorption to the gas adsorbing material 2 through the moisture poorly permeable air permeable film 5 is larger than the air intrusion rate. By designing so as to be, it is possible to keep the inside of the jacket material 9 at a low pressure and to maintain excellent heat insulation performance.

  The moisture-impermeable air-permeable film is not limited to a biaxially stretched polyethylene film, but can be obtained at low cost by using a non-stretched low-density polyethylene film, a non-stretched polypropylene film, or the like, thereby suppressing deterioration due to water vapor. Can do.

  A vacuum heat insulating material is a heat insulating material in which heat conduction by gas is reduced by evacuating the inside of the jacket material.

  The jacket material is a film that can reduce the amount of gas per unit time entering the vacuum space, and is excellent as a plastic film laminated with metal foil or a plastic film deposited with metal or inorganic matter It has gas barrier properties.

  The core material is a spacer for maintaining the thickness of the decompressed jacket material against compression due to atmospheric pressure. The glass fiber aggregate is formed into a plate shape, and the inorganic powder is formed into a plate shape. A thing etc. can be used, However, It is not limited to these, What is necessary is just a thing with small heat conductivity and few gas generations.

  The moisture adsorbing material can adsorb moisture contained in the gas, and includes activated carbon, silica gel, calcium oxide, and the like.

(Embodiment 3)
FIG. 3 is a schematic view of the gas adsorption device according to the third embodiment of the present invention.

In FIG. 3, the gas adsorbing device 1 includes a gas-adsorbing material 2 covered with a barrier container 3, a protrusion 4 adjacent to the gas adsorbing material 2, and a two-sided polyethylene film which is overlapped and sealed in three directions. In this embodiment, in the first embodiment, the barrier container 3 and the protrusion 4 are vacuum-sealed before being applied to a vacuum device, and other configurations, operations, The operation is equivalent to that of the first embodiment.

  Since the barrier container 3 and the protrusions 4 are vacuum-sealed with the hardly moisture permeable air permeable film 5, stress is applied so that the protrusions 4 are pressed against the barrier container 3 from the outside of the hardly permeable moisture permeable film 5. Then, a through hole is formed in the barrier container 3. Since the moisture poorly permeable air permeable film 5 is transparent, the formation of the through hole of the barrier container 3 can be easily confirmed from the outside. Therefore, the formation of the through hole of the barrier container 3 is ensured. As a result, the performance of the vacuum device can be reliably exhibited and the yield can be improved.

  The operation and action after the gas adsorption device 1 is installed in the vacuum apparatus are the same as those in the first embodiment.

  Hereinafter, an Example is shown about a gas adsorption device and its usage.

Example 1
In Embodiment 1, 1.2 g of ZSM-5 type zeolite in which the gas adsorbent was subjected to copper ion exchange (the gas adsorption amount per gram at 10 Pa is 5 cc, so the gas adsorption amount of the device is 6 cc), barrier container A 50 μm thick low-density polyethylene film, a 6 μm thick aluminum foil, a 25 μm thick biaxially stretched polypropylene film, and a moisture poorly permeable air permeable film as an unstretched polypropylene film (oxygen permeability: 30000 cc / m ² · day · atm, water vapor transmission rate 3.3 g / m ² · day, area: 0.01 m ² ) to produce a gas adsorption device.

  The gas adsorbing device was manufactured by vacuum-sealing the gas adsorbing material in a barrier container in a glove box filled with argon and then putting the gas adsorbing material in a three-side sealed polyethylene film.

  The core material of the vacuum heat insulating material was formed into a rectangular shape of 300 mm × 400 mm by molding a glass fiber aggregate into a plate shape. Calcium oxide was used as the moisture adsorbing material. It was confirmed in advance that a dew point temperature of −40 ° C. was obtained by using calcium oxide.

  The jacket material was a laminate of a low-density polyethylene film having a thickness of 50 μm, an aluminum foil having a thickness of 6 μm, a nylon film having a thickness of 25 μm, and a nylon film having a thickness of 15 μm, and was a rectangle of 350 mm × 500 mm.

  After sealing the core material and the gas adsorbing device to the jacket material, aging is carried out at 80 ° C. for 2 hours to adsorb the water vapor in the jacket material to the moisture adsorbing material, so that the dew point temperature in the jacket material is −40 ° C. It was. It was 0.0020 W / mK when heat conductivity was measured with the heat conductivity measuring apparatus auto-lambda073 by Eihiro Seiki Co., Ltd. after aging.

  A small amount of air enters the vacuum heat insulating material through the jacket material. In general, the gas permeability of plastic increases as the temperature increases.

  By utilizing this phenomenon, the physical properties can be evaluated by allowing a gas corresponding to the passage of a long time in a short time to enter the jacket of the vacuum heat insulating material.

  By holding the vacuum heat insulating material 6 at 100 ° C. for 500 days, air (4.7 cc) and water vapor equivalent to 30 years have passed into the jacket material, and then the thermal conductivity is measured to be 0.0020 W / mK. Met.

  Since there is no increase in thermal conductivity, that is, no increase in internal pressure has occurred, it can be seen that air and water vapor entering from the outside are adsorbed by the gas adsorption device and the gas adsorbent. Furthermore, the vacuum heat insulating material was disassembled, the gas adsorption device was taken out, and the amount of nitrogen adsorbed at an equilibrium pressure of 10 Pa was measured by auto soap. As a result, it was 0.8 cc.

  Therefore, the gas adsorbent consumed 5.2 cc of the adsorption capacity before disassembly. On the other hand, since the amount of air entering the jacket material is 4.7 cc, the amount of adsorption of the gas adsorbent reduced by water vapor is 0.5 cc, which is about 12% of the amount of air adsorbed. You can see that

  As described above, according to the gas adsorption device of the present invention, a decrease in the adsorption capacity of air is suppressed, and a sufficient gas adsorption capacity for air can be ensured. Thereby, in order to adsorb | suck a required quantity of gas with respect to adsorption | suction object gas, gas adsorbent appropriate metering can be decreased.

(Comparative Example 1)
As a gas adsorption device, the adsorbent according to Patent Document 1 having a structure in which a gas adsorbent is covered with a moisture adsorbent was applied to a vacuum heat insulating material. Other conditions were the same as in Example 1.

  After sealing the jacket material, aging was performed at 80 ° C. for 2 hours to adsorb the water vapor in the jacket material to the moisture adsorbing material, thereby setting the dew point temperature to −40 ° C.

  A vacuum heat insulating material was produced in the same manner as in Example 1, and the thermal conductivity after aging was measured to be 0.0020 W / mK.

  Thereafter, by aging at 100 ° C., air (4.7 cc) and water vapor equivalent to the passage of 30 years were allowed to enter the outer cover material. Thereafter, the thermal conductivity was measured to be 0.0250 W / mK. Furthermore, the vacuum heat insulating material was disassembled and the amount of gas inside was measured. As a result, it was 3.9 cc. Thereby, it turns out that 0.8 cc of air was adsorbed in the vacuum heat insulating material.

  On the other hand, as a result of measuring the gas adsorption amount at 10 Pa before application to the vacuum heat insulating material, it was 2.0 cc.

  As a result, the adsorption amount of the gas adsorbent lowered by water vapor after application to the vacuum heat insulating material is 1.2 cc, the air adsorption amount of the air adsorbent, and the amount used for air adsorption is 40%, It can be seen that it is smaller than 60% of the amount deteriorated by moisture, and the reduction in the amount of air adsorbed by moisture is large.

(Comparative Example 2)
Cover the gas adsorbent with a barrier container in a glove box without using a moisture-permeable air-permeable film as ZSM-5 type zeolite (gas adsorption amount at 10 Pa is 5 cc) with copper ion exchange as the gas adsorbent. And then applied to a vacuum insulation. Other conditions were the same as in Example 1.

  Here, a protrusion was adjacent to the barrier container, and the through hole was formed at atmospheric pressure applied when applied to the vacuum heat insulating material.

  A vacuum heat insulating material was produced in the same manner as in Example 1, and the thermal conductivity after aging was measured to be 0.0020 W / mK.

  Thereafter, by aging at 100 ° C., air (4.7 cc) and water vapor equivalent to the passage of 30 years were allowed to enter the outer cover material. Thereafter, the thermal conductivity was measured to be 0.0290 W / mK. As a result, it can be seen that the gas adsorption device cannot adsorb the invading air. This factor is considered as follows.

  After producing the vacuum heat insulating material, the water vapor in the jacket material decreases to the equilibrium water vapor pressure of the gas adsorbent. Since the equilibrium water vapor pressure of the gas adsorbent is lower than that of the water adsorbent, the water adsorbent cannot adsorb moisture. Since water vapor entering from the outside of the jacket material is similarly adsorbed by the gas adsorbent, the adsorbing power of the gas adsorbent is reduced. As a result, the air that has entered from the outside cannot be adsorbed, and the internal pressure increases, so that the thermal conductivity of the vacuum heat insulating material cannot be maintained.

  The gas adsorption device concerning this invention can be used for the use which adsorb | sucks the gas of the space containing water vapor | steam, such as a vacuum heat insulating material, by adsorb | sucking gas preferentially in the gas containing water vapor | steam.

DESCRIPTION OF SYMBOLS 1 Gas adsorption device 2 Gas adsorption material 3 Barrier container 5 Moisture-permeable air permeable film 6 Vacuum heat insulating material 7 Moisture adsorption material 8 Core material 9 Cover material

Claims (6)

A gas adsorption device comprising: a gas adsorbent; a barrier container that covers the gas adsorbent; and a moisture poorly permeable air permeable film that covers the barrier container. The gas adsorption device according to claim 1, wherein the moisture-permeable air-permeable film is transparent. The gas adsorption device according to claim 1 or 2, wherein the moisture poorly permeable air permeable film contains one of polyethylene and polypropylene. The gas adsorption device according to any one of claims 1 to 3, wherein the gas permeability of the gas to be adsorbed by the moisture poorly permeable air permeable film is 10 cc / day · atm or more. The gas adsorbing device according to any one of claims 1 to 4, a core material, and a moisture adsorbing material are installed together in the outer covering material, and the outer covering material is evacuated to produce a vacuum heat insulating material. To use the gas adsorption device. The method for using the gas adsorption device according to claim 5, wherein the through hole is formed in the barrier container and then installed in the jacket of the vacuum heat insulating material.