JP2006029413A - Vacuum heat insulating material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum heat insulating material and its manufacturing method, having irregularity corresponding to the irregular shape of a fixing face to which the vacuum heat insulating material is fixed, and having superior heat insulating performance. <P>SOLUTION: In this vacuum heat insulating material composed of at least a core material, and an outer wrapping material for wrapping the core material and keeping the inside in a decompressed state, the core material is composed of a laminated body of a plate material composed of open-cell synthetic resin foam, and a fibrous material composed of inorganic fiber and/or organic fiber. and the irregularity corresponding to the shape of a member surface to which the vacuum heat insulating material is formed on an outer face on a plate material side, of the vacuum heat insulating material. This manufacturing method of the vacuum heat insulating material comprises laminating the plate material composed of open-cell synthetic resin foam and the fibrous material composed of inorganic fiber and/or organic fiber, wrapping the laminate by the outer wrapping material, sealing an opening part of the outer wrapping material in a state of keeping the decompressed state inside to achieve the vacuum heat insulating material, and applying the irregularity processing to the vacuum heat insulating material from an outer surface on the plate material side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum heat insulating material used as a heat insulating material in a heat insulating chamber that keeps the temperature constant, such as a refrigerator, a vending machine, a cold box, a cold car, and the like, and a manufacturing method thereof.

  Conventionally, heat insulating materials having various structures and performances are used in heat insulating cabinets such as refrigerators, vending machines, cold storage boxes, and cold cars. In recent years, vacuum heat insulating materials having very excellent heat insulating properties are known and are used in many applications. The vacuum heat insulating material generally has a structure in which a core material is filled in an outer packaging material made of a metal vapor-deposited film having gas barrier properties, and the inside thereof is decompressed and sealed. As the core material, a synthetic resin foam composed of open cells has been used alone, but in recent years, glass wool having excellent heat insulation performance has been used alone (Patent Documents 1 and 2).

Such a vacuum heat insulating material is normally used in the state integrated in the heat insulation wall which comprises a heat insulation. For example, a heat insulating cabinet 1 such as a refrigerator schematically shown in FIG. 1 is constituted by heat insulating walls (2a, 2b, 2c, 2d), and a vacuum heat insulating material is installed inside the heat insulating wall (on the drawing, (The insulation wall in the front direction is omitted.) In FIG. 1, a schematic position where the vacuum heat insulating material is arranged is indicated by a dotted line. As shown in FIG. 4, such a heat insulating wall is formed by fixing the vacuum heat insulating material 4 mainly to the outer box 3 a by adhesion or adhesion, and fitting the outer box 3 a with the inner box 3 b, followed by another heat insulation. It is formed by filling a substance (for example, urethane foam heat insulating material) 5 (Patent Document 3). 4 is a schematic cross-sectional view of the heat insulating wall 2b in FIG. 1 when viewed from the B direction (up and down direction in the drawing). The vacuum heat insulating material 4 is usually fixed by applying an adhesive to a fixed surface such as an outer box.
JP-A-62-59375 JP-A-7-96563 Japanese Patent Laid-Open No. 11-351493

  However, since the glass wool core material is originally a collection of fibers, and has been subjected to needle punching or binder processing to make it planar, it can also be fixed on the outer box, etc. by pressing, etc. It is extremely difficult to shape according to the shape. Therefore, for example, when there is an uneven portion (particularly the protruded portion 6; see FIG. 4) such as piping and wiring on the fixed surface, or when there is an uneven portion on the structure, the vacuum heat insulating material cannot be shaped corresponding to the uneven portion. . Therefore, a void portion (7; see FIG. 4) derived from such an uneven portion is generated between the vacuum heat insulating material and the fixed surface, and the heat insulating performance as a heat insulating wall is greatly reduced.

  The present invention has been made in order to solve the above-described problems, and has vacuum unevenness corresponding to the uneven shape on the fixing surface to which the vacuum heat insulating material is to be fixed, and has excellent heat insulating performance. It aims at providing a material and its manufacturing method.

  The present invention comprises at least a core material and an outer packaging material that can store the core material and maintain the inside in a reduced pressure state, and the core material is composed of a plate-like material made of open-cell synthetic resin foam and inorganic fibers and / or organic fibers. It is a vacuum heat insulating material that is a laminate of fibrous materials, and the vacuum heat insulating material has unevenness corresponding to the shape of the member surface to which the vacuum heat insulating material is applied on the outer surface of the vacuum heat insulating material on the plate-like material side Regarding materials.

  The present invention also laminates a plate-like material made of open-cell synthetic resin foam and a fibrous material made of inorganic fibers and / or organic fibers and stores them in an outer packaging material, and the inside is decompressed to seal the outer packaging material opening. It is related with the manufacturing method of the vacuum heat insulating material characterized by performing an uneven | corrugated process from the outer surface by the side of a plate-shaped material with respect to this vacuum heat insulating material after stopping and obtaining a vacuum heat insulating material.

  Since the vacuum heat insulating material of the present invention and the manufacturing method thereof use a laminated core material made of a plate-like material and a fibrous material made of an open-cell synthetic resin foam, the vacuum heat insulation is carried out by applying unevenness after vacuum sealing. It is possible to impart irregularities to the material itself with relatively high precision and stability. Therefore, even when there are uneven portions such as wiring and piping on the fixing surface to which the vacuum heat insulating material is to be fixed or when there are uneven portions on the structure, it is possible to produce a vacuum heat insulating material corresponding to the uneven portions.

  The vacuum heat insulating material of the present invention comprises at least a core material and an outer packaging material that can store the core material and maintain the inside in a reduced pressure state.

  The core material used in the present invention is a laminate of a plate material and a fibrous material. In such a laminate, as long as at least one of the lowermost layer and the uppermost layer is made of a plate-like material, the number of layers and the order of lamination are not particularly limited. For example, in a part or all of the laminate, the plate-like material and the fibrous material may be alternately laminated, or the plate-like material or the fibrous material may be continuously laminated. When the laminate has a plurality of plate-like material layers, all the plate-like material layers may be the same type, or some or all of the plate-like material layers may be different. The same applies when the laminate has a plurality of fibrous material layers. From the viewpoint of manufacturability and production efficiency, a laminate composed of one layer of plate material and one layer or multiple layers of fiber material is preferable.

  The plate-like material constituting the core material is an open-cell synthetic resin foam. If a closed cell synthetic resin foam is used, even if the inside of the heat insulating material is depressurized, an effect of improving the heat insulating property due to the depressurization cannot be obtained, so that a sufficient heat insulating property cannot be obtained. Open-cell synthetic resin foam has an open-cell structure and can retain its shape even when brought to atmospheric pressure after sealing the opening of the outer packaging material under reduced pressure during the manufacture of vacuum insulation Any synthetic resin foam may be used. Specific examples of the open cell synthetic resin foam include so-called rigid polyurethane foam, rigid polystyrene foam, rigid polyethylene foam, rigid polypropylene foam, rigid phenol resin foam, rigid urea resin foam, and the like. Preferred are rigid polyurethane foams and rigid polystyrene foams, especially rigid polyurethane foams. Open-cell rigid polyurethane foam is a thermosetting polyurethane foam that is foam-molded to form an open-cell structure with a polyol component and an isocyanate component as the main reaction components, and has better heat insulation performance than other synthetic resin foams. Very good. Moreover, the shape retention property by hot press etc. is high, and it can shape in various shapes.

The density of the open cell synthetic resin foam is usually 40 to 80 Kg / m ³ , and preferably 50 to 70 Kg / m ³ . As the density, a value measured according to a method defined in JISK7222 is used. Regarding the closed cell ratio, those having 10% or less are used, and those having higher open cell properties, that is, those having a lower closed cell ratio are preferable. The closed cell ratio is measured according to the method defined in ASTM D2856.

  Moreover, as an average cell diameter of an open cell synthetic resin foam, it is 20-120 micrometers normally, Preferably it is 30-100 micrometers. The average cell diameter was measured by processing the CCD camera image at two locations per cell for 10 cells, and the average value of the diameters at a total of 20 locations was obtained and used as the average cell diameter value.

  The open-cell synthetic resin foam having the above-mentioned preferable physical properties can be obtained as many commercial products, for example, those manufactured by Kurashiki Boseki Co., Ltd. can be used.

  The thickness of the open cell synthetic resin foam is not particularly limited, and is usually 1 to 20 mm, preferably about 10 mm, and the thickness hardly changes even under reduced pressure.

  As the fibrous material, inorganic fibers, organic fibers, or mixed fibers thereof are used. The form of the fibrous material used in the present invention is not particularly limited, but from the viewpoint of handling workability, it is preferable that the fibrous material has a mat-like form made of the fibers.

Examples of the inorganic fiber include glass fiber (glass wool), alumina fiber, slag wool fiber, silica fiber, rock wool, and the like.
Examples of the organic fiber include polyester fiber, nylon fiber, and aramid fiber. Preferred fibrous materials are inorganic fibers, especially glass fibers. Glass fibers exhibit very good thermal conductivity.

The average fiber diameter of the fibrous material is not particularly limited, but is usually 0.1 to 30 μm, particularly 1 to 5 μm. In particular, when glass fiber is used, a preferable average fiber diameter is about 0.5 to 5 μm from the viewpoint of ease of production.
The average fiber length is also not particularly limited, but 1 to 100 mm, particularly 3 to 10 mm is preferable from the viewpoint of moldability of the mat-like form.

  The fibrous material can be easily formed into a mat shape by a so-called needle punch method, a binder method, a papermaking method, or the like.

  The thickness of the fibrous material is not particularly limited, and usually 1 to 100 mm, preferably 3 to 30 mm, when used as a vacuum heat insulating material.

  As the outer packaging material, any material can be used as long as it has gas barrier properties and can store the core material and maintain the inside in a reduced pressure state. Especially, what can be heat-sealed is preferable. Preferable specific examples include, for example, a gas barrier film having a four-layer structure of nylon, aluminum vapor-deposited PET (polyethylene terephthalate), aluminum foil, and high-density polyethylene as the innermost layer from the outermost layer, polyethylene terephthalate resin, intermediate layer from the outermost layer Gas barrier film made of high-density polyethylene resin in the innermost layer, PET-barrier resin in the outermost layer, ethylene-vinyl alcohol copolymer resin having an aluminum vapor deposition layer in the intermediate layer, and gas barrier film made of high-density polyethylene resin in the innermost layer Etc.

  Even if only the core material is included in the outer packaging material, it is possible to obtain a vacuum heat insulating material with excellent heat insulation performance, but it is difficult to completely remove impurities from the core material. In order to prevent a significant decrease in heat insulation performance, it is also preferable to enclose an adsorbent (getter material).

  The vacuum heat insulating material of the present invention made of the material as described above is provided with unevenness. A preferred embodiment of the vacuum heat insulating material of the present invention will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view of an example of the vacuum heat insulating material of the present invention.

  In the vacuum heat insulating material 10 of the present invention, at least the core material 12 is accommodated in the outer packaging material 16 in a reduced pressure state. In the vacuum heat insulating material 10 of the present invention, the core material 12 is a laminate of the plate-like material 13 and the fibrous material 14, and at least one of the lowermost layer or the uppermost layer is made of a plate-like material. Therefore, unevenness is satisfactorily imparted to the outer surface of the lowermost layer or the uppermost plate-like material of the core material, and as a result, the outer surface of the vacuum heat insulating material on the plate-like material side has irregularities (recesses 15). The unevenness imparted to the outer surface of the plate-like material in the lowermost layer or the uppermost layer of the core material is the shape of the surface of the member to which the vacuum heat insulating material is applied (fixed) (for example, unevenness in wiring, piping, etc., or structural unevenness When the unevenness corresponding to) is formed, almost no gap is generated between the vacuum heat insulating material and the fixed surface, so that the heat insulating property of the heat insulating wall in which the vacuum heat insulating material is incorporated is improved. In FIG. 2, 17 is a heat-sealing part.

  The wall surface inside the heat insulating wall into which the vacuum heat insulating material is incorporated is a flat surface, and the wiring and piping inside the wall are generally hung down on the wall surface without being embedded in the wall surface. The unevenness is preferably groove-shaped (concave).

  In the present invention, it is preferable that the unevenness provided is a relatively small size to a certain extent that the portion (region) to which the unevenness is provided is a part of the vacuum heat insulating material. In general, the smaller the unevenness is, the more difficult it is to form, but in the present invention, even if the unevenness is a relatively small size, it can be imparted satisfactorily. Such irregularities are suitable when the irregularities are groove-like and on the outer surface of the vacuum heat insulating material, the width is 1 to 200 mm, especially 3 to 30 mm, and the depth is 1 to 50 mm, especially 3 to 15 mm. .

  The dimensions of the vacuum heat insulating material of the present invention depend on the sizes of the core material and the outer packaging material, and the sizes of the core material and the outer packaging material may be appropriately determined according to the use of the vacuum heat insulating material.

  FIG. 3 shows an example of the state of use when the vacuum heat insulating material of the present invention in which irregularities (particularly concave portions) are formed on the outer surface is used in a heat insulating cabinet (for example, a refrigerator) shown in FIG. FIG. 3 is a schematic cross-sectional view of the heat insulating wall 2b in FIG. 1 when viewed from the B direction. Since the vacuum heat insulating material 10 of the present invention has a recess corresponding to the wiring / piping 6, there is almost no gap between the vacuum heat insulating material 10 and the fixed surface 11 in the heat insulating wall 2 b.

  Such a heat insulating wall 2b is formed by the following procedure, for example. The vacuum heat insulating material 10 is fixed to the outer box 3a by adhesion or adhesion while guiding the wiring / piping 6 into the recess of the vacuum heat insulating material 10. The fixing is usually performed by applying an adhesive to the fixing surface 11. Next, after the outer box 3a is fitted with the inner box 3b, another heat insulating material (for example, urethane foam heat insulating material) 5 is filled to form the heat insulating wall 2b.

Hereinafter, the manufacturing method of the vacuum heat insulating material of this invention is demonstrated.
A plate-like material and a fibrous material (preferably mat-like) are each cut into an appropriate size and shape (for example, a square shape), and dried to remove moisture and the like contained therein. The drying is usually performed under conditions of about 120 ° C. for about 1 hour. However, in order to more effectively remove moisture and the like from the open cell synthetic resin foam and the fibrous material, vacuum drying at 120 ° C. is preferable. Furthermore, you may use together the drying by far infrared rays. The degree of vacuum is preferably about 0.5 to 0.001 Torr, and the temperature is preferably 100 to 150 ° C.

  Next, the plate-like material and the fibrous material are laminated and inserted into an outer packaging material sealed in a bag shape. At this time, it is preferable to insert a getter material together. In this state, it is put in a vacuuming device and evacuated under reduced pressure so that the internal pressure becomes a degree of vacuum of about 0.1 to 0.001 Torr. Thereafter, the bag-like opening of the outer packaging material is sealed by heat sealing to obtain a vacuum heat insulating material.

In this invention, after obtaining a vacuum heat insulating material once as mentioned above, an unevenness | corrugation is provided to the outer surface by the side of a plate-shaped material. Concavity and convexity are imparted by concave and convex processing. Examples of the concavo-convex processing include press processing and the like. However, press processing is most preferable in view of excellent productivity and processing without damaging the outer packaging material of the vacuum heat insulating material. The press conditions are, for example, a pressure of 5 to 15 kg / cm ² and a press time of 2 to 5 seconds. In addition, it is necessary to provide uneven processing corresponding to, for example, piping and wiring on the inner surface of the outer box, and it is preferable from the viewpoint of productivity and workability to be formed into a groove shape by pressing. .

  The provision of irregularities on the outer surface on the plate-like material side in the vacuum heat insulating material is performed by applying irregularities to the plate-like material in advance, storing the core material in the outer packaging material, and putting the outer packaging material in a reduced pressure state. It is also possible to make it adhere to the core material so that irregularities of the core material appear on the surface of the vacuum heat insulating material. However, when the concavo-convex process is performed before the decompression step, the provided concavo-convex shape is restored in the drying step normally performed as a step immediately before the decompression step, and the shaping becomes insufficient, and the precision is high. Can not be shaped properly. Therefore, in the present invention, the laminated core material of the plate-like material and the fibrous core material is first stored in the outer packaging material, the inside is brought into a reduced pressure state, and the vacuum-sealed state is set, and then the plate-like material is interposed via the outer packaging material. Concavity and convexity processing is performed on When the concave and convex process is performed after the vacuum-sealed state as described above, the applied concave and convex shape is hardly restored, and the desired concave and convex shape can be imparted relatively accurately and stably.

  In particular, when providing groove-shaped unevenness, the projections of the mold during unevenness processing can be precisely shaped. Therefore, the protrusion shape of the mold may be a shape that directly corresponds to the uneven size of the vacuum heat insulating material.

Example 1
As the core material, open-celled rigid urethane foam (density: 55 Kg / m ³ , average cell diameter: 75 μm, closed cell ratio 5%, manufactured by Kurashiki Boseki Co., Ltd.) and glass wool (average fiber length: 10 mm, An average fiber diameter of 3 μm) is used. The size is 500 mm × 1500 mm and the thickness is 10 mm.

  The core material was first laminated and dried at a temperature of 120 ° C. for 1 hour. The laminated core material after drying is inserted into a gas barrier film envelope made of nylon, aluminum vapor-deposited PET, aluminum foil, and high-density polyethylene, and at the same time, one getter material (SAES Getters: COMBO) is included. Inserted into the material. Then, it sealed, performing evacuation with an evacuation apparatus so that an internal pressure might be 0.05 Torr. The obtained vacuum heat insulating material was 500 mm x 1500 mm, and the thickness was 16 mm. Moreover, the thickness of the fibrous material at this time was 6 mm.

Then, the press work was performed with the press machine and the vacuum heat insulating material was obtained. The press working was performed to shape a groove shape along the longitudinal direction on the surface of the vacuum heat insulating material. A semi-cylindrical protrusion having a diameter of 10 mm and a height of 5 mm was provided on the press die (upper die), and pressing was performed at 7 kg / cm ² for 3 seconds. In addition, the groove depth obtained was 5 mm, and the groove width was 10 mm, and it was precisely shaped to match the pipe diameter installed on the outer box surface of the heat insulating box. The number of grooves was two, and was provided on a straight line from one end in the longitudinal direction to the other end. In order to prevent an adverse effect on the outer packaging material, the die shape of the press working has been designed so that the corner portion has a curved shape so as not to generate an acute angle portion in the vacuum heat insulating material as much as possible.

(Comparative Example 1)
A vacuum heat insulating material was obtained in the same manner as in Example 1 except that glass wool (average fiber length: 10 mm, average fiber diameter: 3 μm, thickness: 10 mm) formed into a mat by a papermaking method was used as the core material.

(Comparative Example 2)
A vacuum heat insulating material is obtained by the same material and method as in Example 1 except that the pressing process for the open-celled rigid urethane foam is performed before the drying process, and the drying, vacuuming and sealing processes are performed after the pressing process. It was.

(Evaluation)
Evaluation of the heat insulation performance was performed by measuring the thermal conductivity at an average temperature of 20 ° C. using “AutoΛ HC-074” (manufactured by Eihiro Seiki Co., Ltd.). The measurement was made after 1 day from the vacuuming step.

It is a schematic block diagram of the heat insulation (refrigerator) which can use the vacuum heat insulating material of this invention. It is an example of the schematic sectional drawing of the vacuum heat insulating material of this invention. It is a schematic sectional drawing which shows an example of the use condition at the time of using the vacuum heat insulating material of this invention for the heat insulation shown in FIG. It is a schematic sectional drawing which shows an example of the use condition at the time of using the conventional vacuum heat insulating material for the heat insulation shown in FIG.

Explanation of symbols

1: heat insulation (refrigerator), 2a: 2b: 2c: 2d: heat insulation wall, 3a: outer box, 3b: inner box, 4; conventional vacuum heat insulating material, 5: another heat insulating material (foamed urethane heat insulating material), 6: Wiring and piping, 7: Air gap, 10: Vacuum heat insulating material of the present invention, 12: Core material, 13: Plate material, 14: Fibrous material, 15: Recess, 16: Outer packaging material, 17: Thermal fusion Department.

Claims (4)

  At least a core material and an outer packaging material that can store the core material and can maintain the inside in a reduced pressure state, and the core material is a plate-like material made of open-cell synthetic resin foam and a fibrous material made of inorganic fibers and / or organic fibers A vacuum heat insulating material that is a laminate of the above, wherein the vacuum heat insulating material has irregularities corresponding to the shape of the surface of the member to which the vacuum heat insulating material is applied on the outer surface of the vacuum heat insulating material on the plate-like material side.   The vacuum heat insulating material according to claim 1, wherein the unevenness is formed into a groove shape by press working.   A plate-like material made of open-cell synthetic resin foam and a fibrous material made of inorganic fiber and / or organic fiber are laminated and stored in the outer packaging material, and the inside is decompressed to seal the outer packaging material opening, and vacuum insulation A method for producing a vacuum heat insulating material, characterized in that after the material is obtained, the vacuum heat insulating material is subjected to uneven processing from the outer surface on the plate-like material side. The method for producing a vacuum heat insulating material according to claim 3, wherein the plate-like material is open-celled rigid urethane foam, and the fibrous material is glass fiber.

Images