JP2006029686A - Vacuum thermal insulation panel and refrigerator using vacuum thermal insulation panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum thermal insulation panel capable of preventing a surface of a film from being damaged by rubbing and contact from the outside in a manufacturing process of the vacuum thermal insulation panel to prevent durability performance of a gas barrier vessel from worsening, improving durability of heat performance to withstand use for a long time even if the gas barrier vessel is formed by a film of not only resin film type formed by laminating aluminum foil but also aluminum deposition type, and prolonging performance maintenance time even under high humidity condition and to provide a refrigerator using this panel. <P>SOLUTION: In this vacuum thermal insulation panel 1 storing a core material 2 in the gas barrier vessel 3 and evacuating the inside to form a panel body, the gas barrier vessel 3 is formed by the aluminum deposition film or a multi-ply resin film formed by laminating aluminum foil, and a reinforcing layer formed by mixing ethylene vinyl alcohol copolymer and an inorganic material in a hybrid manner is provided in the resin film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum heat insulation panel with improved durability and a refrigerator using this vacuum heat insulation panel.

  Conventionally, as a heat insulating material for a heat-insulating cabinet in a refrigerator, it has been a mainstream to use a polyurethane foam that has a low thermal conductivity and is integrated with an outer box and an inner box that form a cabinet by foam filling and becomes a rigid body. In recent years, vacuum as a heat insulator has been used to further improve the heat insulation performance of refrigerator cabinets and reduce power consumption by preventing heat leakage, or by reducing the heat insulation wall thickness to improve volume efficiency as a refrigerator. Some insulation panels have been put to practical use.

  As an example of application to a refrigerator, the vacuum heat insulation panel (55) having a basic configuration shown in FIG. 5 has a material cost of about 1 to several hundreds of Pa in order to obtain long-term reliability by facilitating maintenance of exhaust and vacuum. In order to function at a relatively high internal pressure, a resin foam having an open cell structure capable of forming a micro space and maintaining the form under atmospheric pressure, an inorganic fine powder, and a fiber are used as the core material (55a). This core material (55a) is covered with a gas barrier container (55b) made of a laminate film of synthetic resin and aluminum foil, the inside of the container (55b) is evacuated, and then the opening is heat sealed (55c) and sealed. is there.

  In order to maintain the degree of vacuum by suppressing deterioration over time due to the outgas generated from the core material (55a) and the internal pressure increase due to the permeated gas entering the inside from the sealing surface or surface of the gas barrier container (55b), Metals such as titanium and magnesium, alloys such as barium / lithium, oxides such as cobalt oxide, calcium oxide, and zeolite, activated carbon, etc., and substances that adsorb air, moisture, oxygen, nitrogen and other gases, and gases such as hydrogen It is common to enclose a getter agent (55e) consisting of

As for the heat insulation performance, as shown in FIG. 6, a material using inorganic fine powder such as pearlite as a core material has a large heat conduction of the fine powder solid itself and a small space volume for heat insulation. In the case where the resin foam is used as the core material, the size of the bubble cell has a strength limit, so the thermal conductivity of the vacuum heat insulating panel is about 0.005 to 0.006 W / mK. And to obtain a thermal conductivity of less than that, it is possible to realize a low thermal conductivity of about 0.002 W / mK by forming many small spaces with glass wool having a fiber diameter of several μm or less as a core material. For example, Patent Document 1 has a configuration in which a vacuum heat insulation panel having a core material made of an inorganic fiber aggregate formed in a flat plate shape by a bonded body is provided in a machine room and a partition in a refrigerator. It is shown.
JP 2003-314951 A

  However, in the process of manufacturing a vacuum panel, external damage such as rubbing and contact is often caused by post-evacuation post-processing or transportation for incorporation into the refrigerator body, and the gas barrier container (53) is cracked. When it occurs, there is a problem that the scratch leaks through the inner and outer layers of the barrier container, and the heat insulation performance as a refrigerator is extremely deteriorated, and there is a problem that the cost greatly increases as the defect rate increases.

  In addition, in order to prevent leakage due to breakage of the panel, if the panel is subdivided according to the shape of the arrangement surface, the effect of heat leakage from the heat bridge from the downsized panel end face increases, and the entire refrigerator The heat insulation effect is reduced.

  In addition, as a gas barrier container (53), a so-called vapor deposition type vacuum heat insulation panel in which aluminum is vacuum-deposited (vacuum metallizing) is gas permeable, so that the pressure increase with time in the panel is accelerated. Compared to the aluminum foil panel, there was a problem in durability due to deterioration of thermal conductivity.

  In order to improve this durability, we considered the use of EVOH (ethylene vinyl alcohol copolymer) with good gas barrier properties. In this case, however, the durability in a high-humidity atmosphere is extremely deteriorated, and further improvements are made. Was demanded.

  The present invention has been made in consideration of the above points, and prevents the durability of the gas barrier container from being greatly deteriorated by damaging the film surface due to external rubbing or impact caused by hitting in the manufacturing process of the vacuum heat insulating panel. At the same time, even if the gas barrier container is formed not only with a resin film type laminated with an aluminum foil, but also with an aluminum vapor deposition type film, it can withstand long-term use by sufficiently improving the durability against thermal performance. An object of the present invention is to provide a vacuum heat insulation panel capable of extending the performance maintenance time even under high conditions, and a refrigerator using the vacuum heat insulation panel.

  In order to solve the above-mentioned problems, the vacuum heat insulation panel of the present invention contains a core material in a gas barrier container, evacuates the inside to form a panel body, and the gas barrier container is made of an aluminum vapor deposition film or aluminum foil. A laminated multilayer resin film is formed, and a reinforcing layer in which EVOH and an inorganic material are hybrid-mixed is provided in the resin film, and the vacuum heat insulating panel is provided on the outer box or inner box surface in the heat insulating wall. The refrigerator is characterized in that the vacuum insulation panel is embedded by foaming and filling polyurethane foam in the remaining space.

  According to the configuration of the present invention, EVOH and inorganic system can be used even when cracks occur in the gas barrier container due to external damage such as rubbing or contact in post-processing after evacuation in the manufacturing process of the vacuum heat insulation panel. A film layer that is a hybrid mixture of materials that is less likely to break and can improve durability, prevent deterioration of thermal insulation performance due to leakage, greatly improve the defect rate in the vacuum insulation panel manufacturing process, and reduce manufacturing costs It is. In addition, the performance maintenance time can be significantly extended even under high humidity conditions, and the heat insulation performance and stability over time as a refrigerator can be maintained over a long period of time, thereby improving the reliability.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic cross-sectional view of the refrigerator according to the present invention, in which a heat insulating space is provided between an outer box (9) made of a thin steel plate forming the outer shape of the main body and an inner box (10) forming a storage chamber. The refrigerator main body (8) is comprised.

  A vacuum heat insulation panel (1), which will be described in detail later, is pasted on both side surfaces, the back surface and the inner surface of the ceiling surface of the outer box (9) forming the heat insulation space, and the remaining inner box (10) A stock solution of foam insulation material (11) made of polyurethane foam is injected into the gap between the inner and outer boxes (9), (10) and the vacuum insulation panel (1) to be bonded and solidified integrally. And form a rigid heat insulation cabinet.

  As shown in FIG. 1 and FIG. 2 showing the panel vacuuming device (4), the vacuum heat insulating panel (1) is made of glass wool, which is a cotton-like material of thin glass fibers, as a core material (2). The core material (2) is inserted into a gas barrier container (3), the details of which will be described later, and the container (3) is placed on the base (5a) after the core material is inserted. Installed on the stage (5b) provided in the chamber (5) and evacuated to about 0.03-30 Pa by the vacuum pump (5c), and then closed the opening of the container with a binding margin of 20-50 mm. Then, by heat-sealing (6) over the 10 mm width of the binding margin, the inside of the container (3) is formed into a panel shape maintained in a vacuum and reduced pressure state.

  Then, the vacuum insulation panel (1) whose core material (2) is further compressed to about one half by the pressure difference by opening the inside of the vacuum chamber (5) to the atmospheric pressure, and finally the thickness is 10 to 12 mm. The vacuum heat insulation panel (1) has a heat seal bar (5f) that moves up and down in the same manner by rotating the chamber mantle (5e) in the upward arrow direction with the hinge (5d) as a support shaft. It is slid out from the opened opening.

  The core material (2) of glass wool is selected to have a fiber diameter of 10 μm or less, which is generally considered to have good heat insulation performance as a vacuum heat insulation panel, but in this example, a fiber having a diameter of 2 to 6 μm is adopted. As for the fiber length, a long fiber body of 50 mm or more was also mixed, but a needling process was performed mainly using a short fiber of about 10 mm.

  And the random orientation of the glass wool fiber is maintained by the fiber diameter and the fiber length, and the fibers are entangled in the thickness direction by needling processing, so that the thermal conductivity in the thickness direction is lowered and the heat insulation effect is increased, and the raw cotton In the state, a 50 mm thick material is compressed to a thickness of about 10 to 20 mm, the surface becomes smooth, and a so-called firm core material (2) having elasticity and stickiness can be obtained.

  The mat-shaped core material (2) formed as described above is inserted into the gas barrier container (3) after being cut into a predetermined size or appropriately overlaid with a mat so as to finally have a required thickness. Is.

  Next, the gas barrier container (3) that houses the mat-shaped core material (2) will be described. As shown in FIG. 4, the gas barrier container (3) is, for example, a film in which aluminum is deposited on a 15 μm thick nylon resin (3a) as an outer layer and a 12 μm thick PET (polyethylene-terephthalate) resin as an intermediate layer. Two vapor-deposited PET (3b) are superposed, and 50 μm HDPE (high density polyethylene) (3c) is provided as an inner layer.

  Thus, between the middle layer deposited PET (3b) and the inner layer HDPE (3c), the EVOH (ethylene vinyl alcohol copolymer) and an inorganic material are mixed and applied to PP (polypropylene). The reinforcing layer (3d) is interposed, and is formed in a flat bag shape having a predetermined width, length, and thickness so as to be attached to the inner surface side of the outer box (9). At least one end in the length direction is opened, and the mat-like core material (2) is inserted and stored.

  As the inorganic material in the reinforcing layer (3d), natural montmorillonite, natural mica, synthetic mica, synthetic hectorite, or synthetic saponite is suitable. Since natural montmorillonite has a large aspect ratio of particles, the flow path length of the gas that permeates through the organic material is increased, and the thickness of the barrier material is increased. Greatly improved.

  The position of the reinforcing layer (3d) is not only between the inner layer and the middle layer, but is additionally interposed between the two layers of vapor-deposited PET (3b) (3b) as the middle layer, or the middle layer is a 6 μm aluminum foil. As an alternative, it may be interposed between the HDPE (3c) of the inner layer. Further, the reinforcing layer (3d) may be applied by post-processing to the exterior body before panel formation, or may be applied by post-processing to a finished body that is a vacuum heat insulation panel.

  Further, the combination with the sealant and other resin configurations can be applied to all the above cases, and the vapor deposition film is not limited to aluminum but can be applied to all materials such as alumina and silica.

  The opening of the gas barrier container (3) is closed after evacuation and heat sealed (6) to form the vacuum heat insulation panel (1). The heat seal portion may be heat sealed in a state where the closed portions of the opening of the gas barrier container are overlapped, and further folded and fixed to the end face side of the panel (1).

  In the present invention, as the exterior body of the gas barrier container (3), the reinforcing layer (3d) is formed by hybrid mixing EVOH with an inorganic material having high gas barrier properties and excellent impact resistance and wear properties. Even when cracks are generated on the outer surface of the gas barrier container (3) in the manufacturing process after panel formation due to external force such as rubbing or contact, the damage can be reduced by the reinforcing layer (3d), and the aluminum foil Even a vacuum-deposited type gas barrier container that is inferior in durability to thermal performance compared to the type can greatly improve durability by preventing extreme deterioration of heat insulation performance.

  In addition, the weak point that durability at high humidity deteriorates with EVOH alone is improved, and the performance against humidity is improved by hybrid mixing of inorganic materials that have a very high gas barrier property and hardly allow gas permeation compared to organic materials. In addition, the durability can be enhanced and the heat insulation performance can be maintained for long-term use.

  The vacuum heat insulation panel (1) comprised as mentioned above is conveyed to the assembly production line of a refrigerator, and as shown in FIG. 3, the both-side wall inner surface and ceiling surface of the outer box (9) of a refrigerator main body (8), Is to form a predetermined panel spacing on the back surface, etc., if necessary, and attach it to a predetermined position with hot melt adhesive or double-sided tape. However, in the unlikely event of panel transportation or incorporation into the refrigerator body (8) Even if it is in contact with the process equipment and rubs or abuts against the protrusion and receives external force, the presence of the reinforcing layer (3d) of the gas barrier container (3) can alleviate damage such as breakage due to external force. Furthermore, even if a crack occurs, the inside and outside of the layer do not penetrate, and the entry of outside air into the panel can be prevented.

  Further, as described above, the vacuum heat insulation panel (1) has a high durability against a high humidity atmosphere, so it can be arranged on the inner box side where the humidity is high in the heat insulation wall in the refrigerator. It is possible to widen the allowable range of the panel placement location.

  And, after the vacuum insulation panel (1) and the inner box (10) after installation, the stock solution of the polyurethane foam insulation material (11) is injected and foamed by in-situ foaming method, and solidified by filling and solidifying the panel (1). The inner box (10) and the outer box (9) are integrated and are further protected from external forces by embedding in polyurethane foam, providing good heat insulation performance and stability over time as a refrigerator. While maintaining for a long period of time, improving durability and improving reliability, the cooling efficiency in the storage chamber can be improved to contribute to reduction of power consumption.

  The refrigerator is not limited to household use, and can be similarly applied to a heat insulation cabinet configuration such as a business use, a showcase, and a vending machine.

  INDUSTRIAL APPLICABILITY The present invention can be used for a vacuum heat insulating panel having good heat insulating performance and high durability, and a refrigerator with low power consumption using the vacuum heat insulating panel.

It is a section detail drawing of a vacuum heat insulation panel which shows one embodiment of the present invention. It is the schematic which shows the vacuum drawing state of the vacuum heat insulation panel of FIG. It is a schematic sectional drawing of the refrigerator which affixed the vacuum heat insulation panel of FIG. It is a partial cross section figure which shows the detail of the gas barrier container of the vacuum heat insulation panel of FIG. It is sectional drawing which shows the basic structure of a vacuum heat insulation panel. It is a comparative graph which shows the difference of the vacuum degree by a core material, and thermal conductivity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum heat insulation panel 2 Mat-shaped core material 3 Gas barrier container 3a Nylon resin layer 3b Deposition PET layer 3c HDPE layer 3d Reinforcement layer 4 Vacuum drawing apparatus 5 Vacuum chamber 6 Heat seal 8 Refrigerator main body 9 Outer box
10 Inner box 11 Urethane foam

Claims (4)

  In a vacuum insulation panel in which the core material is housed in a gas barrier container and the inside is evacuated to form a panel body, the gas barrier container is formed of an aluminum vapor deposited film or a multilayer resin film laminated with an aluminum foil, and this resin. A vacuum heat insulating panel comprising a reinforcing layer in which a hybrid mixture of an ethylene vinyl alcohol copolymer and an inorganic material is provided in a film.   The multilayer resin film forming the gas barrier container is formed by laminating a nylon resin, vapor-deposited PET, high-density polyethylene, and a reinforcing layer in which an ethylene-vinyl alcohol copolymer and an inorganic material are hybrid-mixed. Item 2. The vacuum insulation panel according to Item 1.   2. The vacuum heat insulating panel according to claim 1, wherein the outer surface of the gas barrier container formed of a multilayer resin film is coated with a hybrid mixture of an ethylene vinyl alcohol copolymer and an inorganic material. The vacuum heat insulation panel according to any one of claims 1 to 3 is attached to an outer box or an inner box surface in a heat insulation wall, and polyurethane foam is filled in the remaining space by embedding the vacuum heat insulation panel. Refrigerator.

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