JP2008111493A - Vacuum container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum container having high heat insulating performance, a container shape, in particular, high gas barrier property, improved abnormal shape property and high reliability. <P>SOLUTION: The vacuum container 1 is a box body consisting of at least an outer box 3 and an inner box 4. It has a vacuum double wall structure where a core material 6 is provided in a heat insulating space 5 between the outer box 3 and the inner box 4 and the heat insulating space 5 is depressurized. At least the box body is constructed in multi-layers by applying in-mold molding of a high gas barrier property material (a metal film 2) to a resin material. With the in-mold molding of the high gas barrier property material in the resin material, the vacuum container 1 has high performance, high heat insulating performance and high abnormal shape property. The Clark rigidity and smoothness of the in-mold product is optimized, resulting in the vacuum container 1 having less bubbles or wrinkles and good and high gas barrier property. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vacuum container that can be used as a heat insulator such as a refrigerator, a heat insulating container, a vending machine, an electric water heater, and a vehicle house.

  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 refrigerators, etc., heat entry is cut off and the operating rate of the refrigeration system is lowered, contributing to energy saving. In the heat-reserving liquid storage container that is built into the circulation system of an automobile engine, the heated and cooled water is kept warm and used effectively By doing so, the combustion efficiency from the initial stage of engine operation can be secured. From the above viewpoint, the heat insulation performance improvement of the heat insulation box is calculated | required.

  In the case where heat conduction is performed through the presence of air, there is a mean free path of gas as a physical property affecting the heat insulation performance.

  The mean free path of a gas is the distance traveled until one of the molecules that make up the air collides with another molecule. If the void formed is larger than the mean free path, the molecules in the gap Collide and heat conduction by gas occurs, so that the thermal conductivity increases.

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

  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. Although the vacuum heat insulator is mainly used as a vacuum heat insulating panel, a vacuum vessel which is a container-like vacuum heat insulating material is also required due to diversification of forms.

  For example, in the heat insulation structure of a resin vacuum double container used for heat insulation such as tableware and cups for weight reduction, the surface in contact with the internal space is subjected to electroplating, electroless plating, or vapor deposition in order to improve the gas barrier property. A metal film is formed. In addition, blow molding or injection molding is performed to obtain a degree of freedom in shape, and plating is performed after welding the inner box and the outer box (see Patent Document 1).

In addition, in the blow-molding of heat-resistant polyphenylene oxide resin, a cylindrical parison is formed by an extrusion molding machine, and an aluminum film is set in the die inside the parison. A hollow panel is formed by inscribing an aluminum film on the inner side and sandwiched between molds, and then a powder such as pearlite is injected as a structural material, and a vacuum heat insulating member is formed by reducing the pressure (Patent Document 2). reference).
JP-A-6-113963 Japanese Patent No. 2966503

  However, in the configuration of Patent Document 1, there is no problem in moldability, weight, and gas barrier properties, but after forming, a vapor deposition film is formed, which increases man-hours and decreases productivity. In addition, in the case of a complicated shape, there is a portion where the vapor deposition film cannot be formed, and thus there is a limitation on the shape.

  Also in electrolytic plating, since resin does not have electrical conductivity, it is necessary to impart conductivity, which increases the number of steps and productivity is also poor. In electroless plating, the number of processes increases and there is a problem of using an environmentally hazardous substance such as formaldehyde as a reducing agent. Furthermore, since both the electrolytic plating method and the electroless plating method are performed in a liquid, cleaning and drying processes are required after the plating film is produced. If the drying is insufficient, the degree of vacuum deteriorates and the heat insulation performance deteriorates. Furthermore, the resin material has a lower strength than the metal material, and when the pressure is reduced, there is a problem that a compressive force is applied by the atmosphere, and the resin material is cracked or deformed.

  There is also a method of enclosing an inert low thermal conductive gas such as Xe inside, but the thermal conductivity of the gas is increased and the heat insulation performance is inferior compared to vacuum. Also, by increasing the thickness of the resin material, the strength can be improved, but since the thickness increases, the amount of heat leak increases, the material cost is high, and the space of the wall material increases, Volumetric efficiency becomes worse.

  Moreover, in the structure of patent document 2, although the aluminum film is installed with extrusion, wrinkles generate | occur | produce or air enters between an aluminum film and resin, and an air pool remains easily. If there is air accumulation, the aluminum film in that portion is easily damaged, and the gas barrier property may be lowered.

  In addition, since the resin material and the aluminum film are multi-layered in the parison state, the elongation rate of the aluminum film and the resin material is different in subsequent blow molding, so the aluminum film may break, and the resin material is also broken. There is a possibility of bagging. Moreover, the air in the air pool may enter the inside of the vacuum heat insulating member due to the broken bag. Moreover, even if there is no broken bag, it is difficult to perform molding with a large profile.

  An object of the present invention is to provide a vacuum insulator having a high heat insulation performance, in particular a vacuum container having a container shape, having a high gas barrier property, excellent atypical properties, and high reliability. It is.

  In order to achieve the above object, a vacuum container according to the present invention is a box composed of at least an outer box and an inner box, and a core material is provided in a space between the outer box and the inner box, and the space is decompressed. Thus, a vacuum container having a vacuum double wall structure is characterized in that at least the box has a structure in which a high gas barrier material is in-mold molded into a resin material to form a multilayer structure.

  Vacuum containers require high thermal insulation properties. Therefore, the hollow space atmosphere of the double wall structure of the outer box and the inner box is in a reduced pressure or vacuum state. Therefore, in order to maintain the reduced pressure or vacuum state of the hollow space, it is necessary to configure the material with a high gas barrier property that hardly allows external gas to pass therethrough.

  Moreover, if the thermal conductivity of the material constituting the vacuum container is high, the heat conduction through the container is increased even if the heat conduction through the hollow space is low. Therefore, high heat insulation performance can be obtained by using a resin material having a relatively low thermal conductivity.

  Furthermore, if it is a resin material, it is rich in a moldability and it becomes possible to form a vacuum vessel of a complicated shape. In addition, since it is in-mold molding, it is formed into a multi-layer at the same time as molding, so that molding with high irregularity can be performed even if the resin material and the high gas barrier material have different elongation rates.

  The vacuum container of the present invention is further characterized in that the high gas barrier material has a Clark stiffness of 5 or more and 500 or less. Here, Clark stiffness is resistance to bending and is also called stiffness. Theoretically, this property is proportional to the cube of the thickness, proportional to the elastic modulus, and measured according to JIS P-8143. Is.

  In in-mold molding, when the coating material is placed in a mold, if the Clark stiffness is lower than 5, wrinkles are likely to be formed, and it is bent. On the other hand, if the Clark stiffness is higher than 500, the unevenness and the curved portion are lifted, and molding and misalignment with high adhesion tend to occur.

  The vacuum container of the present invention is further characterized in that the high gas barrier material has a smoothness of 10 seconds to 3000 seconds. Here, the smoothness is a scale indicating the smoothness of the surface and is measured according to JIS P-8119. When the smoothness is 10 seconds or less, the gap increases and the adhesion is inferior. In addition, if the smoothness exceeds 3000 seconds, it is difficult for air to escape, and air retention tends to occur on the bonding surface between the resin material and the high gas barrier material during in-mold molding.

  The vacuum vessel of the present invention is further characterized in that the total thickness of the high gas barrier material is 500 μm or less. When the thickness of all the layers exceeds 500 μm, the deformation of the molded product molded in-mold increases.

  The vacuum container of the present invention can realize a high-performance, high heat insulation performance, and highly unusual vacuum container by in-mold molding of a high gas barrier material into a resin material. A smoothness can be optimized, and a vacuum container having good and high gas barrier properties with less air accumulation and wrinkles can be provided.

  The invention of the vacuum container according to claim 1 of the present invention is a box composed of at least an outer box and an inner box, and a core material is provided in a space between the outer box and the inner box, and the space is decompressed. Thus, a vacuum container having a vacuum double wall structure is characterized in that at least the box has a structure in which a high gas barrier material is in-mold molded into a resin material to form a multilayer structure.

  As a result, it is composed of a high gas barrier material for maintaining the vacuum state of the space, and the heat conductivity of the material constituting the vacuum container is relatively low, thereby suppressing heat leak transmitted through the container. In addition, high heat insulation performance can be obtained.

  Furthermore, if it is a resin material, it is rich in a moldability and it becomes possible to form a vacuum vessel of a complicated shape. In addition, since it is in-mold molding, it is formed into a multi-layer at the same time as molding, so that molding with high irregularity can be performed even if the resin material and the high gas barrier material have different elongation rates.

  The core material is not particularly limited as to the material system, and is not particularly limited to organic or inorganic fibers, powder, solidified powder, foamed resin, and the like.

  For example, in the case of a core material using fibers, inorganic fibers such as glass wool, glass fibers, alumina fibers, silica alumina fibers, silica fibers, rock wool, silicon carbide fibers, natural fibers such as cotton, synthetic fibers such as polyester and nylon, etc. Known materials such as organic fibers can be used.

  In order to use the fiber, there are methods such as compression or heat compression of the fiber, compression or heat compression using water or a binder, needling, spunlace, and papermaking.

  On the other hand, in the core material using powder, inorganic powder such as silica, pearlite and carbon black, organic powder such as synthetic resin powder, or a mixture thereof is filled as it is or filled into a breathable bag. Or solidifying with a fiber binder or an inorganic or organic liquid binder.

  In the foamed resin, urethane foam, phenol foam, styrene foam, or the like can be used.

  In order to maintain the vacuum, an adsorbent may be used. The adsorption mechanism may be any of physical adsorption, chemical adsorption, occlusion, and sorption, but a substance that acts as a non-evaporable getter is good.

  Specifically, physical adsorbents such as synthetic zeolite, activated carbon, activated alumina, silica gel, dosonite, hydrotalcite and the like.

  As the chemical adsorbent, alkali metal or alkaline earth metal oxides, alkali metal or alkaline earth metal hydroxides, etc. can be used, and in particular, lithium oxide, lithium hydroxide, calcium oxide, calcium hydroxide, Magnesium oxide, magnesium hydroxide, barium oxide, and barium hydroxide are effective.

  In addition, calcium sulfate, magnesium sulfate, sodium sulfate, sodium carbonate, potassium carbonate, calcium chloride, lithium carbonate, unsaturated fatty acid, iron compound and the like also act effectively.

  Further, it is more effective to apply a getter material obtained by singly or alloying materials such as barium, magnesium, calcium, strontium, titanium, zirconium, and vanadium.

  Furthermore, in order to adsorb and remove at least nitrogen, oxygen, moisture, and carbon dioxide, the getter material can be applied in various mixtures.

  More preferably, it is adsorbed at room temperature. A plurality of types of gas adsorbents may be used.

  Further, the gas adsorbent can be used as a powder or a molded body, but is not particularly specified. In addition, the molded gas adsorbent can be used in the form of compression molding, tableting, pelletizing, etc., or the powder in a separate container and the powder in the container compressed Further, the gas adsorbent may be covered with another gas adsorbent.

  As for the method of using the gas adsorbing material, the inside of the vacuum container is evacuated while the container containing the core material and the gas adsorbing material is vented to the hollow part of the vacuum container, and then the vacuum container is sealed. By creating a vacuum heat insulation space and maintaining the degree of vacuum in the heat insulator with a gas adsorbent, or evacuating the hollow part of the vacuum vessel to an industrially easy reach, and then sealing the vacuum vessel In this case, the gas in the hollow part of the vacuum vessel remaining at that time is adsorbed with a gas adsorbent, so that it acts like a two-stage decompression, or the gas adsorbent is sealed in a separate container, After evacuating the hollow part to a predetermined pressure, the gas adsorbent can be communicated with the hollow part of the vacuum vessel in some way, which works like a two-stage decompression while keeping the gas adsorbent more highly active. Let me Although it is also possible, it does not specify particular for usage.

  Further, the gas adsorbing material may be arranged at one place or at a plurality of places in order to further improve the production efficiency. Further, it is possible to remove the gas adsorbent at the time of dismantling such as recycling.

  The in-mold molding method is not limited, but blow molding, injection molding, vacuum molding, and pressure molding are the most common, easy to mold, and any molding method may be used. In addition, blow molding has the shape of the container, injection molding has precision molding, vacuum molding and pressure molding have the advantages of low cost molding of large products, so these molding methods can be combined. I do not care.

  The invention of the vacuum container according to claim 2 of the present invention is characterized in that the high gas barrier material in the invention of claim 1 is made of at least a metal material.

  Since the metal material is very difficult to pass gas, it is suitable as a high gas barrier material. A material containing a metal material, for example, a metal foil such as an aluminum foil, or a laminate film in which a metal foil and a resin material are laminated in a sheet shape are suitable, but the shape and the amount of metal used are not limited. Moreover, although a metal seed | species is not limited, aluminum, iron, copper, and stainless steel are preferable as a general purpose metal foil. The metal may be a vapor deposition film or a plating film, and the shape does not need to be a sheet, and may be a slice, chip, strip, or the like. A plurality of them may be used.

  In addition, the resin material to be laminated in the laminate film is not particularly limited, but polyethylene, polyethylene terephthalate, polypropylene, nylon, ethylene-vinyl alcohol copolymer is often used, and needs to be a single layer. However, the multilayer is preferable from the viewpoint of durability.

  The invention of the vacuum container according to claim 3 of the present invention is characterized in that the high gas barrier material in the invention of claim 1 is made of at least a high gas barrier resin.

  A high gas barrier resin is inferior to a metal material having the same thickness, but has a very high gas barrier property and has an atypical property not found in a metal material, and is excellent in moldability.

  Examples of the high gas barrier resin include ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyamide 6, polyamide 11, polyamide 12, polybutylene terephthalate, polybutylene naphthalate, polyethylene naphthalate, polyvinylidene fluoride, and polyvinylidene chloride. , Ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, polyphenylene fluoride, polyetheretherketone, polyimide, polyacrylic acid resin, and at least one of these groups is used, or a plurality of them are combined As a result, a vacuum container having high gas barrier properties and high moldability can be provided.

  The invention of the vacuum vessel according to claim 4 of the present invention is that the Clark stiffness of the high gas barrier material in the invention according to any one of claims 1 to 3 is 5 or more and 500 or less. It is a feature.

  Here, Clark stiffness is resistance to bending and is also called stiffness. Theoretically, this property is proportional to the cube of the thickness, proportional to the elastic modulus, and measured according to JIS P-8143. Is.

  In in-mold molding, when the coating material is placed in a mold, if the Clark stiffness is lower than 5, wrinkles are likely to be formed, and it is bent. On the other hand, if the Clark stiffness is higher than 500, the unevenness and the curved portion are lifted, and molding and misalignment with high adhesion tend to occur.

  The invention of the vacuum vessel according to claim 5 of the present invention is such that the smoothness of the high gas barrier material in the invention according to any one of claims 1 to 4 is not less than 10 seconds and not more than 3000 seconds. It is characterized by this.

  Here, the smoothness is a scale indicating the smoothness of the surface and is measured according to JIS P-8119. When the smoothness is 10 seconds or less, the gap increases and the adhesion is inferior. In addition, if the smoothness exceeds 3000 seconds, it is difficult for air to escape, and air retention tends to occur on the bonding surface between the resin material and the high gas barrier material during in-mold molding.

  In the vacuum vessel according to claim 6 of the present invention, the thickness of all layers of the high gas barrier material in the invention according to any one of claims 1 to 5 is 500 μm or less. It is characterized by.

  When the thickness of all layers exceeds 500 μm, the deformation of the in-molded product becomes large due to differences due to unevenness, differences in shrinkage, etc., and therefore the thickness of all layers is preferably 500 μm or less.

  The invention of the vacuum container according to claim 7 of the present invention is characterized in that the high gas barrier material according to any one of claims 1 to 6 is provided with perforations.

  Since the high gas barrier material has perforations, air between the resin material and the high gas barrier material is discharged from the perforations, so that air accumulation between the resin material and the high gas barrier material is less likely to occur. In addition, it is possible to prevent deterioration of the gas barrier property due to the intrusion of air in the air reservoir and the swelling or spreading of the metal foil, thereby forming a highly reliable vacuum container.

  Further, since the size and number of the perforations vary depending on the molding conditions and the shape of the molded body, they are not particularly limited. However, it is preferable that the total area of the perforations is as small as possible because the gas barrier property is higher. Further, the shape of the perforation is not particularly specified, and there is no problem even if it is circular, square or linear.

  The invention of the vacuum vessel according to claim 8 of the present invention is characterized in that the resin material according to any one of claims 1 to 7 includes an FRP molding material. .

  By using FRP (Fiber Reinforced Plastic) resin as the resin material, it is possible to provide a vacuum container that is less deformed at the time of decompression and has improved impact resistance and excellent durability.

  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 longitudinal sectional view of a vacuum vessel according to Embodiment 1 of the present invention, and FIGS. 2 (a) and 2 (b) are schematic views of housing manufacture for the vacuum vessel according to Embodiment 1. FIG.

  The configuration of the vacuum container according to the first embodiment will be described with reference to FIG.

  In a vacuum container 1 having a hollow double wall structure, a metal film 2 is in-mold formed on the surfaces of an outer box 3 and an inner box 4. A hollow part is the heat insulation space 5, and the inside is filled with the core material 6 which is a structure. The core material 6 is injected from the injection port 7. After the injection, the heat insulating space 5 is decompressed from the exhaust port 8, and after the decompression, the injection port 7 and the exhaust port 8 are sealed to form a vacuum heat insulating structure. In the heat insulating space 5, a gas adsorbing material 9 and a moisture adsorbing material 10 for adsorbing air entering from the outside and air adsorbed inside are installed in advance.

  Next, with reference to FIG. 2, manufacturing of the vacuum container casing in the first embodiment will be described. Detailed description of components having the same configuration as in FIG. 1 is omitted.

  In FIG. 2A, the resin material is extruded from the extruder 11, and the cylindrical resin parison 13 is extruded from the die 12. The metal film 2 is installed on the surface of the mold 14, and the mold 14 is sandwiched so that the parison 13 is sandwiched.

  As shown in FIG. 2B, after sandwiching the mold, air is blown from the air blowing port 15 to be molded, and at the same time, the metal film 2 is thermally welded and in-mold molded.

  In the first embodiment, a metal film is used as the high gas barrier material. However, the type of the metal film is not limited. For example, a metal foil such as an aluminum foil, or a metal foil and a resin material are formed in a sheet shape. A laminated film is suitable, but it does not limit the shape or the amount of metal used. Moreover, although a metal seed | species is not limited, aluminum, iron, copper, and stainless steel are preferable as a general purpose metal foil.

  The metal may be a vapor deposition film or a plating film, and the shape does not need to be a sheet, and may be a slice, chip, strip, or the like. A plurality of them may be used.

  Moreover, even if it says a metal film, it does not need to be covered with the whole surface metal film, and the gas barrier property should just be improved with the metal. Preferably, a larger coating area of the metal foil is better.

  In addition, the resin material to be laminated in the laminate film is not particularly limited, but polyethylene, polyethylene terephthalate, polypropylene, nylon, ethylene-vinyl alcohol copolymer is often used, and needs to be a single layer. However, the multilayer is preferable from the viewpoint of durability.

  A high gas barrier resin material may be used as the high gas barrier material. Although it is inferior to a metal material having the same thickness, it has a very high gas barrier property, and has an atypical property not found in a metal material, and is excellent in moldability.

  Examples of the high gas barrier resin include ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyamide 6, polyamide 11, polyamide 12, polybutylene terephthalate, polybutylene naphthalate, polyethylene naphthalate, polyvinylidene fluoride, and polyvinylidene chloride. , Ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, polyphenylene fluoride, polyetheretherketone, polyimide, polyacrylic acid resin, and at least one of these groups is used, or a plurality of them are combined As a result, a vacuum container having high gas barrier properties and high moldability can be provided.

The gas barrier material has an air permeation rate of 10 [cm ³ · 10 μm / m ² · day · atm] or less, preferably 1 [cm ³ · 10 μm / m ² · day · atm] or less, more preferably 0.8. It is desirable that it is 1 [cm ³ · 10 μm / m ² · day · atm] or less. When the air permeation speed is greater than 10 [cm ³ · 10 μm / m ² · day · atm], the amount of air permeation from the outside increases and the long-term reliability is poor.

  In addition, in order to obtain a hollow double wall structure, the first embodiment is formed by blow molding, but the present invention is not limited to this. For example, there is no problem even if a hollow structure is formed by in-mold molding by injection molding, vacuum molding, pressure molding, or the like, and joined by heat welding or an adhesive. Moreover, you may combine these shaping | molding methods.

  Also, a plurality of hollow double-walled vacuum containers can be combined or joined together to form a vacuum container of another shape.

  The core material is not particularly limited as to the material system, and is not particularly limited to organic or inorganic fibers, powder, solidified powder, foamed resin, and the like.

  For example, in the case of a core material using fibers, inorganic fibers such as glass wool, glass fibers, alumina fibers, silica alumina fibers, silica fibers, rock wool, silicon carbide fibers, natural fibers such as cotton, synthetic fibers such as polyester and nylon, etc. Known materials such as organic fibers can be used.

  In order to use the fiber, there are methods such as compression or heat compression of the fiber, compression or heat compression using water or a binder, needling, spunlace, and papermaking.

  On the other hand, in the core material using powder, inorganic powder such as silica, pearlite and carbon black, organic powder such as synthetic resin powder, or a mixture thereof is filled as it is or filled into a breathable bag. Or solidifying with a fiber binder or an inorganic or organic liquid binder.

  In the foamed resin, urethane foam, phenol foam, styrene foam, or the like can be used.

  Further, the method of encapsulating the core material is not limited to the method of encapsulating from the encapsulation port. For example, the core material may be sealed from the air blowing port, the sealing port and the exhaust port may be one, or conversely there is no problem.

  For core materials that are difficult to seal from the sealing port, such as glass wool, the vacuum container may be separated into an inner box and an outer box, and the solidified core material may be sealed. Thus, there is no problem even if the core material is enclosed by sheet blow molding.

  Further, since the core material also serves as a structural material, the volume change rate is preferably within 50%. The volume change rate of the core material is, for example, that the core material volume reduced by compressing to the atmosphere by enclosing the core material in a bag having high gas barrier properties such as a laminated film bag and reducing the pressure to the core material volume before the pressure reduction It is the rate of change of the core material volume that is reduced. Even if the box is compressed by atmospheric compression by decompression, since the volume change of the core material is small, deformation of the box can also be suppressed, and reliability such as deformation and crack suppression can be improved.

  Further, the gas adsorbing material and the moisture adsorbing material are not limited to the material types. The adsorption mechanism may be any of physical adsorption, chemical adsorption, occlusion, and sorption, but a substance that acts as a non-evaporable getter is good.

  Specifically, physical adsorbents such as synthetic zeolite, activated carbon, activated alumina, silica gel, dosonite, hydrotalcite and the like.

  As the chemical adsorbent, alkali metal or alkaline earth metal oxides, alkali metal or alkaline earth metal hydroxides, etc. can be used, and in particular, lithium oxide, lithium hydroxide, calcium oxide, calcium hydroxide, Magnesium oxide, magnesium hydroxide, barium oxide, and barium hydroxide are effective.

  In addition, calcium sulfate, magnesium sulfate, sodium sulfate, sodium carbonate, potassium carbonate, calcium chloride, lithium carbonate, unsaturated fatty acid, iron compound and the like also act effectively.

  Further, it is more effective to apply a getter material obtained by singly or alloying materials such as barium, magnesium, calcium, strontium, titanium, zirconium, and vanadium.

  Furthermore, in order to adsorb and remove at least nitrogen, oxygen, moisture, and carbon dioxide, the getter material can be applied in various mixtures.

  More preferably, it is adsorbed at room temperature. A plurality of types of gas adsorbents may be used.

  Further, the gas adsorbent can be used as a powder or a molded body, but is not particularly specified. In addition, the molded gas adsorbent can be used in the form of compression molding, tableting, pelletizing, etc., or the powder in a separate container and the powder in the container compressed Further, the gas adsorbent may be covered with another gas adsorbent.

  As for the method of using the gas adsorbing material, the inside of the vacuum container is evacuated while the container containing the core material and the gas adsorbing material is vented to the hollow part of the vacuum container, and then the vacuum container is sealed. By creating a vacuum heat insulation space and maintaining the degree of vacuum in the heat insulator with a gas adsorbent, or evacuating the hollow part of the vacuum vessel to an industrially easy reach, and then sealing the vacuum vessel In this case, the gas in the hollow part of the vacuum vessel remaining at that time is adsorbed with a gas adsorbent, so that it acts like a two-stage decompression, or the gas adsorbent is sealed in a separate container, After evacuating the hollow part to a predetermined pressure, the gas adsorbent can be communicated with the hollow part of the vacuum vessel in some way, which works like a two-stage decompression while keeping the gas adsorbent more highly active. Let me Although it is also possible, it does not specify particular for usage.

  Further, the gas adsorbing material may be arranged at one place or at a plurality of places in order to further improve the production efficiency. Further, it is possible to remove the gas adsorbent at the time of dismantling such as recycling.

  Further, the Clark stiffness of the high gas barrier material to be molded in-mold is preferably 5 or more and 500 or less. Here, Clark stiffness is resistance to bending and is also called stiffness. Theoretically, this property is proportional to the cube of the thickness, proportional to the elastic modulus, and measured according to JIS P-8143. Is.

  In in-mold molding, when the coating material is placed in a mold, if the Clark stiffness is lower than 5, wrinkles are likely to be formed, and it is bent. On the other hand, if the Clark stiffness is higher than 500, the unevenness and the curved portion are lifted, and molding and misalignment with high adhesion tend to occur.

  Moreover, it is preferable that the smoothness of the high gas barrier material to be molded in-mold is 3000 seconds or less. Here, the smoothness is a scale indicating the smoothness of the surface and is measured according to JIS P-8119. If the surface is not smooth, there will be more gaps and air will remain. If the smoothness exceeds 3000 seconds, air will easily accumulate on the bonding surface between the resin material and the high gas barrier material during in-mold molding. Therefore, the smoothness is set to 3000 seconds or less.

  Moreover, it is preferable that the thickness of all the layers of the high gas barrier material to be molded in-mold is 500 μm or less. When the thickness of all layers exceeds 500 μm, the deformation of the in-molded product becomes large due to differences due to unevenness, differences in shrinkage, etc., and therefore the thickness of all layers is preferably 500 μm or less.

  Moreover, it is preferable to provide perforations in the high gas barrier material to be molded in-mold. By having perforations in the high gas barrier material, air between the resin material and the high gas barrier material is discharged from the perforations, so that air accumulation between the resin material and the high gas barrier material is less likely to occur, A highly reliable vacuum container can be configured by preventing the intrusion of air into the air reservoir and the deterioration of the gas barrier property due to the tearing or spreading of the metal foil.

  Further, since the size and number of the perforations vary depending on the molding conditions and the shape of the molded body, they are not particularly limited. However, it is preferable that the total area of the perforations is as small as possible because the gas barrier property is higher. Further, the shape of the perforation is not particularly specified, and there is no problem even if it is circular, square or linear.

  Moreover, it is preferable that FRP molding material is included in the resin material which forms the inner box and outer box of a vacuum vessel. By using the FRP resin as the resin material, it is possible to provide a vacuum container that is less deformed during decompression, has improved impact resistance, and is excellent in durability.

  Example 1 to Example 4 show the evaluation results of appearance and heat insulation performance in a vacuum vessel in which the conditions of the high gas barrier material are changed.

(Example 1)
The core material is a mixture of 84.5 wt% dry silica with an average primary particle diameter of 7 nm, 5.5 wt% carbon black with an average particle diameter of 42 nm, and 10 wt% glass wool with an average fiber diameter of 7 μm as a fiber material. And molded.

  After mixing the powder with a cutter mill, the fiber material was further added and mixed. The core material thus produced is dried in a drying furnace at 110 ° C. for 1 hour.

  The inner box and the outer box are multilayer materials having a structure in which two 0.5 mm thick polypropylenes are sandwiched between 100 μm thick ethylene-vinyl alcohol copolymer (EVOH), and molding is performed by blow molding. Polypropylene and EVOH are bonded with a bonding material (10 μm).

  Then, an aluminum film (total thickness: 100 μm) made of a multilayer material of nylon, aluminum foil and polypropylene having a Clark stiffness of 150 is placed on the inner surface of the mold at the time of blow molding, and integrated into the inner box at the same time as molding. Perform insert molding. Clark stiffness was appropriate, and in-mold molding without wrinkles could be performed. Also, the total thickness was appropriate, and no deformation after molding was observed.

  An injection port is attached to the housing, and the core material is sealed in the hollow portion while reducing the pressure from the exhaust port.

  Further, a gas adsorbent and a moisture adsorbent are inserted. Zeolite was used as the gas adsorbent, and calcium oxide was used as the water adsorbent.

  After reducing the pressure to 20 Pa, which is a predetermined pressure, the inlet and the exhaust port were sealed to obtain a vacuum container.

(Example 2)
The core material, jacket material, gas adsorbing material, and moisture adsorbing material were the same as those in Example 1, and the construction method was also produced in the same manner. As the sheet to be molded in-mold, a high gas barrier resin sheet made of a multilayer material (total thickness 60 μm) in which EVOH was sandwiched between polypropylenes having a smoothness of 300 seconds was used.

  As a result, since the smoothness is an appropriate value, in-mold molding can be performed with almost no air accumulation. Also, the total thickness was appropriate, and no deformation after molding was observed.

(Example 3)
The core material, jacket material, gas adsorbing material, and moisture adsorbing material were the same as those in Example 1, and the construction method was also produced in the same manner.

  The sheet to be in-molded uses an aluminum film (total thickness: 100 μm) made of a multilayer material of nylon, aluminum foil and polypropylene having a smoothness of 800 seconds, and the multilayer material containing the aluminum foil has 0 at 20 mm intervals. A punching hole of 5 mmφ was provided.

  As a result, the smoothness is an appropriate value and air escapes from the punching hole, so that in-mold molding without air accumulation can be performed.

Example 4
The core material, the sheet, the gas adsorbent, and the moisture adsorbent were the same as those in Example 1, and the construction method was also produced in the same manner.

  The inner box and the outer box are made of polyester FRP resin containing glass fiber having a thickness of 0.5 mm. Then, an aluminum film (total thickness 100 μm) made of a multilayer material of nylon, aluminum foil and polypropylene having a Clark stiffness of 150 is placed on the inner surface of the mold at the time of blow molding, and integrated into the inner box at the same time as molding. Perform insert molding.

  Clark stiffness was appropriate, and in-mold molding without wrinkles could be performed. Also, the total thickness was appropriate, and no deformation after molding was observed. Moreover, the main body is made of FRP resin, and is excellent in impact resistance.

(Embodiment 2)
FIG. 3 is a schematic configuration diagram showing an automotive heat storage type warming device using a vacuum vessel according to Embodiment 2 of the present invention.

  In FIG. 3, the regenerative warming device 16 is a circulation path in which the cooling water heated by the engine 18 is cooled by the radiator 19 through the cooling water circuit 17 and returned to the engine 18 again. Further, when the cooling water at the time of starting the engine is not warmed, the thermostat 20 is fully closed, and the cooling water circulates through the bypass passage 21 without passing through the radiator 19 having a heat radiation action, and the cooling water is heated. Speed up.

  Further, during continuous running of the automobile, the cooling water warmed in the cooling water circuit 19 is allowed to flow through the flow control valve 22 from the switching inlet pipe 23 to the vacuum vessel 25 to keep it warm. After that, when the engine is started, the flow control valve 22 is caused to flow from the switching outlet pipe 24 to the cooling water circuit and mixed with the cooling water to accelerate the temperature rise of the cooling water. Therefore, it is possible to improve the fuel efficiency of the vehicle when starting the engine.

  The vacuum vessel 25 uses the vacuum vessel formed by the method of Embodiment 1, has good in-mold molding, and has high gas barrier properties and high heat retention performance.

(Embodiment 3)
FIG. 4 is a longitudinal sectional view of a vacuum container applied to the refrigerator in the third embodiment of the present invention.

  The refrigerator 26 has a vacuum heat insulating box structure, and includes an inner box 27 constituting the inside of the refrigerator and an outer box 28 constituting the outer wall, and a heat insulating layer 29 exists between the inner box 27 and the outer box 28.

  The outer box 28 is composed of a PCM steel plate, and the inner box 27 is made of a multilayer resin material of ABS and EVOH obtained by in-mold molding of an aluminum sheet by differential pressure molding, and has an aluminum sheet on the heat insulating layer side.

  The inside of the heat insulation layer 29 is filled with a core material 30 and has a gas adsorbent 31 and a moisture adsorbent 32. Reference numeral 33 denotes an exhaust port, 34 denotes a machine room, and 35 denotes a compressor. Isobutane is used as the refrigerant.

  The aluminum sheet has Clark stiffness of 150, smoothness of 500 seconds, total thickness of 100μm, punching holes of 0.5mmφ at intervals of 20mm, and good and high gas barrier without wrinkles and air accumulation in in-mold molding A vacuum vessel having a property can be formed.

  Further, the outer box and the inner box are bonded with an epoxy resin.

  Next, a comparative example for the vacuum container of the present invention will be shown.

(Comparative Example 1)
The envelope material, the core material, the gas adsorbing material, and the moisture adsorbing material were the same as those in Example 1, and a vacuum container having substantially the same structure and construction method was manufactured. The sheet to be molded in-mold is an aluminum film (total thickness 300 μm) made of a multilayer material of nylon, aluminum foil and polypropylene having a Clark stiffness of 650. As a result, the Clark stiffness was too large, resulting in in-mold molding with many wrinkles.

(Comparative Example 2)
The envelope material, the core material, the gas adsorbing material, and the moisture adsorbing material were the same as those in Example 1, and a vacuum container having substantially the same structure and construction method was manufactured. The sheet to be in-molded is an aluminum film (total thickness 200 μm) made of a multilayer material of nylon, aluminum foil and polypropylene having a smoothness of 4000 seconds. As a result, since the smoothness was too large, in-mold molding with a large amount of air accumulation was achieved.

(Comparative Example 3)
The envelope material, the core material, the gas adsorbing material, and the moisture adsorbing material were the same as those in Example 1, and a vacuum container having substantially the same structure and construction method was manufactured. The sheet to be in-molded is an aluminum film (total thickness 600 μm) made of a multilayer material of nylon, aluminum foil and polypropylene. As a result, after molding, in-mold molding was performed with great deformation of the molded product.

  As described above, the vacuum container according to the present invention can realize a high-performance, high heat insulation performance, and highly unusual vacuum container by in-mold molding a high gas barrier material into a resin material. Optimized Clark stiffness and smoothness of molded products, can provide a vacuum container with good and high gas barrier properties with less air accumulation and wrinkles, heat storage warming device for automobiles and heat pump thermal insulation tank, Furthermore, it can be applied to various heat insulation applications such as a refrigerator / freezer and a heating / cooling device such as a refrigeration device and a physical object to be protected from heat and cold.

The longitudinal cross-sectional view of the vacuum vessel in Embodiment 1 of this invention (A) Explanatory drawing which shows the state before the metal mold | die pinching at the time of manufacture of the housing | casing of the vacuum vessel of the embodiment (b) The state after metal mold clamping at the time of the housing | casing manufacture of the vacuum container of the same embodiment Explanatory drawing showing Schematic configuration diagram of an automotive heat storage type warming device using a vacuum vessel according to Embodiment 2 of the present invention The longitudinal cross-sectional view of the vacuum vessel applied to the refrigerator in Embodiment 3 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Metal film 3 Outer box 4 Inner box 5 Thermal insulation space 6 Core material 25 Vacuum container 27 Inner box 28 Outer box 30 Core material

Claims (8)

  A box composed of at least an outer box and an inner box, a vacuum vessel having a vacuum double wall structure by providing a core material in a space between the outer box and the inner box, and depressurizing the space, A vacuum vessel characterized in that at least the box has a structure in which a high gas barrier material is molded in-mold into a resin material to form a multilayer.   The vacuum container according to claim 1, wherein the high gas barrier material is made of at least a metal material.   The vacuum container according to claim 1, wherein the high gas barrier material is made of at least a high gas barrier resin.   The vacuum vessel according to any one of claims 1 to 3, wherein a Clark stiffness of the high gas barrier material is 5 or more and 500 or less.   The vacuum container according to any one of claims 1 to 4, wherein the high gas barrier material has a smoothness of 10 seconds to 3000 seconds.   6. The vacuum container according to claim 1, wherein a thickness of all layers of the high gas barrier material is 500 μm or less.   The vacuum container according to any one of claims 1 to 6, wherein the high gas barrier material is provided with perforations.   The vacuum container according to claim 1, wherein the resin material includes an FRP molding material.

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